WorldWideScience

Sample records for cluster doped glasses

  1. Influence of silver and copper doping on luminescent properties of zinc-phosphate glasses after x-ray irradiation

    Science.gov (United States)

    Murashov, Alexander A.; Sidorov, Alexander I.; Shakhverdov, Teimur A.; Stolyarchuk, Maxim V.

    2017-11-01

    It is shown, experimentally, that in silver- and copper-containing zinc-phosphate glasses, metal molecular clusters are formed during the glass synthesis. X-ray irradiation of these glasses led to the considerable increase of its luminescence in visible spectral range. This effect is caused by the transformation of the charged metal molecular clusters into the neutral state. Luminescence and excitation spectra of the glass, doped with silver and copper simultaneously, change significantly in comparison with the spectra of glasses doped with one metal. The reason for this can be the formation of hybrid AgnCum molecular clusters. The computer simulation of the structure and optical properties of such clusters by the time-dependent density functional theory method is presented. It is shown that the optimal luminescent material for photonics application, in comparison with other studied materials, is glass, containing hybrid molecular clusters.

  2. Fluorescence yield in rare-earth-doped sol-gel silicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Silversmith, A.J., E-mail: asilvers@hamilton.ed [Physics Department, Hamilton College, 198 College Hill Road, Clinton, NY 13323 (United States); Nguyen, Nguyen T.T.; Campbell, D.L. [Physics Department, Hamilton College, 198 College Hill Road, Clinton, NY 13323 (United States); Boye, D.M.; Ortiz, C.P. [Davidson College, Davidson, NC 28035 (United States); Hoffman, K.R. [Whitman College, Walla Walla, WA 99362 (United States)

    2009-12-15

    We have used trivalent terbium to investigate the mechanism behind fluorescence enhancement by Al{sup 3+} co-doping. Our results indicate that rare-earth (RE) ions cluster together in aluminum-rich regions of the glass, and behave as if they were dispersed uniformly throughout these regions when the ratio of Al to RE is {approx}10 or greater. We also studied the effects of adding chemical drying agents to the precursor solution for the synthesis of sol-gel-derived silicate glasses. Such glasses can be treated at significantly higher annealing temperatures without degradation of optical quality, and have the density of melt glass. Fluorescence yield from doped RE ions improves markedly with the addition of the drying agents, and the denser glasses are not subject to rehydration.

  3. NEW ERBIUM DOPED ANTIMONY GLASSES FOR LASER AND GLASS AMPLIFICATION

    Directory of Open Access Journals (Sweden)

    B. Tioua

    2015-07-01

    Full Text Available Because of the special spectroscopic properties of the rare earth ions, rare earth doped glasses are widely used in bulk and fiber lasers or amplifiers. The modelling of lasers and searching for new laser transitions require a precise knowledge of the spectroscopic properties of rare earth ions in different host glasses. In this poster will offer new doped erbium glasses synthesized in silicate crucibles were obtained in the combination Sb2O3-WO3-Na2O. Several properties are measured and correlated with glass compositions. The absorption spectral studies have been performed for erbium doped glasses. The intensities of various absorption bands of the doped glasses are measured and the Judd-Ofelt parameters have been computed. From the theory of Judd-Ofelt, various radiative properties, such as transition probability, branching ratio and radiative life time for various emission levels of these doped glasses have been determined and reported. These results confirm the ability of antimony glasses for glass amplification.

  4. Ag clustering investigation in laser irradiated ion-exchanged glasses by optical and vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Trave, E., E-mail: enrico.trave@unive.it [Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venezia, Dorsoduro 2137, I-30123 Venezia (Italy); Cattaruzza, E.; Gonella, F.; Calvelli, P. [Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venezia, Dorsoduro 2137, I-30123 Venezia (Italy); Quaranta, A. [Department of Materials Engineering and Industrial Technologies, University of Trento, via Mesiano 77, I-38050 Povo (Italy); Rahman, A.; Mariotto, G. [Department of Computer Science, University of Verona, Strada le Grazie 15, 37134 Verona (Italy)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We modify the properties of Ag{sup +} exchanged glasses by thermal and laser treatment. Black-Right-Pointing-Pointer The induced microstructural changes are analyzed by optical and Raman spectroscopy. Black-Right-Pointing-Pointer Ag-based species in the glass show a peculiar PL activity in the UV-Vis range. Black-Right-Pointing-Pointer Raman and OA analysis allow for determining the Ag cluster size evolution. Black-Right-Pointing-Pointer Laser processing leads to different cluster formation and fragmentation mechanisms. - Abstract: Ion exchange process is widely used to dope silicate glass layers with silver for several applications, ranging from light waveguide to nanostructured composite glass fabrication. The silver-doped structure and its physical properties depend on the preparation parameters as well as on subsequent treatments. In particular, laser irradiation of the ion exchanged glasses has been demonstrated to be an effective tool to control cluster size and size distribution. Nevertheless, a complete comprehension of the basic phenomena and a systematic characterization of these systems are still lacking. In this paper, an extended optical characterization is presented for soda-lime glass slides, doped with silver by Ag{sup +}-Na{sup +} ion exchange, thermally treated and irradiated with a Nd:YAG laser beam at different wavelengths, and for different energy density. The samples were characterized by various spectroscopic techniques, namely, optical absorption, photoluminescence and micro-Raman analysis. The availability of all these characterization techniques allowed pointing out a suitable scenario for the Ag clustering evolution as a function of the ion exchange, annealing and laser irradiation parameters.

  5. Radiophotoluminescence from silver-doped phosphate glass

    International Nuclear Information System (INIS)

    Miyamoto, Y.; Takei, Y.; Nanto, H.; Kurobori, T.; Konnai, A.; Yanagida, T.; Yoshikawa, A.; Shimotsuma, Y.; Sakakura, M.

    2011-01-01

    Glass dosimeter utilizing radiophotoluminescence (RPL) is one of accumulation type solid state dosimeters, which is based on luminescence phenomenon of silver (Ag + ions)-doped phosphate glass exposed to ionizing radiation. In this study, to clarify the emission mechanism of yellow and blue RPL peaks, optical properties of Ag + -doped glass, such as optical absorption spectrum, RPL excitation spectrum before and after X-ray irradiation as well as the lifetime of both RPL peaks are measured. From the results, we discuss the emission mechanism of yellow (peaked at 2.21 eV) and blue (peaked at 2.70 eV) RPL using a proposed energy band diagram for RPL emission and excitation in Ag + -doped phosphate glass. It is found that the radiative lifetime of blue RPL is three orders of magnitude faster than that of yellow RPL.

  6. Investigations on vanadium doped glasses

    International Nuclear Information System (INIS)

    Madhusudana Rao, P.

    2013-01-01

    The glass samples studied in the present work have been prepared by melt quenching technique. They were prepared by mixing and grinding together by appropriate amounts of Li 2 O - Na 2 O - B 2 O 3 doped with V 2 O 5 in an agate motor before transferring into crucible. The mixtures were heated in an electric furnace at 1225K for 20 mm. The melt was then quenched to room temperature by pouring it on plane brass plate and pressing it with another brass plate. White and yellow coloured glasses have been obtained with good optical quality and high transparency. Finally the vitreous sample were annealed for 3 hrs at 423K to relieve residual internal stress and slowly cooled to room temperature. The polished glasses have been used for XRD, FTIR analysis and for DSC report. The DSC thermo grams for all the glasses were recorded on in the temperature range 50-550℃ with a heating rate of 10℃/min. Electron spin resonance and optical absorption of 20Li 2 O - 10 Na 2 O - (70-X)B 2 O 3 doped with XV 2 O 5 glass system are studied. ESR spectra of V 4+ ions doped in the glass exhibit peak at g =1.98. Spin Hamiltonian parameters are calculated. It was found that these parameters are dependent upon alkali ion concentration in the glass and the VO +2 ion in an octahedral coordination with a tetragonal compression. The physical parameters of all glasses were also evaluated with respect to the composition

  7. Optical properties of thermally reduced bismuth-doped sodium aluminosilicate glasses

    DEFF Research Database (Denmark)

    Nielsen, K.H.; Smedskjær, Morten Mattrup; Yue, Yuanzheng

    Heat-treatment of multivalent ion containing glasses in a hydrogen atmosphere may cause both reduction of the multivalent ions and ionic inward diffusion, resulting in improved glass properties. Bismuth-doped glasses are also interesting objects not only concerning the reduction induced diffusion...... pressure of hydrogen. Here, we present results on the effect of the heat-treatment on the optical properties of bismuth-doped sodium aluminosilicate glasses.......Heat-treatment of multivalent ion containing glasses in a hydrogen atmosphere may cause both reduction of the multivalent ions and ionic inward diffusion, resulting in improved glass properties. Bismuth-doped glasses are also interesting objects not only concerning the reduction induced diffusion...

  8. Spectroscopic properties of highly Nd-doped lead phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Novais, A.L.F. [Instituto de Física, Universidade Federal de Alagoas, Grupo de Fotônica e Fluidos Complexos, 57072-970 Maceió, AL (Brazil); Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, 38400-902 Uberlândia, MG (Brazil); Guedes, I. [Departamento de Física, Universidade Federal do Ceará, Campus do PICI, Caixa Postal 6030, 60455-760 Fortaleza, CE (Brazil); Vermelho, M.V.D., E-mail: vermelho@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, Grupo de Fotônica e Fluidos Complexos, 57072-970 Maceió, AL (Brazil)

    2015-11-05

    The spectroscopic characteristics of highly Nd{sup 3+}-doped lead phosphate glasses (xNd:Pb{sub 3}(PO{sub 4}){sub 2}) have been investigated. The X-ray spectra show that the matrices are glassy up to 25 wt% of Nd{sup 3+} doping. From the Judd–Ofelt analysis we observe that while the Ω{sub (2)} parameter remains constant indicating that the 4f{sup N} and 4f{sup N−1}5 d{sup 1} configurations are not affected by the Nd{sup 3+} doping, the behavior of both Ω{sub (4)} and Ω{sub (6)} changes for 15 wt% of Nd{sup 3+} doping. The reduction of the Ω{sub (6)} parameter is related to the increase of the covalence bonding between the ligands and the Nd{sup 3+} ions. At this particular concentration, the radiative lifetime has a four-fold enhancement. Such behaviors are likely to be related to a modification in the glass structure for high Nd{sup 3+} concentrations. - Graphical abstract: Highly doped lead-phosphate glass matrix, with nominal concentration of up to 25 wt%, maintain the spectroscopic properties without deterioration. The analysis concerning the point of view of Nd{sup 3+} ions showed that high concentrations only affects the rare earth electronic charge density distribution. - Highlights: • Spectroscopic characterization of Nd{sub 2}O{sub 3} highly doped lead phosphate glasses. • Phosphate glass doped with Nd{sup 3+} for applications in photonic devices. • Judd–Ofelt analysis in phosphate glasses doped with Neodymium.

  9. In vitro study of manganese-doped bioactive glasses for bone regeneration

    International Nuclear Information System (INIS)

    Miola, Marta; Brovarone, Chiara Vitale; Maina, Giovanni; Rossi, Federica; Bergandi, Loredana; Ghigo, Dario; Saracino, Silvia; Maggiora, Marina; Canuto, Rosa Angela; Muzio, Giuliana; Vernè, Enrica

    2014-01-01

    A glass belonging to the system SiO 2 –P 2 O 5 –CaO–MgO–Na 2 O–K 2 O was modified by introducing two different amounts of manganese oxide (MnO). Mn-doped glasses were prepared by melt and quenching technique and characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) observation and energy dispersion spectrometry (EDS) analysis. In vitro bioactivity test in simulated body fluid (SBF) showed a slight decrease in the reactivity kinetics of Mn-doped glasses compared to the glass used as control; however the glasses maintained a good degree of bioactivity. Mn-leaching test in SBF and minimum essential medium (MEM) revealed fluctuating trends probably due to a re-precipitation of Mn compounds during the bioactivity process. Cellular tests showed that all the Mn-doped glasses, up to a concentration of 50 μg/cm 2 (μg of glass powders/cm 2 of cell monolayer), did not produce cytotoxic effects on human MG-63 osteoblasts cultured for up to 5 days. Finally, biocompatibility tests demonstrated a good osteoblast proliferation and spreading on Mn-doped glasses and most of all that the Mn-doping can promote the expression of alkaline phosphatase (ALP) and some bone morphogenetic proteins (BMPs). - Highlights: • Novel bioactive glasses doped with manganese were prepared. • Mn-doped bioactive glasses were not cytotoxic towards human MG-63 osteoblasts. • The Mn introduction promotes the expression of ALP and bone morphogenetic proteins. • Mn-doped glass may be a promising material for bone regeneration procedures

  10. New Erbium Doped Antimony Glasses for Laser and Glass ...

    African Journals Online (AJOL)

    Because of the special spectroscopic properties of the rare earth ions, rare earth doped glasses are widely used in bulk and fiber lasers or amplifiers. The modelling of lasers and searching for new laser transitions require a precise knowledge of the spectroscopic properties of rare earth ions in different host glasses.

  11. Optical and spectroscopic properties of Eu-doped tellurite glasses and glass ceramics

    International Nuclear Information System (INIS)

    Stambouli, W.; Elhouichet, H.; Gelloz, B.; Férid, M.

    2013-01-01

    Tellurite glasses doped with trivalent europium were prepared by the conventional melt quenching technique, in the chemical composition of (85−x) TeO 2 +5La 2 O 3 +10TiO 2 +xEu 2 O 3 by varying the concentration of the rare-earth ion in the order 0.5, 1 and 1.5 mol%. Using Judd–Ofelt analysis, we calculated intensity parameters (Ω 2 and Ω 4 ), spontaneous emission probabilities, the radiative lifetime, luminescence branching factors, the quantum yield of luminescence, and the stimulated emission cross-sections for 5 D 0 → 7 F 2 transition. The change in optical properties with the variation of Eu 3+ ion concentration have been discussed and compared with other glasses. The luminescence intensity ratio, quantum efficiency and emission cross-section values support that the TeEu1.5 tellurite glass is a suitable candidate for red laser source applications. Optical properties for Eu 3+ doped tellurite glass, heated for different temperature, were investigated. Crystalline phases for α-TeO 2 , γ-TeO 2 and TiTe 3 O 8 system were determined by the XRD method. The effect of heat treatment on luminescence properties in the tellurite glass was discussed. By using Eu 3+ as a probe, the local structure of rare-earth ion in tellurite glass, vitro-ceramic and ceramic glass has been investigated. The evaluated J–O intensity parameters have been used to calculate different radiative and laser characteristic parameters of the 5 D 0 excited level. The large magnitudes of stimulated emission cross-section (σ e ), branching ratio (β) and Gain bandwidth (σ e ×Δλ eff ) obtained for 5 D 0 → 7 F 2 (613 nm) transition for ceramic glass indicate that the present glass ceramic is promising host material for Eu 3+ doped fiber amplifiers. The measured lifetime of 5 D 0 excited state increases with increase of the heat treatment which further indicate that some Eu 3+ ions were successfully embedded in the crystal phase and prove the low phonon energy environment of Eu 3+ ions

  12. Formation and partial melting of two types of spin-cluster glass behavior in vanadate spinel

    International Nuclear Information System (INIS)

    Huang Yuanjie; Pi Li; Tan Shun; Zhang Yuheng; Yang Zhaorong

    2012-01-01

    We report the doping effect on the various properties of spinels Co 1-x Zn x V 2 O 4 (0 ≤ x ≤ 0.2). For the parent compounds, the rise in magnetization, the valley in thermal conductance, the transition from the ferromagnetic arrangement to non-collinear alignment indicated by the specific heat for the V sublattice, especially the frequency dependence of AC susceptibility around T 1 = 59 K, verify the occurrence of the transition at T 1 besides the ferrimagnetic transition at T C . The ferrimagnetic transition at T C induces the spin-cluster glass behavior and the transition at T 1 yields the new spin-cluster glass (NSCG) behavior. As the Zn 2+ -doped content increases, the above phenomena are gradually weakening to vanishing, but the glassy behavior at T C still exists for all samples. Through the fourth-order perturbation theory, we discuss the reasons for the gradual vanishing of the transition at T 1 . (paper)

  13. Dosimetric properties of dysprosium doped lithium borate glass irradiated by 6 MV photons

    International Nuclear Information System (INIS)

    Ab Rasid, A.; Wagiran, H.; Hashim, S.; Ibrahim, Z.; Ali, H.

    2015-01-01

    Undoped and dysprosium doped lithium borate glass system with empirical formula (70–x) B 2 O 3 –30 Li 2 O–(x) Dy 2 O 3 (x=0.1, 0.3, 0.5, 0.7, 1.0 mol%) were prepared using the melt-quenching technique. The dosimetric measurements were performed by irradiating the samples to 6 MV photon beam using linear accelerator (LINAC) over a dose range of 0.5–5.0 Gy. The glass series of dysprosium doped lithium borate glass produced the best thermoluminescence (TL) glow curve with the highest intensity peak from sample with 1.0 mol% Dy 2 O 3 concentration. Minimum detectable dose was detected at 2.24 mGy, good linearity of regression coefficient, high reproducibility and high sensitivity compared to the undoped glass are from 1.0 mol% dysprosium doped lithium borate glass. The results indicated that the series of dysprosium doped lithium glasses have a great potential to be considered as a thermoluminescence dosimetry (TLD). - Highlights: • TL response of undoped and dysprosium doped lithium borate glass subjected to 6 MV photons irradiation at low dose range. • TL linear response of dysprosium doped lithium borate glass. • The sensitivity of dysprosium doped lithium borate glass is approximately 93 times higher than undoped glass

  14. A Kondo cluster-glass model for spin glass Cerium alloys

    International Nuclear Information System (INIS)

    Zimmer, F M; Magalhaes, S G; Coqblin, B

    2011-01-01

    There are clear indications that the presence of disorder in Ce alloys, such as Ce(Ni,Cu) or Ce(Pd,Rh), is responsible for the existence of a cluster spin glass state which changes continuously into inhomogeneous ferromagnetism at low temperatures. We present a study of the competition between magnetism and Kondo effect in a cluster-glass model composed by a random inter-cluster interaction term and an intra-cluster one, which contains an intra-site Kondo interaction J k and an inter-site ferromagnetic one J 0 . The random interaction is given by the van Hemmen type of randomness which allows to solve the problem without the use of the replica method. The inter-cluster term is solved within the cluster mean-field theory and the remaining intra-cluster interactions can be treated by exact diagonalization. Results show the behavior of the cluster glass order parameter and the Kondo correlation function for several sizes of the clusters, J k , J 0 and values of the ferromagnetic inter-cluster average interaction I 0 . Particularly, for small J k , the magnetic solution is strongly dependent on I 0 and J 0 and a Kondo cluster-glass or a mixed phase can be obtained, while, for large J k , the Kondo effect is still dominant, both in good agreement with experiment in Ce(Ni,Cu) or Ce(Pd,Rh) alloys.

  15. Intrinsic luminescence of un-doped borate glasses

    International Nuclear Information System (INIS)

    Kindrat, I.I.; Padlyak, B.V.; Drzewiecki, A.

    2017-01-01

    The nature of intrinsic luminescence in the un-doped borate glasses of different compositions has been investigated using spectroscopic methods including photoluminescence, optical absorption, electron paramagnetic resonance (EPR), and thermally stimulated luminescence (TSL). The un-doped borate glasses with Li 2 B 4 O 7 , LiKB 4 O 7 , CaB 4 O 7 , and LiCaBO 3 basic compositions were obtained from corresponding polycrystalline compounds in the air with usage the standard technology of glasses. Three different broad emission bands in the UV–Visible spectral range have been observed under different wavelength of photoexcitation. The luminescence kinetics of the observed emission bands have been registered and analysed. The nature and possible mechanisms of the intrinsic luminescence in the investigated borate glasses are considered and discussed based on the obtained results and referenced data.

  16. Characterization of Fe -doped silver phosphate glasses

    Indian Academy of Sciences (India)

    ... to their several spe- cial properties such as large thermal expansion coefficients, ... increase the conductivity of these glasses is to increase the modifier or dopant ... phosphate glasses were measured by the a.c. impedance spectroscopic .... and Fe2O3-doped Ag2O–P2O5 glasses were determined from. DSC curves and ...

  17. In vitro study of manganese-doped bioactive glasses for bone regeneration.

    Science.gov (United States)

    Miola, Marta; Brovarone, Chiara Vitale; Maina, Giovanni; Rossi, Federica; Bergandi, Loredana; Ghigo, Dario; Saracino, Silvia; Maggiora, Marina; Canuto, Rosa Angela; Muzio, Giuliana; Vernè, Enrica

    2014-05-01

    A glass belonging to the system SiO2-P2O5-CaO-MgO-Na2O-K2O was modified by introducing two different amounts of manganese oxide (MnO). Mn-doped glasses were prepared by melt and quenching technique and characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) observation and energy dispersion spectrometry (EDS) analysis. In vitro bioactivity test in simulated body fluid (SBF) showed a slight decrease in the reactivity kinetics of Mn-doped glasses compared to the glass used as control; however the glasses maintained a good degree of bioactivity. Mn-leaching test in SBF and minimum essential medium (MEM) revealed fluctuating trends probably due to a re-precipitation of Mn compounds during the bioactivity process. Cellular tests showed that all the Mn-doped glasses, up to a concentration of 50 μg/cm(2) (μg of glass powders/cm(2) of cell monolayer), did not produce cytotoxic effects on human MG-63 osteoblasts cultured for up to 5 days. Finally, biocompatibility tests demonstrated a good osteoblast proliferation and spreading on Mn-doped glasses and most of all that the Mn-doping can promote the expression of alkaline phosphatase (ALP) and some bone morphogenetic proteins (BMPs). Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Thermal property of holmium doped lithium lead borate glasses

    Science.gov (United States)

    Usharani, V. L.; Eraiah, B.

    2018-04-01

    The new glass system of holmium doped lithium lead borate glasses were prepared by conventional melt quenching technique. The thermal stability of the different compositions of Ho3+ ions doped lithium lead borate glasses were studied by using TG-DTA. The Tg values are ranging from 439 to 444 °C with respect to the holmium concentration. Physical parameters like polaron radius(rp), inter-nuclear distance (ri), field strength (F) and polarizability (αm) of oxide ions were calculated using appropriate formulae.

  19. Improved terbium-doped, lithium-loaded glass scintillator fibers

    International Nuclear Information System (INIS)

    Spector, G.B.; McCollum, T.; Spowart, A.R.

    1993-01-01

    An improved terbium-doped, 6 Li-loaded glass scintillator has been drawn into fibers. Tests indicate that the neutron detection response of the fibers is superior to the response with fibers drawn from the original terbium-doped glass. The new fibers offer less attenuation (1/e length of ∝40 cm) and improved gamma ray/neutron discrimination. The improved fibers will be incorporated in a scintillator fiber optic long counter for neutron detection. (orig.)

  20. Upconversion in rare earth ions doped TeO2-ZnO glass

    International Nuclear Information System (INIS)

    Mohanty, Deepak Kumar; Rai, Vineet Kumar

    2012-01-01

    The Er 3+ /Yb 3+ doped/codoped TeO 2 -ZnO glasses have been fabricated by conventional melt and quenching technique. The absorption spectra of the doped/codoped glasses have been performed. The visible upconversion emissions of both doped and codoped glasses have been observed using 808 nm diode laser excitation. The process involved in upconversion emissions has been discussed in detail. (author)

  1. Microstructures and luminescent properties of Ce-doped transparent mica glass-ceramics

    International Nuclear Information System (INIS)

    Taruta, Seiichi; Iwasaki, Yoshitomo; Nishikiori, Hiromasa; Yamakami, Tomohiko; Yamaguchi, Tomohiro; Kitajima, Kunio; Okada, Kiyoshi

    2012-01-01

    Highlights: ► Ce-doped transparent glass-ceramics and their parent glasses. ► TEM and STEM images for the microstructures. ► Each mica crystal did not contain Ce uniformly. ► Emission due to Ce 3+ ions in the glass phase and/or Ce 3+ ions in the mica crystals. - Abstract: Transparent mica glass-ceramics were prepared by heating parent glasses that had been doped with 0.5–15 mol% CeO 2 . During the melting and heat treatment, Ce 4+ ions in the specimens were reduced to Ce 3+ ions, and one or both of these ion species were then replaced with Li + ions in the interlayers of the separated mica crystals. However, scanning transmission electron microscope (STEM) and Z-contrast imaging revealed that the mica crystals did not contain the same amount of Ce. On excitation at 254 nm, the parent glasses and glass-ceramics emitted blue light, which originated from the 5d to 4f transition of the Ce 3+ ions. The emission of the glass-ceramic containing a smaller amount of Ce was attributed to the Ce 3+ ions in both the glass phase and the mica crystals, whereas that of the glass-ceramics containing a larger amount of Ce was caused mainly by Ce 3+ ions in the mica crystals. The dependence of the emission band of the parent glasses on the amount of Ce was a unique feature of the Ce-doped transparent mica glass-ceramics and was not observed in previous studies of Eu-doped parent glasses and mica glass-ceramics.

  2. X-ray absorption spectroscopy on phosphoric-salt pellets. Determination of the geometric and electronic structure of metal-oxide doped sodium-phosphate glasses

    International Nuclear Information System (INIS)

    Brendebach, B.

    2004-02-01

    Sodium metaphosphate glasses doped with transition metal oxides show characteristic colors. X-ray absorption spectroscopy (XAS) investigations provide information whether the coloration stems from different electronic transitions or changes in the geometrical structure of the glasses. Even though the violet color of MnO y -doped glasses is considered as an evidence for Mn 3+ -ions, Mn K-XAS reveals that the majority of the manganese ions are in the oxidation state +II and have a mixed coordination of four and six oxygen atoms, respectively. The oxygen coordination around the nickel ions in NiO-doped glasses with different metall oxide concentrations is always six. The change of color from citreous to auburn with increasing nickel oxide content is attributed to a systematic change in the bonding characteristic from mainly ionic-like to a small but significant contribution of covalent-like bonding. Analysis of higher coordination shells provides no indication of the formation of metal oxide clusters. (orig.)

  3. Low-temperature photoluminescence in chalcogenide glasses doped with rare-earth ions

    Energy Technology Data Exchange (ETDEWEB)

    Kostka, Petr, E-mail: petr.kostka@irsm.cas.cz [Institute of Rock Structure and Mechanics AS CR, V Holešovičkách 41, 182 09 Praha 8 (Czech Republic); Zavadil, Jiří [Institute of Photonics and Electronics AS CR, Chaberská 57, 182 51 Praha 8, Kobylisy (Czech Republic); Iovu, Mihail S. [Institute of Applied Physics, Academy of Sciences of Moldova, Str. Academiei 5, MD-28 Chisinau, Republic of Moldova (Moldova, Republic of); Ivanova, Zoya G. [Institute of Solid State Physics, Bulgarian Academy of Sciences, 1784 Sofia (Bulgaria); Furniss, David; Seddon, Angela B. [Mid-Infrared Photonics Group, George Green Institute for Electromagnetics Research, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2015-11-05

    Sulfide and oxysulfide bulk glasses Ga-La-S-O, Ge-Ga-S and Ge-Ga-As-S doped, or co-doped, with various rare-earth (RE{sup 3+}) ions are investigated for their room temperature transmission and low-temperature photoluminescence. Photoluminescence spectra are collected by using external excitation into the Urbach tail of the fundamental absorption edge of the host-glass. The low-temperature photoluminescence spectra are dominated by the broad-band luminescence of the host glass, with superimposed relatively sharp emission bands due to radiative transitions within 4f shells of RE{sup 3+} ions. In addition, the dips in the host-glass luminescence due to 4f-4f up-transitions of RE{sup 3+} ions are observed in the Ge-Ga-S and Ge-Ga-As-S systems. These superimposed narrow effects provide a direct experimental evidence of energy transfer between the host glass and respective RE{sup 3+} dopants. - Highlights: • An evidence of energy transfer from host-glass to doped-in RE ions is presented. • Energy transfer is manifested by dips in host-glass broad-band luminescence. • This channel of energy transfer is documented on selected RE doped sulfide glasses. • Photoluminescence spectra are dominated by broad band host-glass luminescence. • Presence of RE ions is manifested by superimposed narrow 4f-4f transitions.

  4. Er3+-Al2O3 nanoparticles doping of borosilicate glass

    International Nuclear Information System (INIS)

    Massera, Jonathan; Petit, Laeticia; Hupa, Leena; Hupa, Mikko; Koponen, Joona; Glorieux, Benoit

    2015-01-01

    Novel borosilicate glasses were developed by adding in the glass batch Er 3+ -Al 2 O 3 nanoparticles synthetized by using a soft chemical method. A similar nanoparticle doping with modified chemical vapour deposition (MCVD) process was developed to increase the efficiency of the amplifying silica fibre in comparison to using MCVD and solution doping. It was shown that with the melt quench technique, a Er 3+ -Al 2 O 3 nanoparticle doping neither leads to an increase in the Er 3+ luminescence properties nor allows one to control the rare-earth chemical environment in a borosilicate glass. The site of Er 3+ in the Er 3+ -Al 2 O 3 nanoparticle containing glass seems to be similar as in glasses with the same composition prepared using standard raw materials. We suspect the Er 3+ ions to diffuse from the nanoparticles into the glass matrix. There was no clear evidence of the presence of Al 2 O 3 nanoparticles in the glasses after melting. (author)

  5. Preparation method and thermal properties of samarium and europium-doped alumino-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sava, B.A., E-mail: savabogdanalexandru@yahoo.com [National Institute of Research and Development for Optoelectronics, Department for Optospintronics, 409 Atomistilor Street, P.O. Box MG – 5, RO-77125 Magurele (Romania); Elisa, M., E-mail: astatin18@yahoo.com [National Institute of Research and Development for Optoelectronics, Department for Optospintronics, 409 Atomistilor Street, P.O. Box MG – 5, RO-77125 Magurele (Romania); Boroica, L., E-mail: boroica_lucica@yahoo.com [National Institute for Lasers, Plasma and Radiation Physics, 77125 Magurele (Romania); Monteiro, R.C.C., E-mail: rcm@fct.unl.pt [Center of Materials Research/Institute for Nanostructures, Nanomodelling and Nanofabrication, (CENIMAT/I3N), Department of Materials Sciences, Faculty of Sciences and Technology, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2013-12-01

    Highlights: • Improved preparation method of rare-earth-doped phosphate glasses was done. • Working and annealing temperatures were lower than for undoped phosphate glass. • Doped glass viscosity is also lower and has quasi-linear variation with temperature. • Exothermic peak appears at about 555 °C and 685 °C, due to devitrification in glass. -- Abstract: The present work investigates alumino-phosphate glasses from Li{sub 2}O–BaO–Al{sub 2}O{sub 3}–La{sub 2}O{sub 3}–P{sub 2}O{sub 5} system containing Sm{sup 3+} and Eu{sup 3+} ions, prepared by two different ways: a wet raw materials mixing route followed by evaporation and melt-quenching, and by remelting of shards. The linear thermal expansion coefficient measured by dilatometry is identical for both rare-earth-doped phosphate glasses. Comparatively to undoped phosphate glass the linear thermal expansion coefficient increases with 2 × 10{sup −7} K{sup −1} when dopants are added. The characteristic temperatures very slowly decrease but can be considered constant with atomic weight, atomic number and f electrons number of the doping ions in the case of T{sub g} (vitreous transition temperature) and T{sub sr} (high annealing temperature) but slowly increase in the case of T{sub ir} (low annealing temperature–strain point) and very slowly increase, being practically constant in the case of T{sub D} (dilatometric softening temperature). Comparatively to undoped phosphate glass the characteristic temperatures of Sm and Eu-doped glasses present lower values. The higher values of electrical conductance for both doped glasses, comparatively to usual soda-lime-silicate glass, indicate a slightly reduced stability against water. The viscosity measurements, showed a quasi-linear variation with temperature the mean square deviation (R{sup 2}) being ranged between 0.872% and 0.996%. The viscosity of doped glasses comparatively to the undoped one is lower at the same temperature. Thermogravimetric

  6. Synthesis, characterization of CaF2 doped silicate glass-ceramics.

    Science.gov (United States)

    Riaz, Madeeha; Zia, Rehana; Mirza, Ambreen; Hussain, Tousif; Bashir, Farooq; Anjum, Safia

    2017-06-01

    This paper reports the fabrication and characterization of silicate glass-ceramics doped with (0-12mol%) CaF 2 . TGA-DSC analysis was carried out to determine the crystallization temperature and stability of glass measured by two glass parameters; Hruby parameter K H =(T x -T g )/(T L -T x ) and Weinberg parameter K W =(T c -T g )/T L . It was found that with CaF 2 doping improved sinterability at low temperature and provided stability to the glass. The XRD pattern exhibits a single phase of combeite and doping of CaF 2 cause increase in crystallite size. Microstructure of samples was also improved with CaF 2 addition, pores were significantly reduced. After 15days immersion in simulated body fluid all samples developed apatite layer onto its surface. Hence, the addition of CaF 2 provided bioactive glass-ceramic material having a low processing temperature. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Binary eutectic clusters and glass formation in ideal glass-forming liquids

    International Nuclear Information System (INIS)

    Lu, Z. P.; Shen, J.; Xing, D. W.; Sun, J. F.; Liu, C. T.

    2006-01-01

    In this letter, a physical concept of binary eutectic clusters in 'ideal' glass-forming liquids is proposed based on the characteristics of most well-known bulk metallic glasses (BMGs). The authors approach also includes the treatment of binary eutectic clusters as basic units, which leads to the development of a simple but reliable method for designing BMGs more efficiently and effectively in these unique glass-forming liquids. As an example, bulk glass formers with superior glass-forming ability in the Zr-Ni-Cu-Al and Zr-Fe-Cu-Al systems were identified with the use of the strategy

  8. Magnetically sensitive nanodiamond-doped tellurite glass fibers.

    Science.gov (United States)

    Ruan, Yinlan; Simpson, David A; Jeske, Jan; Ebendorff-Heidepriem, Heike; Lau, Desmond W M; Ji, Hong; Johnson, Brett C; Ohshima, Takeshi; Afshar V, Shahraam; Hollenberg, Lloyd; Greentree, Andrew D; Monro, Tanya M; Gibson, Brant C

    2018-01-19

    Traditional optical fibers are insensitive to magnetic fields, however many applications would benefit from fiber-based magnetometry devices. In this work, we demonstrate a magnetically sensitive optical fiber by doping nanodiamonds containing nitrogen vacancy centers into tellurite glass fibers. The fabrication process provides a robust and isolated sensing platform as the magnetic sensors are fixed in the tellurite glass matrix. Using optically detected magnetic resonance from the doped nanodiamonds, we demonstrate detection of local magnetic fields via side excitation and longitudinal collection. This is a first step towards intrinsically magneto-sensitive fiber devices with future applications in medical magneto-endoscopy and remote mineral exploration sensing.

  9. Preparation and spectroscopic properties of Yb-doped and Yb-Al-codoped high silica glasses

    International Nuclear Information System (INIS)

    Qiao Yanbo; Wen Lei; Wu Botao; Ren Jinjun; Chen Danping; Qiu Jianrong

    2008-01-01

    Yb-doped and Yb-Al-codoped high silica glasses have been prepared by sintering nanoporous glasses. The absorption, fluorescent spectra and fluorescent lifetimes have been measured and the emission cross-section and minimum pump intensities were calculated. Codoping aluminum ions enhanced the fluorescence intensity of Yb-doped high silica glass obviously. The emission cross-sections of Yb-doped and Yb-Al-codoped high silica glasses were 0.65 and 0.82 pm 2 , respectively. The results show that Yb-Al-codoped high silica glass has better spectroscopic properties for a laser material. The study of high silica glass doped with ytterbium is helpful for its application in Yb laser systems, especially for high-power and high-repetition lasers

  10. Optical properties of 3d transition metal ion-doped sodium borosilicate glass

    International Nuclear Information System (INIS)

    Wen, Hongli; Tanner, Peter A.

    2015-01-01

    Graphical abstract: Photographs of undoped (SiO 2 ) 50 (Na 2 O) 25 (B 2 O 3 ) 25 (SiNaB) glass and transition metal ion-doped (TM) 0.5 (SiO 2 ) 49.5 (Na 2 O) 25 (B 2 O 3 ) 25 glass samples. - Highlights: • 3d transition metal ion (from Ti to Zn) doped SiO 2 -Na 2 O-B 2 O 3 glasses. • Optical properties of doped glasses investigated. • V(IV,V); Cr(III, VI); Mn(II,III); Fe(II,III); Co(II); Ni(II); Cu(II) by XANES, DRS. • Strong visible absorption but only vanadium ion gives strong emission in glass. - Abstract: SiO 2 -Na 2 O-B 2 O 3 glasses doped with 3d-transition metal species from Ti to Zn were prepared by the melting-quenching technique and their optical properties were investigated. The X-ray absorption near edge spectra of V, Cr, and Mn-doped glasses indicate that the oxidation states of V(IV, V), Cr(III, VI) and Mn(II, III) exist in the studied glasses. The oxidation states revealed from the diffuse reflectance spectra of the glasses are V(IV, V), Cr(III, VI), Mn(III), Fe(II, III), Co(II), Ni(II), and Cu(II). Most of the 3d transition element ions exhibit strong absorption in the visible spectral region in the glass. Under ultraviolet excitation, the undoped sodium borosilicate glass produces weak and broad emission, while doping of vanadium introduces strong and broad emission due to the V(V) charge transfer transition. Only weak emission is observed from Ti(IV), Mn(II), Fe(III) and Cu(II), partly resulting from the strong electron–phonon coupling of the 3d-electrons and the relatively high phonon energy of the studied glass host, with the former leading to dominant nonradiative relaxation based on multiphonon processes for most of the 3d excited states

  11. Study of aluminum-doped silicon clusters

    International Nuclear Information System (INIS)

    Zhan Shichang; Li Baoxing; Yang Jiansong

    2007-01-01

    Using full-muffin-tin-orbital molecular-dynamics (FP-LMTO-MD) method, we have investigated the effect of aluminum heteroatoms on the geometric structures and bond characteristics of Si n (n=5-10) clusters in detail. It is found that the geometric framework of the ground state structures for Si n (n=5-10) clusters change to some extent upon the substitution of Al atoms in some Si atoms. The effect of aluminum doping on the silicon clusters depends on the geometric structures of Si n (n=5-10) clusters. In particular, the calculations suggest that the aluminum doping would improve the bond strength of some Si-Si bonds in the mixed Si n - m Al m clusters

  12. Sb/Mn co-doped oxyfluoride silicate glasses for potential applications in photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chaofeng [Key Laboratory of Processing and Testing Technology of Glass & Functional Ceramics of Shandong Province, Qilu University of Technology, Jinan 250353 (China); Laboratoire des Verres et Céramiques, UMR-CNRS 6226, Université de Rennes 1, Rennes 35042 (France); Zhang, Xianghua, E-mail: xiang-hua.zhang@univ-rennes1.fr [Laboratoire des Verres et Céramiques, UMR-CNRS 6226, Université de Rennes 1, Rennes 35042 (France); Ma, Hongli [Laboratoire des Verres et Céramiques, UMR-CNRS 6226, Université de Rennes 1, Rennes 35042 (France)

    2016-03-15

    A series of Sb/Mn co-doped oxyfluoride silicate glasses were prepared via the melt-quenching method to explore red luminescent materials for potential applications in photosynthesis of green plants, and these glasses are investigated by means of luminescence decay curves, absorption, emission, and excitation spectra. We find that the as-prepared glasses are transparent in the visible region and can emit strong red light under ultraviolet, purple, and green light excitations. Furthermore, energy transfer from Sb{sup 3+} to Mn{sup 2+} ions occurs in Sb/Mn co-doped glasses. The results demonstrate that the as-prepared Sb/Mn co-doped oxyfluoride silicate glasses may serve as a potential candidate for developing glass greenhouse, which can enhance the utilization of solar energy for the photosynthesis of the green plants.

  13. Crystal growth and optical properties of CdS-doped lead silicate glass

    International Nuclear Information System (INIS)

    Liu Hao; Liu Qiming; Zhao Xiujian

    2007-01-01

    The crystal growth and optical properties of CdS microcrystallite-doped lead silicate glass is investigated in this paper. The existence of CdS nanocrystals was confirmed via X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results reveal that a two-stage heat-treat procedure can produce a better size distribution of CdS nanocrystals than a one-stage heat-treat procedure in glasses. The second harmonic generation (SHG) from the base glass and CdS microcrystallite doped glasses was observed, and the effects of the heat treatments and the thermal poling temperature on the crystallization of CdS and second-order harmonic (SH) intensity were discussed, respectively. It is indicated that samples doped with CdS microcrystallite showed larger SH intensity than that of the base glass. Use of a higher thermal poling temperature than the glass transformation temperature does not result in a good SH intensity in glasses

  14. Third-order nonlinearity of Er3+-doped lead phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Santos, C. C. [Universidade Federal do Ceara, Ceara, Brazil; Guedes Da Silva, Ilde [ORNL; Siqueira, J. P. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Misoguti, L. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Zilio, S. C. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Boatner, Lynn A [ORNL

    2010-01-01

    The third-order optical susceptibility and dispersion of the linear refractive index of Er3+-doped lead phosphate glass were measured in the wavelength range between 400 and 1940 nm by using the spectrally resolved femtosecond Maker fringes technique. The nonlinear refractive index obtained from the third-order susceptibility was found to be five times higher than that of silica, indicating that Er3+-doped lead phosphate glass is a potential candidate to be used as the base component for the fabrication of photonic devices. For comparison purposes, the Z-scan technique was also employed to obtain the values of the nonlinear refractive index of E-doped lead phosphate glass at several wavelengths, and the values obtained using the two techniques agree to within 15%.

  15. Application of lanthanide ions doped in different glasses

    International Nuclear Information System (INIS)

    Dhondiyal, Charu Chandra

    2015-01-01

    The transfer of optical excitation energy from one ion/molecule to another ion/molecule has proved to be of potential importance in industrial application as well as research. Rare earth elements (RE) although not as rare as some of them occur more prevalently then other well known material (e.g. silver, tin, tungsten) are special group of elements of the periodic table comprising lanthanide series (from lanthanum to lutetium) and actinide series (from actinium to lawrencium). Most of the actinides are highly radioactive hence their uses are limited. Fluorescence is the particular optical property of lanthanide (RE) ions. The narrow absorption and emission lines exhibited by the RE ions in crystals, glasses and solutions have always made these ions attractive as sensitive probes of solids and liquid state and also makes them useful in laser technology, CRT displays, UV to visible converters and optical communications etc. In recent years there has been a special interest to study the properties and applications of rare earth doped in glasses. Lanthanide ions in glasses play an important role, especially by retaining their emission capabilities, in the host matrix. Glass as a dielectric material plays an important role in science and industry. Its chemical, physical and particular optical properties make it suitable for applications such as opto-electronic materials, laboratory equipment, laser gain media, etc. Photoluminescence from rare earth doped glasses are of major interest in the research area of optoelectronic device applications like phosphors, display monitors, lasers and amplifiers for communication systems. Now a days, development of optical devices based on rare-earth ions doped materials is one of the interesting fields of research. Rare earth doped glasses are widely used as laser materials, optical amplifiers, optical memory devices, magneto-optical devices, medical lasers, eye safe lasers, flat panel displays, fluorescent lamps, white LED's etc

  16. Dosimetric properties of dysprosium doped lithium borate glass irradiated by 6 MV photons

    Science.gov (United States)

    Ab Rasid, A.; Wagiran, H.; Hashim, S.; Ibrahim, Z.; Ali, H.

    2015-07-01

    Undoped and dysprosium doped lithium borate glass system with empirical formula (70-x) B2O3-30 Li2O-(x) Dy2O3 (x=0.1, 0.3, 0.5, 0.7, 1.0 mol%) were prepared using the melt-quenching technique. The dosimetric measurements were performed by irradiating the samples to 6 MV photon beam using linear accelerator (LINAC) over a dose range of 0.5-5.0 Gy. The glass series of dysprosium doped lithium borate glass produced the best thermoluminescence (TL) glow curve with the highest intensity peak from sample with 1.0 mol% Dy2O3 concentration. Minimum detectable dose was detected at 2.24 mGy, good linearity of regression coefficient, high reproducibility and high sensitivity compared to the undoped glass are from 1.0 mol% dysprosium doped lithium borate glass. The results indicated that the series of dysprosium doped lithium glasses have a great potential to be considered as a thermoluminescence dosimetry (TLD).

  17. Radiation-induced transmission spectral variations of Ce3+-doped heavy germanate glasses

    International Nuclear Information System (INIS)

    Yang Yunxia; Baccaro, S.; Cecilia, A.; Rao Jinhua; Zhang Junbiao; Xia Fang; Chen Guorong

    2005-01-01

    Radiation-induced transmission spectral variations of Ce 3+ -doped heavy germanate glasses used as scintillating materials are presented. Glass matrix contains mainly GeO 2 , BaO and Gd 2 O 3 with a density higher than 5 g/cm 3 . Glasses are melted in the different atmosphere. The transmission spectra of glasses before and after radiation treatments are measured and compared. Unlike exhibiting the monotonous deterioration effect on the glass matrix, radiation plays the radiation protection role, even making enhanced transmission of Ce 3+ -doped glasses, depending upon glass melting atmosphere and radiation dose. Radiation-induced reducing and oxidizing mechanism is proposed to explain phenomena

  18. Radiation hardening in sol-gel derived Er3+-doped silica glasses

    International Nuclear Information System (INIS)

    Hari Babu, B.; León Pichel, Mónica; Ollier, Nadège; El Hamzaoui, Hicham; Bigot, Laurent; Savelii, Inna; Bouazaoui, Mohamed; Poumellec, Bertrand; Lancry, Matthieu; Ibarra, Angel

    2015-01-01

    The aim of the present paper is to report the effect of radiation on the Er 3+ -doped sol-gel silica glasses. A possible application of these sol-gel glasses could be their use in harsh radiation environments. The sol-gel glasses are fabricated by densification of erbium salt-soaked nanoporous silica xerogels through polymeric sol-gel technique. The radiation-induced attenuation of Er 3+ -doped sol-gel silica is found to increase with erbium content. Electron paramagnetic resonance studies reveal the presence of E′ δ point defects. This happens in the sol-gel aluminum-silica glass after an exposure to γ-rays (kGy) and in sol-gel silica glass after an exposure to electrons (MGy). The concentration levels of these point defects are much lower in γ-ray irradiated sol-gel silica glasses. When the samples are co-doped with Al, the exposure to γ-ray radiation causes a possible reduction of the erbium valence from Er 3+ to Er 2+ ions. This process occurs in association with the formation of aluminum oxygen hole centers and different intrinsic point defects

  19. Nonlinear optical studies in semiconductor-doped glasses under ...

    Indian Academy of Sciences (India)

    Abstract. Nonlinear optical studies in semiconductor-doped glasses (SDGs) are per- formed under femtosecond laser pulse excitation. Z-scan experiments with 800 nm wave- length pulses are used to excite SDG samples in the resonance and non-resonance regimes. Schott colour glass filter OG 515 shows stronger ...

  20. Luminescence properties of Ce3+ doped gadolinium-calcium-silicaborate glass scintillator

    International Nuclear Information System (INIS)

    Park, J.M.; Ha, D.H.; Kaewjeang, S.; Maghanemi, U.; Kothan, S.; Kaewkhao, J.; Kim, H.J.

    2016-01-01

    In this work, the Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators of the composition ratio 25Gd 2 O 3 :10CaO:10SiO 2 :(55−x)B 2 O 3 :xCeF 3 , have been fabricated by using the melt-quenching technique. The doping concentration of the Ce 3+ was varied from 0.05 mol% to 2.5 mol%. The 4f-5d transition of the Ce 3+ allowed scintillation with a fast decay time. The absorption spectrum, X-ray induced emission spectrum, photo luminescence spectrum, laser luminescence spectrum and decay time of the scintillators were measured for studying the luminescence properties. From the X-ray induced emission spectrum result, we checked the trend between doping concentration and light yield. The laser induced luminescence spectrum was measured while changing the temperature from 300 K to 10 K. We also measured the decay time by using the laser excitation of the 0.15 mol% Ce 3+ doped glass scintillator. - Highlights: • Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators were developed. • Glass is easily fabricated with large sizes and various doping materials. • The luminescence properties are studied by using various radiation sources. • The light yield and decay time were measured at low temperature. • One decay time component is found.

  1. Study of optical properties of Erbium doped Tellurite glass-polymer composite

    Science.gov (United States)

    Sushama, D.

    2014-10-01

    Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er2O3 doped TeO2-WO3-La2O3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

  2. Laser properties of an improved average-power Nd-doped phosphate glass

    International Nuclear Information System (INIS)

    Payne, S.A.; Marshall, C.D.; Bayramian, A.J.

    1995-01-01

    The Nd-doped phosphate laser glass described herein can withstand 2.3 times greater thermal loading without fracture, compared to APG-1 (commercially-available average-power glass from Schott Glass Technologies). The enhanced thermal loading capability is established on the basis of the intrinsic thermomechanical properties (expansion, conduction, fracture toughness, and Young's modulus), and by direct thermally-induced fracture experiments using Ar-ion laser heating of the samples. This Nd-doped phosphate glass (referred to as APG-t) is found to be characterized by a 29% lower gain cross section and a 25% longer low-concentration emission lifetime

  3. Effect of CASP glass doping on sintering and dielectric properties of SBN ceramics

    International Nuclear Information System (INIS)

    Chen Guohua; Qi Bing

    2009-01-01

    16CaO-29Al 2 O 3 -34SiO 2 -13PbO-4B 2 O 3 -2ZnO-2P 2 O 5 (CASP) glass doped-Sr 0.5 Ba 0.5 Nb 2 O 6 (SBN50) ceramics have been synthesized by solid-state ceramic route. The effects of CASP glass on the firing, microstructure and dielectric characterization of SBN50 ceramics are investigated. The densities of the ceramic samples firstly increase and then slightly decrease with increasing CASP glass content. The appropriate amount of doping glass is 2%. The SBN50 ceramics doped with CASP glass can be sintered at a relatively low temperature, 1200 deg. C. X-ray diffraction analysis shows the single phase (tetragonal tungsten bronze type structure) is preserved for all the samples. The diffuse character of the ceramic system increases and the dielectric constant at phase transition temperature (T c ) markedly decreases as CASP glass content increases. Interestingly, the CASP glass addition drastically alters the microstructure of the sintered ceramics. The isotropic grains in the pure SBN50 ceramics transform to rod like grains after the addition of CASP glass. The grain size of SBN phase is found to obviously increase with increase in CASP glass doping level

  4. Infrared luminescence and thermoluminescence of lithium borate glasses doped with Sm3+ ions

    Directory of Open Access Journals (Sweden)

    Anjaiah J.

    2015-03-01

    Full Text Available Thermoluminescence (TL characteristics of X-ray irradiated pure and doped with Sm3+ ions Li2O-MO-B2O3 (where MO=ZnO, CaO, CdO glasses have been studied in the temperature range of 303 to 573 K. All the pure glasses exhibited single TL peaks at 382 K, 424 K and 466 K. When these glasses were doped with Sm3+ ions no additional peaks have been observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve was found to be maximum for Sm3+ doped glasses mixed with cadmium oxide as a modifier. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen’s formulae. The possible use of these glasses in radiation dosimetry has been described. The results clearly showed that samarium doped cadmium borate glass has a potential to be considered as a thermoluminescence dosimeter.

  5. Characterization of a gamma radiation dosimeter based of glass doped with copper

    International Nuclear Information System (INIS)

    Laameri, Mohamed Hadi; Ben Mansour, Issam

    2010-01-01

    Commercial sodo-calcic silicate glass was studied by thermo luminescence in order to evaluate its potential like material sensitive to the gamma radiation for dosimetric application. We have examined in particular the effect of doping glass copper ion exchange C U-N A for different concentrations technique and multiple conditions of doping on luminescent thermo sensitivity on a very wide range of doses ranging from 10 mGy up to 100 kGy. We have also tried to explain the origin of thermoluminescence observed by exploiting the doped and non-doped samples EPR spectra.

  6. Photovoltaic Properties of Co-doped ZnO Thin Film on Glass Substrate

    International Nuclear Information System (INIS)

    Sabia Aye; Zin Ma Ma; May Nwe Oo; Than Than Win; Yin Maung Maung; Ko Ko Kyaw Soe

    2011-12-01

    Cobalt (Co) 0.4 mol doped zinc oxide (ZnO) fine powder was prepared by solid state mixed oxide route. Phase formation and crystal structure of Co-doped ZnO (CZO) powder were examined by X-ray diffraction (XRD). Scanning Electron Microscopy (SEM) was used to observe the micro structure of Co doped ZnO powder. Energy Dispersive X-ray Fluorescent (EDXRF) technique gave the elemental content of cobalt and zinc. Co-doped ZnO film was formed on glass substrate by spin coating technique. Photovoltaic properties of CZO/glass cell were measured.

  7. Study of optical properties of Erbium doped Tellurite glass-polymer composite

    Energy Technology Data Exchange (ETDEWEB)

    Sushama, D., E-mail: sushasukumar@gmail.com [Research Awardee, LAMP, Dept. of Physics, Nit, Calicut, India and Dept. of Physics, M.S.M. College, Kayamkulam, Kerala (India)

    2014-10-15

    Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er{sub 2}O{sub 3} doped TeO{sub 2}‐WO{sub 3}‐La{sub 2}O{sub 3} Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

  8. Study of optical properties of Erbium doped Tellurite glass-polymer composite

    International Nuclear Information System (INIS)

    Sushama, D.

    2014-01-01

    Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er 2 O 3 doped TeO 2 ‐WO 3 ‐La 2 O 3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption

  9. Structure and spectroscopy of rare earth – Doped lead phosphate glasses

    International Nuclear Information System (INIS)

    Pisarski, Wojciech A.; Żur, Lidia; Goryczka, Tomasz; Sołtys, Marta; Pisarska, Joanna

    2014-01-01

    Highlights: • Lead phosphate glasses doped with rare earth ions were prepared. • The local structure was examined using X-ray diffraction and spectroscopic methods. • Different structural phosphate groups are present in lead phosphate glasses. • The electron–phonon coupling strength and phonon energy of the glass host was determined. • Several observed emission bands are due to 4f–4f electronic transitions of rare earth ions. -- Abstract: Lead–gallium phosphate glasses doped with rare the earth ions (Eu 3+ , Dy 3+ , Tb 3+ , Er 3+ ) were synthesized. The structure of obtained glasses was examined by means of use: X-ray diffraction (XRD), nuclear magnetic resonance ( 207 Pb and 31 P NMR), fourier transform infrared (FT-IR) and Raman spectroscopy. In contrast to fully amorphous Ln-doped samples (Ln = Eu, Dy, Tb), in Er-doped sample the GaPO 4 crystalline phase was identified. It was found from the NMR, FT-IR and Raman spectroscopic techniques that, different structural phosphate groups were present in lead phosphate glasses. Based on absorption measurements, the UV–VIS cut-off wavelength for lead phosphate glass was determined and its value is close to 305 nm. Excitation and emission spectra of rare earths were also detected. From excitation spectra of Eu 3+ the electron–phonon coupling strength and phonon energy of the glass host were determined. Due to 4f 6 –4f 6 (Eu 3+ ), 4f 8 –4f 8 (Tb 3+ ), 4f 9 –4f 9 (Dy 3+ ) and 4f 11 –4f 11 (Er 3+ ) electronic transitions of trivalent rare earth ions several luminescence bands were stated

  10. Dosimetric and kinetic parameters of lithium cadmium borate glasses doped with rare earth ions

    Directory of Open Access Journals (Sweden)

    J. Anjaiah

    2014-10-01

    Full Text Available Thermoluminescence (TL characteristics of X-ray irradiated pure and doped with four different rare earth ions (viz., Pr3+, Nd3+, Sm3+ and Eu3+ Li2O–Cdo–B2O3 glasses have been studied in the temperature range 303–573 K; the pure glass has exhibited single TL peak at 466 K. When this glass is doped with different rare earth ions no additional peaks are observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve is found to be maximum for Eu3+ doped glasses. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen's formulae. The possible use of these glasses in radiation dosimetry has been described. The result clearly showed that europium doped cadmium borate glass has a potential to be considered as the thermoluminescence dosimeter.

  11. Color tunability of Sm{sup 3+} doped antimony–phosphate glass phosphors showing broadband fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, P. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Zhang, J.J., E-mail: zhangjj@dlpu.edu.cn [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Shen, L.F. [Department of Electronic Engineering and State Key Laboratory of Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Wang, Z.Q. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Pun, E.Y.B. [Department of Electronic Engineering and State Key Laboratory of Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Lin, H., E-mail: lhai8686@yahoo.com [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering and State Key Laboratory of Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2016-10-15

    Sm{sup 3+} doped multicomponent antimony phosphate (MSP) luminescent glasses were prepared and tunable white fluorescence has been investigated. Broad visible emission depending on excitation wavelength is validated to be dominated by discrepant Sb{sup 3+} emitting centers. Group of narrow emissions from Sm{sup 3+} is beneficial to adding yellow and red components in Sm{sup 3+} doped MSP glasses, which is strengthened by effective energy transfer from Sb{sup 3+} to Sm{sup 3+}. Excitation wavelength selection and Sm{sup 3+} concentration adjustment are two feasible routes to optimize luminescence color in Sm{sup 3+} doped MSP glasses and the color tunability of fluorescence indicates that amorphous Sm{sup 3+} doped MSP glass phosphors possess potential for ideal white light devices.

  12. Effects of CuO co-doping on γ-ray irradiation resistance of active ions doped phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhihuan [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); ENEA-UTTMAT, Via Anguillarese 301, 00123 Rome (Italy); Baccaro, Stefania; Cemmi, Alessia [ENEA-UTTMAT, Via Anguillarese 301, 00123 Rome (Italy); Shen, Wei [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen, Guorong, E-mail: grchen@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2013-09-15

    The effect of copper ion doping on the γ-ray irradiation resistance of Mn{sup 2+} and Pr{sup 3+} doped phosphate glasses has been studied. UV–visible transmission spectra and photoluminescence spectra have been measured before and after γ-irradiation to characterize the radiation-induced defects. The electron paramagnetic resonance spectra of the irradiated samples with, and without Cu ions have been compared to show the ability of Cu ions to suppress the generation of radiation-induced color centers. The differential transmission spectra and the radiation-induced absorption coefficients have also been calculated for discussion of the observed phenomena. The much improved γ-irradiation resistance of Mn{sup 2+} and Pr{sup 3+} doped phosphate glasses has been demonstrated through CuO co-doping.

  13. Ion beam induced nanosized Ag metal clusters in glass

    International Nuclear Information System (INIS)

    Mahnke, H.-E.; Schattat, B.; Schubert-Bischoff, P.; Novakovic, N.

    2006-01-01

    Silver metal clusters have been formed in soda lime glass by high-energy heavy-ion irradiation at ISL. The metal cluster formation was detected with X-ray absorption spectroscopy (EXAFS) in fluorescence mode, and the shape of the clusters was imaged with transmission electron microscopy. While annealing in reducing atmosphere alone, leads to the formation of metal clusters in Ag-containing glasses, where the Ag was introduced by ion-exchange, such clusters are not very uniform in size and are randomly distributed over the Ag-containing glass volume. Irradiation with 600-MeV Au ions followed by annealing, however, results in clusters more uniform in size and arranged in chains parallel to the direction of the ion beam

  14. Origin of broad NIR photoluminescence in bismuthate glass and Bi-doped glasses at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Mingying; Zollfrank, Cordt; Wondraczek, Lothar [Lehrstuhl fuer Glas und Keramik, WW3, Friedrich Alexander Universitaet Erlangen-Nuernberg, Martensstrasse 5, D-91058 Erlangen (Germany)], E-mail: mingying.peng@ww.uni-erlangen.de, E-mail: lothar.wondraczek@ww.uni-erlangen.de

    2009-07-15

    Bi-doped glasses with broadband photoluminescence in the near-infrared (NIR) spectral range are presently receiving significant consideration for potential applications in telecommunications, widely tunable fiber lasers and spectral converters. However, the origin of NIR emission remains disputed. Here, we report on NIR absorption and emission properties of bismuthate glass and their dependence on the melting temperature. Results clarify that NIR emission occurs from the same centers as it does in Bi-doped glasses. The dependence of absorption and NIR emission of bismuthate glasses on the melting temperature is interpreted as thermal dissociation of Bi{sub 2}O{sub 3} into elementary Bi. Darkening of bismuthate glass melted at 1300 deg. C is due to the agglomeration of Bi atoms. The presence of Bi nanoparticles is confirmed by transmission electron microscopy, high-resolution energy dispersive x-ray spectroscopy and element distribution mapping. By adding antimony oxide as an oxidation agent to the glass, NIR emission centers can be eliminated and Bi{sup 3+} is formed. By comparing with atomic spectral data, absorption bands at {approx}320 , {approx}500 , 700 , 800 and 1000 nm observed in Bi-doped glasses are assigned to Bi{sup 0} transitions {sup 4}S{sub 3/2}{yields}{sup 2}P{sub 3/2}, {sup 4}S{sub 3/2}{yields}{sup 2}P{sub 1/2}, {sup 4}S{sub 3/2}{yields}{sup 2}D{sub 5/2}, {sup 4}S{sub 3/2}{yields}{sup 2}D{sub 3/2}(2) and {sup 4}S{sub 3/2}{yields}{sup 2}D{sub 3/2}(1), respectively, and broadband NIR emission is assigned to the transition {sup 2}D{sub 3/2}(1){yields}{sup 4}S{sub 3/2}.

  15. Doping of ZnO nanowires using phosphorus diffusion from a spin-on doped glass source

    International Nuclear Information System (INIS)

    Bocheux, A.; Robin, I. C.; Bonaimé, J.; Hyot, B.; Feuillet, G.; Kolobov, A. V.; Fons, P.; Mitrofanov, K. V.; Tominaga, J.; Tamenori, Y.

    2014-01-01

    In this article, we report on ZnO nanowires that were phosphorus doped using a spin on dopant glass deposition and diffusion method. Photoluminescence measurements suggest that this process yields p-doped ZnO. The spatial location of P atoms was studied using x-ray near-edge absorption structure spectroscopy and it is concluded that the doping is amphoteric with P atoms located on both Zn and O sites

  16. Structural properties of lithium borate glasses doped with rare earth ions

    Directory of Open Access Journals (Sweden)

    Thomazini D.

    2001-01-01

    Full Text Available This paper presents the study on lithium triborate glass (LBO in the system (1-x|3B2O3.Li2O| (xNb2O5 yPr3+ zYb3+ wNd3+ with 0 <= x <= 20 mol% (y, z and w in mol%. The samples were studied by Raman spectroscopy, infrared absorption and differential thermal analysis. Pr3+-doped LBO and Pr3+/Yb3+-doped LBO samples show an increase of the glass transition and crystallization temperatures and a decrease of the fusion temperature associated with the increase of the praseodymium concentration in the LBO matrix. For the Nd3+-doped LBO and Pr3+/Yb3+-doped (LBO+Nb2O5 samples, a decrease of the glass transition temperature of the samples was observed. The increase of the rare earth doping leads to an increase of the difference between the glass transition and the crystallization temperatures. From infrared analysis it was possible to identify all the modes associated to the B-O structure. The NbO6 octahedra was also identified by IR spectroscopy for samples with x=5, 10, 15 and 20 mol% and y=0.05, z=1.1 mol%. Raman spectroscopy shows the presence of boroxol rings, tetrahedral and triangular coordination for boron. For samples containing niobium, the Raman spectra show the vibrational mode associated with the Nb-O bond in the niobium octahedra (NbO6.

  17. Eu-, Tb-, and Dy-Doped Oxyfluoride Silicate Glasses for LED Applications

    DEFF Research Database (Denmark)

    Zhu, C.F.; Wang, J.; Zhang, M.M.

    2014-01-01

    Luminescence glass is a potential candidate for the light-emitting diodes (LEDs) applications. Here, we study the structural and optical properties of the Eu-, Tb-, and Dy-doped oxyfluoride silicate glasses for LEDs by means of X-ray diffraction, photoluminescence spectra, Commission Internationale...... de L’Eclairage (CIE) chromaticity coordinates, and correlated color temperatures (CCTs). The results show that the white light emission can be achieved in Eu/Tb/Dy codoped oxyfluoride silicate glasses under excitation by near-ultraviolet light due to the simultaneous generation of blue, green, yellow......, and red-light wavelengths from Tb, Dy, and Eu ions. The optical performances can be tuned by varying the glass composition and excitation wavelength. Furthermore, we observed a remarkable emission spectral change for the Tb3+ single-doped oxyfluoride silicate glasses. The 5D3 emission of Tb3+ can...

  18. Rotation of small clusters in sheared metallic glasses

    International Nuclear Information System (INIS)

    Delogu, Francesco

    2011-01-01

    Graphical abstract: When a Cu 50 Ti 50 metallic glass is shear-deformed, the irreversible rearrangement of local structures allows the rigid body rotation of clusters. Highlights: → A shear-deformed Cu 50 Ti 50 metallic glass was studied by molecular dynamics. → Atomic displacements occur at irreversible rearrangements of local structures. → The dynamics of such events includes the rigid body rotation of clusters. → Relatively large clusters can undergo two or more complete rotations. - Abstract: Molecular dynamics methods were used to simulate the response of a Cu 50 Ti 50 metallic glass to shear deformation. Attention was focused on the atomic displacements taking place during the irreversible rearrangement of local atomic structures. It is shown that the apparently disordered dynamics of such events hides the rigid body rotation of small clusters. Cluster rotation was investigated by evaluating rotation angle, axis and lifetimes. This permitted to point out that relatively large clusters can undergo two or more complete rotations.

  19. Optical spectroscopy and luminescence properties of Ho3+ doped zinc fluorophosphate (ZFP) glasses for green luminescent device applications

    Science.gov (United States)

    Reddy Prasad, V.; Damodaraiah, S.; Ratnakaram, Y. C.

    2018-04-01

    Ho3+ doped zinc fluorophosphate (ZFP) glasses with molar chemical compositions, (60-x) NH4H2PO4+20ZnO+10BaF2+10NaF+xHo2O3 (where x = 0.1, 0.3, 0.5, 1.0 and 1.5 mol%) were prepared by melt quenching technique. These glasses were characterized through physical, structural, optical, excitation, luminescence and decay curve analysis. From the absorption spectra, spectral intensities (fexp and fcal), Judd-Ofelt intensity parameters (Ω2, Ω4 and Ω6), radiative transition probabilities (AT), radiative lifetimes (τR) and branching ratios (βR) were evaluated for all Ho3+ doped ZFP glass matrices. From the photoluminescence spectra, peak stimulated emission cross-sections (σP) were calculated for all Ho3+ doped ZFP glasses. The Ho3+ doped ZFP glasses show strong green emission at 545 nm and red emission at 656 nm under excitation, 450 nm. The measured lifetimes (τmeas) of (5S2)5F4 level of Ho3+ doped ZFP glasses were obtained from decay profiles. The CIE color coordinates of Ho3+ doped ZFP glasses were calculated from emission spectra and 1.0 mol% of Ho3+ doped ZFP glass matrix gives green emission. Hence, these results confirm that the Ho3+ doped ZFP glasses could be considered as a promising candidate for visible green laser applications.

  20. Er –Al2O3 nanoparticles doping of borosilicate glass

    Indian Academy of Sciences (India)

    Administrator

    for determining the optical properties.2 While in homoge- ... of RE-doped single crystals (higher absorption/emission ... nanoparticles doping on the thermal, optical, structural ... The density of the bulk glass materials was measured.

  1. Sol-gel synthesis and in vitro bioactivity of copper and zinc-doped silicate bioactive glasses and glass-ceramics.

    Science.gov (United States)

    Bejarano, Julian; Caviedes, Pablo; Palza, Humberto

    2015-03-11

    Metal doping of bioactive glasses based on ternary 60SiO2-36CaO-4P2O5 (58S) and quaternary 60SiO2-25CaO-11Na2O-4P2O5 (NaBG) mol% compositions synthesized using a sol-gel process was analyzed. In particular, the effect of incorporating 1, 5 and 10 mol% of CuO and ZnO (replacing equivalent quantities of CaO) on the texture, in vitro bioactivity, and cytocompatibility of these materials was evaluated. Our results showed that the addition of metal ions can modulate the textural property of the matrix and its crystal structure. Regarding the bioactivity, after soaking in simulated body fluid (SBF) undoped 58S and NaBG glasses developed an apatite surface layer that was reduced in the doped glasses depending on the type of metal and its concentration with Zn displaying the largest inhibitions. Both the ion release from samples and the ion adsorption from the medium depended on the type of matrix with 58S glasses showing the highest values. Pure NaBG glass was more cytocompatible to osteoblast-like cells (SaOS-2) than pure 58S glass as tested by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The incorporation of metal ions decreased the cytocompatibility of the glasses depending on their concentration and on the glass matrix doped. Our results show that by changing the glass composition and by adding Cu or Zn, bioactive materials with different textures, bioactivity and cytocompatibility can be synthesized.

  2. Optical and structural characterization of rare earth doped niobium phosphate glasses

    International Nuclear Information System (INIS)

    Sene, F.F.; Martinelli, J.R.; Gomes, L.

    2004-01-01

    Phosphate glasses containing up to 45mol% of niobium were obtained. X-ray diffraction, infrared, Raman, and optical absorption spectroscopy were used to analyze those materials. The refractive index varies from 1.70 to 1.85 as the amount of Nb increases. Niobium phosphate glasses with optical transparence in the (400-2500nm) range were produced. The cut off varied from 342nm to 378nm as a function of the Nb concentration. The cut off is due to the charge transfer O 2 ->Nb 5+ . Glasses containing 10mol% of Nb 2 O 5 are the most promising materials to be used as rare-earth ions hosts because they are chemically resistant, and show optical transparency in the spectral range of visible to infrared. Doping the glasses with 1-5mol% of Er, Ho, Pr, and Yb ions does not change the glass structure, as measured by X-ray diffraction, infrared, and Raman spectroscopy. The fluorescence lifetimes were determined for Nd, Yb, and Er, and the absorption cross-section were determined for all ions. The energy transfer in co-doped Yb-Er system was measured, and the lifetime of excited states and the luminescence efficiency were determined to be 91% for the Er 4 I 11/2 level, in the Yb-Er co-doped glasses

  3. Cerium doped heavy metal fluoride glasses, a possible alternative for electromagnetic calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Auffray, E. [CERN, Geneva (Switzerland); Bouttet, D. [LPCM Lyon, CNRS and Universite Claude Bernard, Villeurbanne (France); Dafinei, I. [CERN, Geneva (Switzerland); Fay, J. [IPN Lyon, IN2P3-CNRS and Universite Claude Bernard, Villeurbanne (France); Lecoq, P. [CERN, Geneva (Switzerland); Mares, J.A. [Institute of Physics, Praha (Czech Republic); Martini, M. [University of Milan, Department of Physics, Milan (Italy); Maze, G. [Le Verre Fluore, F - 35770 Vern/Seiche, Bretagne (France); Meinardi, F. [University of Milan, Department of Physics, Milan (Italy); Moine, B. [LPCM Lyon, CNRS and Universite Claude Bernard, Villeurbanne (France); Nikl, M. [Institute of Physics, Praha (Czech Republic); Pedrini, C. [LPCM Lyon, CNRS and Universite Claude Bernard, Villeurbanne (France); Poulain, M. [Le Verre Fluore, F - 35770 Vern/Seiche, Bretagne (France); Schneegans, M. [LAPP, IN2P3-CNRS, Annecy-le-Vieux (France); Tavernier, S. [VUB, Vrije Universiteit Brussels, Brussels (Belgium); Vedda, A. [University of Milan, Department of Physics, Milan (Italy)

    1996-10-11

    The article is an overview of the research activity made in the framework of the Crystal Clear Collaboration aimed at obtaining scintillating glasses able to fit the constraints imposed for the active medium of the central Electromagnetic Calorimeter at CMS. The manufacturing of heavy metal fluoride glasses doped with Ce{sup 3+} is discussed. The luminescence and scintillation characteristics as well as the radiation hardness properties are extensively studied in the case of Ce doped fluorohafnate, found to be the most convenient glass scintillator for high energy physics applications. (orig.).

  4. Cerium doped heavy metal fluoride glasses, a possible alternative for electromagnetic calorimetry

    International Nuclear Information System (INIS)

    Auffray, E.; Bouttet, D.; Dafinei, I.; Fay, J.; Lecoq, P.; Mares, J.A.; Martini, M.; Maze, G.; Meinardi, F.; Moine, B.; Nikl, M.; Pedrini, C.; Poulain, M.; Schneegans, M.; Tavernier, S.; Vedda, A.

    1996-01-01

    The article is an overview of the research activity made in the framework of the Crystal Clear Collaboration aimed at obtaining scintillating glasses able to fit the constraints imposed for the active medium of the central Electromagnetic Calorimeter at CMS. The manufacturing of heavy metal fluoride glasses doped with Ce 3+ is discussed. The luminescence and scintillation characteristics as well as the radiation hardness properties are extensively studied in the case of Ce doped fluorohafnate, found to be the most convenient glass scintillator for high energy physics applications. (orig.)

  5. The far from equilibrium structure of argon clusters doped with krypton or xenon.

    Science.gov (United States)

    Lindblad, A; Bergersen, H; Rander, T; Lundwall, M; Ohrwall, G; Tchaplyguine, M; Svensson, S; Björneholm, O

    2006-04-28

    Heterogeneous clusters created by doping Ar host clusters with Kr or Xe are shown to have radically different structures from the mixed clusters of the same type created by co-expansion of Ar-Kr or Ar-Xe gas mixtures. In contrast to the co-expansion case, the doped mixed clusters can be produced with Kr or Xe on the surface and Ar in the bulk. With the doping technique it is thus possible to control the surface composition of a specific cluster. A study of the cluster properties as a function of the doping pressure is also reported for the case of Ar clusters doped with Xe. The clusters have been studied by means of synchrotron radiation based X-ray photoelectron spectroscopy.

  6. Optical properties of single doped Cr3+ and co-doped Cr3+-Nd3+ aluminum tantalum tellurite glasses

    International Nuclear Information System (INIS)

    Rodriguez-Mendoza, U.R.; Speghini, A.; Jaque, D.; Zambelli, M.; Bettinelli, M.

    2004-01-01

    The optical properties for single doped Cr 3+ and co-doped Cr 3+ -Nd 3+ aluminum tantalum tellurite glasses have been studied as a function of temperature. For the single doped glass, the existence of two bands in the emission spectra at low temperature indicates the presence of two different sites for the Cr 3+ ions, labelled as usual as low- and high-field sites. The broad band centred in the Near Infrared region, corresponds to low-field sites transition 4 T 2 → 4 A 2 , and the narrow band centred at approximately 715 nm to the high-field sites transition 2 E→ 4 A 2 . The emission intensity for both high- and low-field sites shows a strong decrease with increasing temperature, with the emission for the former sites vanishing at RT. In both cases the quenching observed with the increase of temperature can be ascribed to the presence of non-radiative relaxation mechanisms. Experimental observations for the co-doped glass show that both radiative and non-radiative energy transfer processes from Cr 3+ to Nd 3+ are present

  7. Nitrogen doped germania glasses with enhanced optical and mechanical properties

    DEFF Research Database (Denmark)

    Storgaard-Larsen, Torben; Poulsen, Christian; Leistiko, Otto

    1997-01-01

    A new type of ultraviolet photosensitive germanium doped glass has been developed for use in the fabrication of optical waveguide structures. By adding ammonia to the source gases during a plasma enhanced chemical vapor deposition of these glasses, ultraviolet induced refractive index changes of ...

  8. Optical spectroscopy and optical waveguide fabrication in Eu3+ and Eu3+/Tb3+ doped zinc–sodium–aluminosilicate glasses

    International Nuclear Information System (INIS)

    Caldiño, U.; Speghini, A.; Berneschi, S.; Bettinelli, M.; Brenci, M.; Pasquini, E.; Pelli, S.; Righini, G.C.

    2014-01-01

    Optical and spectroscopic properties of 2.0% Eu(PO 3 ) 3 singly doped and 5.0% Tb(PO 3 ) 3 –2.0% Eu(PO 3 ) 3 codoped zinc–sodium–aluminosilicate glasses were investigated. Reddish-orange light emission, with x=0.64 and y=0.36 CIE1931 chromaticity coordinates, is obtained in the europium singly doped glass excited at 393 nm. Such chromaticity coordinates are close to those (0.67,0.33) standard of the National Television System Committee for the red phosphor. When the sodium–zinc–aluminosilicate glass is co-doped with Tb 3+ and Eu 3+ , reddish-orange light emission, with (0.61,0.37) CIE1931 chromaticity coordinates, is obtained upon Tb 3+ excitation at 344 nm. This reddish-orange luminescence is generated mainly by 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 emissions of Eu 3+ , europium being sensitized by terbium through a non-radiative energy transfer. From an analysis of the Tb 3+ emission decay curves it is inferred that the Tb 3+ →Eu 3+ energy transfer might take place between Tb 3+ and Eu 3+ clusters through a short-range interaction mechanism, so that an electric dipole–quadrupole interaction appears to be the most probable transfer mechanism. The efficiency of this energy transfer is about 62% upon excitation at 344 nm. In the singly doped and codoped glasses multimode optical waveguides were successfully produced by Ag + –Na + ion exchange, and they could be characterized at various wavelengths. -- Highlights: • Reddish-orange light emission can be generated from Tb 3+ and Eu 3+ codoped zinc–sodium–aluminosilicate glasses excited at 344 nm. • The Eu 3+ is sensitized by Tb 3+ through a non-radiative energy transfer. • Highly multimode waveguides can be fabricated by diluted silver–sodium exchange. • This type of AlGaN LEDs pumped glass phosphors might be useful for generation of reddish-orange light

  9. Quantum efficiencies of near-infrared emission from Ni2+-doped glass-ceramics

    International Nuclear Information System (INIS)

    Suzuki, Takenobu; Arai, Yusuke; Ohishi, Yasutake

    2008-01-01

    A systematic method to evaluate potentials of Ni 2+ -doped transparent glass-ceramics as a new broadband optical gain media is presented. At first, near-infrared emission of various ceramics were investigated to explore the suitable crystalline phase to be grown in the glass-ceramics. The quantum efficiency of Ni 2+ near-infrared emission estimated by the Struck-Fonger analysis was higher than 95% for spinel-type structure gallate crystals MgGa 2 O 4 and LiGa 5 O 8 at room temperature. Transparent glass-ceramics containing Ni 2+ :LiGa 5 O 8 could be prepared and the quantum efficiency for the glass-ceramics was measured to be about 10%. This value shows a potential of Ni-doped transparent glass-ceramics as a broadband gain media

  10. Spectroscopic properties and thermal stability of Er3+-doped tungsten-tellurite glass for waveguide amplifier application

    International Nuclear Information System (INIS)

    Zhao Shilong; Wang Xiuli; Fang Dawei; Xu Shiqing; Hu Lili

    2006-01-01

    Tungsten-tellurite glass with molar composition of 60TeO 2 -30WO 3 -10Na 2 O has been investigated for developing planar broadband waveguide amplifier application. Spectroscopic properties and thermal stability of Er 3+ -doped tungsten-tellurite glass have been discussed. The results show that the introduction of WO 3 increases significantly the glass transition temperature and the maximum phonon energy. Er 3+ -doped tungsten-tellurite glass exhibits high glass transition temperature (377 deg. C), large emission cross-section (0.91 x 10 -20 cm 2 ) at 1532 nm and broad full width at half maximum (FWHM), which make it preferable for broadband Er 3+ -doped waveguide amplifier application

  11. Linear and nonlinear optical characteristics of Te nanoparticles-doped germanate glasses

    Science.gov (United States)

    Xu, Zhousu; Guo, Qiangbing; Liu, Chang; Ma, Zhijun; Liu, Xiaofeng; Qiu, Jianrong

    2016-10-01

    Te nanoparticles (NPs)-doped GeO2-MgO-B2O3-Al2O3-TeO2 glasses were prepared by the conventional melt-quenching method. Based on X-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscope observation, the coloration of the glass at high TeO2 concentration is ascribed to the precipitation of elemental Te NPs with a size of 5-10 nm in the germanate glass. Optical absorption spectra and nonlinear optical (NLO) properties of the glass samples were analyzed by UV-3600 spectrophotometry and Z-scan technique, respectively. The nonlinear absorption coefficient ( β) and the imaginary part of the third-order NLO susceptibility (Im χ (3)) were estimated to be 1.74 cm/GW and 1.142 × 10-12 esu for laser power of 95 μW, respectively. Due to the excellent NLO properties, the Te NPs-doped germanate glasses may have potential applications for ultrafast optical switch and photonics.

  12. Optical properties of zinc–vanadium glasses doped with samarium ...

    Indian Academy of Sciences (India)

    Abstract. Zinc–vanadium glasses doped with samarium oxide having the chemical composition Sm2O3(x). ZnO(40−x)V2O5(60)(where x = 0·1–0·5 mol%) were prepared by melt quenching method. The density of these glasses was measured by Archimedes method; the corresponding molar volumes have also been ...

  13. Optical studies on Eu3+ doped boro-tellurite glasses

    Science.gov (United States)

    Maheshvaran, K.; Marimuthu, K.

    2012-06-01

    Eu3+ doped boro-tellurite glasses with the chemical composition (39-x)B2O3+30TeO2+15MgO+15K2O +xEu2O3 (where x = 0.01, 0.1, 1, 2 and 3 wt%) have been prepared by following conventional melt quenching technique. Spectroscopic properties of the Eu3+ doped boro-tellurite glasses have been studied by recording the optical absorption and luminescence measurements. Through the optical absorption spectra, bonding parameters (β¯, δ) have been calculated to identify the ionic/covalent nature of the glasses. Judd-Ofelt (JO) analysis have been carried out using the luminescence spectra. The JO parameters (Ωλ = 2, 4 and 6) were used to calculate the radiative properties for the 5D0 → 7FJ (J = 1, 2, 3 and 4) emission transitions of the Eu3+ ions. The change in optical properties with the variation of Eu3+ ion concentration have been studied and discussed with similar studies.

  14. Luminescent properties of Ln3+ doped tellurite glasses containing AlF3

    Science.gov (United States)

    Walas, Michalina; Pastwa, Agata; Lewandowski, Tomasz; Synak, Anna; Gryczyński, Ignacy; Sadowski, Wojciech; Kościelska, Barbara

    2016-09-01

    The low-phonon energy tellurite glasses TeO2-BaO-Bi2O3 and TeO2-BaO-Bi2O3-AlF3 triply doped with Eu3+, Tb3+, Tm3+ ions in two different molar ratios were synthesized using melt-quenching technique. Their structure and luminescence properties were widely investigated by X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Photoluminescence Spectroscopy (PL). The luminescence spectra of Eu3+, Tb3+, Tm3+ co-doped glasses show apart of the bands corresponding to the 4f-4f transitions of lanthanide ions also band corresponding to glass matrix. AlF3 doping increases emission intensity, although to improve overall emission color further studies on molar composition of samples and the molar ratio of the components should be carried out.

  15. Comparative investigation on the spectroscopic properties of Pr3+-doped boro-phosphate, boro-germo-silicate and tellurite glasses

    Science.gov (United States)

    Zhang, Liaolin; Dong, Guoping; Peng, Mingying; Qiu, Jianrong

    We report on the spectroscopic properties of Pr3+-doped boro-phosphate, boro-germo-silicate and tellurite glasses. The stimulated absorption and emission cross sections were estimated. Only one emission at 596 nm and 605 nm is observed in Pr3+-doped boro-phosphate and boro-germo-silicate glasses, respectively, while three emissions at 605 nm, 612 nm and 645 nm are observed in Pr3+-doped tellurite glass when excited at 467 nm. The fluorescence lifetime at 600 nm in Pr3+-doped boro-phosphate, boro-germo-silicate and tellurite glasses is 137 μs, 73 μs and 51 μs, respectively. The emissions from Pr3+-doped boro-phosphate, boro-germo-silicate and tellurite glasses show different decay behaviors and can be well explained by multiphonon relaxation theory.

  16. Spectroscopy of Yb-doped tungsten-tellurite glass and assessment of its lasing properties

    Science.gov (United States)

    Merzliakov, M. A.; Kouhar, V. V.; Malashkevich, G. E.; Pestryakov, E. V.

    2018-01-01

    Glasses of the TeO2-WO3-Yb2O3 system are synthesized for wide range of Yb3+ concentrations of up to 6.0 × 1021 ions/cm3. The spectral-luminescent properties of lightly doped samples are investigated at room temperature and at the boiling point of liquid nitrogen. The energies of the Stark levels of the ground and excited states of Yb3+ ions incorporated into tungsten-tellurite glass are determined by analyzing the low-temperature spectra. The absorption, emission, and gain cross section spectra are obtained. The excess of the measured fluorescence decay time over the radiative lifetime ∼0.3 ms derived from the absorption spectra is attributed to the reabsorption effect in bulk samples. Measurements of lightly doped glass powder in the immersion liquid are made to reduce the effect of reabsorption. The fluorescence decay time of the powder is very close to the calculated radiative lifetime. Compared with phosphate, silicate, and other Yb3+-doped glasses, the tungsten-tellurite glass has a promising potential as a gain medium for lasers and amplifiers.

  17. Physical and optical properties of lithium borosilicate glasses doped with Dy3+ ions

    Science.gov (United States)

    Ramteke, D. D.; Gedam, R. S.; Swart, H. C.

    2018-04-01

    The borosilicate glasses with Dy3+ ions were prepared by the melt quench technique with varying concentration of Dy2O3. The glasses were characterized by the density calculation, absorbance and photoluminescence (PL) spectroscopy measurements. Density and molar volume of the glasses increases with increase in Dy3+ ions in the glass matrix. This behavior is correlated with the higher molecular weight and larger ionic radius of Dy3+ ion compared to the other constituents of glass matrix. Emission of Dy3+ doped glasses showed three bands at 482, 573 and at 665 nm which correspond to 6H15/2 (blue), 6H13/2 (yellow) and 6H11/2 (red) transitions. The emission spectra of glasses with different concentration of Dy3+ ions shows that, glasses with 0.5 mol% of Dy2O3 shows highest emission and decreases with further doping. CIE 1931 chromaticity diagram showed that the emission of these glasses was in the white region. Photographs of these glasses under 349 nm Light emitting diode excitation also confirmed the white light emission from these glasses.

  18. Spin-glass-like dynamics of ferromagnetic clusters in La0.75Ba0.25CoO3

    International Nuclear Information System (INIS)

    Kumar, Devendra

    2014-01-01

    We report a magnetization study of the compound La 0.75 Ba 0.25 CoO 3 where the Ba 2+ doping is just above the critical limit for percolation of ferromagnetic clusters. The field cooled and zero-field cooled (ZFC) magnetization exhibit thermomagnetic irreversibility and the ac susceptibility shows a frequency dependent peak at the ferromagnetic ordering temperature (T C  ≈ 203 K) of the clusters. These features indicate the presence of a non-equilibrium state below T C . For the non-equilibrium state, the dynamic scaling of the imaginary part of the ac susceptibility and the static scaling of the nonlinear susceptibility clearly establish a spin-glass-like cooperative freezing of ferromagnetic clusters at 200.9(2) K. The assertion of the occurrence of spin-glass-like freezing of ferromagnetic clusters is further substantiated by ZFC ageing and memory experiments. We also observe certain dynamical features which are not present in a typical spin glass, such as: the initial magnetization after ZFC ageing first increases and then decreases with the waiting time; and there is an imperfect recovery of relaxation in negative temperature cycling experiments. This imperfect recovery transforms to perfect recovery for concurrent field cycling. Our analysis suggests that these additional dynamical features have their origin in the inter-cluster exchange interaction and cluster size distribution. The inter-cluster exchange interaction above the magnetic percolation level gives a superferromagnetic state in some granular thin films, but our results show the absence of a typical superferromagnetic-like state in La 0.75 Ba 0.25 CoO 3 . (paper)

  19. Inverted opal luminescent Ce-doped silica glasses

    Directory of Open Access Journals (Sweden)

    R. Scotti

    2006-01-01

    Full Text Available Inverted opal Ce-doped silica glasses (Ce : Si molar ratio 1 ⋅ 10−3 were prepared by a sol-gel method using opals of latex microspheres as templates. The rare earth is homogeneously dispersed in silica host matrix, as evidenced by the absence of segregated CeO2, instead present in monolithic Ce-doped SG with the same cerium content. This suggests that the nanometric dimensions of bridges and junctions of the host matrix in the inverted opal structures favor the RE distribution avoiding the possible segregation of CeO2.

  20. Spectroscopic properties of Sm{sup 3+}-doped lanthanum borogermanate glass

    Energy Technology Data Exchange (ETDEWEB)

    Rajaramakrishna, R. [Department of Physics, Bangalore University, Bangalore 560056 (India); Knorr, Brian; Dierolf, Volkmar [Department of Physics, Lehigh University Bethlehem, PA 18015 (United States); Anavekar, R.V., E-mail: anavekar_271@yahoo.co.in [Department of Physics, Bangalore University, Bangalore 560056 (India); Jain, H. [Department of Materials Science and Engineering, Lehigh University Bethlehem, PA 18015 (United States)

    2014-12-15

    Ultraviolet–visible–near infrared (UV–vis–NIR) absorption and photoluminescence of (25−x) La{sub 2}O{sub 3}–25B{sub 2}O{sub 3}–50GeO{sub 2} glass series have been studied with different concentrations (x=0.1–1.0 wt%) of Sm{sub 2}O{sub 3} as an optically active dopant. The values of Judd–Ofelt (JO) parameters (Ω{sub t}) follow the trend Ω{sub 2}>Ω{sub 4}>Ω{sub 6}. Visible emission and decay times from the {sup 4}G{sub 5/2} level and its relative quantum efficiencies are measured. Intense reddish-orange emission corresponding to {sup 4}G{sub 5/2}→{sup 6}H{sub 7/2} transition has been observed in these glasses under 488 nm excitation. A decrease in the quantum yield is observed with increasing Sm{sup 3+} ion concentration beyond 1% doping level. - Highlights: • Lanthanum boro-germanate glasses doped with samarium ions are good laser host matrix. • These glasses show large emission cross-sections (σ{sub P}) values. • These glasses show large gain bandwidth and optical gain parameters. • These glasses are suitable candidate for reddish-orange laser applications.

  1. Thermoluminescence Response of Copper-Doped Potassium Borate Glass Subjected to 6 Megavolt X-Ray Irradiation

    Science.gov (United States)

    Hossain, I.; Shekaili, N. K.; Wagiran, H.

    2015-03-01

    This study addresses the characteristics of Cu-doped and undoped potassium borate glass for use as ionizing radiation dosimeters by investigating and comparing the thermoluminescence responses, linearity, sensitivity and dose response s of the two types of glasses. A number of samples based on xK 2 CO 3 + (100 - x)H 3 BO 3 , where 10 ≤ x ≤ 30 mol.%, have been prepared using a melt quenching technique. The amorphous phases were identified using X-ray diffraction (XRD). The undoped potassium borate samples 20K 2 CO 3 + 80H 3 BO 3 (mol.%) and Cu-doped (0.5 mol.%) samples were placed in a solid phantom apparatus and irradiated with in X-ray tube under 6 MV accelerating voltage with doses ranging from 0.5 to 4.0 Gy. This beam was produced by the Primus MLC 3339 linear accelerator (LINAC) available at Hospital Sultan Ismail, Johor Bahru, Malaysia. The results clearly show the superiority of Cu-doped glass in terms of response and sensitivity to producing luminescence over undoped potassium borate glass. The sensitivity of Cu-doped glass is 6.75 times greater than that of undoped glass.

  2. Concentration quenching in Nd-doped glasses

    International Nuclear Information System (INIS)

    Stokowski, S.E.; Cook, L.; Mueller, H.; Weber, M.J.

    1984-01-01

    Fluorescence from trivalent Nd in solids is unfortunately quenched by interactions between Nd ions. Thus, laser materials with high Nd concentrations have reduced efficiencies because of this self-quenching, also known as concentration quenching. Nd self-quenching in different crystals and glasses varies considerably. We are therefore investigating this effect in a large number of materials in an effort to: (1) find those materials with long Nd fluorescent lifetimes at high Nd concentrations; and (2) elucidate the basic mechanisms of quenching and how the material structure controls its magnitude. We have concentrated on Nd-doped glasses because they provide a rich variety of structures, albeit complicated by Nd site inhomogeneities, and are easily and quickly made

  3. Synthesis, characterization, bioactivity and antibacterial studies of silver doped calcium borosilicate glass-ceramics

    Science.gov (United States)

    Kumar, Alesh; Mariappan, C. R.

    2018-04-01

    Bioactive glass-ceramics 45.8 mol% SiO- 45.8 CaO - 8.4 B2O3 doped with Ag2O were synthesized by sol-gel method. The glass-ceramic nature of samples was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. Fourier transform infrared (FT-IR) spectra reveal the probable stretching and bending vibration modes of silicate and borate groups. UV-Visible spectra reveal the presence of Ag+ ions and metallic Ag in the glass matrix for Ag2O doped ceramic sample. Biocompatibility of the glass nature of samples was studied by soaking of samples in Dulbecco's Modified Eagle's Medium (DMEM) with subsequent XRD studies. It was found that bone-like apatite formation on the glasses after soaked in DMEM. Antibacterial studies of glass ceramics powder against gram positive and negative microorganisms were carried out.

  4. Multimodal emissions from Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate glass: Upconversion, downshifting and quantum cutting

    Energy Technology Data Exchange (ETDEWEB)

    Bahadur, A.; Yadav, R.S.; Yadav, R.V.; Rai, S.B., E-mail: sbrai49@yahoo.co.in

    2017-02-15

    This paper reports the optical properties of Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate (LB) glass prepared by melt quench method. The absorption spectrum of the Yb{sup 3+} doped LB glass contains intense NIR band centered at 976 nm due to {sup 2}F{sub 7/2}→{sup 2}F{sub 5/2} transition. The emission spectra of the prepared glasses have been monitored on excitation with 266, 355 and 976 nm. The Yb{sup 3+} doped glass emits a broad NIR band centered at 976 nm whereas the Tb{sup 3+} doped glass gives off visible bands on excitations with 266 and 355 nm. When the Tb{sup 3+} and Yb{sup 3+} ions are co-doped together, the emission intensity in the visible region decreases whereas it increases in the NIR region significantly. The increase in the emission intensity in the NIR region is due to efficient cooperative energy transfer (CET) from Tb{sup 3+} to Yb{sup 3+} ions. The quantum cutting efficiency for Tb{sup 3+}/Yb{sup 3+} co-doped glass has been calculated and compared for 266 and 355 nm excitations. The quantum cutting efficiency is larger for 355 nm excitation (137%). The Tb{sup 3+}/Yb{sup 3+} co-doped LB glass also emits upconverted visible bands on excitation with 976 nm. The mechanisms involved in the energy transfer have been discussed using schematic energy level diagram. The Tb{sup 3+}/Yb{sup 3+} co-doped LB glass may be used in the optical devices and in solar cell for solar spectral conversion and behaves as a multi-modal photo-luminescent material. - Graphical abstract: The Tb{sup 3+}/Yb{sup 3+} co-doped lithium borate (LB) glass prepared by melt quench method emits upconverted visible emissions through upconversion CET from Yb{sup 3+} to Tb{sup 3+} ions and quantum cutting emissions through downconversion CET from Tb{sup 3+} to Yb{sup 3+} ions. Therefore, the Tb{sup 3+}/Yb{sup 3+} co-doped LB glass may find applications in optical devices and solar cell and behaves as a multi-modal photo-luminescent material. - Highlights: • The Tb{sup 3+}/Yb{sup 3

  5. Luminescent properties of fluorophosphate glasses with lead chalcogenides molecular clusters

    International Nuclear Information System (INIS)

    Kolobkova, E.V.; Kukushkin, D.S.; Nikonorov, N.V.; Shakhverdov, T.A.; Sidorov, A.I.; Vasiliev, V.N.

    2015-01-01

    Fluorophosphate glasses containing lead, selenium, and sulfur exhibit an intense luminescence in the 400–620 nm spectral region when excited by the 240–420 nm radiation. This luminescence is due to the presence of (PbSe) n and/or (PbS) n molecular clusters in the glasses, which appear in the as-prepared glasses before quantum dots formation. The thermal treatment at temperatures less than the glass transition temperature results in the red-shift of the luminescence bands and in an increase in the luminescence intensity. Heating the thermally treated glass samples leads to the reversible thermal quenching of the luminescence. - Highlights: • Fluorophosphate glasses with Pb, Se, and S ions contain (PbSe) n or (PbS) n molecular clusters. • (PbSe) n and (PbS) n molecular clusters possess luminescence in the visible with UV excitation. • Heating the glass leads to the reversible thermal quenching of the luminescence

  6. Structure, reactivity and electronic properties of Mn doped Ni13 clusters

    International Nuclear Information System (INIS)

    Banerjee, Radhashyam; Datta, Soumendu; Mookerjee, Abhijit

    2013-01-01

    In this work we have studied the structural and magnetic properties of Ni 13 cluster mono- and bi-doped with Mn atoms. We have noted their tendency of being reactive toward the H 2 molecule. We have found unusually enhanced stability in the mono-doped cluster (i.e. of the Ni 12 Mn) and the diminished stability of the corresponding chemisorbed cluster, Ni 12 MnH 2 . Our analysis of the stability and HOMO–LUMO gap explains this unusual behavior. Interestingly, we have also seen the quenching in the net magnetic moment upon H 2 absorption in the doped Ni 13−m Mn m alloy clusters. This has been reported earlier for smaller Ni n clusters [1

  7. Structure, reactivity and electronic properties of Mn doped Ni13 clusters

    Science.gov (United States)

    Banerjee, Radhashyam; Datta, Soumendu; Mookerjee, Abhijit

    2013-06-01

    In this work we have studied the structural and magnetic properties of Ni13 cluster mono- and bi-doped with Mn atoms. We have noted their tendency of being reactive toward the H2 molecule. We have found unusually enhanced stability in the mono-doped cluster (i.e. of the Ni12Mn) and the diminished stability of the corresponding chemisorbed cluster, Ni12MnH2. Our analysis of the stability and HOMO-LUMO gap explains this unusual behavior. Interestingly, we have also seen the quenching in the net magnetic moment upon H2 absorption in the doped NiMnm alloy clusters. This has been reported earlier for smaller Nin clusters [1].

  8. Composition dependence of the optical and structural properties of Eu-doped oxyfluoride glasses

    DEFF Research Database (Denmark)

    Zhu, C.F.; Wu, D.Q.; Zhang, Y.F.

    2015-01-01

    Europium doped oxyfluoride glasses were prepared by the melt quenching method for the light emitting diodes applications. The optical and structural properties of these glasses were studied by means of photoluminescence spectra, Commission Internationale de L'Eclairage chromaticity coordinates, X...... compositions. Finally, we propose a mechanism to explain how the glass structure affects the reduction of Eu ions as well as optical properties of the glasses.......Europium doped oxyfluoride glasses were prepared by the melt quenching method for the light emitting diodes applications. The optical and structural properties of these glasses were studied by means of photoluminescence spectra, Commission Internationale de L'Eclairage chromaticity coordinates, X...... on the base glass compositions. For certain base glass compositions, CaF2 crystals can form during the melt cooling process, and thereby enhance the conversion from Eu3+ to Eu2+. The formation of CaF2 crystals can be suppressed by adding CaO, Al2O3 and B2O3, but enhanced by adding Na2O and K2O in glass...

  9. Conductivity in alkali doped CoO-B2O3 glasses

    International Nuclear Information System (INIS)

    Nagaraja, N; Sankarappa, T; Santoshkumar; Sadashivaiah, P J; Yenkayya

    2009-01-01

    Two series of cobalt-borate glasses doped with Li 2 O and K 2 O in single and mixed proportions have been synthesized by melt quenching method and investigated for ac conductivity in the frequency range of 50Hz to 5MHz and temperature range of 310K to 610K. From the measured total conductivity, the pure ac component and its frequency exponent, s were determined. In the single alkali doped glasses, for all the frequencies, the conductivity increased with increase of Li 2 O up to 0.4 mole fractions and decreased for further increase of Li 2 O. The temperature dependence of conductivity has been analyzed using Mott's small polaron hopping model and activation energy for ac conduction has been determined. Based on conductivity and activation behaviors, in single alkali glasses, a change over of conduction mechanism predominantly from ionic to electronic has been predicted. In mixed alkali doped glasses, the conductivity passed through minimum and activation energy passed through maximum for second alkali (K 2 O) content of 0.2 mole fractions. This result revealed the mixed alkali effect to be occurring at 0.2 mole fractions of K 2 O. The frequency exponent, s, was compared with theoretical models such as Quantum Mechanical Tunneling and Correlated Barrier Hopping models and found them to be inadequate to explain the experimental observations. Time-temperature superposition principle has been verified in both the sets of glasses.

  10. Comparative study of scintillation properties of RE doped NaPO3-Al(PO3)3 glasses

    International Nuclear Information System (INIS)

    Kuro, Tomoaki; Yanagida, Takayuki; Okada, Go; Fujimoto, Yutaka; Masai, Hirokazu

    2015-01-01

    We systematically investigated photoluminescence (PL), scintillation and dosimeter properties of rare-earth (RE) doped NaPO 3 -Al(PO 3 ) 3 (NAP) glasses. Ag-doped NAP glass is widely used for individual radiation dosimeter, however, there have been few reports on studies about NAP glasses when RE ions are doped as the luminescence center. The NAP glasses doped with 0.3 wt% RE (La∼Yb) were prepared by the conventional melt-quenching method. PL decay time and scintillation decay time profiles showed fast (ns) and slow (μs or ms) components: the fast components were from several tens to 100 ns due to the host emission or 5d-4f transition emission, and the slow component from few μs to few ms was caused by 4f-4f transition emission of RE 3+ . Thermally stimulated luminescence (TSL) was evaluated as a dosimeter property, and glow peaks appeared around 400degC in all the samples. The TSL dose response function was examined in the dose range from 10 mGy to 10 Gy, and good linearity was observed in RE-doped NAP glasses. (author)

  11. Enhanced frequency upconversion study in Er3+/Yb3+ doped/codoped TWTi glasses

    Science.gov (United States)

    Azam, Mohd; Rai, Vineet Kumar

    2018-04-01

    Er3+/Yb3+ doped/codoped TeO2-WO3-TiO2 (TWTi) glasses have been prepared by using the melt-quenching technique. The upconversion (UC) emission spectra of the developed glasses have been recorded upon 980 nm laser excitation. Three intense UC emission bands have been observed within the green and red region centered at ˜532 nm, ˜553 nm and ˜669 nm corresponding to the 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions respectively in the singly Er3+ doped glass. On introducing Yb3+ ions in the singly Er3+ doped glass, an enhancement of about ˜ 12 times and ˜50 times in the green and red bands respectively have been observed even at low pump power ˜ 364 mW followed by two photon absorption process. Colour tunability from yellowish green to pure green colour region has been observed on varying the pump power. The prepared glass can be used to produce NIR to green upconverter and colour tunable display devices.

  12. Structural and optical study on antimony-silicate glasses doped with thulium ions.

    Science.gov (United States)

    Dorosz, D; Zmojda, J; Kochanowicz, M; Miluski, P; Jelen, P; Sitarz, M

    2015-01-05

    Structural, spectroscopic and thermal properties of SiO₂-Al₂O₃-Sb₂O₃-Na₂O glass system doped with 0.2 mol% Tm₂O₃ have been presented. Synthesis of antimony-silicate glasses with relatively low phonon energy (600 cm(-1), which implicates a small non-radiative decay rate) was performed by conventional high-temperature melt-quenching methods. The effect of SiO₂/Sb₂O₃ ratio in fabricated Tm(3+) doped glass on thermal, structural and luminescence properties was investigated. On the basis of structural investigations decomposition of absorption bands in the infrared FTIR region was performed, thus determining that antimony ions are the only glass-forming ions, setting up the lattice of fabricated glasses. Luminescence band at the wavelength of 1.8 μm corresponding to (3)F₄→(3)H₆ transition in thulium ions was obtained under 795 nm laser pumping. It was observed that combination of relatively low phonon energy and greater separation of optically active centers in the fabricated glasses influenced in decreasing the luminescence intensity at 1800 nm. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Optical and structural investigation on sodium borosilicate glasses doped with Cr2O3

    Science.gov (United States)

    Ebrahimi, E.; Rezvani, M.

    2018-02-01

    In this work, Sodium borosilicate glasses with chemical composition of 60% SiO2-20% B2O3-20%Na2O doped with different contents of Cr2O3 were prepared by melting-quenching method. Physical, structural and optical properties of glasses were investigated by studying density and molar volume, Fourier Transform Infrared (FT-IR) Spectra and UV-visible absorption spectroscopy. The results showed an increase in density of glasses with the increase of Cr2O3 that can be due to addition of oxide with high molar mass. The optical absorption spectra of un-doped glass reveals UV absorption due to trace iron impurities with no visible band however Cr2O3 doped glasses shows absorption in visible range that are characteristic. Increasing of Cr3 + ions in the glassy microstructure of samples provides a semiconducting character to Sodium borosilicate glass by reducing the direct and indirect optical band gaps of glass samples from 3.79 to 2.59 (ev) and 3.36 to 2.09 (ev), respectively. These changes could be attributed to the role of Cr3 + ions as the network former which asserts improvement of semiconducting behavior in presence of Cr2O3.

  14. Ge nanoclusters in PECVD-deposited glass caused only by heat treatment

    DEFF Research Database (Denmark)

    Ou, Haiyan; Rørdam, Troels Peter; Rottwitt, Karsten

    2008-01-01

    This paper reports the formation of Ge nanoclusters in a multi-layer structure consisting of alternating thin films of Ge-doped silica glass and SiGe, deposited by plasma-enhanced chemical vapor deposition (PECVD) and post annealed at 1100 °C in N2 atmosphere. We studied the annealed samples...... embedded with Ge nanoclusters after annealing. These nanoclusters are crystalline and varied in size. There were no clusters in the Ge-doped glass layer. Raman spectra verified the existence of crystalline Ge clusters. The positional shift of the Ge vibrational peak with the change of the focus depth...

  15. Thermal, optical and structural properties of Dy3+ doped sodium aluminophosphate glasses

    Science.gov (United States)

    Kaur, Manpreet; Singh, Anupinder; Thakur, Vanita; Singh, Lakhwant

    2016-03-01

    Trivalent Dysprosium doped sodium aluminophosphate glasses with composition 50P2O5-10Al2O3-(20-x)Na2O-20CaO-xDy2O3 (x varying from 0 to 5 mol%) were prepared by melt quench technique. The density of the prepared samples was measured using Archimedes principle and various physical properties like molar volume, rare earth ion concentration, polaron radius, inter nuclear distance and field strength were calculated using different formulae. The differential scanning calorimetry (DSC) was carried out to study the thermal stability of prepared glasses. The UV Visible absorption spectra of the dysprosium doped glasses were found to be comprised of ten absorption bands which correspond to transitions from ground state 6H15/2 to various excited states. The indirect optical band gap energy of the samples was calculated by Tauc's plot and the optical energy was found to be attenuated with Dy3+ ions. The photoluminescence spectrum revealed that Dy3+ doped aluminophosphate glasses have strong emission bands in the visible region. A blue emission band centred at 486 nm, a bright yellow band centred at 575 nm and a weak red band centred at 668 nm were observed in the emission spectrum due to excitation at 352 nm wavelength. Both FTIR and Raman spectra assert slight structural changes induced in the host glass network with Dy3+ ions.

  16. Comparative study of ion conducting pathways in borate glasses

    International Nuclear Information System (INIS)

    Hall, Andreas; Swenson, Jan; Adams, Stefan

    2006-01-01

    The conduction pathways in metal-halide doped silver, lithium, and sodium diborate glasses have been examined by bond valence analysis of reverse Monte Carlo (RMC) produced structural models of the glasses. Although all glass compositions have basically the same short-range structure of the boron-oxygen network, it is evident that the intermediate-range structure is strongly dependent on the type of mobile ion. The topography of the pathways and the coordination of the pathway sites differ distinctly between the three glass systems. The mobile silver ions in the AgI-doped glass tend to be mainly iodine-coordinated and travel in homogeneously distributed pathways located in salt-rich channels of the borate network. In the NaCl-doped glass, there is an inhomogeneous spatial distribution of pathways that reflects the inhomogeneous introduction of salt ions into the glass. However, since the salt clusters are not connected, no long-range conduction pathways are formed without including also oxygen-rich regions. The pathways in the LiCl-doped glass are slightly more evenly distributed compared to the NaCl-doped glass (but not as ordered as in the AgI-doped glass), and the regions of mainly oxygen-coordinated pathway sites are of higher importance for the long-range migration. In order to more accurately investigate how these differences in the intermediate-range order of the glasses affect the ionic conductivity, we have compared the realistic structure models to more or less randomized structures. An important conclusion from this comparison is that we find no evidence that a pronounced intermediate-range order in the atomic structure or in the network of conduction pathways, as in the AgI-doped glass, is beneficial for the dc conductivity

  17. Luminescence properties of the Sm-doped borate glasses

    International Nuclear Information System (INIS)

    Kindrat, I.I.; Padlyak, B.V.; Drzewiecki, A.

    2015-01-01

    The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li 2 B 4 O 7 , LiKB 4 O 7 , CaB 4 O 7 , and LiCaBO 3 compositions were investigated and analysed. The Li 2 B 4 O 7 :Sm, LiKB 4 O 7 :Sm, CaB 4 O 7 :Sm, and LiCaBO 3 :Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm 3+ (4f 5 , 6 H 5/2 ) ions, exclusively. All observed 4f – 4f transitions of the Sm 3+ centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm 3+ ions peaked about 598 nm ( 4 G 5/2 → 6 H 7/2 transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm 3+ luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm 3+ centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd–Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce 3+ non-controlled impurity and intrinsic luminescence centres to the Sm 3+ centres has been observed. Peculiarities of the Sm 3+ local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. - Highlights: • The Sm-doped Li 2 B 4 O 7 , LiKB 4 O 7 , CaB 4 O 7 , and LiCaBO 3 glasses of high quality were obtained. • EPR, optical absorption and luminescence spectra of Sm 3+ ions in obtained glasses were

  18. Pump-induced refractive index changes in Tb{sup 3+} doped glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, T.A.; Santos, J.F.M. dos; Auad, Y.M; Nunes, L.A.O. [Instituto de Física de São Carlos, Universidade de São Paulo, SP (Brazil); Astrath, N.G.C; Baesso, M.L. [Departamento de Física, Universidade Estadual de Maringá, PR (Brazil); Catunda, T., E-mail: tomaz@ifsc.usp.br [Instituto de Física de São Carlos, Universidade de São Paulo, SP (Brazil)

    2016-01-15

    It now well known in laser materials, that a refractive index change appears when the active ions are pumped from ground to excited state due to the polarizability difference between ground and excited states (metastable). In this paper this effect was investigated in Tb{sup 3+} doped glasses: calcium alumino phosphate (CAP), low-silica calcium aluminosilicate (LSCAS) and calcium aluminosilicate (CAS). The measurements were performed using the time resolved Z-scan technique, with an Ar{sup +} laser at 488 nm, close to the resonance of {sup 7}F{sub 6}→{sup 5}D{sub 4} absorption line, where {sup 5}D{sub 4} is a metastable state. We obtained for low-silica calcium aluminosilicate glass Δα{sub p}~10{sup −24} cm{sup 3} which is the highest value ever reported for a RE doped material. - Highlights: • Time resolved Z-scan measurements in 3 different Tb{sup 3+} doped glass. • Very high polarizability difference (Δα{sub p}), typically 1 order of magnitude higher than other rare earth ions. • Observations of higher order nonlinearities, such as-third, fifth and senventh order effects.

  19. Development of continuous glass melting for production of Nd-doped phosphate glasses for the NIF and LMJ laser system

    International Nuclear Information System (INIS)

    Campbell, J. H.; Ficini-Dorn, G.; Hawley-Fedder, R.; McLean, M. J.; Suratwala, T.; Trombert, J. H.

    1998-01-01

    The NIF and LMJ laser systems require about 3380 and 4752 Nd-doped laser glass slabs, respectively. Continuous laser glass melting and forming will be used for the first time to manufacture these slabs. Two vendors have been chosen to produce the glass: Hoya Corporation and Schott Glass Technologies. The laser glass melting systems that each of these two vendors have designed, built and tested are arguably the most advanced in the world. Production of the laser glass will begin on a pilot scale in the fall of 1999

  20. White emission materials from glass doped with rare Earth ions: A review

    Energy Technology Data Exchange (ETDEWEB)

    Yasaka, P.; Kaewkhao, J., E-mail: mink110@hotmail.com [Center of Excellence in Glass Technology and Materials Science (CEGM), Nakhon Pathom Rajabhat University, Nakhon Pathom 73000 (Thailand); Physics Program, Faculty of Science and Technology, Nakhon Pathom Rajabhat University, 73000 (Thailand)

    2016-03-11

    Solid State Lighting (SSL) based devices are predicted to play a crucial role in the coming years. Development of W-LED, which have an edge over traditional lighting sources due to their compact size, higher reliability, shock resistance, interesting design possibilities, higher transparency and an extremely long lifetime. Over the fifteen trivalent lanthanide ions, Dy{sup 3+} ions doped glasses are most appropriate for white light generation because of the fact that it exhibits two intense emission bands corresponds to the {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2} (magnetic dipole) and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} (electric dipole) transitions at around 480-500 nm and 580-600 nm pertaining to blue and yellow regions respectively. In this work, the developments of Dy3+ doped in several glass structures for white emitting materials application have reviewed. Properties of Dy{sup 3+} doped in glasses were discussed for use as a solid state lighting materials application.

  1. Praseodymium ion doped phosphate glasses for integrated broadband ion-exchanged waveguide amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Shen, L.F. [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Chen, B.J. [Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Lin, H., E-mail: lhai8686@yahoo.com [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Pun, E.Y.B. [Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China)

    2015-02-15

    Highlights: • Effective near-infrared emission (1380-1525 nm) is observed in Pr{sup 3+}-doped phosphate glasses. • Effective bandwidth of {sup 1}D{sub 2} → {sup 1}G{sub 4} transition emission is obtained to be 124 nm. • Channel waveguides have been fabricated by K{sup +}-Na{sup +} ion-exchange method. • Pr{sup 3+}-doped phosphate glasses are promising in developing integrated broadband waveguide amplifier. - Abstract: Effective near-infrared emission covering the fifth optical telecommunication window (1380-1525 nm) has been observed in Pr{sup 3+}-doped phosphate (NMAP) glasses. Judd-Ofelt parameters Ω{sub 2} (6.38 × 10{sup −20} cm{sup 2}), Ω{sub 4} (20.30 × 10{sup −20} cm{sup 2}) and Ω{sub 6} (0.40 × 10{sup −20} cm{sup 2}) indicate a high inversion asymmetrical and strong covalent environment in the optical glasses. The effective bandwidth (Δλ{sub eff}) of the corresponding {sup 1}D{sub 2} → {sup 1}G{sub 4} transition emission is obtained to be 124 nm, and the maximum stimulated emission cross-section (σ{sub em-max}) at 1468 nm is derived to be 1.14 × 10{sup −20} cm{sup 2}. Channel waveguide was fabricated successfully by K{sup +}-Na{sup +} ion-exchange method with mode field diameter of 8.8 μm in the horizontal direction and 6.7 μm in the vertical direction. Broad effective bandwidth, large emission cross-section and perfect thermal ion-exchangeability indicate that Pr{sup 3+}-doped NMAP phosphate glasses are promising in developing integrated broadband waveguide amplifier, especially operating at E- and S-bands which belong to the fifth optical telecommunication window.

  2. Comparative investigation on the spectroscopic properties of Pr³⁺-doped boro-phosphate, boro-germo-silicate and tellurite glasses.

    Science.gov (United States)

    Zhang, Liaolin; Dong, Guoping; Peng, Mingying; Qiu, Jianrong

    2012-07-01

    We report on the spectroscopic properties of Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses. The stimulated absorption and emission cross sections were estimated. Only one emission at 596 nm and 605 nm is observed in Pr(3+)-doped boro-phosphate and boro-germo-silicate glasses, respectively, while three emissions at 605 nm, 612 nm and 645 nm are observed in Pr(3+)-doped tellurite glass when excited at 467 nm. The fluorescence lifetime at 600 nm in Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses is 137 μs, 73 μs and 51 μs, respectively. The emissions from Pr(3+)-doped boro-phosphate, boro-germo-silicate and tellurite glasses show different decay behaviors and can be well explained by multiphonon relaxation theory. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Migration behaviour of Pu released from Pu-doped glass in compacted bentonite

    International Nuclear Information System (INIS)

    Ashida, T.; Kohara, Y.; Yui, M.

    1994-01-01

    In order to investigate the coupled behavior of Pu release from the waste glass and transport in bentonite, a migration experiment with compacted sodium-type bentonite saturated with distilled water was carried out at room temperature, in which Pu-doped borosilicate glass was sandwiched. Under these conditions, leaching of Pu from the glass, diffusion and sorption of Pu in the compacted bentonite occur simultaneously. (orig.)

  4. Spectroscopic properties of 1.8 μm emission in Tm3+ doped bismuth silicate glass

    International Nuclear Information System (INIS)

    Zhao, Guoying; Tian, Ying; Wang, Xin; Fan, Huiyan; Hu, Lili

    2013-01-01

    The emission properties around 1.8 μm in Tm 3+ doped bismuth silicate glass have been investigated. Based on the obtained Raman spectroscopy and differential scanning calorimetry curves, it is found the introduced Bi 2 O 3 can efficiently reduce the phonon energy of silicate glass to 926 cm −1 . The energy gap between glass transition temperature and onset temperature of crystallization is 169 °C. The OH − content maintains lower in glass by bubbling dry O 2 during the melting process. The cut-off wavelength in mid-infrared range is as long as 5 μm. Bismuth silicate glass has high radiative transition probability of 238.80 s −1 corresponding to the Tm 3+ : 3 F 4 → 3 H 6 transition compared with conventional silicate glasses. The strongest emission at 1.8 μm with a large full width at half-maximum of 238 nm is achieved from this bismuth silicate glass doped with 0.9 mol% Tm 2 O 3 . Its fluorescence lifetime at 1.8 μm is 640 μs. - Highlights: ► The 1.8 μm fluorescence of Tm 3+ -doped bismuth silicate glass is investigated. ► The prepared glass has lower phonon energy than other typical silicate glasses. ► A broadband 1.8 μm emission with the FWHM of 238 nm is observed. ► The fluorescence lifetime of Tm 3+ : 3 F 4 level reaches 640 μs.

  5. Structure, reactivity and electronic properties of Mn doped Ni{sub 13} clusters

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Radhashyam; Datta, Soumendu; Mookerjee, Abhijit, E-mail: abhijit.mookerjee61@gmail.com

    2013-06-15

    In this work we have studied the structural and magnetic properties of Ni{sub 13} cluster mono- and bi-doped with Mn atoms. We have noted their tendency of being reactive toward the H{sub 2} molecule. We have found unusually enhanced stability in the mono-doped cluster (i.e. of the Ni{sub 12}Mn) and the diminished stability of the corresponding chemisorbed cluster, Ni{sub 12}MnH{sub 2}. Our analysis of the stability and HOMO–LUMO gap explains this unusual behavior. Interestingly, we have also seen the quenching in the net magnetic moment upon H{sub 2} absorption in the doped Ni{sub 13−m}Mn{sub m} alloy clusters. This has been reported earlier for smaller Ni{sub n} clusters [1].

  6. X-ray absorption spectroscopy on phosphoric-salt pellets. Determination of the geometric and electronic structure of metal-oxide doped sodium-phosphate glasses; Roentgenabsorptionsspektroskopie an Phosphorsalzperlen. Bestimmung der geometrischen und elektronischen Struktur von metalloxid-dotierten Natriumphosphatglaesern

    Energy Technology Data Exchange (ETDEWEB)

    Brendebach, B.

    2004-02-01

    Sodium metaphosphate glasses doped with transition metal oxides show characteristic colors. X-ray absorption spectroscopy (XAS) investigations provide information whether the coloration stems from different electronic transitions or changes in the geometrical structure of the glasses. Even though the violet color of MnO{sub y}-doped glasses is considered as an evidence for Mn{sup 3+}-ions, Mn K-XAS reveals that the majority of the manganese ions are in the oxidation state +II and have a mixed coordination of four and six oxygen atoms, respectively. The oxygen coordination around the nickel ions in NiO-doped glasses with different metall oxide concentrations is always six. The change of color from citreous to auburn with increasing nickel oxide content is attributed to a systematic change in the bonding characteristic from mainly ionic-like to a small but significant contribution of covalent-like bonding. Analysis of higher coordination shells provides no indication of the formation of metal oxide clusters. (orig.)

  7. Tm-Yb Doped Optical Fiber Performance with Variation of Host-Glass Composition

    Directory of Open Access Journals (Sweden)

    Anirban Dhar

    2014-01-01

    Full Text Available The fabrication process of Thulium-Ytterbium doped optical fiber comprising different host glass through the Modified Chemical Vapor Deposition (MCVD coupled with solution doping technique is presented. The material and optical performance of different fibers are compared with special emphasis on their lasing efficiency for 2 µm application.

  8. Luminescence properties of the Sm-doped borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kindrat, I.I. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Padlyak, B.V., E-mail: B.Padlyak@if.uz.zgora.pl [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Vlokh Institute of Physical Optics, 23 Dragomanov Street, 79-005 Lviv (Ukraine); Drzewiecki, A. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland)

    2015-10-15

    The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, CaB{sub 4}O{sub 7}, and LiCaBO{sub 3} compositions were investigated and analysed. The Li{sub 2}B{sub 4}O{sub 7}:Sm, LiKB{sub 4}O{sub 7}:Sm, CaB{sub 4}O{sub 7}:Sm, and LiCaBO{sub 3}:Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm{sup 3+} (4f{sup 5}, {sup 6}H{sub 5/2}) ions, exclusively. All observed 4f – 4f transitions of the Sm{sup 3+} centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm{sup 3+} ions peaked about 598 nm ({sup 4}G{sub 5/2} → {sup 6}H{sub 7/2} transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm{sup 3+} luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm{sup 3+} centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd–Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce{sup 3+} non-controlled impurity and intrinsic luminescence centres to the Sm{sup 3+} centres has been observed. Peculiarities of the Sm{sup 3+} local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. - Highlights: • The Sm-doped Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, Ca

  9. Orange and reddish-orange light emitting phosphors: Sm{sup 3+} and Sm{sup 3+}/Eu{sup 3+} doped zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Meza-Rocha, A.N., E-mail: ameza@fis.cinvestav.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F., México (Mexico); Speghini, A. [Dipartimento di Biotecnologie, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); IFAC CNR, Nello Carrara Institute of Applied Physics, MDF Lab, I-50019 Sesto Fiorentino, FI (Italy); Bettinelli, M. [Dipartimento di Biotecnologie, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); Caldiño, U. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F., México (Mexico)

    2015-11-15

    A spectroscopy study of Sm{sup 3+} and Sm{sup 3+}/Eu{sup 3+} doped zinc phosphate glasses is performed through photoluminescence spectra and decay time profile measurements. Under Sm{sup 3+} excitation at 344 nm, the Sm{sup 3+} singly doped glass shows an orange global emission with x=0.579 and y=0.414 CIE1931 chromaticity coordinates, whereas the Sm{sup 3+}/Eu{sup 3+} co-doped sample exhibits orange overall emissions (x=0.581 and y=0.398, and x=0.595 and y=0.387) and reddish-orange overall emission (x=0.634 and y=0.355) upon excitations at 344, 360 and 393 nm, respectively. Such luminescence from the co-doped sample is originated by the simultaneous emission of Sm{sup 3+} and Eu{sup 3+}. Under Sm{sup 3+} excitation at 344 and 360 nm, the Eu{sup 3+} emission is sensitized and enhanced by Sm{sup 3+} through a non-radiative energy transfer process. The non-radiative nature was inferred from the shortening of the Sm{sup 3+} lifetime observed in the Sm{sup 3+}/Eu{sup 3+} co-doped sample. An analysis of the Sm{sup 3+} emission decay time profiles using the Inokuti–Hirayama model suggests that an electric quadrupole–quadrupole interaction into Sm–Eu clusters might dominate the energy transfer process, with an efficiency of 0.17. - Highlights: • Zinc phosphate glasses are optically activated with Sm{sup 3+}/Eu{sup 3+} (ZPOSmEu). • Non-radiative energy transfer Sm{sup 3+}→Eu{sup 3+} takes place in ZPOSmEu. • ZPOSmEu overall emission can be modulated with the excitation wavelength. • ZPOSmEu might be useful as orange/reddish-orange phosphor for UV-white LEDs.

  10. Structural, thermal and spectroscopic properties of highly Er3+-doped novel oxyfluoride glasses for photonic application

    Energy Technology Data Exchange (ETDEWEB)

    Kesavulu, C.R. [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Sreedhar, V.B.; Jayasankar, C.K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Jang, Kiwan [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Shin, Dong-Soo [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of); Yi, Soung Soo, E-mail: ssyi@silla.ac.kr [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of)

    2014-03-01

    Graphical abstract: - Highlights: • Er{sup 3+}-doped novel oxyfluoride glasses have been prepared by melt quenching technique. • Structural, thermal and spectroscopic properties have been carried out. • SALSFEr glasses exhibit intense green and weak red emissions at 365 nm excitation. • Major laser transition for Er{sup 3+} ion in SALSFEr glasses is {sup 4}I{sub 13/2} → {sup 4}I{sub 15/2} (1.53 μm). • These results suggest the possibility of using SALSFEr glasses as photonic devices. - Abstract: The Er{sup 3+}-doped novel oxyfluoride glasses of composition (43 − x)SiO{sub 2}–10Al{sub 2}O{sub 3}–24LiF–23SrF{sub 2}–xEr{sub 2}O{sub 3}, where x = 1.0, 2.0, 4.0 and 6.0 mol%, have been prepared by conventional melt quenching technique and are characterized through X-ray diffraction (XRD), differential thermal analysis (DTA), Raman, Fourier transform infrared (FT-IR) analysis, optical absorption spectra, visible (vis) and near-infrared (NIR) emission spectra measurements. Judd–Ofelt (JO) intensity parameters (Ω{sub λ}, λ = 2, 4 and 6) have been derived from the absorption spectrum of 1.0 mol% Er{sub 2}O{sub 3} doped glass and are in turn used to calculate radiative properties for the important luminescent levels of Er{sup 3+} ions. The studied glasses show intense green and weak red visible emissions under 365 nm excitation. The decrease in visible emission intensities with concentration of Er{sup 3+} ions has been explained due to energy transfer processes between Er{sup 3+} ions. Upon excitation at 980 nm laser diode, an intense 1.53 μm NIR emission has been observed with the maximum full width at half maximum (FWHM) for Er{sup 3+}-doped oxyfluoride glasses. The higher Er{sup 3+} ion doping capability and relatively high gain and broad emission at 1.5 μm are the most notable features of these glasses to realize efficient short-length optical amplifiers.

  11. Doping influence by some transition elements on the irradiation effects in nuclear waste glasses

    International Nuclear Information System (INIS)

    Florent, Olivier

    2006-06-01

    High-level waste glasses are submitted to auto-irradiation. Modelling it using external irradiations on simple glasses revealed defects production and non negligible structural changes. This thesis aims at determining the impact of a more complex composition on these effects, especially the influence of adding polyvalent transition metals. Silicate, soda-lime and alumino-borosilicate glasses are doped with different iron, chromium and manganese concentrations then β irradiated at different doses up to 10 9 Gy. Non doped glasses show an increase of their density and polymerisation coupled with a molecular oxygen and point defects production. Adding 0.16 mol% Fe decreases the amount of defects by 85 % and all irradiation effects. A Fe 3+ reduction is also observed by EPR, optical absorption and indirectly by Raman spectroscopy. A higher than 0.32 mol% Fe concentration causes complete blockage of the evolution of polymerisation, density and defect production. The same results are obtained on chromium or manganese doped glasses. An original in situ optical absorption device shows the quick decrease of Fe 3+ amount to a 25 % lower level during irradiation. Stopping irradiation causes a lower decrease of 65 %, suggesting a dynamic (h 0 /e-) consuming equilibrium. He + and Kr 3+ ions and γ irradiated glasses tend to confirm these phenomena for all kind of irradiation with electronic excitations. (author)

  12. Shear-driven dynamic clusters in a colloidal glass

    Science.gov (United States)

    Eisenmann, Christoph; Kim, Chanjoong; Mattsson, Johan; Weitz, David

    2007-03-01

    We investigate the effect of shear applied to a colloidal glass on a microscopic level using a shear device that can be mounted on top of a confocal microscope. We find that the glass yields at a critical strain of about 10%, independently of the shear rate. Surprisingly, the yielding is accompanied by an increase of cooperative particle movements and a formation of dynamic clusters which is in contrast to the normal glass transition where one typically finds heterogeneity increasing whilst moving towards the glass transition.

  13. Clustered field evaporation of metallic glasses in atom probe tomography

    International Nuclear Information System (INIS)

    Zemp, J.; Gerstl, S.S.A.; Löffler, J.F.; Schönfeld, B.

    2016-01-01

    Field evaporation of metallic glasses is a stochastic process combined with spatially and temporally correlated events, which are referred to as clustered evaporation (CE). This phenomenon is investigated by studying the distance between consecutive detector hits. CE is found to be a strongly localized phenomenon (up to 3 nm in range) which also depends on the type of evaporating ions. While a similar effect in crystals is attributed to the evaporation of crystalline layers, CE of metallic glasses presumably has a different – as yet unknown – physical origin. The present work provides new perspectives on quantification methods for atom probe tomography of metallic glasses. - Highlights: • Field evaporation of metallic glasses is heterogeneous on a scale of up to 3 nm. • Amount of clustered evaporation depends on ion species and temperature. • Length scales of clustered evaporation and correlative evaporation are similar.

  14. Spectroscopic and ultrasonic investigations on structural characterization of borate glass specimen doped with transition metal ions.

    Science.gov (United States)

    Sathish, K; Thirumaran, S

    2015-08-05

    The present work describes the glass samples of composition (x% V₂O₅-(80-x)% B₂O₃-20% Na₂CO₃) VBS glass system and (x%MnO₂-(80-x)% B₂O₃-20% Na₂CO₃) in MBS glass system with mol% ranging from x=3, 6, 9, 12, 15 and 18 in steps of 3 mol% are prepared by melt quenching technique. For these prepared glass systems, sound velocity (longitudinal and shear velocities) and density have been measured. The sound velocity (longitudinal and shear) was measured by using pulse-echo technique at 5 MHz. The XRD study was carried to out to ascertain the amorphous nature of the glass specimen. Using these measured values, the elastic moduli, Poisson's ratio, Debye temperature, acoustic impedance and thermal expansion coefficient of the two glass systems were evaluated. The elastic and mechanical properties of the prepared glass systems are analyzed from ultrasonic study and the structural characterization from spectroscopic study. The effects due to the doping of transition metal ions with borate have been discussed. In the V₂O₅ doped glass system,(VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO₂ doped glass system (VBS glass system). The present study critically observes the doping of V₂O₅ with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO₂. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO₃ or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na₂CO₃, V₂O₅ and MnO₂ contents on the structures of borate glass is evaluated from the FTIR spectra. The topological aspects of the prepared glass samples are exhaustively reported from SEM micrographs

  15. Effect of Ga2O3 on the spectroscopic properties of erbium-doped boro-bismuth glasses.

    Science.gov (United States)

    Ling, Zhou; Ya-Xun, Zhou; Shi-Xun, Dai; Tie-Feng, Xu; Qiu-Hua, Nie; Xiang, Shen

    2007-11-01

    The spectroscopic properties and thermal stability of Er3+-doped Bi2O3-B2O3-Ga2O3 glasses are investigated experimentally. The effect of Ga2O3 content on absorption spectra, the Judd-Ofelt parameters Omega t (t=2, 4, 6), fluorescence spectra and the lifetimes of Er3+:4I 13/2 level are also investigated, and the stimulated emission cross-section is calculated from McCumber theory. With the increasing of Ga2O3 content in the glass composition, the Omega t (t=2, 4, 6) parameters, fluorescence full width at half maximum (FWHM) and the 4I 13/2 lifetimes of Er3+ first increase, reach its maximum at Ga2O3=8 mol.%, and then decrease. The results show that Er3+-doped 50Bi2O3-42B2O3-8Ga2O3 glass has the broadest FWHM (81nm) and large stimulated emission cross-section (1.03 x1 0(-20)cm2) in these glass samples. Compared with other glass hosts, the gain bandwidth properties of Er+3-doped Bi2O3-B2O3-Ga2O3 glass is better than tellurite, silicate, phosphate and germante glasses. In addition, the lifetime of 4I 13/2 level of Er(3+) in bismuth-based glass, compared with those in other glasses, is relative low due to the high-phonon energy of the B-O bond, the large refractive index of the host and the existence of OH* in the glass. At the same time, the glass thermal stability is improved in which the substitution of Ga2O3 for B2O3 strengthens the network structure. The suitability of bismuth-based glass as a host for a Er3+-doped broadband amplifier and its advantages over other glass hosts are also discussed.

  16. Effects of manganese doping on the structure evolution of small-sized boron clusters

    Science.gov (United States)

    Zhao, Lingquan; Qu, Xin; Wang, Yanchao; Lv, Jian; Zhang, Lijun; Hu, Ziyu; Gu, Guangrui; Ma, Yanming

    2017-07-01

    Atomic doping of clusters is known as an effective approach to stabilize or modify the structures and properties of resulting doped clusters. We herein report the effect of manganese (Mn) doping on the structure evolution of small-sized boron (B) clusters. The global minimum structures of both neutral and charged Mn doped B cluster \\text{MnB}nQ (n  =  10-20 and Q  =  0, ±1) have been proposed through extensive first-principles swarm-intelligence based structure searches. It is found that Mn doping has significantly modified the grow behaviors of B clusters, leading to two novel structural transitions from planar to tubular and then to cage-like B structures in both neutral and charged species. Half-sandwich-type structures are most favorable for small \\text{MnB}n-/0/+ (n  ⩽  13) clusters and gradually transform to Mn-centered double-ring tubular structures at \\text{MnB}16-/0/+ clusters with superior thermodynamic stabilities compared with their neighbors. Most strikingly, endohedral cages become the ground-state structures for larger \\text{MnB}n-/0/+ (n  ⩾  19) clusters, among which \\text{MnB}20+ adopts a highly symmetric structure with superior thermodynamic stability and a large HOMO-LUMO gap of 4.53 eV. The unique stability of the endohedral \\text{MnB}\\text{20}+ cage is attributed to the geometric fit and formation of 18-electron closed-shell configuration. The results significantly advance our understanding about the structure and bonding of B-based clusters and strongly suggest transition-metal doping as a viable route to synthesize intriguing B-based nanomaterials.

  17. Gamma ray interactions with undoped and CuO-doped lithium disilicate glasses

    International Nuclear Information System (INIS)

    Elbatal, H.A.; Mandouh, Z.; Zayed, H.; Marzouk, S.Y.; Elkomy, G.; Hosny, A.

    2010-01-01

    Ultraviolet-visible absorption of undoped lithium disilicate glass reveals strong UV absorption and no visible bands could be identified. Such UV absorption is related to the presence of unavoidable trace iron impurities within raw materials used for the preparation of this glass. Optical absorption of the CuO-doped samples show an extra broad visible band centered at 780 nm and in high CuO contents samples obvious splitting to several component peaks are observed. This characteristic visible absorption of copper-doped samples is correlated with the presence of Cu +2 ions in octahedral coordination with tetragonal distortion. Gamma irradiation of the prepared samples produces radiation-induced defects, which are related to the sharing of host lithium disilicate glass, trace iron impurities and copper iron in their formation. The visible spectrum of the CuO samples shows shielding effect towards successive gamma irradiation.

  18. Enhanced Luminescent Properties in Tm3+/Dy3+ Co-doped Transparent Phosphate Glass Ceramic

    OpenAIRE

    Yao L. Q.; Chen G. H.; Zhong H. J.; Cui S. C.; Li F.; Gan J.Y.

    2016-01-01

    Novel Tm3+/Dy3+ co-doped phosphate glass and glass ceramic samples for white light emitting diodes were prepared by melt quenching method. Under 353 nm excitation, the colors of the luminescence of the glass and glass ceramic samples are white. The CIE chromaticity coordinates (0.338, 0.328) of the emission from the glass ceramic is close to the standard white-light illumination (0.333, 0.333). Compared to the glass, the fluorescence intensity in the glass ceramic is greatly enhanced.

  19. Thermoluminescence characteristics of Cu2O doped Calcium Lithium borate glass irradiated with the cobalt-60 gamma rays

    International Nuclear Information System (INIS)

    Rammadhan, Ismail; Taha, Saddon; Wagiran, H.

    2017-01-01

    The aim of this study is to prepare and investigate the thermoluminescence characteristics for the un-doped and Cu 2 O doped calcium lithium borate glass upon adding various Cu 2 O concentrations of 0.005% to 0.1 mol%. The glasses were prepared by melt quenching method and irradiated with 60 CO gamma-ray having different doses in the range of (0.5–4) Gy, (5–10) Gy, and (20–100) Gy. The amorphous phases were identified for optimization glass samples, effect of heating rate, glowing curves, linearity, sensitivity, fading, reproducibility of response and minimum detectable dose are also studied. The TL sample with 0.02 mol% Cu 2 O concentration has higher response compared to the other samples concentration for a delivered dose of 50 Gy, The recorded glow curves consist a dominant peak at 187 °C for a heating rate of 5 °C s −1 . However, the value of effective atomic number Z eff is 8.84 for 0.02Cu 2 O doped which are near to the atomic number of soft tissue. - Highlights: •We have prepared and investigate the crystalline structure for the un-doped and Cu 2 O doped calcium lithium borate glass are carried out. •Investigate the amorphous structure of calcium lithium borate glass. •Determine the best setting of annealing temperature, annealing time and heating rate for Cu 2 O doped calcium lithium borate glass. •The doping effects of Cu 2 O on the thermoluminescence properties of calcium lithium borate glass subjected gamma radiations. •The new dosimeter showed simple glow curve with single prominent peak centred at 187 °C and linear dose–response range 0.5–100 Gy, good reproducibility, the fading of the signal is relatively slow. •Effective atomic number for Cu 2 O doped Calcium lithium borate close to the effective atomic number of soft tissue.

  20. Photoluminescence characteristics of sintered silica glass doped with Cu ions using mesoporous SiO{sub 2}-PVA nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Hiroshi [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Murata, Takahiro [Faculty of Education and Master' s Course in Education, Kumamoto University, 2-40-1 Kurokami, Chuo-ku, Kumamoto 860-8555 (Japan); Fujino, Shigeru, E-mail: fujino@astec.kyushu-u.ac.jp [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

    2015-07-15

    Monolithic silica glasses doped with Cu ions were prepared by immersing a mesoporous SiO{sub 2}-polyvinyl alcohol (PVA) nanocomposite in a copper nitrate solution followed by sintering at 1100 °C for 12 h in air. The Cu ions were reduced from divalent to monovalent during the sintering process and consequently Cu{sup +} was doped into the silica glass matrix. The sintered glass possessed blue or yellow photoluminescence (PL) under UV irradiation, depending on the total concentration of Cu ions in the sintered silica glass. At a lower concentration below 30 ppm, the isolated Cu{sup +} existed in the glass matrix resulting in the blue PL. However, above 70 ppm, the Cu{sup +}–Cu{sup +} pairs were present, exhibiting the yellow PL. It was demonstrated that the PL characteristics of the sintered silica glasses doped with monovalent copper ions were affected by the total concentration of Cu ions in the glass, which can be adjusted as a function of the immersion conditions. - Highlights: • Silica glass doped with Cu{sup +} was fabricated by sintering the nanocomposite. • The Cu ions were reduced from divalent to monovalent during the sintering process. • The sintered glass possessed blue or yellow PL under UV irradiation. • The blue and yellow PL are due to isolated Cu{sup +} and Cu{sup +}–Cu{sup +} pairs, respectively. • The PL characteristics depended on the total concentration of Cu ions in the glass.

  1. Pr3 + -doped GeSx-based glasses for fiber amplifiers at 1.3 µm

    Science.gov (United States)

    Simons, D. R.; Faber, A. J.; de Waal, H.

    1995-03-01

    The photoluminescence properties of Pr3+ -doped GeS x -based glasses are studied and compared with those of other sulfide and fluoride glasses. The possibility of highly pump-power-efficient fiber amplifiers based on these GeSx-containing glasses in the telecommunications window at 1.3 mu m is discussed.

  2. Shielding behavior of V2O5 doped lead borate glasses towards gamma irradiation

    International Nuclear Information System (INIS)

    Ghoneim, N.A.; ElBatal, H.A.; Abdelghany, A.M.; Ali, I.S.

    2011-01-01

    Highlights: → Base lead borate glass together with samples of the same composition doped with varying V 2 O 5 contents were prepared. → UV-visible and infrared spectroscopy were measured before and after successive gamma irradiation. → Glass samples are observed to absorb strongly in the UV. → Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites. - Abstract: Undoped lead borate glass of the composition PbO 70%-B 2 O 3 30% together with samples of the same composition and doped with varying V 2 O 5 contents were prepared. UV-visible absorption spectra were measured out in the range 200-1500 nm before and after successive gamma irradiation. Infrared absorption measurements within the range 4000-400 cm -1 were carried out for the undoped and V 2 O 5 doped samples before gamma irradiation and after being irradiated with a dose of 6 Mrad. All the glass samples are observed to absorb strongly in the UV region due to the combined contributions of absorption due to trace iron impurities and that from the divalent lead Pb 2+ ions. The V 2 O 5 -doped glasses reveal extra visible absorption bands which are attributed to the existence of V 3+ ions in measurable content but not neglecting the other valence states of vanadium ions (V 4+ , V 5+ ). Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites.

  3. Thermal Stability and Optical Activity of Erbium Doped Chalcogenide Glasses for Photonics

    Science.gov (United States)

    Tonchev, D.; Koughia, K.; Kasap, S. O.; Maeda, K.; Sakai, T.; Ikuta, J.; Ivanova, Z. G.

    The glass transition and crystallization temperatures (T g , T c ), heat capacity, thermal stability and glass uniformity of GeSGa, GeSeGa, Ge(SeTe)Ga chalcogenide glasses doped with Er3+ by the addition of Er2S3 have been investigated by conventional differential scanning calorimetry (DSC) and Temperature-Modulated DSC (TMDSC). While some of the glasses have two crystallization peaks, these glasses were nonetheless optically actively and uniform. Essential optical properties have been evaluated, such as the photoluminescence (PL) intensity and lifetime as a function of the glass composition. We present typical results to emphasize some of the important characteristics of these systems and discuss trends within a glass system; and also highlight differences between glass systems.

  4. Red light emission from europium doped zinc sodium bismuth borate glasses

    Science.gov (United States)

    Hegde, Vinod; Viswanath, C. S. Dwaraka; Upadhyaya, Vyasa; Mahato, K. K.; Kamath, Sudha D.

    2017-12-01

    Zinc sodium bismuth borate (ZNBB) glasses doped with different concentrations of europium were prepared by conventional melt quenching method and characterized through the measurements of density, refractive index, X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectra, optical absorption, luminescence and radiative lifetimes. FTIR spectra showed seven characteristic peaks of bismuth and borate functional groups in the range of 400-1600 cm-1. The optical band gap and bonding parameters have been calculated from absorption spectra. Photoluminescence spectra recorded in the visible region with 394 nm excitation are used to calculate the Judd-Ofelt (JO) intensity parameters (Ω2 and Ω4). The JO intensity parameters have been used to calculate the radiative parameters such as branching ratio (β), stimulated emission cross-section (σse), transition probability (A) for the fluorescent level of 5D0→7F2. Decay rates through single exponential are used to calculate the lifetime (τm) of the meta-stable state 5D0 of (Eu3+ ion) these glasses. The radiative parameters measured for all these glasses show 0.7 mol% europium doped zinc sodium bismuth borate glass 5D0→7F2 transition has the potential for red laser applications. The quality of the colour emitted by the present glasses are estimated quantitatively by CIE chromaticity coordinates, which confirms the suitability of these glasses as a red emitting material for field emission technologies and LEDs.

  5. Pr3+-doped GeSx-based glasses for fiber amplifiers at 1.3 mm

    NARCIS (Netherlands)

    Simons, D.R.; Faber, A.J.; Waal, de H.

    1995-01-01

    The luminescence of Pr3+-doped GeSx-based glasses were studied and compared with those of other sulfide and fluoride glasses. The possibility of highly pump-power-efficient fiber amplifiers based on these GeSx-contg. glasses in the telecommunications window at 1.3 mm is discussed. [on SciFinder (R)

  6. Icosahedral binary clusters of glass-forming Lennard-Jones binary alloy

    International Nuclear Information System (INIS)

    Iwamatsu, Masao

    2007-01-01

    It is widely believed that the local icosahedral structure is related to the formation of bulk metallic glasses (BMGs). Specifically the existence of 13-atom icosahedral cluster in undercooled liquid is imagined to play a key role to initiate the glass formation as the seed of amorphous structure or to block the nucleation of regular crystal as the impurity. The existence of 13-atom icosahedral clusters in one-component liquids was predicted more than half a century ago by Frank from his total energy calculation for isolated clusters. In BMG alloys, however, the situation is less clear. In this report, we present the lowest-energy structures of 13-atom Lennard-Jones binary cluster calculated from the modified space-fixed genetic algorithm. We study, in particular, the artificial Lennard-Jones potential designed by Kob and Andersen [W. Kob, H.C. Andersen, Phys. Rev. E 51 (1995) 4626] that is known to form BMG. Curiously, the lowest-energy structures of 13-atom cluster are non-icosahedral for almost all compositions. Our result suggests that the existence of the icosahedral cluster is not a necessary condition but only a sufficient condition for glass formation

  7. Gamma-ray irradiation resistance of silver doped GeS2–Ga2S3–AgI chalcohalide glasses

    International Nuclear Information System (INIS)

    Shen, W.; Baccaro, S.; Cemmi, A.; Ren, J.; Zhang, Z.; Zhou, Y.; Yang, Y.; Chen, G.

    2014-01-01

    Highlights: • The γ-ray irradiation resistance of Ag doped chalcohalide glasses (GeS 2 –Ga 2 S 3 –AgI) has been investigated. • The introduction of silver ions plays a specific role in the modification of the gamma-ray irradiation resistance of glasses. • The sulfur exerts an important effect on the photo-sensitivity of chalcogenide glasses. - Abstract: In the present work, series of silver doped Ge–Ga–S–AgI chalcohalide glasses have been prepared and their optical transmission spectra are compared before and after γ-ray irradiation at different doses. The differential transmission spectra of the irradiated samples with and without Ag doping have been compared to characterize the γ-ray irradiation induced red-shift of electronic absorption and formation of color centers. Ag doping plays an important role in increasing γ-ray irradiation resistance of the chalcohalide glasses due to its specific effect on the valence band and the network structure of glasses

  8. Scintillation property of rare earth-free SnO-doped oxide glass

    OpenAIRE

    Masai, Hirokazu; Yanagida, Takayuki; Fujimoto, Yutaka; Koshimizu, Masanori; Yoko, Toshinobu

    2012-01-01

    The authors have demonstrated scintillation of rare earth (RE)-free Sn-doped oxide glass by excitation of ionizing radiation. It is notable that light emission is attained for RE-free transparent glass due to s[2]-sp transition of Sn[2+] centre and the emission correlates with the excitation band at 20 eV. We have also demonstrated that excitation band of emission centre can be tuned by the chemical composition of the host glass. The present result is valuable not only for design of RE-free i...

  9. Composition dependence of the optical and structural properties of Eu-doped oxyfluoride glasses

    International Nuclear Information System (INIS)

    Zhu, Chaofeng; Wu, Dongqun; Zhang, Yanfei; Zhang, Meimei; Yue, Yuanzheng

    2015-01-01

    Highlights: • Eu doped oxyfluoride glasses for LED applications are studied. • Conversion of Eu 3+ to Eu 2+ is realized in the glasses prepared in air atmosphere. • CaF 2 crystals formed during melt cooling enhance the conversion of Eu 3+ to Eu 2+ . • Content of CaF 2 crystals can be controlled by adjusting base glass compositions. - Abstract: Europium doped oxyfluoride glasses were prepared by the melt quenching method for the light emitting diodes applications. The optical and structural properties of these glasses were studied by means of photoluminescence spectra, Commission Internationale de L’Eclairage chromaticity coordinates, X-ray diffraction, and Fourier transform infrared spectra. We find that the spontaneous reduction of Eu 3+ to Eu 2+ is realized by Eu 3+ ions occupying the sites of Ca 2+ in the glasses prepared in air atmosphere. The Eu 3+ to Eu 2+ conversion efficiency, optical performances and structure of the glasses strongly depend on the base glass compositions. For certain base glass compositions, CaF 2 crystals can form during the melt cooling process, and thereby enhance the conversion from Eu 3+ to Eu 2+ . The formation of CaF 2 crystals can be suppressed by adding CaO, Al 2 O 3 and B 2 O 3 , but enhanced by adding Na 2 O and K 2 O in glass compositions. Finally, we propose a mechanism to explain how the glass structure affects the reduction of Eu ions as well as optical properties of the glasses

  10. Synthesis of nanocrystalline LaF3 doped silica glasses by hydrofluoric acid catalyzed sol–gel process

    International Nuclear Information System (INIS)

    Nagayama, Shuhei; Kajihara, Koichi; Kanamura, Kiyoshi

    2012-01-01

    Highlights: ► Silica glasses doped by LaF 3 nanocrystals are obtained by HF-catalyzed sol–gel method. ► The processing time (∼1 week) is much shorter than that of previous studies. ► The uptake of SiF groups in the glass matrix greatly reduces the SiOH concentration. ► Effects of sintering conditions and properties of Er 3+ -doped samples are presented. - Abstract: Silica glasses doped with LaF 3 nanocrystals were prepared by HF-catalyzed sol–gel method. HF was used both as fluorine source and as catalyst of the sol–gel reaction, making it possible to shorten the processing time with reducing the concentration of SiOH groups to ∼10 18 cm −3 . The resultant glasses are transparent at visible spectral range, and the optical loss at the ultraviolet absorption edge is dominated by the Rayleigh scattering from LaF 3 crystallites. The size of LaF 3 crystallites increases with an increase in the sintering temperature and time, and is smaller than ∼40 nm in samples showing good visible transparency. Green upconversion photoluminescence is observed in an Er 3+ -doped sample under excitation at 980 nm.

  11. Silver lead borate glasses doped with europium ions for phosphors ...

    Indian Academy of Sciences (India)

    2017-07-25

    Jul 25, 2017 ... C. The investigation of Fourier transformer infrared spectra shows the presence of ... around the ions, these kinds of Eu3+ doped glasses find wide range of ... is attributed to hydroxyl (OH) or water group [12]. The broad water ...

  12. Optical spectroscopy and optical waveguide fabrication in Eu{sup 3+} and Eu{sup 3+}/Tb{sup 3+} doped zinc–sodium–aluminosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Caldiño, U., E-mail: cald@xanum.uam.mx [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 México D.F. (Mexico); Speghini, A. [Dipartimento di Biotecnologie, Università di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, 50019 Sesto Fiorentino (Firenze) (Italy); Berneschi, S. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, 50019 Sesto Fiorentino (Firenze) (Italy); Bettinelli, M. [Dipartimento di Biotecnologie, Università di Verona and INSTM, UdR Verona, Strada Le Grazie 15, I-37314 Verona (Italy); Brenci, M. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, 50019 Sesto Fiorentino (Firenze) (Italy); Pasquini, E. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, 50019 Sesto Fiorentino (Firenze) (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Firenze) (Italy); Pelli, S. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, 50019 Sesto Fiorentino (Firenze) (Italy); Righini, G.C. [Istituto di Fisica Applicata Nello Carrara, C.N.R., Via Madonna del Piano 10, 50019 Sesto Fiorentino (Firenze) (Italy); Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Piazza del Viminale 2, 00184 Roma (Italy)

    2014-03-15

    Optical and spectroscopic properties of 2.0% Eu(PO{sub 3}){sub 3} singly doped and 5.0% Tb(PO{sub 3}){sub 3}–2.0% Eu(PO{sub 3}){sub 3} codoped zinc–sodium–aluminosilicate glasses were investigated. Reddish-orange light emission, with x=0.64 and y=0.36 CIE1931 chromaticity coordinates, is obtained in the europium singly doped glass excited at 393 nm. Such chromaticity coordinates are close to those (0.67,0.33) standard of the National Television System Committee for the red phosphor. When the sodium–zinc–aluminosilicate glass is co-doped with Tb{sup 3+} and Eu{sup 3+}, reddish-orange light emission, with (0.61,0.37) CIE1931 chromaticity coordinates, is obtained upon Tb{sup 3+} excitation at 344 nm. This reddish-orange luminescence is generated mainly by {sup 5}D{sub 0}→{sup 7}F{sub 1} and {sup 5}D{sub 0} →{sup 7}F{sub 2} emissions of Eu{sup 3+}, europium being sensitized by terbium through a non-radiative energy transfer. From an analysis of the Tb{sup 3+} emission decay curves it is inferred that the Tb{sup 3+}→Eu{sup 3+} energy transfer might take place between Tb{sup 3+} and Eu{sup 3+} clusters through a short-range interaction mechanism, so that an electric dipole–quadrupole interaction appears to be the most probable transfer mechanism. The efficiency of this energy transfer is about 62% upon excitation at 344 nm. In the singly doped and codoped glasses multimode optical waveguides were successfully produced by Ag{sup +}–Na{sup +} ion exchange, and they could be characterized at various wavelengths. -- Highlights: • Reddish-orange light emission can be generated from Tb{sup 3+} and Eu{sup 3+} codoped zinc–sodium–aluminosilicate glasses excited at 344 nm. • The Eu{sup 3+} is sensitized by Tb{sup 3+} through a non-radiative energy transfer. • Highly multimode waveguides can be fabricated by diluted silver–sodium exchange. • This type of AlGaN LEDs pumped glass phosphors might be useful for generation of reddish-orange light.

  13. A Rapid Method for Deposition of Sn-Doped GaN Thin Films on Glass and Polyethylene Terephthalate Substrates

    Science.gov (United States)

    Pat, Suat; Özen, Soner; Korkmaz, Şadan

    2018-01-01

    We report the influence of Sn doping on microstructure, surface, and optical properties of GaN thin films deposited on glass and polyethylene terephthalate (PET) substrate. Sn-doped GaN thin films have been deposited by thermionic vacuum arc (TVA) at low temperature. TVA is a rapid deposition technology for thin film growth. Surface and optical properties of the thin films were presented. Grain size, height distribution, roughness values were determined. Grain sizes were calculated as 20 nm and 13 nm for glass and PET substrates, respectively. Nano crystalline forms were shown by field emission scanning electron microscopy. Optical band gap values were determined by optical methods and photoluminescence measurement. The optical band gap values of Sn doped GaN on glass and PET were determined to be approximately ˜3.40 eV and ˜3.47 eV, respectively. As a result, TVA is a rapid and low temperature deposition technology for the Sn doped GaN deposited on glass and PET substrate.

  14. Upconversion in Nd3+-doped glasses: Microscopic theory and spectroscopic measurements

    International Nuclear Information System (INIS)

    Oliveira, S. L.; Sousa, D. F. de; Andrade, A. A.; Nunes, L. A. O.; Catunda, T.

    2008-01-01

    In this work, we report a systematic investigation of upconversion losses and their effects on fluorescence quantum efficiency and fractional thermal loading in Nd 3+ -doped fluoride glasses. The energy transfer upconversion (γ up ) parameter, which describes upconversion losses, was experimentally determined using different methods: thermal lens (TL) technique and steady state luminescence (SSL) measurements. Additionally, the upconversion parameter was also obtained from energy transfer models and excited state absorption measurements. The results reveal that the microscopic treatment provided by the energy transfer models is similar to the macroscopic ones achieved from the TL and SSL measurements because similar γ up parameters were obtained. Besides, the achieved results also point out the migration-assisted energy transfer according to diffusion-limited regime rather than hopping regime as responsible for the upconversion losses in Nd-doped glasses

  15. Structures of Pt clusters on graphene doped with nitrogen, boron, and silicon: a theoretical study

    Institute of Scientific and Technical Information of China (English)

    Dai Xian-Qi; Tang Ya-Nan; Dai Ya-Wei; Li Yan-Hui; Zhao Jian-Hua; Zhao Bao; Yang Zong-Xian

    2011-01-01

    The structures of Pt clusters on nitrogen-, boron-, silicon- doped graphenes are theoretically studied using densityfunctional theory. These dopants (nitrogen, boron and silicon) each do not induce a local curvature in the graphene and the doped graphenes all retain their planar form. The formation energy of the silicon-graphene system is lower than those of the nitrogen-, boron-doped graphenes, indicating that the silicon atom is easier to incorporate into the graphene.All the substitutional impurities enhance the interaction between the Pt atom and the graphene. The adsorption energy of a Pt adsorbed on the silicon-doped graphene is much higher than those on the nitrogen- and boron-doped graphenes.The doped silicon atom can provide more charges to enhance the Pt-graphene interaction and the formation of Pt clusters each with a large size. The stable structures of Pt clusters on the doped-graphenes are dimeric, triangle and tetrahedron with the increase of the Pt coverage. Of all the studied structures, the tetrahedron is the most stable cluster which has the least influence on the planar surface of doped-graphene.

  16. Thermoluminescence characteristics of Cu{sub 2}O doped Calcium Lithium borate glass irradiated with the cobalt-60 gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Rammadhan, Ismail, E-mail: ismail.rammadhan@koyauniversity.org [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Department of Physics, Faculty of Sciences and Health, Koya University, Danielle Mitterrand Boulevard, Koya 45, Kurdistan Region (Iraq); Taha, Saddon [Department of Physics, Faculty of Sciences and Health, Koya University, Danielle Mitterrand Boulevard, Koya 45, Kurdistan Region (Iraq); Wagiran, H. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2017-06-15

    The aim of this study is to prepare and investigate the thermoluminescence characteristics for the un-doped and Cu{sub 2}O doped calcium lithium borate glass upon adding various Cu{sub 2}O concentrations of 0.005% to 0.1 mol%. The glasses were prepared by melt quenching method and irradiated with {sup 60}CO gamma-ray having different doses in the range of (0.5–4) Gy, (5–10) Gy, and (20–100) Gy. The amorphous phases were identified for optimization glass samples, effect of heating rate, glowing curves, linearity, sensitivity, fading, reproducibility of response and minimum detectable dose are also studied. The TL sample with 0.02 mol% Cu{sub 2}O concentration has higher response compared to the other samples concentration for a delivered dose of 50 Gy, The recorded glow curves consist a dominant peak at 187 °C for a heating rate of 5 °C s{sup −1}. However, the value of effective atomic number Z{sub eff} is 8.84 for 0.02Cu{sub 2}O doped which are near to the atomic number of soft tissue. - Highlights: •We have prepared and investigate the crystalline structure for the un-doped and Cu{sub 2}O doped calcium lithium borate glass are carried out. •Investigate the amorphous structure of calcium lithium borate glass. •Determine the best setting of annealing temperature, annealing time and heating rate for Cu{sub 2}O doped calcium lithium borate glass. •The doping effects of Cu{sub 2}O on the thermoluminescence properties of calcium lithium borate glass subjected gamma radiations. •The new dosimeter showed simple glow curve with single prominent peak centred at 187 °C and linear dose–response range 0.5–100 Gy, good reproducibility, the fading of the signal is relatively slow. •Effective atomic number for Cu{sub 2}O doped Calcium lithium borate close to the effective atomic number of soft tissue.

  17. Sintering process of Eu doped luminescent glass prepared from porous glass

    International Nuclear Information System (INIS)

    Akai, T; Murakami, M; Yamashita, M; Okajima, T; Umesaki, N

    2011-01-01

    Eu doped high silica glass prepared by sintering porous glass exhibits blue luminescence with high quantum efficiency. In this work, we studied effects of sintering temperature on valance state of europium ion. To investigate a change of valance state of Eu, X-ray absorption near edge structure (XANES) spectroscopy measurements were carried out. Intensity of blue emission at around 430nm drastically increases when the sintering temperature is above 1000 deg. C. From XANES spectra, it is found that almost all the Eu exist as Eu 3+ in a samples sintered below 900 deg. C, while more than 70% of Eu exist as Eu 2+ in the sample sintered at 1050 deg. C and 1100 deg. C. The drastic change of oxidation state of europium ion between 900 and 1050 deg. C is discussed in relation to the structural change probed by infrared (IR) spectroscopy.

  18. Optical and physical properties of samarium doped lithium diborate glasses

    Science.gov (United States)

    Hanumantharaju, N.; Sardarpasha, K. R.; Gowda, V. C. Veeranna

    2018-05-01

    Sm3+ doped lithium di-borate glasses with composition 30Li2O-60B2O3-(10-x) PbO, (where 0 molar volume with samarium ion content indicates the openness of the glass structure. The gradual increase in average separation of boron-boron atoms with VmB clearly indicates deterioration of borate glass network, which in turn leads to decrease in the oxygen packing density. The replacements of Sm2O3 for PbO depolymerise the chain structure and that would increase the concentration of non-bridging oxygens. The marginal increase of optical band gap energy after 1.0 mol.% of Sm2O3 is explained by considering the structural modification in lead-borate. The influence of Sm3+ ion on physical and optical properties in lithium-lead-borate glasses is investigated and the results were discussed in view of the structure of borate glass network.

  19. Influence of tellurite on lifetime for samarium doped lanthanum lead borate glass

    Science.gov (United States)

    Madhu, A.; Eraiah, B.

    2018-04-01

    Samarium substituted tellurium lanthanum lead borate glass is prepared using melt quenching technique. Luminescence spectra have been recorded upon excitation with 402 nm various transitions from 4G5/2 level, for samarium doped tellurite glasses are studied and also lifetime for all the samples exhibit single exponential behaviour of decay curve. Luminescence spectra of present glasses show quenching effect due to cross-relation channels of samarium ions. The lifetime of glass samples decrease as the tellurite concentration is decreased. So, it evidences that to attain longer lifetime for lasing material one can tune the host by selecting concentration of tellurite.

  20. Laser ablation of silicate glasses doped with transuranic actinides

    International Nuclear Information System (INIS)

    Gibson, J.K.; Haire, R.G.

    1998-01-01

    Direct sampling laser ablation plasma mass spectrometry (DS-LAMS) was applied to silica glasses doped with 237 Np, 242 Pu or 241 Am using a unique instrument recently installed into a transuranic glovebox. The primary goal was to assess the utility of mass spectrometry of directly ablated ions for facile evaluation of actinide (An) constituents of silicate glass immobilization matrices used for encapsulation of radionuclides. The instrument and general procedures have been described elsewhere. Three high-purity silicate glasses prepared by a sol-gel process (SG) and one conventional high-temperature (HT; melting point ∼ 1,450 C) borosilicate glass were studied. These glasses comprised the following constituents, with compositions expressed in mass percentages: Np-HT ∼ 30% SiO 2 + 6% B 2 O 3 + 3% BaO + 13% Al 2 O 3 + 10% PbO + 30% La 2 O 3 + 8% 237 NpO 2 ; Np-SG ∼ 70% SiO 2 + 30% 237 NpO 2 ; Pu-SG ∼ 70% SiO 2 + 30% 242 PuO 2 ; Am-SG ∼ 85% SiO 2 + 15% 241 AmO 2

  1. Mg- and/or Sr-doped tricalcium phosphate/bioactive glass composites: Synthesis, microstructure and biological responsiveness

    Energy Technology Data Exchange (ETDEWEB)

    Bellucci, Devis, E-mail: devis.bellucci@unimore.it [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Sola, Antonella [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Cacciotti, Ilaria [University of Rome " Niccolò Cusano" , UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy); Bartoli, Cristina; Gazzarri, Matteo [Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM — Pisa, Via Risorgimento 35, 56127 Pisa (Italy); Bianco, Alessandra [Department of Enterprise Engineering, INSTM RU “Rome-Tor Vergata”, Via del Politecnico 1, 00133 Roma (Italy); Chiellini, Federica [Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM — Pisa, Via Risorgimento 35, 56127 Pisa (Italy); Cannillo, Valeria [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy)

    2014-09-01

    Presently, there is an increasing interest towards the composites of calcium phosphates, especially β-tricalcium phosphate (TCP), and bioactive glasses. In the present contribution, the recently developed BG{sub C}a/Mix glass has been used because its low tendency to crystallize allows to sinter the composites at relatively low temperature (i.e. 850 °C), thus minimizing the glass devitrification and the interaction with TCP. A further improvement is the introduction of lab-produced TCP powders doped with specific ions instead of non-doped commercial powders, since the biological properties of materials for bone replacement can be modulated by doping them with certain metallic ions, such as Mg and Sr. Therefore, novel binary composites have been produced by sintering the BG{sub C}a/Mix glass with the addition of pure, Mg-substituted, Sr-substituted or Mg/Sr bisubstituted TCP powders. After an accurate characterization of the starting TCP powders and of the obtained samples, the composites have been used as three-dimensional supports for the culture of mouse calvaria-derived pre-osteoblastic cells. The samples supported cell adhesion and proliferation and induced promising mechanisms of differentiation towards an osteoblastic phenotype. In particular, the Mg/Sr bi-doped samples seemed to better promote the differentiation process thus suggesting a combined stimulatory effect of Mg{sup 2+} and Sr{sup 2+} ions.

  2. Mg- and/or Sr-doped tricalcium phosphate/bioactive glass composites: Synthesis, microstructure and biological responsiveness

    International Nuclear Information System (INIS)

    Bellucci, Devis; Sola, Antonella; Niccolò Cusano, UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy))" data-affiliation=" (University of Rome Niccolò Cusano, UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy))" >Cacciotti, Ilaria; Bartoli, Cristina; Gazzarri, Matteo; Bianco, Alessandra; Chiellini, Federica; Cannillo, Valeria

    2014-01-01

    Presently, there is an increasing interest towards the composites of calcium phosphates, especially β-tricalcium phosphate (TCP), and bioactive glasses. In the present contribution, the recently developed BG C a/Mix glass has been used because its low tendency to crystallize allows to sinter the composites at relatively low temperature (i.e. 850 °C), thus minimizing the glass devitrification and the interaction with TCP. A further improvement is the introduction of lab-produced TCP powders doped with specific ions instead of non-doped commercial powders, since the biological properties of materials for bone replacement can be modulated by doping them with certain metallic ions, such as Mg and Sr. Therefore, novel binary composites have been produced by sintering the BG C a/Mix glass with the addition of pure, Mg-substituted, Sr-substituted or Mg/Sr bisubstituted TCP powders. After an accurate characterization of the starting TCP powders and of the obtained samples, the composites have been used as three-dimensional supports for the culture of mouse calvaria-derived pre-osteoblastic cells. The samples supported cell adhesion and proliferation and induced promising mechanisms of differentiation towards an osteoblastic phenotype. In particular, the Mg/Sr bi-doped samples seemed to better promote the differentiation process thus suggesting a combined stimulatory effect of Mg 2+ and Sr 2+ ions

  3. Study of boro-tellurite glasses doped with neodymium oxide

    Science.gov (United States)

    Sanjay, Kishore, N.; Sheoran, M. S.; Devi, S.

    2018-05-01

    Borotellurite glasses doped with Nd2O3 [xB2O3(95-x)TeO25Nd2O3] have been prepared by the standard melt-quenching technique. Amorphous nature of the present system was estimated by XRD patterns. The thermal parameters like glass transition temperature (Tg), crystallization (Tc) and melting (Tm) temperatures have been estimated from differential scanning calorimetry (DSC) traces. Density and molar volume have been determined. It was found that Tg is increased due to increasing number of Te-O bonds were replaced by a number of stronger B-O bonds whereas density was decreased with an increase in B2O3 content is due to the higher degree of cross-bonding between the Boron and non-bridging oxygen ions resulting in a strengthening of glass network.

  4. Preparation of high-purity Pr{sup 3+} doped Ge–As–Se–In–I glasses for active mid-infrared optics

    Energy Technology Data Exchange (ETDEWEB)

    Karaksina, E.V.; Shiryaev, V.S., E-mail: shiryaev@ihps.nnov.ru; Kotereva, T.V.; Velmuzhov, A.P.; Ketkova, L.A.; Snopatin, G.E.

    2016-09-15

    The multi-stage method for the synthesis of high-purity Ge–As–Se–In–I glasses doped with Pr{sup 3+} ions is developed. It is based on the chemical distillation purification of glass-forming melt and the chemical transport reactions for purification and vacuum loading of indium. The level of purity of glasses, synthesized by this method, is higher in comparison with the traditional direct melting method for glass synthesis. The high-purity Pr{sup 3+}-doped Ge–As–Se–In and Pr{sup 3+}-doped Ge–As–Se–In–I glass samples are prepared; the optical, thermal and luminescent properties are investigated. The purest host glass samples, obtained by the multi-stage purification techniques, contain a low concentration of limiting impurities: hydrogen − ≤0.05 ppm (wt) and oxygen − ≤0.1 ppm (wt), that is, at present, the best result for multi-component chalcogenide glasses for mid-IR active fibers. The samples of Pr{sup 3+}-doped Ge–As–Se–In glass fibers have the minimum optical losses of 0.58 dB/m at the wavelength of 2.72 μm and exhibit an intense broadband luminescence in the spectral range of 3.5–5.5 μm, with a maximum shifted to longer wavelengths as compared with the bulk samples.

  5. Structural and optical properties of antimony-germanate-borate glass and glass fiber co-doped Eu3+ and Ag nanoparticles.

    Science.gov (United States)

    Zmojda, Jacek; Kochanowicz, Marcin; Miluski, Piotr; Baranowska, Agata; Pisarski, Wojciech A; Pisarska, Joanna; Jadach, Renata; Sitarz, Maciej; Dorosz, Dominik

    2018-08-05

    In the paper analysis of structural and luminescent properties of antimony-germanate-borate glasses and glass fiber co-doped with 0.6AgNO 3 /0.2Eu 2 O 3 are presented. Heat treatment of the fabricated glass and optical fiber (400 °C, 12 h) enabled to obtain Ag nanoparticles (NPs) with average size 30-50 nm on their surface. It has been proofed that silver ions migrate to the glass surface, where they are reduced to Ag 0 nanoparticles. Simultaneously, FTIR analysis showed that heat treatment of the glass and optical fiber increases the local symmetry of the Eu 3+ site. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. A DFT study of arsine adsorption on palladium doped graphene: Effects of palladium cluster size

    International Nuclear Information System (INIS)

    Kunaseth, Manaschai; Mudchimo, Tanabat; Namuangruk, Supawadee; Kungwan, Nawee; Promarak, Vinich; Jungsuttiwong, Siriporn

    2016-01-01

    Graphical abstract: The relationship between charge difference and adsorption strength demonstrates that charge migration from Pd_n-SDG to AsH_x significantly enhanced adsorption strength, the Pd_6 clusters doped SDG with a steep slope is recommended as a superior adsorbent material for AsH_3 removal from gas stream. - Highlights: • Pd atom and Pd clusters bind strongly onto the defective graphene surface. • Larger size of Pd cluster adsorbs arsine and its hydrogenated products stronger. • Order of adsorption strength on Pd_n doped graphene: As > AsH > AsH_2 > > AsH_3. • Charge migration characterizes the strong adsorption of AsH_2, AsH, and As. • Pd cluster doped graphene is thermodynamically preferable for arsine removal. - Abstract: In this study, we have investigated the size effects of palladium (Pd) doped single-vacancy defective graphene (SDG) surface to the adsorption of AsH_3 and its dehydrogenated products on Pd using density functional theory calculations. Here, Pd cluster binding study revealed that Pd_6 nanocluster bound strongest to the SDG surface, while adsorption of AsH_x (x = 0–3) on the most stable Pd_n doped SDG showed that dehydrogenated arsine compounds adsorbed onto the surface stronger than the pristine AsH_3 molecule. Charge analysis revealed that considerable amount of charge migration from Pd to dehydrogenated arsine molecules after adsorption may constitute strong adsorption for dehydrogenated arsine. In addition, study of thermodynamic pathways of AsH_3 dehydrogenation on Pd_n doped SDG adsorbents indicated that Pd cluster doping on SDG adsorbent tends to be thermodynamically favorable for AsH_3 decomposition than the single-Pd atom doped SDG. Hence, our study has indicated that Pd_6 clusters doped SDG is more advantageous as adsorbent material for AsH_3 removal.

  7. Structural, electronic, and magnetic properties of 3D metal trioxide and tetraoxide superhalogen cluster-doped monolayer BN

    International Nuclear Information System (INIS)

    Meng, Jingjing; Li, Dan; Niu, Yuan; Zhao, Hongmin; Liang, Chunjun; He, Zhiqun

    2016-01-01

    The structural, electronic, and magnetic properties of monolayer BN doped with 3D metal trioxide and tetraoxide superhalogen clusters are investigated using first-principle calculations. TMO_3_(_4_)-doped monolayer BN exhibits a low negative formation energy, whereas TM atoms embedded in monolayer BN show a high positive formation energy. TMO_3_(_4_) clusters are embedded more easily in monolayer BN than TM atoms. Compared with TMO_3-doped structures, TMO_4-doped structures have a higher structural stability because of their higher binding energies. Given their low negative formation energies, TMO_4-doped structures are more favored for specific applications than TMO_3-doped structures and TM atom-doped structures. Large magnetic moments per supercell and significant ferromagnetic couplings between a TM atom and neighboring B and N atoms on the BN layer were observed in all TMO_4-doped structures, except for TiO_4-doped structures. - Highlights: • TMO_3_(_4_) superhalogen clusters incorporated into monolayer BN were investigated. • TMO_3_(_4_) clusters are embedded more easily in monolayer BN than TM atoms. • TMO_4-doped structures are more favored for specific applications. • Large magnetic moments were observed in TMO_4-doped structures. • The band gap was sensitively dependent on the doped clusters.

  8. Magnetic nanoparticles formed in glasses co-doped with iron and larger radius elements

    OpenAIRE

    Edelman , Irina; Ivanova , Oxana; Ivantsov , Ruslan; Velikanov , D.; Zabluda , V.; Zubavichus , Y.; Veligzhanin , A.; Zaikovskiy , V.; Stepanov , S.; Artemenko , Alla; Curély , Jacques; Kliava , Janis

    2012-01-01

    International audience; A new type of nanoparticle-containing glasses based on borate glasses co-doped with low contents of iron and larger radius elements, Dy, Tb, Gd, Ho, Er, Y, and Bi, is studied. Heat treatment of these glasses results in formation of magnetic nanoparticles, radically changing their physical properties. Transmission electron microscopy and synchrotron radiation-based techniques: x-ray diffraction, extended x-ray absorption fine structure, x-ray absorption near-edge struct...

  9. Spectroscopic properties of Er3+ and Yb3+ co-doped glass ceramics containing SrF2 nanocrystals

    International Nuclear Information System (INIS)

    Qiao Xvsheng; Fan Xianping; Wang Minquan; Zhang Xianghua

    2009-01-01

    The spectroscopic properties of Er 3+ /Yb 3+ co-doped 50SiO 2 -10Al 2 O 3 -20ZnF 2 -20SrF 2 glass and glass ceramic containing SrF 2 nanocrystals were investigated. The formation of SrF 2 nanocrystals in the glass ceramic was confirmed by XRD. The oscillator strengths for several transitions of the Er 3+ ions in the glass ceramic have been obtained and the Judd-Ofelt parameters were then determined. The XRD result and Judd-Ofelt parameters suggested that Er 3+ and Yb 3+ ions had efficiently enriched in the SrF 2 nanocrystals in the glass ceramic. The lifetime of excited states has been used to reveal the surroundings of luminescent Er 3+ and Yb 3+ and energy transfer (ET) mechanism between Er 3+ and Yb 3+ . Much stronger upconversion luminescence and longer lifetime of the Er 3+ /Yb 3+ co-doped glass ceramic were observed in comparison with the Er 3+ /Yb 3+ co-doped glass, which could be ascribed to more efficient ET from Yb 3+ to Er 3+ due to the enrichment of Yb 3+ and Er 3+ and the shortening of the distance between lanthanide ions in the precipitated SrF 2 nanocrystals.

  10. Evolution of ferromagnetic interactions from cluster spin glass state in Co–Ga alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad Yasin, Sk. [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Saha, Ritwik [Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai 400005 (India); Srinivas, V., E-mail: veeturi@iitm.ac.in [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Kasiviswanathan, S. [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Nigam, A.K. [Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai 400005 (India)

    2016-11-15

    Low temperature magnetic properties of binary Co{sub x}Ga{sub 100−x} (x=54–57) alloy have been investigated. Analysis of frequency dependence of ac susceptibility provided a conclusive evidence for the existence of cluster spin glass like behavior with the freezing temperature ~8, 14 K for x=54, 55.5 respectively. The parameters for conventional ‘slowing down’ of the spin dynamics have been extracted from the acs data, which confirm the presence of glassy phase. The magnitude of Mydosh parameter obtained from the fits is larger than that reported for typical canonical spin glasses and smaller than those for non-interacting ideal superparamagnetic systems but comparable to those of known cluster-glass systems. Memory phenomena using specific cooling protocols also support the spin-glass features in Co{sub 55.5}Ga{sub 44.5} composition. Further the development of ferromagnetic clusters from the cluster spin glass state has been observed in x=57 composition. - Highlights: • Temperature dependence of DC and AC susceptibility (acs) analysis has been carried out on Co{sub x}Ga{sub 1−x,} (x=54–57). • M–H data above transition suggests presence of spin clusters. • A detailed analysis of acs data suggests a cluster glass behavior as oppose to SPM state for x=54 and 55.5. • Memory phenomena using specific cooling protocols also support the spin-glass features in Co{sub 55.5}Ga{sub 44.5} composition. • Development of ferromagnetic like behavior for x≥57 has been suggested from DC and AC magnetization data.

  11. Nanosecond (ns) laser transfer of silver nanoparticles from silver-exchanged soda-lime glass to transparent soda-lime glass and shock waves formation

    International Nuclear Information System (INIS)

    Sow, Mohamed Chérif; Blondeau, Jean-Philippe; Sagot, Nadine; Ollier, Nadège; Tite, Teddy

    2015-01-01

    Highlights: • Silver nanoparticles growth by nanosecond laser irradiation of silver exchanged soda-lime glasses. • Silver nanoparticles transfer. • Nanosecond laser induced shock waves formation on glass. - Abstract: In this contribution, we showed for the first time in our knowledge a single-step process for silver clusters and nanoparticles growth and transfer from silver-exchanged soda-lime glass to un-exchanged soda-lime glass (transparent glass in visible and NIR domain) by nanosecond (ns) laser irradiation. The transferred silver nanoparticles in transparent glass are strongly linked to the glass surface. In addition, we point out the formation of shock waves, with selective silver clustering on the top wave. This technique provides an alternative and simple way to obtain metallic nanoparticles in different media which can be traversed by laser wavelength used. Moreover, this experiment is made at room temperature and air environment. It is worth noting that our technique requires a glass previously doped with the corresponding silver ions

  12. Novel strontium-doped bioactive glass nanoparticles enhance proliferation and osteogenic differentiation of human bone marrow stromal cells

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, L. A. [University of Erlangen-Nuremberg Medical Center, Department of Plastic and Hand Surgery (Germany); Hild, N.; Mohn, D.; Stark, W. J. [ETH Zurich, Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering (Switzerland); Hoppe, A. [University of Erlangen-Nuremberg, Department of Materials Science and Engineering, Institute of Biomaterials (Germany); Gbureck, U. [University of Wuerzburg, Department for Functional Materials in Medicine and Dentistry (Germany); Horch, R. E.; Kneser, U. [University of Erlangen-Nuremberg Medical Center, Department of Plastic and Hand Surgery (Germany); Boccaccini, A. R., E-mail: aldo.boccaccini@ww.uni-erlangen.de [University of Erlangen-Nuremberg, Department of Materials Science and Engineering, Institute of Biomaterials (Germany)

    2013-07-15

    The present study investigates a new family of bioactive glass nanoparticles with and without Sr-doping focusing on the influence of the nanoparticles on human bone marrow stromal cells (hBMSCs) in vitro. The bioactive glass nanoparticles were fabricated by flame spray synthesis and a particle diameter of 30-35 nm was achieved. Glass nanoparticles were undoped (BG 13-93-0Sr) or doped with 5 wt% strontium (Sr) (BG 13-93-5Sr) and used at concentrations of 10 and 100 {mu}g/cm Superscript-Two (particles per culture plate area), respectively. Cells were cultured for 14 days after which the samples were analysed regarding metabolic activity and expression of various bone-specific genes. Cell growth and morphology indicated the high cytocompatibility of the nanoparticulate bioactive glass. The presence of the nanoparticles enhanced cell growth compared to the plain polystyrene control group. At a concentration of 100 {mu}g/cm Superscript-Two , Sr-doped particles led to significantly enhanced gene expression of osteocalcin, collagen type 1 and vascular endothelial growth factor. Thus, Sr-doped nanoparticles showing a dose-dependent increase of osteogenic differentiation in hBMSCs are a promising biomaterial for bone regeneration purposes.

  13. Novel strontium-doped bioactive glass nanoparticles enhance proliferation and osteogenic differentiation of human bone marrow stromal cells

    International Nuclear Information System (INIS)

    Strobel, L. A.; Hild, N.; Mohn, D.; Stark, W. J.; Hoppe, A.; Gbureck, U.; Horch, R. E.; Kneser, U.; Boccaccini, A. R.

    2013-01-01

    The present study investigates a new family of bioactive glass nanoparticles with and without Sr-doping focusing on the influence of the nanoparticles on human bone marrow stromal cells (hBMSCs) in vitro. The bioactive glass nanoparticles were fabricated by flame spray synthesis and a particle diameter of 30–35 nm was achieved. Glass nanoparticles were undoped (BG 13-93-0Sr) or doped with 5 wt% strontium (Sr) (BG 13-93-5Sr) and used at concentrations of 10 and 100 μg/cm² (particles per culture plate area), respectively. Cells were cultured for 14 days after which the samples were analysed regarding metabolic activity and expression of various bone-specific genes. Cell growth and morphology indicated the high cytocompatibility of the nanoparticulate bioactive glass. The presence of the nanoparticles enhanced cell growth compared to the plain polystyrene control group. At a concentration of 100 μg/cm², Sr-doped particles led to significantly enhanced gene expression of osteocalcin, collagen type 1 and vascular endothelial growth factor. Thus, Sr-doped nanoparticles showing a dose-dependent increase of osteogenic differentiation in hBMSCs are a promising biomaterial for bone regeneration purposes

  14. Novel strontium-doped bioactive glass nanoparticles enhance proliferation and osteogenic differentiation of human bone marrow stromal cells

    Science.gov (United States)

    Strobel, L. A.; Hild, N.; Mohn, D.; Stark, W. J.; Hoppe, A.; Gbureck, U.; Horch, R. E.; Kneser, U.; Boccaccini, A. R.

    2013-07-01

    The present study investigates a new family of bioactive glass nanoparticles with and without Sr-doping focusing on the influence of the nanoparticles on human bone marrow stromal cells (hBMSCs) in vitro. The bioactive glass nanoparticles were fabricated by flame spray synthesis and a particle diameter of 30-35 nm was achieved. Glass nanoparticles were undoped (BG 13-93-0Sr) or doped with 5 wt% strontium (Sr) (BG 13-93-5Sr) and used at concentrations of 10 and 100 μg/cm² (particles per culture plate area), respectively. Cells were cultured for 14 days after which the samples were analysed regarding metabolic activity and expression of various bone-specific genes. Cell growth and morphology indicated the high cytocompatibility of the nanoparticulate bioactive glass. The presence of the nanoparticles enhanced cell growth compared to the plain polystyrene control group. At a concentration of 100 μg/cm², Sr-doped particles led to significantly enhanced gene expression of osteocalcin, collagen type 1 and vascular endothelial growth factor. Thus, Sr-doped nanoparticles showing a dose-dependent increase of osteogenic differentiation in hBMSCs are a promising biomaterial for bone regeneration purposes.

  15. Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China); Zhao, Shichang [Department of Orthopedic Surgery, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Xiao, Wei [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Xue, Jingzhe [Department of Chemistry, Tongji University, Shanghai 200092 (China); Shen, Youqu [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Zhou, Jie; Huang, Wenhai [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China); Rahaman, Mohamed N. [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Zhang, Changqing, E-mail: shzhangchangqing@163.com [Department of Orthopedic Surgery, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Wang, Deping, E-mail: wdpshk@tongji.edu.cn [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China)

    2016-01-01

    Copper doped borosilicate glasses (BG–Cu) were studied by means of FT-IR, Raman, UV–vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B–O bond of BO{sub 4} groups at 980 cm{sup −1}, while they decrease that of BO{sub 2}O{sup −} groups at 1440–1470 cm{sup −1} as shown by Raman spectra. A negative shift was observed from {sup 11}B and {sup 29}Si NMR spectra. The {sup 11}B NMR spectra exhibited a clear transformation from BO{sub 3} into BO{sub 4} groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG–Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. - Highlights: • Agglutination effect of Cu{sup 2+} and charge balance of agglomerate lead to more stable glass. • Lower degradability and lower ions release were found in BG-Cu scaffolds. • Excellent angiogenesis and sustain Cu{sup 2+} release were endowed by doping Cu.

  16. Cluster glass transition in Ca2-xLaxMnO4

    International Nuclear Information System (INIS)

    Manaka, H.; Mishima, K.; Okuda, T.

    2007-01-01

    We performed linear and nonlinear AC magnetic susceptibility measurements on Ca 2-x La x MnO 4 (x=0.03,0.07,0.10, and 0.14). In such manganites, coexistence or competition brings about various phenomena. We focus on a cluster glass state consisting of ferromagnetic clusters within an antiferromagnetic matrix because the coexistence of the ferromagnetic double exchange interaction and the antiferromagnetic superexchange interaction is closely associated with phase separation. As a result, temperature (T) dependence of a linear susceptibility (X 0 ' (T)) exhibits a sharp peak for x=0.03, and these peaks become broad with increasing x. The X 0 ' (T) curves for x=0.07 and 0.10 show a typical frequency dependence around the peaks, suggesting a cluster (spin) glass transition. Furthermore, a nonlinear susceptibility (X 2 ' (T)) for x=0.10 exhibits successive transitions: the ferromagnetic transition in each cluster occurs at ∼108K and the antiferromagnetic transition between the ferromagnetic clusters occurs at ∼89K. From the X 0 ' (T) and X 2 ' (T) curves for various values of x, we found the existence of the ferromagnetic clusters within the antiferromagnetic matrix, and the cluster glass state was realized for 0.07=< x=<0.14

  17. Femtosecond laser-induced reduction in Eu-doped sodium borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Ki-Soo [Department of Physics and Basic Science Research Institute, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)]. E-mail: kslim@chungbuk.ac.kr; Lee, Sunkyun [Department of Physics and Basic Science Research Institute, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Trinh, Minh-Tuan [Department of Physics and Basic Science Research Institute, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Kim, Suk-Ho [Department of Physics and Basic Science Research Institute, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Lee, Myeongkyu [Departent of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seoul 120-749 (Korea, Republic of); Hamilton, Douglas S. [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States); Gibson, George N. [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States)

    2007-01-15

    In this work, we report permanent reduction of Eu{sup 3+} to Eu{sup 2+} in sodium borate glasses by irradiation of near-infrared femtosecond laser. Glass composition of sodium borate was 85B{sub 2}O{sub 3}-15Na{sub 2}O. The glasses were doped with 0.05, 0.1, and 0.5 mol% Eu{sub 2}O{sub 3}. Absorption and fluorescence dynamics were studied to investigate valence state change of europium ions and the energy transfer between Eu{sup 2+} and Eu{sup 3+} ions. As the femtosecond laser intensity or exposure time increases, the emission band at 400 nm becomes stronger. However, the photoreduction efficiency decreases as the dopant concentration increases. We discuss the photoreduction mechanism under multiphoton absorption.

  18. Optical properties of highly Er{sup 3+}-doped sodium-aluminium-phosphate glasses for broadband 1.5 {mu}m emission

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, A. Amarnath [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Babu, S. Surendra [Laser Instrumentation Design Centre, Instrument Research and Development Establishment, Dehradun 248008 (India); Pradeesh, K. [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Otton, C.J. [Valencia Nanophotonics Technology Center, Universidad Politecnica de Valencia, 46022 Valencia (Spain); Vijaya Prakash, G., E-mail: prakash@physics.iitd.ac.in [Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2011-03-03

    Research highlights: > Highly Er{sup 3+} doped phosphate glasses for the 1.54 {mu}m laser emission were explored. > Emission from these doped glasses shows larger lifetimes and quantum efficiencies. > Optical amplifier parameters are greater than other reported phosphate glasses. > The durability and obtained results are most favourable for short-length amplifiers. - Abstract: Erbium-doped Na{sub 3}Al{sub 2}P{sub 3}O{sub 12} (NAP) glasses with compositions 92NAP-(8-x)Al{sub 2}O{sub 3}-(x)Er{sub 2}O{sub 3} (where x = 2-8) were prepared and characterized for absorption, visible and NIR emission and decay time properties. Judd-Ofelt analysis has been carried out to predict radiative properties of luminescent levels of Er{sup 3+} ions. Comparatively larger photoluminescence lifetimes (7.86 ms) and larger quantum efficiencies (74%) for the laser transition, {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} (at 1.54 {mu}m) are observed. The moisture insensitivity, large Er{sup 3+} ion doping capability and relatively high-gain and broad emission at 1.5 {mu}m are the most notable features of these glasses to realize efficient short-length optical amplifiers.

  19. Photoluminescence study of Sm{sup 3+}–Yb{sup 3+}co-doped tellurite glass embedding silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Reza Dousti, M., E-mail: mrdousti@ifsc.usp.br [Laboratório de Espectroscopia de Materiais Funcionais (LEMAF), Instituto de Fisica de São Carlos, Universidade de São Paulo, Av. Trabalhador So-carlense 400, São Carlos, SP 13566-590 (Brazil); Department of Physics, Tehran-North Branch, Islamic Azad University Tehran (Iran, Islamic Republic of); Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Amjad, R.J. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Hosseinian S, R.; Salehi, M.; Sahar, M.R. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia)

    2015-03-15

    We report on the upconversion emission of Sm{sup 3+} ions doped tellurite glass in the presence of Yb{sup 3+} ions and silver nanoparticles. The enhancement of infrared-to-visible upconversion emissions is achieved under 980 nm excitation wavelength and attributed to the high absorption cross section of Yb{sup 3+} ions and an efficient energy transfer to Sm{sup 3+} ions. Further enhancements are attributed to the plasmonic effect via metallic nanoparticles resulting in the large localized field around rare earth ions. However, under excitation at 406 nm, the addition of Yb{sup 3+} content and heat-treated silver nanoparticles quench the luminescence of Sm{sup 3+} ions likely due to quantum cutting and plasmonic diluent effects, respectively. - Highlights: • Sm{sup 3+} tellurite glasses co-doped with Yb{sup 3+} ions and tri-doped with Yb{sup 3+}:Ag NPs were prepared. • In first step, Yb{sup 3+} ions enhanced the upconversion emissions of Sm{sup 3+} doped samples. • In second step, Ag NPs further enhanced the upconversion emissions in tri-doped glasses. • Finally, the quench in luminescence under 406 nm excitation is observed and discussed.

  20. Asymmetric electroresistance of cluster glass state in manganites

    KAUST Repository

    Lourembam, James

    2014-03-31

    We report the electrostatic modulation of transport in strained Pr0.65(Ca0.75Sr0.25)0.35MnO3 thin films grown on SrTiO3 by gating with ionic liquid in electric double layer transistors (EDLT). In such manganite films with strong phase separation, a cluster glass magnetic state emerges at low temperatures with a spin freezing temperature of about 99 K, which is accompanied by the reentrant insulating state with high resistance below 30 K. In the EDLT, we observe bipolar and asymmetric modulation of the channel resistance, as well as an enhanced electroresistance up to 200% at positive gate bias. Our results provide insights on the carrier-density-dependent correlated electron physics of cluster glass systems.

  1. Preparation of high-purity Pr(3+) doped Ge–Ga–Sb–Se glasses with intensive middle infrared luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Karaksina, E.V.; Shiryaev, V.S., E-mail: shiryaev@ihps.nnov.ru; Kotereva, T.V.; Churbanov, M.F.

    2016-02-15

    Glass materials with high emission characteristics and low content of limiting impurities are required for creation of devices for middle infrared (mid-IR) fiber optics. The paper presents the results of preparation of high-purity Pr{sup 3+}-doped Ga{sub x}Ge{sub y}Sb{sub z}Se{sub 1−(x+y+z)} (x=3÷4, y=20÷26, z=5÷11) glasses. The multi-stage technique for synthesis of these glasses is developed. It is based on chemical distillation purification of glass components and the transport reaction for purification of gallium. Transmitting, as well as thermal and luminescent properties of glasses are investigated. The content of limiting impurities of oxygen, carbon and hydrogen in the glass samples was ≤0.2 ppm wt. The 1300–3000 ppm wt Pr{sup 3+}-doped Ga–Ge–Sb–Se bulk glasses exhibit an intensive photoluminescence in the spectral range of 3.5–5.5 μm.

  2. Impurities good and bad: Doped cluster nanoplasmas in intense ...

    Indian Academy of Sciences (India)

    are small enough to ensure that atomic and molecular effects do not lose their relevance. This combination of ... that CS2, being itself a highly condensing material, can produce large clusters of its own. Consequently, when ..... In contrast, when a CS2 cluster is doped with a dopant (argon) that has higher ionization energy ...

  3. A DFT study of arsine adsorption on palladium doped graphene: Effects of palladium cluster size

    Energy Technology Data Exchange (ETDEWEB)

    Kunaseth, Manaschai, E-mail: manaschai@nanotec.or.th [National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA) , Pathum Thani 12120 (Thailand); Mudchimo, Tanabat [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190 (Thailand); Namuangruk, Supawadee [National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA) , Pathum Thani 12120 (Thailand); Kungwan, Nawee [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Promarak, Vinich [Department of Material Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Rayong 21201 (Thailand); Jungsuttiwong, Siriporn, E-mail: siriporn.j@ubu.ac.th [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190 (Thailand)

    2016-03-30

    Graphical abstract: The relationship between charge difference and adsorption strength demonstrates that charge migration from Pd{sub n}-SDG to AsH{sub x} significantly enhanced adsorption strength, the Pd{sub 6} clusters doped SDG with a steep slope is recommended as a superior adsorbent material for AsH{sub 3} removal from gas stream. - Highlights: • Pd atom and Pd clusters bind strongly onto the defective graphene surface. • Larger size of Pd cluster adsorbs arsine and its hydrogenated products stronger. • Order of adsorption strength on Pd{sub n} doped graphene: As > AsH > AsH{sub 2} > > AsH{sub 3}. • Charge migration characterizes the strong adsorption of AsH{sub 2}, AsH, and As. • Pd cluster doped graphene is thermodynamically preferable for arsine removal. - Abstract: In this study, we have investigated the size effects of palladium (Pd) doped single-vacancy defective graphene (SDG) surface to the adsorption of AsH{sub 3} and its dehydrogenated products on Pd using density functional theory calculations. Here, Pd cluster binding study revealed that Pd{sub 6} nanocluster bound strongest to the SDG surface, while adsorption of AsH{sub x} (x = 0–3) on the most stable Pd{sub n} doped SDG showed that dehydrogenated arsine compounds adsorbed onto the surface stronger than the pristine AsH{sub 3} molecule. Charge analysis revealed that considerable amount of charge migration from Pd to dehydrogenated arsine molecules after adsorption may constitute strong adsorption for dehydrogenated arsine. In addition, study of thermodynamic pathways of AsH{sub 3} dehydrogenation on Pd{sub n} doped SDG adsorbents indicated that Pd cluster doping on SDG adsorbent tends to be thermodynamically favorable for AsH{sub 3} decomposition than the single-Pd atom doped SDG. Hence, our study has indicated that Pd{sub 6} clusters doped SDG is more advantageous as adsorbent material for AsH{sub 3} removal.

  4. Luminescence studies on Dy3+ doped calcium boro-tellurite glasses for White light applications

    Science.gov (United States)

    Karthikeyan, P.; Vijayakumar, R.; Marimuthu, K.

    2017-09-01

    A new series of Dy3+ doped calcium boro-tellurite glasses have been prepared by melt quenching technique and their spectroscopic properties were studied through FTIR, absorption luminescence and lifetime spectral measurements. FTIR studies have been made to explore the presence of various stretching and bending vibrations of different borate and tellurite groups in the prepared glasses. The bonding parameter values were estimated from the absorption band positions using Nephelauxetic ratios to examine the nature of the metal-ligand bond. The optical band gap and Urbach energy (ΔE) values were obtained from the absorption spectra to explore the electronic band structure of the studied glasses. Judd-Ofelt (JO) theory have been used to determine the JO intensity parameters (Ω2, Ω4, Ω6) following the least square fitting procedure between the experimental and calculated oscillator strength values. The luminescence spectra of the Dy3+ doped calcium boro-tellurite glasses exhibit two intense emission bands corresponding to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions. Further, they exhibit less intense emission band due to the 4F9/2→6H11/2 transition. Luminescence spectra were characterized through CIE 1931 chromaticity diagram to obtain the dominant emission color of the prepared glasses. The JO intensity parameters and refractive index values have been used to calculate the radiative parameters such as transition probabilities (AR), branching ratios (βR) and stimulated emission cross-section (σPE) values for the observed transitions in the luminescence spectra. The decay curves of all the studied glasses found to exhibit non-exponential behavior and further to understand the energy transfer process takes place between the Dy3+ ions, the decay curves were fitted to the Inokuti-Hirayama (IH) model. The structural and optical properties of the Dy3+ doped calcium boro-tellurite glasses have been studied as a function of different metal cations (Zn, Cd, Pb and

  5. Optical absorption and gamma-radiation-shielding parameter studies of Tm3+-doped multicomponent borosilicate glasses

    Science.gov (United States)

    Lakshminarayana, G.; Sayyed, M. I.; Baki, S. O.; Lira, A.; Dong, M. G.; Kaky, Kawa M.; Kityk, I. V.; Mahdi, M. A.

    2018-05-01

    Different concentrations (0.1‒2.0 mol%) of Tm3+-doped multicomponent borosilicate glasses with 10 mol% Li2O (alkali) or MgO (alkaline) have been synthesized and their optical absorption and radiation shielding features were studied. For both Li2O and MgO series 0.5 mol% Tm3+-doped glass samples, the evaluated Ωλ ( λ = 2, 4, and 6) Judd-Ofelt (JO) intensity parameters from experimental oscillator strengths were used in estimating the radiative transition probabilities ( A R), branching ratios ( β R), and radiative lifetimes ( τ R) for several emission transitions. Using the XCOM software, the mass attenuation coefficients ( µ/ ρ) for all the fabricated glasses were evaluated within the 0.015‒10 MeV energy range. Also, the ( µ/ ρ) values were calculated at 0.356, 0.662, 1.173, and 1.33 MeV photon energies by MCNP5 simulation code and the results were compared with those obtained by XCOM. The ( µ/ ρ) values for Li2O, as well as MgO series glasses, increase with the addition of Tm2O3 and these values for MgO series glasses are slightly higher with respect to Li2O series glasses. From the ( µ/ ρ) values, effective atomic number ( Z eff), half-value layer (HVL), and mean free path (MFP) were calculated and the HVL and MFP results revealed that high-energy photons have more penetration into a glass sample compared to low-energy photons. Further, geometric progression (GP) fitting method was utilized to calculate the exposure buildup factor (EBF) within the 0.015‒15 MeV energy range. The 2.0 mol% Tm2O3-doped glasses show a better ability to attenuate gamma-rays in comparison to other glass samples, so the addition of Tm2O3 content leads to improvement of the shielding efficiency of the prepared glasses.

  6. Intense upconversion luminescence in ytterbium-sensitized thulium-doped oxychloride germanate glass

    International Nuclear Information System (INIS)

    Sun Hongtao; Zhanga Liyan; Zhang Junjie; Wen Lei; Yu Chunlei; Duan Zhongchao; Dai Shixun; Hu Lili; Jiang Zhonghong

    2005-01-01

    Structural and upconversion fluorescence properties in ytterbium-sensitized thulium-doped oxychloride germanate glass have been studied. The structure of oxychloride germanate glass was investigated by peak-deconvolution of Raman spectrum, and the structural information was obtained from the peak wavenumbers. The Raman spectrum investigation indicates that PbCl 2 plays an important role in the formation of glass network, and has an important influence on the upconversion luminescence. Intense blue and weak red emissions centered at 477 and 650 nm, corresponding to the transitions 1 G 4 → 3 H 6 and 1 G 4 → 3 H 4 , respectively, were observed at room temperature. The possible upconversion mechanisms are discussed and estimated. Intense upconversion luminescence indicates that oxychloride germanate glass can be used as potential host material for upconversion lasers

  7. Application of response surface methodology for the implementation, optimization and characterization of a new radiation sensor based on commercial glass doped with copper

    International Nuclear Information System (INIS)

    Mezzi, Ines

    2012-01-01

    In order to realize a dosimeter based on a silica glass doped with copper and detecting low doses, we used the method of ion exchange and studied the influence of various parameters of doping: the percentage of CuSO4, temperature and heating time in the oven. Our results showed that the doped glass can be used as a dosimeter for gamma radiation in the range of doses of 1 Gy to 100kGy. To optimize the experimental conditions of doping the glass with copper, we used a central composite design (CCD).

  8. Analysis of structure origin and luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glass.

    Science.gov (United States)

    Chen, Fangze; Jing, Xufeng; Wei, Tao; Wang, Fengchao; Tian, Ying; Xu, Shiqing

    2014-08-14

    The near infrared luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glasses have been investigated. The various effects on structure and 1.53 μm emission were analyzed as a function of Yb(3+) concentration. The energy transfer mechanism was proposed. High measured lifetime (10.75 ms), large effective full widths at half maximum (73.71 nm) and large gain per unit length (62.8 × 10(-)(24)cm(2)s) have been achieved in prepared glass. The present glass co-doped with 6mol% YbF3 and 2 mol% ErF3 showed magnificent luminescence properties for telecommunication application. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Luminescence properties of erbium doped sodium barium borate glass with silver nanoparticles

    Science.gov (United States)

    Rajeshree Patwari, D.; Eraiah, B.

    2018-02-01

    Alteration in the absorption features of rare earth (RE) doped glasses with silver nanoparticles is ever-challenging in photonics. Erbium (Er3+) doped glasses with composition (60-x-y)B2O3-30Na2CO3-10BaO-xEr2O3-yAgCl where (x=0.5, 1.0 and y=1.0 mol %) are synthesized using melt-quenching method. The density is determined by Archimedes principle and molar volumes are calculated. Glass samples were characterized by XRD and UV-Visible spectroscopy. UV-Visible spectra shows eleven prominent absorption peaks centred around 366, 378, 408, 442, 452, 489, 521, 547, 652, 800 and 977 nm equivalent to the rare earth (Er3+) ion transitions. The sample without rare earth shows no peaks which specifies that rare earth ion plays a spirited role in the glass matrix. The glass samples with silver and without rare earth ion shows plasmon peak on heat treatment. The energy band gap values calculated for direct and indirect transitions are in the range of 3.126-3.440eV and 2.58-3.177eV respectively. The refractive indices and Urbach energies are also determined. Photoluminescence spectra are recorded and studied for excitation of the most intense peaks of wavelengths 378 and 521nm. The luminescence of erbium ion is enhanced by the presence of silver when the concentration of rare earth ion is less than that of silver.

  10. Effect of co-doped SnO{sub 2} nanoparticles on photoluminescence of cu-doped potassium lithium borate glass

    Energy Technology Data Exchange (ETDEWEB)

    Namma, Haydar Aboud; Wagiran, H.; Hussin, R.; Ariwahjoedi, B. [Department of Physics, Universiti Teknologi Malaysia, Skudai 81310, Malaysia and Baghdad College of Economic Sciences University (Iraq); Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, 31750 Tronoh (Malaysia)

    2012-09-26

    The SnO{sub 2} co-doped lithium potassium borate glasses doped with 0.05, 0.10, 0.25 and 0.50 mol% of Cu were synthesized by the melt quenching technique. The SnO{sub 2} co-dope was added to the compounds in the amounts of 0.05, 0.10, and 0.20 mol%. The photoluminescent spectrum for different concentrations of copper was studied. It was observed that the intensity of blue emission (450, 490 nm) varies with concentration mol%. In addition, with different concentration of SnO{sub 2} to 0.10 mol% Cu, the influence of the luminescence has been observed to enhance intensity and shifted to blue and red (490, 535 nm) emissions.

  11. Efficient enhancement of bismuth NIR luminescence by aluminum and its mechanism in bismuth doped germanate laser glass

    DEFF Research Database (Denmark)

    Wang, L.P.; Tan, L.L.; Yue, Yuanzheng

    2016-01-01

    As a new member of laser glass family, bismuth-doped glasses have received rising interests due to the application of fiber amplifiers and laser sources in the new spectral range for the next-generation optical communication system. For practical application of the glasses, it must be considered ...

  12. Preparation and leaching property of Nd-doped zirconolite-based glass-ceramic

    International Nuclear Information System (INIS)

    Wu Lang; Xu Dong; Teng Yuancheng; Li Yuxiang; Liu Zongqiang

    2014-01-01

    Nd-doped zirconolite-based glass-ceramics were prepared by melting-heat treatment technique. The effects of heat treatment processing on phase structure of the glass-ceramics were investigated. The leaching properties of the glass-ceramics were also evaluated by static leaching experiments (product consistency test, PCT). The results show that glass transformation temperature (T g ) and crystallization temperature of the glass-ceramics are about 580℃ and 740℃, respectively. CaTiO 3 phase forms easily when the glass-ceramics were prepared by two-step method, i.e. the glass was prepared first, and then it was heat-treated at the crystallization temperatures. 2M-zirconolite phase can be obtained by one-step method, i.e. the heat-treatment immediately followed by the melting process. In addition, the zirconolite crystals exhibit a dendritic shape. The normalized mass loss of B and Na in the glass-ceramics remains almost unchanged (about 1 mg/m 2 ) after 14 days, while the normalized mass loss of Nd reaches stable value (about 0.2 mg/m 2 ) after 28 days. The normalized mass loss of B, Na, and Nd in the glass-ceramics is an order of magnitude lower than that of borosilicate glasses, respectively. (authors)

  13. Photoluminescence properties of Er-doped Ge–In(Ga)–S glasses modified by caesium halides

    Czech Academy of Sciences Publication Activity Database

    Ivanova, Z.G.; Zavadil, Jiří; Kostka, P.; Djouama, T.; Reinfelde, M.

    2017-01-01

    Roč. 254, č. 6 (2017), č. článku 1600662. ISSN 0370-1972 Institutional support: RVO:67985882 Keywords : caesium halides * chalcohalide glasses * erbium doping * transmission spectroscopy * photoluminiscence Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass OBOR OECD: Ceramics Impact factor: 1.674, year: 2016

  14. Photoluminescence properties of Er-doped Ge–In(Ga)–S glasses modified by caesium halides

    Czech Academy of Sciences Publication Activity Database

    Ivanova, Z.G.; Zavadil, Jiří; Kostka, Petr; Djouama, T.; Reinfelde, M.

    2017-01-01

    Roč. 254, č. 6 (2017), č. článku 1600662. ISSN 0370-1972 Institutional support: RVO:67985891 Keywords : caesium halides * chalcohalide glasses * erbium doping * transmission spectroscopy * photoluminiscence Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass OBOR OECD: Ceramics Impact factor: 1.674, year: 2016

  15. Role of glass structure in defining the chemical dissolution behavior, bioactivity and antioxidant properties of zinc and strontium co-doped alkali-free phosphosilicate glasses.

    Science.gov (United States)

    Kapoor, Saurabh; Goel, Ashutosh; Tilocca, Antonio; Dhuna, Vikram; Bhatia, Gaurav; Dhuna, Kshitija; Ferreira, José M F

    2014-07-01

    We investigated the structure-property relationships in a series of alkali-free phosphosilicate glass compositions co-doped with Zn(2+) and Sr(2+). The emphasis was laid on understanding the structural role of Sr(2+) and Zn(2+) co-doping on the chemical dissolution behavior of glasses and its impact on their in vitro bioactivity. The structure of glasses was studied using molecular dynamics simulations in combination with solid state nuclear magnetic resonance spectroscopy. The relevant structural properties are then linked to the observed degradation behavior, in vitro bioactivity, osteoblast proliferation and oxidative stress levels. The apatite-forming ability of glasses has been investigated by X-ray diffraction, infrared spectroscopy and scanning electron microscopy-energy-dispersive spectroscopy after immersion of glass powders/bulk in simulated body fluid (SBF) for time durations varying between 1h and 14 days, while their chemical degradation has been studied in Tris-HCl in accordance with ISO 10993-14. All the glasses exhibit hydroxyapatite formation on their surface within 1-3h of their immersion in SBF. The cellular responses were observed in vitro on bulk glass samples using human osteosarcoma MG63 cell line. The dose-dependent cytoprotective effect of glasses with respect to the concentration of zinc and strontium released from the glasses is also discussed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  16. White light emission from Tm3+/Dy3+ co-doped oxyfluoride germanate glasses under UV light excitation

    International Nuclear Information System (INIS)

    Lakshminarayana, G.; Yang Hucheng; Qiu Jianrong

    2009-01-01

    In this paper, we report on the absorption and photoluminescence properties of Tm 3+ /Dy 3+ ions co-doped oxyfluoride germanate glasses for white light emission. The X-ray diffraction (XRD) and differential thermal analysis (DTA) profiles of the host glass have been carried out to confirm its structure and thermal stability. From the measured absorption spectra, Judd-Ofelt (J-O) intensity parameters (Ω 2 , Ω 4 and Ω 6 ) have been evaluated for Tm 3+ and Dy 3+ ions. A combination of blue, yellow and red emissions has emerged in these glasses, which allows the observation of bright white light when the glasses are excited by the ultraviolet light. The white light luminescence colour could be changed by varying the excitation wavelength. Also, various colours of luminescence, including white light, can be easily tuned by adjusting the concentrations of Tm 3+ or Dy 3+ ions in the co-doped glasses. Concentration quenching effect was also investigated and possible energy transfer mechanism from Dy 3+ →Tm 3+ ions was explained which is also confirmed by the decay lifetime measurements. - Graphical Abstract: A combination of blue, yellow and red emissions has emerged from Tm 3+ /Dy 3+ co-doped glasses, which allows the observation of bright white light and makes them as excellent candidates applicable in the solid-state multi-colour three-dimensional display.

  17. Production of a handbook: Nd-doped glass spectroscopic and physical properties

    International Nuclear Information System (INIS)

    Saroyan, R.A.

    1979-01-01

    The production of Lawrence Livermore Laboratory publication M-095, a handbook containing a collection of properties of Nd 3+ -doped glasses, is described. The pros and cons of the method are presented. The bulk of the report is contained in detailed appendices which cover major aspects of production

  18. Boron-doped hydrogenated Al{sub 3} clusters: A material for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Muz, İskender, E-mail: iskender.muz@nevsehir.edu.tr [Faculty of Education, Department of Science Education, Nevsehir Haci Bektas Veli University, 50300, Nevsehir (Turkey); Atiş, Murat [Kayseri Vocational School, Electricity and Energy Department, Erciyes University, 38300, Kayseri (Turkey)

    2016-05-15

    The energetic and structural stabilities of Al{sub 3}BH{sub 2n} (n = 0–6) clusters are investigated using ab initio calculations. Structural isomers are found using the stochastic search method to search for minima structures, followed by B3LYP optimizations; single-point CCSD(T) calculations are performed to compute relative energies. Chemical bonding analysis is also performed using the adaptive natural density partitioning method to investigate the chemical bonding in the clusters and to elucidate their structural evolution. Our results and analyses indicate that the stability of the boron-doped hydrogenated Al{sub 3} clusters increases as more hydrogen molecules are adsorbed, whereas the H{sub 2} loss energy decreases. The results are in good agreement with available theoretical findings. - Highlights: • The boron-doped hydrogenated Al{sub 3} clusters are generated using stochastic search method. • The energetic and structural stabilities are investigated in detail. • The chemical bonding analysis is performed by using AdNDP analysis. • The doping by boron allows development of better aluminum-based metal hydrides.

  19. Cubic to tetragonal phase transition of Tm3+ doped nanocrystals in oxyfluoride glass ceramics

    International Nuclear Information System (INIS)

    Li, Yiming; Fu, Yuting; Shi, Yahui; Zhang, Xiaoyu; Yu, Hua; Zhao, Lijuan

    2016-01-01

    Tm 3+ ions doped β-PbF 2 nanocrystals in oxyfluoride glass ceramics with different doping concentrations and thermal temperatures are prepared by a traditional melt-quenching and thermal treatment method to investigate the structure and the phase transition of Tm 3+ doped nanocrystals. The structures are characterized by X-ray diffraction Rietveld analysis and confirmed with numerical simulation. The phase transitions are proved further by the emission spectra. Both of the doping concentration and thermal temperature can induce an O h to D 4h site symmetry distortion and a cubic to tetragonal phase transition. The luminescence of Tm 3+ doped nanocrystals at 800 nm was modulated by the phase transition of the surrounding crystal field

  20. Ho3+-doped AlF3-TeO2-based glass fibers for 2.1 µm laser applications

    Science.gov (United States)

    Wang, S. B.; Jia, Z. X.; Yao, C. F.; Ohishi, Y.; Qin, G. S.; Qin, W. P.

    2017-05-01

    Ho3+-doped AlF3-TeO2-based glass fibers based on AlF3-BaF2-CaF2-YF3-SrF2-MgF2-TeO2 glasses are fabricated by using a rod-in-tube method. The glass rod including a core and a thick cladding layer is prepared by using a suction method, where the thick cladding layer is used to protect the core from the effect of surface crystallization during the fiber drawing. By inserting the glass rod into a glass tube, the glass fibers with relatively low loss (~2.3 dB m-1 @ 1560 nm) are prepared. By using a 38 cm long Ho3+-doped AlF3-TeO2-based glass fiber as the gain medium and a 1965 nm fiber laser as the pump source, 2065 nm lasing is obtained for a threshold pump power of ~220 mW. With further increasing the pump power to ~325 mW, the unsaturated output power of the 2065 nm laser is about 82 mW and the corresponding slope efficiency is up to 68.8%. The effects of the gain fiber length on the lasing threshold, the slope efficiency, and the operating wavelength are also investigated. Our experimental results show that Ho3+-doped AlF3-TeO2-based glass fibers are promising gain media for 2.1 µm laser applications.

  1. Effect of co-doping Tm3+ ions on the emission properties of Dy3+ ions in tellurite glasses

    International Nuclear Information System (INIS)

    Sasikala, T.; Rama Moorthy, L.; Mohan Babu, A.; Srinivasa Rao, T.

    2013-01-01

    The present work reports the absorption, photoluminescence and decay properties of singly doped Dy 3+ and co-doped Dy 3+ /Tm 3+ ions in TeO 2 +ZnO+K 2 O+CaO (TZKC) glasses prepared by the melt quenching technique. The glassy nature of the host glass has been confirmed by X-ray diffraction analysis and the primary vibrational modes were determined from the Raman spectrum. Judd–Ofelt (JO) analysis has been used to calculate the radiative transition rates, branching ratios and radiative lifetime of the emitting 4 F 9/2 state. The effect of co-doping of different concentrations of Tm 3+ ions on the emission properties of Dy 3+ ions has been investigated. The decay profiles of the 4 F 9/2 level were fitted to double exponential as well as Inokuti–Hirayama (IH) model to determine the energy transfer rates between Dy 3+ and Tm 3+ ions. The energy transfer rates found to increase with the increase of Tm 3+ ions concentration. The chromaticity coordinates and color purity of the emitted light for all glasses were determined. - Graphical abstract: The graphical abstract shows the emission spectra of Dy 3+ , Tm 3+ and Dy 3+ /Tm 3+ co-doped TZKC glasses recorded by exciting at 355 nm wavelength. - Highlights: • Zinc tellurite glasses doped with Dy 3+ , Tm 3+ and Dy 3+ /Tm 3+ ions were prepared. • XRD, DTA and Raman spectral measurements were recorded to know the nature of host. • Energy transfer occurs from Dy 3+ ions to Tm 3+ ions. • The color purity of the emitted light was determined

  2. Influence of rare-earth ions on SiO{sub 2}-Na{sub 2}O-RE{sub 2}O{sub 3} glass structure

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J A [Department of Materials Science and Engineering, University of Tennessee Space Institute, Tullahoma, TN 37388 (United States); Benmore, C J [X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Holland, D [Department of Physics, University of Warwick, CV4 7AL (United Kingdom); Du, J [Department of Material Science and Engineering, University of North Texas, Denton, TX 76203 (United States); Beuneu, B [Laboratoire Leon Brillouin, CEA-CNRS, CEA/Saclay, F-91191 Gif-sur-Yvette (France); Mekki, A, E-mail: jjohnson@utsi.edu [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2011-02-16

    Praseodymium and europium sodium silicate glasses of nominal composition (SiO{sub 2}){sub 0.70-x}(Na{sub 2}O){sub 0.30}(RE{sub 2}O{sub 3}){sub x}, where RE is the rare earth and 0 {<=} x {<=} 0.10, were studied by neutron and high-energy x-ray scattering and classical molecular dynamics simulations. The observation of a significant x-ray intensity in doped as compared to un-doped glasses is indicative of RE-RE correlations at a distance of {approx} 3.7-3.9 A, much shorter than would be expected for a homogeneous distribution, suggesting that clustering of the rare-earth cations occurs in both these glass systems at low concentrations. Above x = 0.075 (nominal), minimal changes in this region indicate that the RE atoms are incorporated much more randomly into the glass structure. The molecular dynamics simulations suggest that the rare-earth ions enter the sodium-rich regions in the sodium silicate glasses and act as modifiers. A cluster analysis performed on the model systems indicates that the tendency for clustering is higher in praseodymium-containing glasses than in the europium glasses.

  3. Physical, thermal, structural and optical properties of Dy3+ doped lithium alumino-borate glasses for bright W-LED

    International Nuclear Information System (INIS)

    Pawar, P.P.; Munishwar, S.R.; Gautam, S.; Gedam, R.S.

    2017-01-01

    Rare earth (RE) doped glasses have potential applications due to their emission efficiencies of 4f–4 f and 4f–5d electronic transitions. Among all the rare earths, Dy 3+ doped glasses have drawn much interest among the researchers for their intense emission in the visible region from 470 to 500 nm and around 570 to 600 nm. The physical, thermal, structural and optical properties of Dy 3+ doped lithium alumino-borate glasses (LABD glasses) have been studied for white LED (W-LED) application. The glasses were synthesized by conventional melt quench technique. X-ray diffraction spectra revealed the amorphous nature of the glass sample. An FTIR spectrum was carried out to study the glass structure and various functional groups present in the LABD glasses. Optical absorption spectra were recorded by UV–vis-NIR spectrometer. Allowed direct and indirect band gaps were obtained by Tauc's plot. Thermal parameters like glass thermal stability (∆T), Hruby's parameter (K gl ), etc. were calculated by DTA graph. Photoluminescence excitation and emission spectra's were measured at room temperature. The emission spectra shows two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponds to the 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 transitions respectively along with one feeble band at 662 nm (red) corresponds to 4 F 9/2 → 6 H 11/2 transition. The CIE chromaticity co-ordinates were calculated for all glass samples. CIE chromaticity diagram shows glass LABD-4 containing 0.5 mol% Dy 2 O 3 with colour co-ordinates X = 0.34 and Y = 0.38 have highest emission intensity. These glasses having emission in the white region and thus can be used for bright white LED.

  4. Properties and structure of high erbium doped phosphate glass for short optical fibers amplifiers

    International Nuclear Information System (INIS)

    Seneschal, Karine; Smektala, Frederic; Bureau, Bruno; Floch, Marie Le; Jiang Shibin; Luo, Tao; Lucas, Jacques; Peyghambarian, Nasser

    2005-01-01

    New phosphate glasses have been developed in order to incorporate high rare-earth ions concentrations. These glasses present a great chemical stability and a high optical quality. The phosphate glass network is open, very flexible, with a linkage of the tetrahedrons very disordered and contains a larger number of non-bridging oxygens (66%). The great stability and resistance against crystallization associated with the possibility to incorporate high doping concentration of rare-earth ions in these phosphate glasses make them very good candidates for the realization of ultra short single mode amplifiers with a high gain at 1.55 μm

  5. Study of Paramagnetic Species in γ-irradiated Lithium Borate Glasses Doped With Cu2+ Ions

    International Nuclear Information System (INIS)

    Mansour, A.; Abd-Allah, W.M.; El-Alaily, N.A.; Ezz-Eldin, F.M.

    2013-01-01

    Mixed alkali borate glasses doped with different concentration of Cu O ranging from (0.1-10) wt% have been prepared by the melt quenching technique. The prepared samples were studied by means of density, molar volume, infrared spectroscopy and electron paramagnetic resonance (EPR) measurements before and after successive gamma irradiation (50-200 kGy). The results showed that the density increase while molar volume decrease with the increase of CuO %. The infrared absorption studies revealed that structure of the glass network consists of BO 3 , BO 4 and B-O-Cu linkages. Gamma irradiation causes minor changes in the IR spectral bands which are related to the bond break of the B-O bond and formation non-bridging oxygen. Gamma irradiation causes irregular change in the intensities of the EPR spectra for samples doped with 0.1, 0.2 and 10 wt % of Cu O, however, no change in the EPR spectra of 2 and 5 wt % of Cu O for all absorbed doses (50-200 kGy). It is expected that the Cu-doped lithium borate glass 2 and 5 wt % of Cu O may be used for radiation shielding.

  6. Spectroscopic properties of Ho{sup 3+}-doped K-Sr-Al phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Linganna, K.; Rathaiah, M.; Venkatramu, V. [Yogi Vemana University, Department of Physics, Kadapa (India); Jayasankar, C.K. [Sri Venkateswara University, Department of Physics, Tirupati (India)

    2014-05-15

    Trivalent holmium-doped K-Sr-Al phosphate glasses (P{sub 2}O{sub 5}-K{sub 2}O-SrO-Al{sub 2}O{sub 3}-Ho{sub 2}O{sub 3}) were prepared, and their spectroscopic properties have been evaluated using absorption, emission, and excitation measurements. The Judd-Ofelt theory has been used to derive spectral intensities of various absorption bands from measured absorption spectrum of 1.0 mol% Ho{sub 2}O{sub 3}-doped K-Sr-Al phosphate glass. The Judd-Ofelt intensity parameters (Ω{sub λ}, x 10{sup -20} cm{sup 2}) have been determined of the order of Ω{sub 2} = 11.39, Ω{sub 4} = 3.59, and Ω{sub 6} = 2.92, which in turn used to derive radiative properties such as radiative transition probability, radiative lifetime, branching ratios, etc. for excited states of Ho{sup 3+} ions. The radiative lifetimes for the {sup 5}F{sub 4}, {sup 5}S{sub 2}, and {sup 5}F{sub 5} levels of Ho{sup 3+} ions are found to be 169, 296, and 317 μs, respectively. The stimulated emission cross-section for 2.05-μm emission was calculated by the McCumber theory and found to be 9.3 x 10{sup -21} cm{sup 2}. The wavelength-dependent gain coefficient with population inversion rate has been evaluated. The results obtained in the titled glasses are discussed systematically and compared with other Ho{sup 3+}-doped systems to assess the possibility for visible and infrared device applications. (orig.)

  7. Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds.

    Science.gov (United States)

    Wang, Hui; Zhao, Shichang; Xiao, Wei; Xue, Jingzhe; Shen, Youqu; Zhou, Jie; Huang, Wenhai; Rahaman, Mohamed N; Zhang, Changqing; Wang, Deping

    2016-01-01

    Copper doped borosilicate glasses (BG-Cu) were studied by means of FT-IR, Raman, UV-vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B-O bond of BO4 groups at 980 cm(-1), while they decrease that of BO2O(-) groups at 1440-1470 cm(-1) as shown by Raman spectra. A negative shift was observed from (11)B and (29)Si NMR spectra. The (11)B NMR spectra exhibited a clear transformation from BO3 into BO4 groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG-Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Refractive index and density in F- and Cl-doped silica glasses

    International Nuclear Information System (INIS)

    Kakiuchida, Hiroshi; Shimodaira, Noriaki; Sekiya, Edson H.; Saito, Kazuya; Ikushima, Akira J.

    2005-01-01

    The refractive index and density of fluorine- and chlorine-doped silica glasses were measured as functions of fictive temperature. The halogen concentrations were observed to have a refractive index or density that is independent of the fictive temperature were found. This implies that these properties are not affected by any heat-treatment conditions

  9. Effects of alkali ions on thermal stability and spectroscopic properties of Er{sup 3+}-doped gallogermanate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Shi, D.M.; Zhao, Y.G.; Wang, X.F.; Liao, G.H. [Department of Materials Science and Engineering, Luoyang Institute of Science and Technology, Luoyang 471023 (China); Zhao, C. [Department of Physics, South China University of Technology, Guangzhou 510641 (China); MOE Key Lab of Specially Functional Materials and Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641 (China); Peng, M.Y. [MOE Key Lab of Specially Functional Materials and Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641 (China); Zhang, Q.Y., E-mail: qyzhang@scut.edu.c [MOE Key Lab of Specially Functional Materials and Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641 (China)

    2011-02-01

    Since information transportation capacity of optical communication network increases rapidly, new optical materials are always demanded with gain bandwidth desirably much broader than traditional erbium-doped silica fiber amplifier (EDFA). We show here in this paper the erbium-doped gallogermanate glasses with a full-width at half-maximum (FWHM) more than 50 nm. Incorporation of alkali ions such as Li{sup +}, Na{sup +}, K{sup +} into the system can on the one hand improve the thermal stability of the glasses, and on the other hand enhance the emission at 1.5 {mu}m due to the {sup 4}I{sub 13/2{yields}}{sup 4}I{sub 15/2} transition of Er{sup 3+} and suppress the upconversion process at the same time. This particularly works best for the case of K{sup +} inclusion. This work might give a general idea on controlling the Er{sup 3+} luminescence by simply adjusting the glass component and find a potential laser glass applicable to developing new broadband fiber amplifier. -- Research highlights: {yields} We report on spectroscopic properties of Er{sup 3+}-doped Ga{sub 2}O{sub 3}-GeO{sub 2}-R{sub 2}O (GGR, R=Li, Na and K) glasses for 1.53 {mu}m fiber amplifier. Effects of alkali metal ions on the thermal stability and spectroscopic properties of Er{sup 3+}-doped GGR glasses have been investigated. {yields} Incorporation of alkali ions such as Li{sup +}, Na{sup +}, K{sup +} into the system can on the one hand improve the thermal stability of the glasses, and on the other hand enhance the emission at 1.5 {mu}m due to the {sup 4}I{sub 13/2{yields}}{sup 4}I{sub 15/2} transition of Er{sup 3+} and suppress the upconversion process at the same time. This particularly works best for the case of K{sup +} inclusion. This work might give a general idea on controlling the Er{sup 3+} luminescence by simply adjusting the glass component and find a potential laser glass applicable to developing new broadband fiber amplifier.

  10. Charge-doping and chemical composition-driven magnetocrystalline anisotropy in CoPt core-shell alloy clusters

    Science.gov (United States)

    Ruiz-Díaz, P.; Muñoz-Navia, M.; Dorantes-Dávila, J.

    2018-03-01

    Charge-doping together with 3 d-4 d alloying emerges as promising mechanisms for tailoring the magnetic properties of low-dimensional systems. Here, throughout ab initio calculations, we present a systematic overview regarding the impact of both electron(hole) charge-doping and chemical composition on the magnetocrystalline anisotropy (MA) of CoPt core-shell alloy clusters. By taking medium-sized Co n Pt m ( N = n + m = 85) octahedral-like alloy nanoparticles for some illustrative core-sizes as examples, we found enhanced MA energies and large induced spin(orbital) moments in Pt-rich clusters. Moreover, depending on the Pt-core-size, both in-plane and off-plane directions of magnetization are observed. In general, the MA of these binary compounds further stabilizes upon charge-doping. In addition, in the clusters with small MA, the doping promotes magnetization switching. Insights into the microscopical origins of the MA behavior are associated to changes in the electronic structure of the clusters. [Figure not available: see fulltext.

  11. Plasmon excitations in doped square-lattice atomic clusters

    Science.gov (United States)

    Wang, Yaxin; Yu, Ya-Bin

    2017-12-01

    Employing the tight-binding model, we theoretically study the properties of the plasmon excitations in doped square-lattice atomic clusters. The results show that the dopant atoms would blur the absorption spectra, and give rise to extra plasmon resonant peaks as reported in the literature; however, our calculated external-field induced oscillating charge density shows that no obvious evidences indicate the so-called local mode of plasmon appearing in two-dimensional-doped atomic clusters, but the dopants may change the symmetry of the charge distribution. Furthermore, we show that the disorder of the energy level due to dopant makes the absorption spectrum has a red- or blue-shift, which depends on the position of impurities; disorder of hopping due to dopant makes a blue- or red-shift, a larger (smaller) hopping gives a blue-shift (red-shift); and a larger (smaller) host-dopant and dopant-dopant intersite coulomb repulsion induces a blue-shift (red-shift).

  12. Investigation on Er{sup 3+}/Ho{sup 3+} co-doped silicate glass for ~2 µm fiber lasers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xueqiang; Huang, Feifei; Cheng, Jimeng; Fan, Xiaokang; Gao, Song [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Graduate School of Chinese Academy of Science, Beijing 100039 (China); Zhang, Junjie [College of Materials Science and Technology, China Jiliang University, Hangzhou 310018 (China); Hu, Lili [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Chen, Danping, E-mail: dpchen2008@aliyun.com [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2015-06-15

    A stable Er{sup 3+}/Ho{sup 3+} co-doped lead silicate glass is developed. Luminescent properties are recorded under pumping with 808 and 1550 nm lasers. Energy-transfer mechanism and efficiency are analyzed. Energy-transfer efficiency from Er{sup 3+}:{sup 4}I{sub 13/2} to Ho{sup 3+}:{sup 5}I{sub 7} reaches 93.8% at 3 mol% Ho{sub 2}O{sub 3} doping concentration. Strong luminescence is detected when pumped at 1550 nm because of efficient energy transfer from Er{sup 3+}:{sup 4}I{sub 13/2} to Ho{sup 3+}:{sup 5}I{sub 7}. Peak gain coefficient at 2056 nm is detected as 1.62 cm{sup −1}. The excellent luminescent property and high stability indicate that Er{sup 3+}/Ho{sup 3+} co-doped lead silicate glass can be applied in 2 µm fiber lasers. - Highlights: • Er{sup 3+}/Ho{sup 3+} co-doped silicate glasses with high stability are prepared. • Strong luminescence is detected under pump of 1550 nm lasers owing to efficient energy transfer from Er{sup 3+} to Ho{sup 3+}. • Transfer efficiency is calculated to be 93.8% when Ho{sub 2}O{sub 3} doping concentration is up to 3 mol%. • Gain coefficient peaks at 2056 nm to be 1.62 cm{sup −1}.

  13. Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO₂.

    Science.gov (United States)

    Wang, Ling; Zeng, Huidan; Yang, Bin; Ye, Feng; Chen, Jianding; Chen, Guorong; Smith, Andew T; Sun, Luyi

    2017-02-28

    Yb 3+ -doped phosphate glasses containing different amounts of SiO₂ were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO₂ on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO₂ possessed the longest fluorescence lifetime (1.51 ms), the highest gain coefficient (1.10 ms·pm²), the maximum Stark splitting manifold of ²F 7/2 level (781 cm -1 ), and the largest scalar crystal-field N J and Yb 3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO₂ promoted the formation of P=O linkages, but broke the P=O linkages when the SiO₂ content was greater than 26.7 mol %. Based on the previous 29 Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO₆] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb 3+ -doped gain medium for solid-state lasers and optical fiber amplifiers.

  14. Asymmetric electroresistance of cluster glass state in manganites

    KAUST Repository

    Lourembam, James; Ding, Junfeng; Bera, Ashok; Lin, Weinan; Wu, Tao

    2014-01-01

    cluster glass magnetic state emerges at low temperatures with a spin freezing temperature of about 99 K, which is accompanied by the reentrant insulating state with high resistance below 30 K. In the EDLT, we observe bipolar and asymmetric modulation

  15. Ab-initio molecular dynamics studies of magnesium-doped sodium clusters

    International Nuclear Information System (INIS)

    Roethlisberger, U.; Andreoni, W.

    1993-01-01

    Structural, electronic, and vibrational properties of magnesium-doped sodium clusters have been determined using the Car-Parrinello method. It is found that in the energetically preferred structures the magnesium impurity never is located at the centre of the cluster. The validity of spherical jellium models and the effects of temperature are discussed. 9 refs, 3 figs, 1 tab

  16. Dosimetric properties of germanium doped calcium borate glass subjected to 6 MV and 10 MV X-ray irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Tengku Kamarul Bahri, T.N.H., E-mail: tnhidayah2@gmail.com [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia); Wagiran, H.; Hussin, R.; Saeed, M.A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia); Hossain, I. [Department of Physics, College of Science and Arts, King Abdul Aziz University, 21911 Rabigh (Saudi Arabia); Ali, H. [Department of Radiotherapy and Oncology, Hospital Sultan Ismail, 81100 Johor Bahru (Malaysia)

    2014-10-01

    Highlights: •The TL properties of 29.9CaO–70B{sub 2}O{sub 3}: 0.1GeO{sub 2} glass has been investigated. •We exposed glass samples to 6 MV and 10 MV in a dose range of 0.5–4.0 Gy. •This glass has a potential material to be used for application in radiotherapy. -- Abstract: Germanium doped calcium borate glasses are investigated in term of thermoluminescence properties to seek their possibility to use as glass radiation dosimeter. The samples were exposed to 6 MV, and 10 MV photon beams in a dose range of 0.5–4.0 Gy. There is a single and broad thermoluminescence glow curve that exhibits its maximum intensity at about 300 °C. Linear dose response behavior has been found in this dose range for the both photon energies. Effective atomic number, TL sensitivity, and reproducibility have also been studied. It is found that the sensitivity of germanium doped sample at 6 MV is only 1.28% and it is superior to the sensitivity at 10 MV. The reproducibility of germanium doped sample is good with a percentage of relative error less than 10%. The results indicate that this glass has a potential to be used as a radiation dosimetry, especially for application in radiotherapy.

  17. Dosimetric properties of germanium doped calcium borate glass subjected to 6 MV and 10 MV X-ray irradiations

    International Nuclear Information System (INIS)

    Tengku Kamarul Bahri, T.N.H.; Wagiran, H.; Hussin, R.; Saeed, M.A.; Hossain, I.; Ali, H.

    2014-01-01

    Highlights: •The TL properties of 29.9CaO–70B 2 O 3 : 0.1GeO 2 glass has been investigated. •We exposed glass samples to 6 MV and 10 MV in a dose range of 0.5–4.0 Gy. •This glass has a potential material to be used for application in radiotherapy. -- Abstract: Germanium doped calcium borate glasses are investigated in term of thermoluminescence properties to seek their possibility to use as glass radiation dosimeter. The samples were exposed to 6 MV, and 10 MV photon beams in a dose range of 0.5–4.0 Gy. There is a single and broad thermoluminescence glow curve that exhibits its maximum intensity at about 300 °C. Linear dose response behavior has been found in this dose range for the both photon energies. Effective atomic number, TL sensitivity, and reproducibility have also been studied. It is found that the sensitivity of germanium doped sample at 6 MV is only 1.28% and it is superior to the sensitivity at 10 MV. The reproducibility of germanium doped sample is good with a percentage of relative error less than 10%. The results indicate that this glass has a potential to be used as a radiation dosimetry, especially for application in radiotherapy

  18. White light emission and color tunability of dysprosium doped barium silicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Lokesh; Sharma, Anchal; Vishwakarma, Amit K.; Jha, Kaushal [Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Jayasimhadri, M., E-mail: jayaphysics@yahoo.com [Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Ratnam, B.V.; Jang, Kiwan [Department of Physics, Changwon National University, Changwon 641-77 (Korea, Republic of); Rao, A.S.; Sinha, R.K. [Department of Applied Physics, Delhi Technological University, Delhi 110042 (India)

    2016-01-15

    The present work elucidates the synthesis of Dy{sup 3+} doped barium silicate glasses, along with the subsequent studies performed to evaluate its viability in solid state lighting applications. The synthesized photonic glasses were investigated via X-Ray Diffraction, Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy. The photoluminescence properties were examined under ultraviolet (UV)/near UV (NUV) excitation. Photoluminescence spectrum exhibited characteristic emission bands at λ{sub em}=483 nm (blue) and λ{sub em}=576 nm (yellow) which are ascribed to the {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} transitions of Dy{sup 3+} ion, respectively. The chromaticity coordinates under excitation of λ{sub ex}=348 nm are (0.31, 0.34), which lies in the white region of CIE 1931 chromaticity diagram and are in excellent proximity with the standard equal energy white illuminant (0.333, 0.333). The calculated correlated color temperature and the yellow to blue (Y/B) ratio are found to be 6602 K and 1.12, respectively for the optimized sample. The synthesized photonic glass also offered the possibility of tuning the color as exemplified through the variation in CIE coordinates, correlated color temperature and the Y/B ratio. The results confirm the possibility of color tunability from the proposed glass and may be useful for various photonic device applications. - Highlights: • Successfully synthesized Dy{sup 3+} doped barium silicate glasses. • Structural properties thoroughly discussed by using XRD and FT-IR. • Photoluminescence and colorimetry properties have been investigated. • Y/B ratio and the reason for color tunability have been successfully explained. • CIE coordinates of Dy{sup 3+}:BBS glass confirm its suitability for w-LEDs.

  19. Structural and spectroscopic studies on Er3+ doped boro-tellurite glasses

    Science.gov (United States)

    Selvaraju, K.; Marimuthu, K.

    2012-04-01

    Er3+ doped boro-tellurite glasses with the chemical composition (69-x)B2O3-xTeO2-15MgO-15K2O-1Er2O3 (where x=0, 10, 20, 30 and 40 wt%) have been prepared and their structural and spectroscopic behavior were studied and reported. The varying tellurium dioxide content in the host matrix that results, changes in structural and spectroscopic behavior around Er3+ ions are explored through XRD, FTIR, UV-VIS-NIR and luminescence measurements. The XRD pattern confirms the amorphous nature of the prepared glasses and the FTIR spectra explore the fundamental groups and the local structural units in the prepared boro-tellurite glasses. The bonding parameters (βbar and δ) have been calculated from the observed band positions of the absorption spectra to claim the ionic/covalent nature of the prepared glasses. The Judd-Ofelt (JO) intensity parameters Ωλ (λ=2, 4 and 6) were determined through experimental and calculated oscillator strengths obtained from the absorption spectra and their results are studied and compared with reported literature. The variation in the JO parameters Ωλ (λ=2, 4 and 6) with the change in chemical composition have been discussed in detail. The JO parameters have also been used to derive the important radiative properties like transition probability (A), branching ratio (βR) and peak stimulated emission cross-section (σPE) for the excited state transitions 2H9/2→4I15/2 and 2H11/2 and 4S3/2→4I15/2 of the Er3+ ions and the results were studied and reported. Using Davis and Mott theory, optical band gap energy (Eopt) values for the direct and indirect allowed transitions have been calculated and discussed along with the Urbach energy values for the prepared Er3+ doped boro-tellurite glasses in the present study. The optical properties of the prepared glasses with the change in tellurium dioxide have been studied and compared with similar results.

  20. Higher Fe{sup 2+}/total Fe ratio in iron doped phosphate glass melted by microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Ashis K., E-mail: ashis@cgcri.res.in [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Sinha, Prasanta K. [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Das, Dipankar [UGC-DAE Consortium for Scientific Research, Kolkata 700098 (India); Guha, Chandan [Department of Chemical Engineering, Jadavpur University, Kolkata 700032 (India); Sen, Ranjan [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India)

    2015-03-15

    Highlights: • Iron doped phosphate glasses prepared using microwave heating and conventional heating under air and reducing atmosphere. • Presence of iron predominantly in the ferrous oxidation state in all the glasses. • Significant concentrations of iron in the ferrous oxidation state on both octahedral and tetrahedral sites in all the glasses. • Ratio of Fe{sup 2+} with total iron is found higher in microwave prepared glasses in comparison to conventional prepared glasses. - Abstract: Iron doped phosphate glasses containing P{sub 2}O{sub 5}–MgO–ZnO–B{sub 2}O{sub 3}–Al{sub 2}O{sub 3} were melted using conventional resistance heating and microwave heating in air and under reducing atmosphere. All the glasses were characterised by UV–Vis–NIR spectroscopy, Mössbauer spectroscopy, thermogravimetric analysis and wet colorimetry analysis. Mössbauer spectroscopy revealed presence of iron predominantly in the ferrous oxidation state on two different sites in all the glasses. The intensity of the ferrous absorption peaks in UV–Vis–NIR spectrum was found to be more in glasses prepared using microwave radiation compared to the glasses prepared in a resistance heating furnace. Thermogravimetric analysis showed increasing weight gain on heating under oxygen atmosphere for glass corroborating higher ratio of FeO/(FeO + Fe{sub 2}O{sub 3}) in glass melted by direct microwave heating. Wet chemical analysis also substantiated the finding of higher ratio Fe{sup +2}/ΣFe in microwave melted glasses. It was found that iron redox ratio was highest in the glasses prepared in a microwave furnace under reducing atmosphere.

  1. UV light induced red emission in Eu3+-doped zincborophosphate glasses

    Science.gov (United States)

    Hima Bindu, S.; Siva Raju, D.; Vinay Krishna, V.; Rajavardhana Rao, T.; Veerabrahmam, K.; Linga Raju, Ch.

    2016-12-01

    This paper reports the preparation of transparent zincborophosphate (ZBP) glasses doped with Eu3+ ions by the conventional melt quenching technique. The prepared glasses were characterized using powder XRD, FTIR, optical absorption, photoluminescence and decay curves. Judd-Ofelt (JO) intensity parameters calculated under various constraints using absorption and emission spectra. These JO intensity parameters have been used to predict the radiative properties such as radiative life time, branching ratios and stimulated emission cross section of the 5D0→7FJ (J = 0-4) transitions. Decay curves for the 5D0 level of Eu3+ ions shows single exponential for all concentrations. Luminescence properties of 5D0→7F2 transitions of Eu3+ions have revealed that the present ZBP:Eu3+ glasses have significant in optical applications at around 613 nm. An intense red luminescence has been observed due to 5D0→7F2 transition of Eu3+ ion in these glasses. From the CIE color coordinate diagram, it is observed that the present glass system is prominent material for red emission.

  2. Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, S. Sreehari, E-mail: sreeharisastry@yahoo.com [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Rao, B. Rupa Venkateswara [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Department of Physics, V.R. Siddhartha Engineering College, Vijayawada 52007 (India)

    2014-02-01

    In this paper spectroscopic investigation of Cu{sup 2+} doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu{sup 2+} state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu{sup 2+} is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds.

  3. Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

    International Nuclear Information System (INIS)

    Sastry, S. Sreehari; Rao, B. Rupa Venkateswara

    2014-01-01

    In this paper spectroscopic investigation of Cu 2+ doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu 2+ state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu 2+ is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds

  4. Eu2+-doped OH− free calcium aluminosilicate glass: A phosphor for smart lighting

    International Nuclear Information System (INIS)

    Lima, S.M.; Andrade, L.H.C.; Rocha, A.C.P.; Silva, J.R.; Farias, A.M.; Medina, A.N.; Baesso, M.L.; Nunes, L.A.O.; Guyot, Y.; Boulon, G.

    2013-01-01

    In this paper, a broad emission band from Eu 2+ -doped OH − free calcium aluminosilicate glass is reported. By changing the excitation wavelengths, the results showed it is possible to tune the emission from green to orange, what combined with the scattered light from the same blue LED used for excitation, provided a color rendering index of 71 and a correlated color temperature of 6550 K. Our preliminary tests indicate this material as a promising phosphor towards the development of smart lighting devices. -- Highlights: • We report a broad emission band from Eu 2+ -doped OH − free calcium aluminosilicate glass. • The maximum emission peak can be tune from green to orange region. • The test with a LED provided a color rendering index of 71 and a correlated color temperature of 6550 K

  5. Experimental and theoretical approach on the optical properties of zinc borotellurite glass doped with dysprosium oxide

    Science.gov (United States)

    Halimah, M. K.; Ami Hazlin, M. N.; Muhammad, F. D.

    2018-04-01

    and blue emission. The white light emission of the glass systems is confirmed by using the Commission International de I'Eclairage 1931 (CIE 1931) chromaticity diagram. The colour coordinate of the zinc borotellurite glass systems doped Dy2O3 is tabulated in Table 3 while Fig. 10 represents the colour chromaticity diagram of Dy2O3 doped zinc borotellurite glass systems. Based on the result obtained, the CIE coordinate for the zinc borotellurite glass doped with dysprosium oxide lies closed to the standard white light point which located at x = 0.333 and y = 0.333 [63,64]. This suggests that the zinc borotellurite glass doped with Dy2O3 may be useful for the solid state lighting application.

  6. Fabrication of planar optical waveguides by 6.0 MeV silicon ion implantation in Nd-doped phosphate glasses

    Science.gov (United States)

    Shen, Xiao-Liang; Dai, Han-Qing; Zhang, Liao-Lin; Wang, Yue; Zhu, Qi-Feng; Guo, Hai-Tao; Li, Wei-Nan; Liu, Chun-Xiao

    2018-04-01

    We report the fabrication of a planar optical waveguide by silicon ion implantation into Nd-doped phosphate glass at an energy of 6.0 MeV and a dose of 5.0 × 1014 ions/cm2. The change in the surface morphology of the glass after the implantation can be clearly observed by scanning electron microscopy. The measurement of the dark mode spectrum of the waveguide is conducted using a prism coupler at 632.8 nm. The refractive index distribution of the waveguide is reconstructed by the reflectivity calculation method. The near-field optical intensity profile of the waveguide is measured using an end-face coupling system. The waveguide with good optical properties on the glass matrix may be valuable for the application of the Nd-doped phosphate glass in integrated optical devices.

  7. Effect of certain alkaline metals on Pr doped glasses to investigate spectroscopic studies

    Science.gov (United States)

    Lenkennavar Susheela, K.; Madhu, A.; Eraiah, B.; Kokila, M. K.

    2018-02-01

    Incorporation of different Alkaline earth metal like Barium, Calcium and strontium in sodium lead borate glass doped with Pr3+ is studied. Physical parameters such as density, molar volume, molar refractivity etc have been evaluated. Effect of different atomic size of alkaline metal using optical and physical parameters is analysed. XRD and FTIR were carried out to know the structural behaviour of the glasses. Absorption and Emission spectra are recorded at room temperature and the results were discussed.

  8. Luminescent properties of Eu2+-doped BaGdF5 glass ceramics a potential blue phosphor for ultra-violet light-emitting diode

    International Nuclear Information System (INIS)

    Zhang, Weihuan; Zhang, Yuepin; Ouyang, Shaoye; Zhang, Zhixiong; Wang, Qian; Xia, Haiping

    2015-01-01

    Eu 2+ doped transparent oxyfluoride glass ceramics containing BaGdF 5 nanocrystals were successfully fabricated by melt-quenching technique under a reductive atmosphere. The structure of the glass and glass ceramics were investigated by differential scanning calorimetry, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The luminescent properties were investigated by transmission, excitation, and emission spectra. The decay time of the Gd 3+ ions at 312 nm excited with 275 nm were also investigated. The results of XRD and TEM indicated the existence of BaGdF5 nanocrystals in the transparent glass ceramics. The excitation spectra of Eu 2+ doped glass ceramics showed an excellent overlap with the main emission region of an ultraviolet light-emitting diode (UV-LED). Compared with the as-made glass, the emission of glass ceramics is much stronger by a factor of increasing energy transfer efficiency from Gd 3+ to Eu 2+ ions, the energy transfer efficiency from Gd 3+ to Eu 2+ ions was discussed. In addition, the chromaticity coordinates of glass and glass ceramics specimens were also discussed, which indicated that the Eu 2+ doped BaGdF 5 glass ceramics may be used as a potential blue-emitting phosphor for UV-LED

  9. Luminescence quenching versus enhancement in WO3-NaPO3 glasses doped with trivalent rare earth ions and containing silver nanoparticles

    Science.gov (United States)

    Dousti, M. Reza; Poirier, Gael Y.; Amjad, Raja J.; de Camargo, Andrea S. S.

    2016-10-01

    We report on the influence of silver nanoparticles (NPs) on the luminescence behavior of trivalent rare earth (RE) ion doped tungsten-phosphate glasses. In order to induce the growth of NPs, the as-prepared glass samples containing silver atoms, are exposed to heat-treatment above the glass transition temperature. The surface plasmon resonance band of the Ag NPs is observed in the visible range around 420 and 537 nm in the glasses with low and high tungsten content, respectively. Such difference in spectral shift of the plasmon band is attributed to the difference in the refractive index of the two studied glass compositions. Heat-treatment results in the general increase in number of NPs, while in the case of glasses with low tungsten content, it also imposes a shift to the Ag plasmon band. The NPs size distribution (4-10 nm) was determined in good agreement with the values obtained by using Mie theory and by transmission electron microscopy. The observed quenching in the visible luminescence of glasses doped with Eu3+, Tb3+ or Er3+is attributed to energy transfer from the RE ions to Ag species, while an enhanced near-infrared emission in Er3+ doped glasses is discussed in terms of the chemical contribution of silver, rather than the most commonly claimed enhancement of localized field or energy transfer from silver species to Er3+. The results are supported by the lifetime measurements. We believe that this study gives further insight and in-depth exploration of the somewhat controversial discussions on the influence of metallic NPs plasmonic effects in RE-doped glasses.

  10. Structural and luminescence properties of Mn2+ ions doped calcium zinc borophosphate glasses

    International Nuclear Information System (INIS)

    Wan, Ming Hua; Wong, Poh Sum; Hussin, Rosli; Lintang, Hendrik O.; Endud, Salasiah

    2014-01-01

    Highlights: • FT-IR revealed that the network structures are from borate and phosphate network. • The PL spectrum exhibits a green emission band at 582 nm ( 4 T 1g → 6 A 1g ). • As the concentration of Mn 2+ ions is increased, the emission band had been red shifted. • These glasses are found to have potential applications as luminescent optical materials. - Abstract: Calcium zinc borophosphate glasses (CaZnBP) doped with various concentrations of Mn 2+ ions and borate and phosphate as variable were prepared using conventional melt quenching technique. The structure of obtained glasses were examined by means of use: X-ray diffraction (XRD) and fourier transform infrared (FT-IR). XRD analysis confirmed amorphous nature of glass samples. The FT-IR spectra reveals the presence of both borate and phosphate vibrational modes in the prepared glasses. The doping of Mn 2+ ions (2–10 mol%) shows no significant changes in the main IR vibrational bands. Optical properties were studied by measuring the near infrared photoluminescence (PL) spectra. CaZnBP glasses exhibited intense green emission peak (582 nm) (tetrahedral symmetry), which is assigned to a transition from the upper 4 T 1g → 6 A 1g ground state of Mn 2+ ions. As the concentration of Mn 2+ ions increases, the emission band increases from 582 nm to 650 nm and exhibited a red light emission (octahedral symmetry). The decay curves of 4 T 1g level were examined for all concentrations and the measured lifetimes are found to depend strongly on Mn 2+ concentrations. From the emission characteristic parameters of 6 A 1g (S) level, it shows that the CaZnBP glasses could have potential applications as luminescent optical materials, visible lasers and fluorescent display devices

  11. Development of large scale production of Nd-doped phosphate glasses for megajoule-scale laser systems

    International Nuclear Information System (INIS)

    Ficini, G.; Campbell, J.H.

    1996-01-01

    Nd-doped phosphate glasses are the preferred gain medium for high-peak-power lasers used for Inertial Confinement Fusion research because they have excellent energy storage and extraction characteristics. In addition, these glasses can be manufactured defect-free in large sizes and at relatively low cost. To meet the requirements of the future mega-joule size lasers, advanced laser glass manufacturing methods are being developed that would enable laser glass to be continuously produced at the rate of several thousand large (790 x 440 x 44 mm 3 ) plates of glass per year. This represents more than a 10 to 100-fold improvement in the scale of the present manufacturing technology

  12. Optical and Physical Investigations of Lanthanum Bismuth Borate glasses doped with Ho2O3

    Science.gov (United States)

    Ramesh, P.; Jagannath, G.; Eraiah, B.; Kokila, M. K.

    2018-02-01

    Holmium doped 10La2O3-15Bi2O3-(75-x) B2O3 (Ho3+: LBB) glasses have been prepared by melt quench technique and the impact of holmium ions concentration on optical and physical properties of present glasses have been examined. Ho3+ dependent density, molar volume, refractive index, rare earth ion concentration, polaron radius, inter ionic distance, field strength and energy band gap are calculated and tabulated. Amorphous nature of the all glasses has been confirmed by XRD patterns. The room temperature (RT) Uv-Vis absorption spectrum doped with 1 mol% of Ho2O3 exhibit eight prominent bands centred at 895, 641, 537, 486, 472, 467, 451 and 416 due to transition between ground state to various excited states. The results show that, the density is increases and molar volume of the glasses is decreases with an increase in Ho2O3 concentration and consequently generate more non-bridging oxygen (NBOs) in the glass matrix. The Urbach energy is increases with holmium concentration which exemplifies the degree of disorder present in the LBB glasses. The considerable increase in field strength observed in present glasses is attributed to occurrence of strong bridge between Ho3+ and B- ions and this strong bridge is possibly due to the displacement between Ho3+ and oxygen atoms which are generated from the conversion BO3-BO4 units.

  13. Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

    Science.gov (United States)

    Vasileva, A. A.; Nazarov, I. A.; Olshin, P. K.; Povolotskiy, A. V.; Sokolov, I. A.; Manshina, A. A.

    2015-10-01

    Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium-phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass.

  14. Improvement on p-type CVD diamond semiconducting properties by fabricating thin heavily-boron-doped multi-layer clusters isolated each other in unintentionally boron-doped diamond layer

    Science.gov (United States)

    Maida, Osamu; Tabuchi, Tomohiro; Ito, Toshimichi

    2017-12-01

    We have developed a new fabrication process to decrease the effective activation energy of B atoms doped in diamond without a significant decrease in the carrier mobility by fabricating heavily B-doped clusters with very low mobility which are embedded in lightly-B-doped diamond layers. The resistivities of the heavily B-doped and unintentionally B-doped diamond stacked layers had almost no temperature dependence, suggesting the presence of an impurity-band conduction in these diamond layers. On the other hand, the resistivities of the samples after the embedding growth process of the stacked layers that had been appropriately divided to innumerable small clusters by means of a suitable etching process increased with decreasing the temperature from 330 to 130 K. The effective activation energies and Hall mobilities at room temperature of both samples were estimated to be 0.21 eV, 106 cm2 V-1 s-1 for micron-sized clusters and 0.23 eV, 470 cm2 V-1 s-1 for nano-sized clusters, respectively, indicating that the diamond film structure fabricated in this work is effective for the improvement of the p-type performance for the B-doped CVD diamond.

  15. Dosimetric properties of germanium doped calcium borate glass subjected to 6 MV and 10 MV X-ray irradiations

    Science.gov (United States)

    Tengku Kamarul Bahri, T. N. H.; Wagiran, H.; Hussin, R.; Saeed, M. A.; Hossain, I.; Ali, H.

    2014-10-01

    Germanium doped calcium borate glasses are investigated in term of thermoluminescence properties to seek their possibility to use as glass radiation dosimeter. The samples were exposed to 6 MV, and 10 MV photon beams in a dose range of 0.5-4.0 Gy. There is a single and broad thermoluminescence glow curve that exhibits its maximum intensity at about 300 °C. Linear dose response behavior has been found in this dose range for the both photon energies. Effective atomic number, TL sensitivity, and reproducibility have also been studied. It is found that the sensitivity of germanium doped sample at 6 MV is only 1.28% and it is superior to the sensitivity at 10 MV. The reproducibility of germanium doped sample is good with a percentage of relative error less than 10%. The results indicate that this glass has a potential to be used as a radiation dosimetry, especially for application in radiotherapy.

  16. First-principle study of silicon cluster doped with rhodium: Rh{sub 2}Si{sub n} (n = 1–11) clusters

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuai; Luo, Chang Geng; Li, Hua Yang [Department of Physics, Nanyang Normal University, Nanyang 473061 (China); Lu, Cheng, E-mail: lucheng@calypso.cn [Department of Physics, Nanyang Normal University, Nanyang 473061 (China); State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Li, Gen Quan; Lu, Zhi Wen [Department of Physics, Nanyang Normal University, Nanyang 473061 (China)

    2015-06-15

    The geometries, stabilities and electronic properties of rhodium-doped silicon clusters Rh{sub 2}Si{sub n} (n = 1–11) have been systematically studied by using density functional calculations at the B3LYP/GENECP level. The optimized results show that the lowest-energy isomers of Rh{sub 2}Si{sub n} clusters favor three-dimensional structures for n = 2–11. Based on the averaged binding energy, fragmentation energy, second-order energy difference and HOMO-LUMO energy gap, the stabilities of Rh{sub 2}Si{sub n} (n = 1–11) clusters have been analyzed. The calculated results suggest that the Rh{sub 2}Si{sub 6} cluster has the strongest relative stability and the doping with rhodium atoms can reduce the chemical stabilities of Si{sub n} clusters. The natural population and natural electron configuration analysis indicate that there is charge transfer from the Si atoms and 5s orbital of the Rh atoms to the 4d and 5p orbitals of Rh atoms. The analysis of electron localization function reveal that the Si–Si bonds are mainly covalent bonds and the Si–Rh bonds are almost ionic bonds. Moreover, the vertical ionization potential, vertical electron affinity, chemical hardness, chemical potential, vibrational spectrum and polarizability are also discussed. - Highlights: • The geometric structures of Rh{sub 2}Si{sub n} (n = 1–11) clusters are determined. • The stabilities and electronic properties of Rh{sub 2}Si{sub n} clusters are discussed. • The Rh{sub 2}Si{sub 6} cluster has the higher stability than other clusters. • The doped rhodium atoms can reduce the chemical stabilities of Si{sub n} clusters.

  17. Er{sup 3+}-doped fluorotellurite thin film glasses with improved photoluminescence emission at 1.53 µm

    Energy Technology Data Exchange (ETDEWEB)

    Morea, R. [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, 28006 Madrid (Spain); Miguel, A. [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Fernandez, T.T. [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, 28006 Madrid (Spain); Maté, B. [Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain); Ferrer, F.J. [Centro Nacional de Aceleradores, Univ. Sevilla-CSIC, Av. Thomas A. Edison 7, 41092 Sevilla (Spain); Maffiotte, C. [CIEMAT, Departamento de Tecnología, Av. Complutense 40, 28040 Madrid (Spain); Fernandez, J.; Balda, R. [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 San Sebastian (Spain); Gonzalo, J., E-mail: j.gonzalo@csic.es [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, 28006 Madrid (Spain)

    2016-02-15

    Transparent oxyfluoride tellurite thin film glasses have been produced at room temperature by pulsed laser deposition in O{sub 2} atmosphere from an Er-doped TeO{sub 2}–ZnO–ZnF{sub 2} bulk glass. Thin film glasses present high refractive index (n≥1.95) and good transparency (T≥80%) in the visible (λ>400 nm) and near infrared range. However, their photoluminescence (PL) performance at 1.5 μm is poor. Thermal annealing at moderate temperatures (T≤315 °C), well below glass crystallization, increases the PL intensity by more than one order of magnitude as well as the PL lifetime up to τ≈3.3 ms. Film glasses present a larger fraction of TeO{sub 3} trigonal pyramids than the bulk glass and a very large OH{sup −} content. The structure and composition of film glasses do not change upon annealing and thus the activation of the PL response is related to the improvement of the surface morphology and the significant decrease of their OH{sup −} content. - Highlights: • Transparent Er-doped fluorotellurite films are produced by pulsed laser deposition. • Post-deposition thermal treatments are required to activate Er{sup 3+} photoluminescence. • {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} emission spectrum is similar for bulk and annealed film glasses. • {sup 4}I{sub 13/2} level fluorescence decay is shorter in annealed films than in bulk glasses. • Photoluminescence response relates to hydroxyl groups concentration in film glasses.

  18. Tunable light emission and similarities with garnet structure of Ce-doped LSCAS glass for white-light devices

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, L.H.C., E-mail: luishca@uems.br [Grupo de Espectroscopia Optica e Fototermica, Universidade Estadual de Mato Grosso do Sul - UEMS, C.P. 351, Dourados, MS (Brazil); Lima, S.M. [Grupo de Espectroscopia Optica e Fototermica, Universidade Estadual de Mato Grosso do Sul - UEMS, C.P. 351, Dourados, MS (Brazil); Baesso, M.L.; Novatski, A.; Rohling, J.H. [Grupo de Estudos de Fenomenos Fototermicos, Departamento de Fisica, Universidade Estadual de Maringa, Av. Colombo 5790, 87020-900 Maringa, PR (Brazil); Guyot, Y.; Boulon, G. [Laboratoire de Physico-Chimie des Materiaux Luminescents, Universite Claude Bernard Lyon 1, UMR 5620 CNRS, 69622 Villeurbanne (France)

    2012-01-05

    Highlights: > Ce{sup 3+}-doped LSCAS glass exhibits broad, simultaneously blue and yellow emissions under UV excitation. > In this phosphor is possible to continuously tune the emission, covering the entire visible spectrum. > The ability to change the color temperature in accordance to the occasion is a feature of this glass system. - Abstract: In this paper, we report results concerning tunable light emission and color temperature in cerium-doped low-silica-calcium-alumino-silicate (LSCAS) glass for smart white-light devices. Spectroscopic results, analyzed using the CIE 1931 x-y chromatic diagram, show that this glass presents two broad emission bands centered at 475 and 540 nm, whose intensities can be tuned by the excitation wavelength. Moreover, the same emission can be achieved from a color temperature range from 3200 to 10,000 K, with a color-rendering index (CRI) of around 75% obtained by changing the optical path length of the sample. Our new phosphor LSCAS glass, which is a unique system that exhibits tunable yellow emission, combines all qualities for white-light devices.

  19. High-power microcavity lasers based on highly erbium-doped sol-gel aluminosilicate glasses

    International Nuclear Information System (INIS)

    Le Ngoc Chung; Chu Thi Thu Ha; Nguyen Thu Trang; Pham Thu Nga; Pham Van Hoi; Bui Van Thien

    2006-01-01

    High-power whispering-gallery-mode (WGM) lasing from highly erbium-doped sol-gel aluminosilicate microsphere cavity coupled to a half-tapered optical fiber is presented. The lasing output power as high as 0.45 mW (-3.5 dBm) was obtained from sol-gel glass microsphere cavity with diameters in the range of 40-150 μm. The sol-gel method for making highly concentration Er-doped aluminosilicate glasses with Er-ion concentrations from 0.125 to 0.65 mol% of Er 3+ is described. Controlling collected lasing wavelength at each WGM is possible by adjusting the distance between the half-taper fiber and the microcavity and by diameter of the waist of half-taper fiber. Using the analytic formulas we calculated the TE and TM lasing modes and it is shown that the experimental results are in good agreement with the calculation prediction

  20. Physical, thermal, infrared and optical properties of Nd3+ doped lithium–lead-germanate glasses

    International Nuclear Information System (INIS)

    Veeranna Gowda, V.C.

    2015-01-01

    The structure–property relationships of neodymium doped lithium–lead-germanate glasses were investigated. The density was found to increase with the increase of Nd 2 O 3 concentration and its variation is explained in terms of its molecular mass, structural transformation and packing density. Addition of modifier oxide to lead-germanate glass suggests a decreased free space within the glass matrix, resulting in the formation of stiff network. The increase in glass transition temperature specifies strengthening of glass by forming bridging oxygens. The optical properties of glass were measured employing UV–visible spectroscopy. The refractive index values varied nonlinearly with Nd 2 O 3 concentration and were speculated to depend on the electronic polarizability of oxide glasses. The frequencies of the infrared absorption bands were affected marginally and the absorption peaks revealed that the glass matrix consists of [GeO 4/2 ], [GeO 6/2 ] and [PbO 4/2 ] structural units

  1. Spectroscopic characterization of Ho3+ ion-doped fluoride glass

    International Nuclear Information System (INIS)

    Florez, A.; Oliveira, S.L.; Florez, M.; Gomez, L.A.; Nunes, L.A.O.

    2006-01-01

    Among the new optical materials available, fluoride glass, which has an extended transmission window, is emerging as an important material for use in optical fibers, lasers, sensors, etc. Here, we analyze the spectroscopic properties of Ho 3+ ions in a fluoroindate glass based on absorption measurements. Ho 3+ -doped fluoroindate glass with the composition (40 - x)InF 3 -20SrF 2 -20ZnF 2 -16BaF 2 -2GdF 3 -2NaF-xHoF 3 , x = 1.0, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0 and 9.0 mol%, was prepared under an argon atmosphere. Absorption spectra in the range 300-2200 nm were then obtained. The experimental oscillator strength f Exp. was calculated from the areas under absorption bands. Using Judd-Ofelt theory and least-squares fitting, the phenomenological intensity parameter Ω λ (λ = 2, 4, 6) and the theoretical oscillator strength f Cal. were calculated. To evaluate potential applications and to analyze the properties of Ho 3+ ions in these host glasses, the following spectroscopy parameters were calculated: the transition probability between multiplets A JJ' , the branching ratio β JJ' , the radiative lifetime τ R , the peak cross-section for stimulated emission σ p , and the emitting-level multiphonon rate W NR for each band. The results were compared with those reported in the literature for similar glasses of the same concentration

  2. Preparation and investigation of Pr{sup 3+}-doped Ge–Sb–Se–In–I glasses as promising material for active mid-infrared optics

    Energy Technology Data Exchange (ETDEWEB)

    Shiryaev, V.S., E-mail: shiryaev@ihps.nnov.ru [G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, 49 Tropinin Str., Nizhny Novgorod 603950 (Russian Federation); Karaksina, E.V.; Kotereva, T.V.; Churbanov, M.F.; Velmuzhov, A.P.; Sukhanov, M.V.; Ketkova, L.A.; Zernova, N.S. [G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, 49 Tropinin Str., Nizhny Novgorod 603950 (Russian Federation); Plotnichenko, V.G.; Koltashev, V.V. [Fiber Optics Research Center of the Russian Academy of Sciences, 38 Vavilov Str., 119333 Moscow (Russian Federation)

    2017-03-15

    For the first time, high purity Ge–Sb–Se–In–I glasses doped with Pr{sup 3+} ions are prepared. The host Ge–Sb–Se–In-I glass samples are fabricated using a combination of chemical and distillation methods of purification as well as a chemical transport reaction route. The glass structure, the content of gas-forming impurities and particles, as well as the optical, thermal and luminescent properties were investigated. The host and Pr{sup 3+}-doped Ge–Sb–Se–In–I glasses are characterized by low optical losses in the mid-IR, low impurity content and high stability against crystallization. The content of hydrogen and oxygen impurities in the purest host glass samples, obtained using the multistep purification procedure, does not exceed 0.1 and 0.5 ppm(wt), respectively. The prepared Pr{sup 3+}-doped Ge–Sb–Se–In–I glasses exhibit intense broadband luminescence in the 3.5–6 μm spectral range, with a lifetime of 6 ms at the wavelength of 4.7 μm.

  3. Effect of silver nanoparticles on the dielectric properties of holmium doped silica glass

    International Nuclear Information System (INIS)

    Rejikumar, P.R.; Jyothy, P.V.; Mathew, Siby; Thomas, Vinoy; Unnikrishnan, N.V.

    2010-01-01

    The effect of silver nanoparticle co-doping on the dielectric properties of holmium doped silica glasses was studied. Silver nanoparticles of size between 20 and 22 nm were produced by the sol-gel technique. One of the samples showed an icosahedral morphology of the nanocrystal formed, along with spherical morphology. It was found that the tuning of the dielectric constant values could be accomplished by co-doping. The sample, with 1 wt% of Ho, had low dielectric constant values within the range 100 Hz-3 MHz due to the formation of quasi-molecular structures of holmium. This effect was evaded to some extent with silver co-doping as a result of the interdispersion of holmium complexes. Also it was found that the co-doping produced a higher dielectric loss which was calculated from the tan δ-log f graph. The Cole-Cole parameters and the Jonscher power law parameters were also calculated and are presented.

  4. Structural, thermal, and optical properties of Er3+/Yb3+ co-doped oxyhalide tellurite glasses, glass-ceramics and ceramics

    International Nuclear Information System (INIS)

    Joshi, C.; Rai, R.N.; Rai, S.B.

    2012-01-01

    Glass-ceramics and ceramics containing nano-crystals of different phases doped with Er 3+ /Yb 3+ ions have been successfully prepared by heat treatment of the precursor oxyhalide glasses synthesized by the melt-quench method. X-ray diffraction patterns and transmission electron microscopy (TEM) images verify the precipitation of nano-crystals. Emission of Er 3+ enhances several times when Yb 3+ ion is added with the matrix. The Stark splitting and the intensity of different emission bands increase to a great extent when we approach to ceramics from glasses via glass-ceramics. The intensity of the blue and green emission bands increases much faster than the red and NIR emission bands. Intense upconversion emission observed by the naked eye has been quantified in terms of standard chromaticity diagram (CIE). Power dependence study shows that the upconversion of NIR radiation to visible radiation takes place mainly via photon avalanche (PA) process.

  5. Spectroscopic properties of Er3+-doped fluorotellurite glasses containing various modifiers

    Science.gov (United States)

    Burtan-Gwizdała, Bożena; Reben, Manuela; Cisowski, Jan; Grelowska, Iwona; Yousef, El Sayed; Algarni, Hamed; Lisiecki, Radosław; Nosidlak, Natalia

    2017-11-01

    We have investigated the optical and spectroscopic properties of new Er3+-doped fluorotellurite glasses with the basic molar composition 75%TeO2-10%P2O5-10%ZnO-5%PbF2, modified by replacing 5%TeO2 by four various metal oxides, namely MgO, PbO, SrO and CdO. The ellipsometric data have provided a Sellmeier-type dispersion relation of the refractive index of the investigated glasses. The optical absorption edge has been described within the Urbach approach, while the absorption and fluorescence spectra have been analyzed in terms of the standard Judd-Ofelt theory along with the photoluminescence decay of the 4I13/2 and 4S3/2 levels of the Er3+ ion. The absorption and emission spectra of the 4I15/2 ↔ 4I13/2 infrared transition have been analyzed within the McCumber theory to yield the peak emission cross-section and figure of merit (FOM) for the amplifier gain. It appears that the glass containing MgO as a modifier is characterized by the largest FOM suggesting that the fluorotellurite matrix with this oxide can be a good novel host for Er3+ ion doping. Finally, we propose a new simple method to calculate the mean transition energy of the McCumber approach as the arithmetic average of the barycenter wavenumbers of absorption and emission spectra.

  6. Fluorescence of Er3+ doped La2S3.3Ga2S3 glasses

    International Nuclear Information System (INIS)

    Reisfeld, R.; Bornstein, A.

    1978-01-01

    In this paper the authors report the preparation and fluorescence of Er 3+ in chalcogenide glasses. In the oxide glasses it has been shown that the multiphonon transition rates of the RE are independent of the coupling between a given oxide glass and rare earth ion, but dependent exponentially on the number of phonons of highest energy bridging the emitting and next-lower level. It is of interest to establish whether changing the glass matrix will affect the amount of electron phonon coupling. In addition, because of their low phonon energy and high refractive index, the RE doped chalcogenide glasses will form a new type of fluorescent material. This may be of interest in new RE lasers. (Auth.)

  7. Contribution of Eu ions on the precipitation of silver nanoparticles in Ag-Eu co-doped borate glasses

    International Nuclear Information System (INIS)

    Jiao, Qing; Qiu, Jianbei; Zhou, Dacheng; Xu, Xuhui

    2014-01-01

    Graphical abstract: - Highlights: • Silver nanoparticles are precipitated from the borate glasses during the melting process without any further heat treatment. • The reduction of Eu 3+ ions to Eu 2+ ions is presented in this material. • The intensity of Ag + luminescence. • The introduction of Eu ions accelerated the reaction between Eu 2+ ions and silver ions inducing the silver clusters formation. - Abstract: Ag + doped sodium borate glasses with different Eu ions concentration were prepared by the melt-quenching method. The absorption at about 410 nm which was caused by the surface plasmon resonance (SPR) of Ag nanoparticles (NPs) is promoted with increasing of Eu ions concentration. Meanwhile, the luminescent spectra showed that the emission intensity of Ag + decreased while that of the Ag aggregates increased simultaneously. The results indicated that the Ag ions intend to form the high-polymeric state such as Ag aggregates and nanoparticles with increasing of europium ions. Owing to the self-reduction of Eu 3+ to Eu 2+ in our glass system, it revealed that Ag + has been reduced by the neighboring Eu 2+ which leads to the formation of Ag aggregates and the precipitation of Ag NPs in the matrix. In addition, energy transfer (ET) process from Ag + /Ag aggregates to the Eu 3+ was investigated for the enhancement of Eu 3+ luminescence

  8. Manganese doped-iron oxide nanoparticle clusters and their potential as agents for magnetic resonance imaging and hyperthermia

    KAUST Repository

    Casula, Maria F.

    2016-06-10

    A simple, one pot method to synthesize water-dispersible Mn doped iron oxide colloidal clusters constructed of nanoparticles arranged into secondary flower-like structures was developed. This method allows the successful incorporation and homogeneous distribution of Mn within the nanoparticle iron oxide clusters. The formed clusters retain the desired morphological and structural features observed for pure iron oxide clusters, but possess intrinsic magnetic properties that arise from Mn doping. They show distinct performance as imaging contrast agents and excellent characteristics as heating mediators in magnetic fluid hyperthermia. It is expected that the outcomes of this study will open up new avenues for the exploitation of doped magnetic nanoparticle assemblies in biomedicine. © the Owner Societies 2016.

  9. Manganese doped-iron oxide nanoparticle clusters and their potential as agents for magnetic resonance imaging and hyperthermia

    KAUST Repository

    Casula, Maria F.; Conca, Erika; Bakaimi, Ioanna; Sathya, Ayyappan; Materia, Maria Elena; Casu, Alberto; Falqui, Andrea; Sogne, Elisa; Pellegrino, Teresa; Kanaras, Antonios G.

    2016-01-01

    A simple, one pot method to synthesize water-dispersible Mn doped iron oxide colloidal clusters constructed of nanoparticles arranged into secondary flower-like structures was developed. This method allows the successful incorporation and homogeneous distribution of Mn within the nanoparticle iron oxide clusters. The formed clusters retain the desired morphological and structural features observed for pure iron oxide clusters, but possess intrinsic magnetic properties that arise from Mn doping. They show distinct performance as imaging contrast agents and excellent characteristics as heating mediators in magnetic fluid hyperthermia. It is expected that the outcomes of this study will open up new avenues for the exploitation of doped magnetic nanoparticle assemblies in biomedicine. © the Owner Societies 2016.

  10. Structural and luminescence properties of Sm3+ -doped bismuth phosphate glass for orange-red photonic applications.

    Science.gov (United States)

    Damodaraiah, S; Reddy Prasad, V; Ratnakaram, Y C

    2018-05-01

    In the present study, the effect of bismuth oxide (Bi 2 O 3 ) content on the structural and optical properties of 0.5Sm 3+ -doped phosphate glass and the effect of concentration on structural and optical properties of Sm 3+ -doped bismuth phosphate (BiP) glass were studied. Structural characterization was accomplished using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and 31 P nuclear magnetic resonance (NMR) spectroscopy. Optical properties were studied using absorption, photoluminescence and decay measurements. Using optical absorption spectra, Judd-Ofelt parameters were derived to determine the local structure and bonding in the vicinity of Sm 3+ ions. The emission spectra of Sm 3+ -doped BiP glass showed two intense emission bands, 4 G 5/2 → 6 H 7/2 (orange) and 4 G 5/2 → 6 H 9/2 (red) for which the stimulated emission cross-sections (σ e ) and branching ratios (β) were found to be higher. The quantum efficiencies were also calculated from decay measurements recorded for the 4 G 5/2 level of Sm 3+ ions. The suitable combination of Bi 2 O 3 (10 mol%) and Sm 3+ (0.5 mol%) ions in these glasses acted as an efficient lasing material and might be suitable for the development of visible orange-red photonic materials. Copyright © 2018 John Wiley & Sons, Ltd.

  11. Thermal and optical properties of Tm3+ doped tellurite glasses.

    Science.gov (United States)

    Ozen, G; Demirata, B; Oveçoğlu, M L; Genç, A

    2001-02-01

    Ultraviolet, visible (UV/VIS) and differential thermal analysis (DTA) measurements were carried out in order to investigate the optical and thermal properties of various 0.5 mol.% Tm2O3 containing (1 - x)TeO2 + xLiCl glasses in molar ratio. The samples were prepared by fusing the mixture of their respective reagent grade powders in a platinum cricuble at 750 degrees C for 30 min. DTA curves taken in the 23-600 degrees C temperature range with a heating rate of 10 degrees C/min reveal a change in the value of the glass transition temperature, Tg, while melting was not observed for the glasses containing LiCl content less than 50 mol.%. These glasses were found to be moisture-resistant. However, the glasses with LiCl content higher than 50 mol.%, in which a melting peak was observed at Tc = 401 degrees C, were moisture-sensitive. Absorption measurements in the UV/VIS region of the glasses without Tm2O3 content show that the Urbach cutoff occurs at about 320 nm and, is relatively independent of the LiCl content. Six absorption bands were observed in the Tm2O3 doped glasses corresponding to the absorption of the 1G4, 3F2, 3F3 and 3F4, 3H5 and 3H4 levels from the 3H6 ground level of Tm3+ ions. The spectra also show that the integrated absorption cross-section of each band depends on the glass composition. Judd-Ofelt theory was used to determine the Judd-Ofelt parameters as well as the radiative transition probabilities for the metastable levels of Tm3+ ions in (0.3)LiCl + (0.7) TeO2: 0.01 Tm2O3 glass which is moisture-resistant.

  12. Downconversion in Pr3+–Yb3+ co-doped ZBLA fluoride glasses

    International Nuclear Information System (INIS)

    Maalej, O.; Boulard, B.; Dieudonné, B.; Ferrari, M.; Dammak, M.; Dammak, M.

    2015-01-01

    Fluorozirconate ZBLA glasses with molar composition 57ZrF 4 –34BaF 2 –5LaF 3 –4AlF 3 –0.5PrF 3 –xYbF 3 (from x=0 to 10) were synthesized to evaluate the rate of the conversion of visible photons into infrared photons. The emission spectra in the near infrared (NIR) at 950–1100 nm and the luminescence decays in the visible and NIR indicate an energy transfer from Pr 3+ to Yb 3+ upon blue excitation of Pr 3+ at 440 nm. The energy transfer efficiency increases with Yb 3+ concentration to reach 86% with 0.5Pr 3+ –10Yb 3+ co-doping (in mol%). However, the quenching of the Yb 3+ emission strongly reduces the efficiency of the downconversion process: the decay time values decrease from 600 µs (x=0.5 mol%) to 85 µs (x=10 mol%). - Highlights: • We synthesized 0.5Pr 3+ –xYb 3+ co-doped ZBLA glasses (from x=0 to 10 mol %). • Photoluminescence of Yb 3+ was observed at 980 nm under blue excitation. • Time resolved measurements have been performed in the visible and near infrared. • Energy transfer efficiency from Pr 3+ to Yb 3+ reaches 86% in 0.5 Pr 3+ –10Yb 3+ glass

  13. Thermal lens study of thermo-optical properties and concentration quenching of Er3+-doped lead pyrophosphate based glasses

    Energy Technology Data Exchange (ETDEWEB)

    Santos, C. C. [Universidade Federal do Ceara, Ceara, Brazil; Rocha, U. [Grupo de Fotônica e Fluidos Complexos, Instituto de Física, Brazil; Guedes, Ilde [Universidade Federal do Ceara, Ceara, Brazil; Vermelho, M. V. D. [Instituto de Fisica, Universidade Federal de Alagoas, Brazil; Boatner, Lynn A [ORNL; Jacinto, C. [Instituto de Fisica, Universidade Federal de Alagoas, Brazil

    2012-01-01

    In this work, we have used the thermal lens technique combined with conventional spectroscopy to characterize the thermo-optical properties of Er3+-doped lead pyrophosphate-based glasses. More precisely, we have investigated and quantified experimentally the fluorescence quantum efficiencies of the Er3+ levels, and we describe the role of concentration quenching effects. The fluorescence quantum efficiency of the 4I13/2 level is very high when compared to other phosphate glasses, while that of the green-coupled levels is very small. Other important photonic materials parameters, such as the thermal diffusivity and temperature coefficient of the optical path length change, were obtained and compared with those of other glass systems. The cumulative results obtained here for the Er-doped lead pyrophosphate glass show that this material is a good candidate for photonic applications with a characteristic Er3+ infrared emission around 1550 nm.

  14. Field-swept pulsed electron paramagnetic resonance of Cr3+-doped ZBLAN fluoride glass

    International Nuclear Information System (INIS)

    Drew, S.C.; Pilbrow, J.R.; Newman, P.J.; MacFarlane, D.R.

    2001-01-01

    Field-swept pulsed electron paramagnetic resonance (EPR) spectra of a ZBLAN fluoride glass doped with a low concentration of Cr 3+ are obtained using echo-detected EPR and hole-burning free induction decay detection. We review the utility of the pulsed EPR technique in generating field-swept EPR spectra, as well as some of the distorting effects that are peculiar to the pulsed detection method. The application of this technique to Cr 3+ -doped ZBLAN reveals that much of the broad resonance extending from g eff =5.1 to g eff =1.97, characteristic of X-band continuous wave EPR of Cr 3+ in glasses, is absent. We attribute this largely to the variation in nutation frequencies across the spectrum that result from sites possessing large fine structure interactions. The description of the spin dynamics of such sites is complicated and we discuss some possible approaches to the simulation of the pulsed EPR spectra. (author)

  15. Plasmon-Assisted Efficiency Enhancement of Eu3+-Doped Tellurite Glass-Covered Solar Cells

    Science.gov (United States)

    Lima, Bismarck C.; Gómez-Malagón, L. A.; Gomes, A. S. L.; Garcia, J. A. M.; Kassab, L. R. P.

    2017-12-01

    Rare-earth-doped tellurite glass containing metallic nanoparticles can be exploited to manage the solar spectrum in order to increase solar cell efficiency. It is therefore possible to modify the incident solar spectrum profile to the spectrum that optimizes the solar cell recombination process by covering the solar cell with plasmonic luminescent downshifting layers. With this approach, the losses due to thermalization are minimized and the efficiency is increased. Due to the down-conversion process that couples the plasmon resonance of the metallic nanoparticles and the rare-earth electronic energy levels, it is possible to convert photons from the ultraviolet region to the visible and near-band-gap region of the semiconductor. It is demonstrated here that plasmon-assisted efficiency enhancements of 14.0% and 34.5% can be obtained for commercial Si and GaP solar cells, respectively, covered with Eu3+-doped TeO2-ZnO glass containing silver nanoparticles.

  16. Influence of alumina on photoluminescence and thermoluminescence characteristics of Gd{sup 3+} doped barium borophosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kalpana, T. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India); Gandhi, Y. [Department of Physics, Kakani Venkata Ratnam College, Nandigama 521 185, A.P. (India); Sanyal, Bhaskar [Food Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Sudarsan, V. [Bhabha Atomic Research Centre, Chemistry Division, Mumbai 400 085 (India); Bragiel, P.; Piasecki, M. [Institute of Physics, Jan Dlugosz University, Ul. Armii Krajowej 13/15, Czestochowa 42-201 (Poland); Kumar, V. Ravi [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India); Veeraiah, N., E-mail: nvr8@rediffmail.com [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India)

    2016-11-15

    Gd{sup 3+} doped barium borophosphate glasses mixed with varying concentration of Al{sub 2}O{sub 3} are synthesized. Photoluminescence, thermoluminescence and other spectroscopic studies viz., IR and EPR spectral studies, have been carried out. IR spectral studies of these glasses indicated that there is a gradual increase in the degree of depolymerization of the glass network with increase in the concentration of Al{sub 2}O{sub 3} upto 3.0 mol%. The EPR spectral studies revealed the lowest concentration of Gd{sup 3+} ion clusters in the glass mixed with 3.0 mol% of Al{sub 2}O{sub 3}. The photoluminescence emission spectra exhibited strong ultraviolet blue emission at 311 under excitation at 273 nm due to {sup 6}P{sub 7/2}→{sup 8}S{sub 7/2} transition of Gd{sup 3+} ions. The intensity of this band is found to be enhanced four times when the glass mixed with 3.0 mol% of Al{sub 2}O{sub 3} with respect to that of alumina free glass. The enrichment of this emission is attributed to the declustering of Gd{sup 3+} ions by Al{sup 3+} ions. Thermoluminescence (TL) characteristics of these glasses have also been investigated after irradiating them with different doses of γ-rays (in the range 0–8.0 kGy). The TL emission exhibited a dosimetric peak at about 200 °C. The TL output under this glow peak is observed to increase with increase of γ-ray dose. For any fixed γ-ray dose, the TL output is increased with increasing Al{sub 2}O{sub 3} content up to 3.0 mol% and beyond this concentration quenching of TL is observed. The mechanisms responsible for TL emission and the variation in TL output with the concentration of Al{sub 2}O{sub 3} are quantitatively discussed in terms of electron and hole centers developed due to interaction of γ-rays with the glass network. The dose response of these glass samples exhibited linear behavior in the dose range 0–8.0 kGy.

  17. Temperature dependence of the ultraviolet luminescence of Pr3+-doped 20Al(PO3)3-80LiF glass scintillator

    International Nuclear Information System (INIS)

    Tsuboi, Mizuki; Takeda, Kohei; Nakazato, Tomoharu

    2017-01-01

    The development of scintillator materials for scattered neutrons is essential in studying laser fusion experiments. We have previously investigated and proposed Pr 3+ -doped 20Al(PO 3 ) 3 -80LiF (APLF + Pr) glasses as scintillators for neutron detection. The APLF + Pr glass emissions are then investigated with synchrotron radiation excitation and varying sample temperature. APLF + Pr glasses exhibit luminescence emission located at 200 to 300 nm and 400 nm attributed to the 4f5d → 4f 2 and 4f 2 → 4f 2 ( 1 S 0 → 3 P j + 1 I 6 ) transitions, respectively. In addition, the 200 to 300-nm emission is not substantially affected by temperature, while the 400-nm emission intensities increase with decreasing sample temperature. This temperature dependence is attributed to cross relaxation whose effect can be controlled by the Pr-doping concentration. Our results suggest that doping concentration of APLF + Pr must be optimized and that APLF + Pr glasses must operate a low temperatures for better neutron detection. (author)

  18. Doping of low-T{sub g} phosphate glass with Al{sub 2}O{sub 3}, B{sub 2}O{sub 3} and SiO{sub 2}: Part I- effect on glass property and stability

    Energy Technology Data Exchange (ETDEWEB)

    Rajbhandari, P., E-mail: p.rajbhandari@sheffield.ac.uk [UCCS UMR-CNRS 8181, Universite de Lille1, Villeneuve d' Ascq (France); Montagne, L. [UCCS UMR-CNRS 8181, Universite de Lille1, Villeneuve d' Ascq (France); Tricot, G. [UCCS UMR-CNRS 8181, Universite de Lille1, Villeneuve d' Ascq (France); LASIR UMR-CNRS 8516, Universite de Lille1, Villeneuve d' Ascq (France)

    2016-11-01

    A zinc alkali pyrophosphate system 46.6ZnO-20Na{sub 2}O-33.5P{sub 2}O{sub 5} presenting low-T{sub g} (339 °C) and good thermal stability has been doped with (1–4) mol% of Al{sub 2}O{sub 3}, B{sub 2}O{sub 3} and SiO{sub 2} to improve the stability of the glass with a minimal increase in glass transition temperature (T{sub g}). XRD and 1D {sup 31}P solid state NMR were used to monitor the isothermal crystallization process occurring at 130 °C above T{sub g}. If the Al{sub 2}O{sub 3} and B{sub 2}O{sub 3} doping significantly improved thermal stability, this property was marginally affected by SiO{sub 2} doping. Viscosity measurements were performed to observe the crystallization effects induced by the doping. It is noteworthy that the T{sub g} values of all the doped compositions with improved stability presented in this work are below 400 °C. Raman spectroscopy, 1D {sup 31}P, {sup 27}Al, {sup 11}B and {sup 29}Si solid state NMR were carried out to determine the structural modifications and coordination states of the doping elements all along the composition line. - Highlights: • Low-Tg phosphate glasses doped with Al{sub 2}O{sub 3}, B{sub 2}O{sub 3} and SiO{sub 2} have been formulated. • Thermal stability of the glass has been improved significantly. • The structural modification induced by doping elements has been studied by employing solid state NMR technique.

  19. Synthesis and optical properties of antimony oxide glasses doped with holmium trioxide

    Energy Technology Data Exchange (ETDEWEB)

    Raghunatha, S.; Eraiah, B., E-mail: eraiah@rediffmail.com [Department of physics, Bangalore University, Bengaluru – 560 056. India (India)

    2016-05-06

    Holmium doped lithium-antimony-lead borate glasses having 1 mol% AgNO{sub 3} with composition 50B{sub 2}O{sub 3}-20PbO-25Sb{sub 2}O{sub 3}-5Li{sub 2}O have been prepared using single step melt quenching technique. The XRD spectrum confirms amorphous nature of glasses. The optical absorbance studies were carried out on these glasses. The optical direct band gap energies were found to be in the range of 3.10 eV to 3.31 eV and indirect band gap energies were found to be in the range of 2.28 eV to 3.00 eV. The refractive indexes have been calculated by using Lorentz-Lorenz formula and the calculated values in the range of 2.31 to 2.37.

  20. Modified magnetic and optical properties of manganese nanoparticles incorporated europium doped magnesium borotellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Siti Maisarah; Sahar, M.R., E-mail: mrahim057@gmail.com; Ghoshal, S.K.

    2017-02-01

    This paper reports the modified optical and magnetic properties of europium (Eu{sup 3+}) ions doped and Manganese nanoparticles (NPs) embedded Magnesium Borotellurite glass synthesized via melt quenching method. The influence of varying Mn NPs concentrations on the magnetic, absorption and emission properties of such glass samples are determined. Stables, transparent and amorphous glasses are obtained. The observed modification of the electronic polarizability is interpreted in terms of the generation of non-bridging oxygen (NBO) and bridging oxygen (BO) in the amorphous network. TEM images manifested the growth of Mn NPs with average diameter 11±1 nm. High-resolution TEM reveals that the lattice spacing of manganese nanoparticles is 0.308 nm at (112) plane. The emission spectra revealed four prominent peaks centered at 587 nm, 610 nm, 651 nm and 700 nm assigned to the transition from {sup 5}D{sub 0} →{sup 7}F{sub J} (J=1, 2, 3, 4) states of Eu{sup 3+} ion. A significant drop in the luminescence intensity due to the incorporation of Mn NPs is ascribed to the enhanced energy transfer from the Eu{sup 3+} ion to NPs. Prepared glass systems exhibited paramagnetic behavior. - Highlights: • The europium doped magnesium borotellurite glasses embedded Mn NPs prepared using the conventional melt-quenching method. • The TEM result reveals the size of Mn NPs while its planar spacing has been determined by HRTEM. • The luminescence properties of TeO{sub 2}–B{sub 2}O{sub 3}–MgO–Eu{sub 2}O{sub 3}–Mn{sub 3}O{sub 4} glasses have been investigated as effect of Mn NPs content. • The magnetization measurement of glass sample is carried out using vibrating sample magnetometer (VSM)

  1. Physical, thermal, structural and optical properties of Dy{sup 3+} doped lithium alumino-borate glasses for bright W-LED

    Energy Technology Data Exchange (ETDEWEB)

    Pawar, P.P.; Munishwar, S.R.; Gautam, S.; Gedam, R.S., E-mail: rupesh_gedam@rediffmail.com

    2017-03-15

    Rare earth (RE) doped glasses have potential applications due to their emission efficiencies of 4f–4 f and 4f–5d electronic transitions. Among all the rare earths, Dy{sup 3+} doped glasses have drawn much interest among the researchers for their intense emission in the visible region from 470 to 500 nm and around 570 to 600 nm. The physical, thermal, structural and optical properties of Dy{sup 3+} doped lithium alumino-borate glasses (LABD glasses) have been studied for white LED (W-LED) application. The glasses were synthesized by conventional melt quench technique. X-ray diffraction spectra revealed the amorphous nature of the glass sample. An FTIR spectrum was carried out to study the glass structure and various functional groups present in the LABD glasses. Optical absorption spectra were recorded by UV–vis-NIR spectrometer. Allowed direct and indirect band gaps were obtained by Tauc's plot. Thermal parameters like glass thermal stability (∆T), Hruby's parameter (K{sub gl}), etc. were calculated by DTA graph. Photoluminescence excitation and emission spectra's were measured at room temperature. The emission spectra shows two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponds to the {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} transitions respectively along with one feeble band at 662 nm (red) corresponds to {sup 4}F{sub 9/2}→{sup 6}H{sub 11/2} transition. The CIE chromaticity co-ordinates were calculated for all glass samples. CIE chromaticity diagram shows glass LABD-4 containing 0.5 mol% Dy{sub 2}O{sub 3} with colour co-ordinates X = 0.34 and Y = 0.38 have highest emission intensity. These glasses having emission in the white region and thus can be used for bright white LED.

  2. Composition effects on optical properties of Tb.sup.3+./sup.-doped heavy germanate glasses

    Czech Academy of Sciences Publication Activity Database

    Chen, G.; Yang, Y.; Zhao, D.; Xia, F.; Baccaro, S.; Cecilia, A.; Nikl, Martin

    2005-01-01

    Roč. 88, č. 2 (2005), s. 293-296 ISSN 0002-7820 Institutional research plan: CEZ:AV0Z10100521 Keywords : luminescence * transmission * germanate glass es * Tb-doped Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.586, year: 2005

  3. Enhanced green and red upconversion emissions in Er3+-doped boro-tellurite glass containing gold nanoparticles

    Science.gov (United States)

    Dousti, M. Reza; Amjad, Raja J.; Mahraz, Zahra Ashur S.

    2015-01-01

    Increasing the cross-section of upconversion emissions from the rare earth ions doped materials is a challenging issue. In this work, we report on the enhancement of the up-converted emissions of Er3+-doped boro-tellurite glasses containing gold nanoparticles which have been prepared by a conventional melt-quench technique. Seven absorption bands and three emission lines are observed using the UV-Vis-IR and photoluminescence spectroscopic techniques, respectively. Red emission is enhanced up to 30 times in a sample having 1 wt% of Au nanoparticles. The presence of the gold nanoparticles with average size of ∼5.74 nm is confirmed by transmission electron microscopy and corresponding surface plasmon band is observed at 630 nm in a singly-doped Au-nanoparticles embedded glass sample. A model to determine the enhancement factor of the emissions is suggested which could not describe the phenomenon for high concentrations of nanoparticles. Enhancement is attributed to the increased local field around the metal, and the results are discussed in details.

  4. UV-visible, Raman and E.S.R. studies of gamma-irradiated NiO-doped sodium metaphosphate glasses.

    Science.gov (United States)

    ElBatal, Fatma H; Morsi, Reham M; Ouis, Mona A; Marzouk, Samir Y

    2010-11-01

    UV-visible spectroscopic measurements of Ni-doped sodium phosphate glasses were carried out before and after successive gamma irradiation. The undoped glass reveals strong UV absorption originating from trace iron impurities. NiO-doped glasses show characteristic absorption bands due mainly to octahedral coordination of Ni(2+) ions. Gamma irradiation produces induced bands generated from intrinsic defects and extrinsic defects. The changes in the spectroscopic data are discussed in relation to the structural evolution caused by the changes in composition and coordination state of nickel ions. The change in the growth behaviour of the induced bands is related to the annihilation or approach saturation of these characteristic induced bands. Raman and E.S.R. spectroscopic measurements confirm the presence of nickel as Ni(2+) ions in octahedral state. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Structural and optical properties of Si-doped Ag clusters

    KAUST Repository

    Mokkath, Junais Habeeb

    2014-03-06

    The structural and optical properties of AgN and Ag N-1Si1 (neutral, cationic, and anionic) clusters (N = 5 to 12) are systematically investigated using the density functional based tight binding method and time-dependent density functional theory, providing insight into recent experiments. The gap between the highest occupied and lowest unoccupied molecular orbitals and therefore the optical spectrum vary significantly under Si doping, which enables flexible tuning of the chemical and optical properties of Ag clusters. © 2014 American Chemical Society.

  6. Structural and optical properties of Si-doped Ag clusters

    KAUST Repository

    Mokkath, Junais Habeeb; Schwingenschlö gl, Udo

    2014-01-01

    The structural and optical properties of AgN and Ag N-1Si1 (neutral, cationic, and anionic) clusters (N = 5 to 12) are systematically investigated using the density functional based tight binding method and time-dependent density functional theory, providing insight into recent experiments. The gap between the highest occupied and lowest unoccupied molecular orbitals and therefore the optical spectrum vary significantly under Si doping, which enables flexible tuning of the chemical and optical properties of Ag clusters. © 2014 American Chemical Society.

  7. The influence of ytterbium doping on the optical properties of tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Jaglarz, Janusz; Burtan, Bozena [Institute of Physics, Cracow University of Technology, ul. Podchorazych 1, 30-084 Cracow (Poland); Reben, Manuela; Wasylak, Jan [Faculty of Materials Science and Ceramics, AGH - University of Science and Technology, al. Mickiewicza 30, 30-059 Cracow (Poland); Cisowski, Jan [Institute of Physics, Cracow University of Technology, ul. Podchorazych 1, 30-084 Cracow (Poland); Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Sklodowskiej 34, 41-819 Zabrze (Poland); Jarzabek, Bozena [Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Sklodowskiej 34, 41-819 Zabrze (Poland)

    2011-09-15

    The goal of this work was to investigate the influence of rare earth ion Yb{sup 3+} doping on the thermal and optical properties of tellurite glass (TG) of the TeO{sub 2}-ZnO-PbO-La{sub 2}O{sub 3} system. The reflectance, transmittance and ellipsometric measurements have been done. Decreasing of the refractive index of TG with the Yb{sup 3+} ion doping has been concluded. For determination of the refractive index variation in the bulk, the small angle light scatter (SALS) measurements have been carried out. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Linear Optical Properties of Zinc Borotellurite Glass Doped with Lanthanum Oxide Nanoparticles for Optoelectronic and Photonic Application

    Directory of Open Access Journals (Sweden)

    Faznny Mohd Fudzi

    2017-01-01

    Full Text Available Enhancing the optical properties of glasses for the sake of optical application in various fields is an ongoing challenge in materials science and technology. Thus, the optical properties of zinc borotellurite glass doped with lanthanum oxide nanoparticles (La2O3 NPs with the chemical composition of {[(TeO20.7(B2O30.3]0.7(ZnO0.3}1−x (La2O3 NPsx, where x = 0.01, 0.02, 0.03, 0.04, and 0.05 molar fraction, have been investigated. Characterization techniques such as x-ray diffraction, Fourier Transform Infrared Spectroscopy, and Ultraviolet-Visible Spectroscopy are employed to yield the structural properties and optical parameter of the glass. The amorphous nature of the fabricated glasses is confirmed with the presence of a broad hump via XRD diffraction pattern. The decreasing amount of high polarizable nonbridging oxygen as the concentration of La2O3 NPs increases has contributed to the increasing trend of energy band gap in the range of 2.70 to 3.52 eV and decreasing value of refractive index between 2.34 and 2.48. The fabricated glasses that have a higher refractive index than the widely used fiber material, pure silica glass, indicate that zinc borotellurite glass doped with lanthanum nanoparticles is a promising material to be applied as optical fibers.

  9. Cluster-based bulk metallic glass formation in Fe-Si-B-Nb alloy systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, C L; Wang, Q; Li, F W; Li, Y H; Wang, Y M; Dong, C [State Key Laboratory of Materials Modification, Dalian University of Technology (DUT), Dalian 116024 (China); Zhang, W; Inoue, A, E-mail: dong@dlut.edu.c [Institute for Materials Research (IMR), Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan)

    2009-01-01

    Bulk metallic glass formations have been explored in Fe-B-Si-Nb alloy system using the so-called atomic cluster line approach in combination with minor alloying guideline. The atomic cluster line refers to a straight line linking binary cluster to the third element in a ternary system. The basic ternary compositions in Fe-B-Si system are determined by the inetersection points of two cluster lines, namely Fe-B cluster to Si and Fe-Si cluster to B, and then further alloyed with 3-5 at. % Nb for enhancing glass forming abilities. BMG rods with a diameter of 3 mm are formed under the case of minor Nb alloying the basic intersecting compositions of Fe{sub 8}B{sub 3}-Si with Fe{sub 12}Si-B and Fe{sub 8}B{sub 2}-Si with Fe{sub 9}Si-B. The BMGs also exhibit high Vickers hardness (H{sub v}) of 1130-1164 and high Young's modulous (E) of 170-180 GPa

  10. Intense green emission from Tb3+- doped Teo2-Wo3-Geo2 glasses

    Science.gov (United States)

    Subrahmanyam, Tallam; Gopal, Kotalo Rama; Suvarna, Reniguntla Padma; Jamalaiah, Bungala Chinna

    2018-04-01

    Tb3+ -doped oxyfluoro tellurite (TWGTb) glasses were prepared by conventional melt quenching technique. The Judd-Ofelt theory has been applied to evaluate the Ωλ (λ=2,4,6) intensity parameters. The TWGTb glasses exhibit 5D3 → 7F5-3 and 5D4 → 7F6-0 transitions when excited at 316 nm wavelength. The variation of intensity of 5D4 → 7F5 (Green) and 5D3 → 7F4 (Blue) transitions and the green to blue (IG/IB) intensity ratios were studied as a function of Tb3+ ions concentration. The laser characteristic parameters such as effective bandwidth (Δλeff), stimulated emission cross-section (σe), gain bandwidth (σe×Δλeff) and optical gain (σe×τR) were determined using the emission spectra and radiative parameters. The luminescence decay profiles exhibit single-exponential nature for all the samples. Based on the experimental results we suggest that the 1.0 mol% of Tb3+-doped TWGTb glass could be the suitable laser host materials to emit intense green luminescence at 545 nm.

  11. Optical basicity and electronic polarizability of zinc borotellurite glass doped La3+ ions

    Directory of Open Access Journals (Sweden)

    M.K. Halimah

    Full Text Available Zinc borotellurite glasses doped with lanthanum oxide were successfully prepared through melt-quenching technique. The amorphous nature of the glass system was validated by the presence of a broad hump in the XRD result. The refractive index of the prepared glass samples was calculated by using the equation proposed by Dimitrov and Sakka. The theoretical value of molar refraction, electronic polarizability, oxide ion polarizability and metallization criterion were calculated by using Lorentz-Lorenz equation. Meanwhile, expression proposed by Duffy and Ingram for the theoretical value of optical basicity of multi-component glasses were applied to obtain energy band gap based optical basicity and refractive index based optical basicity. The optical basicity of prepared glasses decreased with the increasing concentration of lanthanum oxide. Metallization criterion on the basis of refractive index showed an increasing trend while energy band gap based metallization criterion showed a decreasing trend. The small metallization criterion values of the glass samples represent that the width of the conduction band becomes larger which increase the tendency for metallization of the glasses. The results obtained indicates that the fabricated glasses have high potential to be applied on optical limiting devices in photonic field. Keywords: Borotellurite glasses, Refractive index, Electronic polarizability, Oxide ion polarizability, Optical basicity, Metallization criterion

  12. Spectroscopic properties of Er{sup 3+}-doped antimony oxide glass

    Energy Technology Data Exchange (ETDEWEB)

    Ouannes, K.; Soltani, M.T. [Laboratoire de Physique Photonique et Nanomatériaux Multifonctionnels, Université de Biskra, BP 145 RP, 07000 Biskra (Algeria); Poulain, M. [UMR 6226 – Verres et Céramiques – Campus de Beaulieu, Université' de Rennes 1, 35042 Rennes (France); Boulon, G.; Alombert-Goget, G.; Guyot, Y.; Pillonnet, A. [Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne (France); Lebbou, K., E-mail: kheireddine.lebbou@univ-lyon1.fr [Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne (France)

    2014-08-01

    Highlight: • As a function of Er concentration, glasses corresponding to the 60Sb{sub 2}O{sub 3}–20WO{sub 3}–(19 − x) Na{sub 2}O–1Bi{sub 2}O{sub 3}, xEr{sub 2}O{sub 3} formula were prepared. The quantum efficiency shows that this glass could be promised for laser devices. - Abstract: Spectroscopic properties of Er{sup 3+} ions have been studied in the 60Sb{sub 2}O{sub 3}–20WO{sub 3}–19Na{sub 2}O–1Bi{sub 2}O{sub 3} (SWNB) glasses doped with 0.25 and 0.50 mol% Er{sub 2}O{sub 3} respectively. The Judd–Ofelt parameters measured from the absorption spectra have been used to calculate the radiative life-time (τ{sub r}) and the stimulated emission cross section. The low phonon energy, a reduced quenching effect and a high quantum efficiency of 90% for the 1.53 μm expected laser emission into pumping at 980 nm are in favor of promising material laser application.

  13. Synthesis and different optical properties of Gd2O3 doped sodium zinc tellurite glasses

    Science.gov (United States)

    Samanta, Buddhadev; Dutta, Dibakar; Ghosh, Subhankar

    2017-06-01

    A series of Gd2O3 doped sodium zinc tellurite [xGd2O3-(0.8-x) TeO2-0.1Na2O-0.1ZnO] glasses are prepared by the conventional melt quenching method and their optical properties have been studied. UV-vis spectrophotometric studies within the wavelength range from 230 nm-800 nm are carried out in the integrating sphere mode to study the effect of Gd2O3 doping on the optical band gap (Eg), refractive index (n), dielectric constant (εr) and susceptibility (χ). Other physical properties like molar volume, molar refraction, polarizability, metallization criterion, number density of rare-earth ions (N), polaron radius (rp), inter ionic distance (ri), molar cation polarizability (∑αi), number of oxide ions in chemical composition (NO2-), optical band gap based electronic oxide ion polarizability (αO2-) and optical basicity (Λ) of glass samples have been studied on the basis of UV-vis spectra and density profile of the different glasses.

  14. Thermokinetic behaviour of Ag-doped (GeS2)50(Sb2S3)50 glasses.

    Czech Academy of Sciences Publication Activity Database

    Svoboda, R.; Fraenkl, M.; Frumarová, Božena; Wágner, T.; Málek, J.

    2016-01-01

    Roč. 449, 1 October (2016), s. 12-19 ISSN 0022-3093 Institutional support: RVO:61389013 Keywords : DSC * Ag doping * Ge-Sb-S glass Subject RIV: CA - Inorganic Chemistry Impact factor: 2.124, year: 2016

  15. Pr{sup 3+}-doped GeS{sub {ital x}}-based glasses for fiber amplifiers at 1.3 {mu}m

    Energy Technology Data Exchange (ETDEWEB)

    Simons, D.R.; Faber, A.J.; de Waal, H. [Glass Technology, Eindhoven University of Technology, P.O. Box 595, 5600 AN Eindhoven (Netherlands)

    1995-03-01

    The photoluminescence properties of Pr{sup 3+}-doped GeS{sub {ital x}}-based glasses are studied and compared with those of other sulfide and fluoride glasses. The possibility of highly pump-power-efficient fiber amplifiers based on these GeS{sub {ital x}}-containing glasses in the telecommunications window at 1.3 {mu}m is discussed.

  16. Erbium-doped phosphate glass waveguide on silicon with 4.1 dB/cm gain at 1.535 µm

    Science.gov (United States)

    Yan, Y. C.; Faber, A. J.; de Waal, H.; Kik, P. G.; Polman, A.

    1997-11-01

    Erbium-doped multicomponent phosphate glass waveguides were deposited by rf sputtering techniques. The Er concentration was 5.3×1020cm-3. By pumping the waveguide at 980 nm with a power of ˜21 mW, a net optical gain of 4.1 dB at 1.535 μm was achieved. This high gain per unit length at low pump power could be achieved because the Er-Er cooperative upconversion interactions in this heavily Er-doped phosphate glass are very weak [the upconversion coefficient is (2.0±0.5)×10-18 cm3/s], presumably due to the homogeneous distribution of Er in the glass and due to the high optical mode confinement in the waveguide which leads to high pump power density at low pump power.

  17. Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO2

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2017-02-01

    Full Text Available Yb3+-doped phosphate glasses containing different amounts of SiO2 were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO2 on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO2 possessed the longest fluorescence lifetime (1.51 ms, the highest gain coefficient (1.10 ms·pm2, the maximum Stark splitting manifold of 2F7/2 level (781 cm−1, and the largest scalar crystal-field NJ and Yb3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO2 promoted the formation of P=O linkages, but broke the P=O linkages when the SiO2 content was greater than 26.7 mol %. Based on the previous 29Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO6] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb3+-doped gain medium for solid-state lasers and optical fiber amplifiers.

  18. Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO2

    Science.gov (United States)

    Wang, Ling; Zeng, Huidan; Yang, Bin; Ye, Feng; Chen, Jianding; Chen, Guorong; Smith, Andew T.; Sun, Luyi

    2017-01-01

    Yb3+-doped phosphate glasses containing different amounts of SiO2 were successfully synthesized by the conventional melt-quenching method. The influence mechanism of SiO2 on the structural and spectroscopic properties was investigated systematically using the micro-Raman technique. It was worth noting that the glass with 26.7 mol % SiO2 possessed the longest fluorescence lifetime (1.51 ms), the highest gain coefficient (1.10 ms·pm2), the maximum Stark splitting manifold of 2F7/2 level (781 cm−1), and the largest scalar crystal-field NJ and Yb3+ asymmetry degree. Micro-Raman spectra revealed that introducing SiO2 promoted the formation of P=O linkages, but broke the P=O linkages when the SiO2 content was greater than 26.7 mol %. Based on the previous 29Si MAS NMR experimental results, these findings further demonstrated that the formation of [SiO6] may significantly affect the formation of P=O linkages, and thus influences the spectroscopic properties of the glass. These results indicate that phosphosilicate glasses may have potential applications as a Yb3+-doped gain medium for solid-state lasers and optical fiber amplifiers. PMID:28772601

  19. Intense 2.7 µm emission and structural origin in Er3+-doped bismuthate (Bi2O3-GeO2-Ga2O3-Na2O) glass.

    Science.gov (United States)

    Guo, Yanyan; Li, Ming; Hu, Lili; Zhang, Junjie

    2012-01-15

    The 2.7 μm emission properties in Er3+-doped bismuthate (Bi2O3-GeO2-Ga2O3-Na2O) glass were investigated in the present Letter. An intense 2.7 μm emission in Er3+-doped bismuthate glass was observed. It is found that Er3+-doped bismuthate glass possesses high spontaneous transition probability A (65.26 s(-1)) and large 2.7 μm emission cross section σ(em) (9.53×10(-21) cm2) corresponding to the stimulated emission of Er3+:4I11/2→4I13/2 transition. The emission characteristic and energy transfer process upon excitation of a conventional 980 nm laser diode in bismuthate glass were analyzed. Additionally, the structure of bismuthate glass was analyzed by the Raman spectrum. The advantageous spectroscopic characteristics of Er3+ single-doped bismuthate glass together with the prominent thermal property indicate that bismuthate glass might become an attractive host for developing solid-state lasers around 2.7 μm.

  20. Silver nanoparticles enhanced luminescence properties of Er³⁺ doped tellurite glasses: Effect of heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Fares, Hssen; Férid, Mokhtar [Laboratoire de Physico-Chimie des Matériaux Minéraux et leurs Applications, Centre National de Recherches en Sciences des Matériaux, B.P. 95 Hammam-Lif, 2050 (Tunisia); Elhouichet, Habib, E-mail: habib.elhouichet@fst.rnu.tn [Laboratoire de Physico-Chimie des Matériaux Minéraux et leurs Applications, Centre National de Recherches en Sciences des Matériaux, B.P. 95 Hammam-Lif, 2050 (Tunisia); Department of Physics, Sciences Faculty of Tunis, University Tunis ElManar 2092 (Tunisia); Gelloz, Bernard [Graduate School of Engineering, Nagoya University, 2-24-16 Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan)

    2014-09-28

    Tellurite glasses doped Er³⁺ ions and containing Silver nanoparticles (Ag NPs) are prepared using melt quenching technique. The nucleation and growth of Ag NPs were controlled by a thermal annealing process. The X-ray diffraction pattern shows no sharp peak indicating an amorphous nature of the glasses. The presence of Ag NPs is confirmed from transmission electron microscopy micrograph. Absorption spectra show typical surface plasmon resonance (SPR) band of Ag NPs within the 510–550 nm range in addition to the distinctive absorption peaks of Er³⁺ ions. The Judd-Ofelt (J-O) intensity parameters, oscillator strengths, spontaneous transition probabilities, branching ratios, and radiative lifetimes were successfully calculated based on the experimental absorption spectrum and the J-O theory. It was found that the presence of silver NPs nucleated and grown during the heat annealing process improves both of the photoluminescence (PL) intensity and the PL lifetime relative to the ⁴I13/2 → ⁴I15/2 transition. Optimum PL enhancement was obtained after 10 h of heat-treatment. Such enhancements are mainly attributed to the strong local electric field induced by SPR of silver NPs and also to energy transfer from the surface of silver NPs to Er³⁺ ions, whereas the quenching is ascribed to the energy transfer from Er³⁺ ions to silver NPs. Using the Mc Cumber method, absorption cross-section, calculated emission cross-section, and gain cross-section for the ⁴I13/2 → ⁴I15/2 transition were determined and compared for the doped and co-doped glasses. The present results indicate that the glass heat-treated for 10 h has good prospect as a gain medium applied for 1.53 μm band broad and high-gain erbium-doped fiber amplifiers.

  1. Doping and cluster formation in diamond

    KAUST Repository

    Schwingenschlö gl, Udo; Chroneos, Alexander; Grimes, R. W.; Schuster, Cosima

    2011-01-01

    Introducing a cluster formation model, we provide a rational fundamental viewpoint for the difficulty to achieve n-type dopeddiamond. We argue that codoping is the way forward to form appropriately doped shallow regions in diamond and other forms of carbon such as graphene. The electronegativities of the codopants are an important design criterion for the donor atom to efficiently donate its electron. We propose that the nearest neighbour codopants should be of a considerably higher electronegativity compared to the donor atom. Codoping strategies should focus on phosphorous for which there are a number of appropriate codopants.

  2. Doping and cluster formation in diamond

    KAUST Repository

    Schwingenschlögl, Udo

    2011-09-09

    Introducing a cluster formation model, we provide a rational fundamental viewpoint for the difficulty to achieve n-type dopeddiamond. We argue that codoping is the way forward to form appropriately doped shallow regions in diamond and other forms of carbon such as graphene. The electronegativities of the codopants are an important design criterion for the donor atom to efficiently donate its electron. We propose that the nearest neighbour codopants should be of a considerably higher electronegativity compared to the donor atom. Codoping strategies should focus on phosphorous for which there are a number of appropriate codopants.

  3. Photoluminescence quenching by OH in Er- and Pr-doped glasses for 1.5 and 1.3 μm optical amplifiers

    Science.gov (United States)

    Faber, Anne J.; Simons, Dennis R.; Yan, Yingchao; de Waal, Henk

    1994-09-01

    In this paper we report on the effect of hydroxyl (OH) groups on the photoluminescence in the near IR (1.5 and 1.3 micrometers ) in rare earth (Er, Pr)-doped glasses. The 1.5 micrometers emission of Er-doped phosphate glasses was studied, before and after a special heat treatment. The luminescent lifetime of the 1.5 micrometers emission increases substantially, typically from 3 ms up to 7.2 ms for a 2 mole% Er2O3-doped phosphate glass, due to the controlled heat treatment. The increase in lifetime is ascribed to a decrease in OH- concentration, which is confirmed by IR-absorption spectroscopy. The quenching by OH is described by a simplified quenching model, which predicts the 1.5 micrometers emission lifetime as a function of Er- concentration with the OH-concentration as parameter. It appears that the larger part of the OH groups is coupled to Er ions and thus acts as quenching center. Photoluminescence quenching by OH groups is also reported for the 1.3 micrometers emission of Pr in GeS2-glasses: In pure OH-free GeS2 glass the 1.3 micrometers emission lifetime is as high as 350 microsecond(s) , for a 400 ppm dopant level. In GeS2 glasses containing only small amounts of OH (approximately 100 ppm), this lifetime is less than 200 microsecond(s) . Both examples demonstrate that for the fabrication of efficient glass optical amplifiers at the telecommunication windows 1.3 and 1.5 micrometers , the OH-impurity level of the host glass must be kept as low as possible.

  4. Electrophoretic deposition of chitosan/45S5 bioactive glass composite coatings doped with Zn and Sr

    Directory of Open Access Journals (Sweden)

    Marta eMiola

    2015-10-01

    Full Text Available In this research work the original 45S5 bioactive glass (BG was modified by introducing zinc and/or strontium oxide (6% mol in place of calcium oxide. Sr was added for its ability to stimulate bone formation, Zn for its role in bone metabolism, antibacterial properties and anti-inflammatory effect. The glasses were produced by means of melting and quenching process. SEM and XRD analyses evidenced that Zr and Sr introduction did not modify the glass structure and morphology, while compositional analysis (EDS demonstrated the effective addition of these elements inside the glass network. Bioactivity test in simulated body fluid (SBF up to one month evidenced a reduced bioactivity kinetics for Zn-doped glasses. Doped glasses were combined with chitosan to produce organic/inorganic composite coatings on stainless steel AISI 316L by electrophoretic deposition (EPD. Two EPD processes were considered for coating development, namely direct current EPD (DC-EPD and alternating current EPD (AC-EPD. The stability of the suspension was analysed and the deposition parameters were optimized. Tape and bending tests demonstrated a good coating-substrate adhesion for coatings containing 45S5-Sr and 45S5-ZnSr glasses, while the adhesion to the substrate decreased by using 45S5-Zn glass. FTIR analyses demonstrated the composite nature of coatings and SEM observations indicated that glass particles were well integrated in the polymeric matrix, the coatings were fairly homogeneous and free of cracks; moreover the AC-EPD technique provided better results than DC-EPD in terms of coating quality. SEM, XRD analyses and Raman spectroscopy, performed after bioactivity test in SBF solution, confirmed the bioactive behaviour of 45S5-Sr containing coating, while coatings containing Zn exhibited no hydroxyapatite formation.

  5. Optical properties of zinc borotellurite glass doped with trivalent dysprosium ion

    Science.gov (United States)

    Ami Hazlin, M. N.; Halimah, M. K.; Muhammad, F. D.; Faznny, M. F.

    2017-04-01

    The zinc borotellurite doped with dysprosium oxide glass samples with chemical formula {[(TeO2) 0 . 7(B2O3) 0 . 3 ] 0 . 7(ZnO) 0 . 3 } 1 - x(Dy2O3)x (where x=0.01, 0.02, 0.03, 0.04 and 0.05 M fraction) were prepared by using conventional melt quenching technique. The structural and optical properties of the proposed glass systems were characterized by using X-ray diffraction (XRD) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and UV-VIS spectroscopy. The amorphous nature of the glass systems is confirmed by using XRD technique. The infrared spectra of the glass systems indicate three obvious absorption bands which are assigned to BO3 and TeO4 vibrational groups. Based on the absorption spectra obtained, the direct and indirect optical band gaps, as well as the Urbach energy were calculated. It is observed that both the direct and indirect optical band gaps increase with the concentration of Dy3+ ions. On the other hand, the Urbach energy is observed to decrease as the concentration of Dy3+ ions increases.

  6. Theoretical study of the structure and optical properties of rare-earth-doped BeF2 glass

    International Nuclear Information System (INIS)

    Brawer, S.; Weber, M.J.

    1980-01-01

    We investigate the question of whether the local structure of a glass can be deduced directly from its optical spectra by testing such a procedure on a model system. The model system was Eu 3+ -doped BeF 2 glass generated the Monte Carlo technique of statistical mechanics. The optical energy levels of Eu 3+ were calculated from a point charge model. Using the resulting spectra as data, it is shown that details of the structure of the rare-earth ion sites of the simulated glass cannot be reconstructed uniquely from the data. Based on these results, it is concluded that reliable glass structure cannot be deduced from optical spectra

  7. Dielectric relaxation in AgI doped silver selenomolybdate glasses

    Science.gov (United States)

    Palui, A.; Shaw, A.; Ghosh, A.

    2016-05-01

    We report the study of dielectric properties of some silver ion conducting silver selenomolybdate mixed network former glasses in a wide frequency and temperature range. The experimental data have been analyzed in the framework of complex dielectric permittivity. The dielectric permittivity data have been well interpreted using the Cole-Cole function. The temperature dependence of relaxation time obtained from real part of dielectric permittivity data shows an Arrhenius behavior. The activation energy shows a decreasing trend with the increase of doping content. Values of stretched exponential parameter are observed to be independent of temperature and composition.

  8. Optical properties of gold nanoparticle embedded Er{sup 3+} doped lead–tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sazali, E.S.; Sahar, M.R., E-mail: mrahim057@gmail.com; Ghoshal, S.K.; Arifin, R.; Rohani, M.S.; Awang, A.

    2014-09-01

    Highlights: • Er{sup 3+} doped lead–tellurite glass with and without GNPs has been synthesized. • The existence of Au NPs with average diameter of 6.09 nm dispersed in glass matrix. • Plasmonic effect from Au NPs exert prominent enhancement in UC. - Abstract: Enhanced optical properties of rare earth doped glasses for sundry applications are current challenges in materials science and technology. Series of gold nanoparticles (GNPs) embedded Er{sup 3+} doped TeO{sub 2}–PbO–PbO{sub 2} glasses are synthesized and the influences of GNPs on the optical behaviors are examined. XRD spectra confirm the amorphous nature of all the glass samples. TEM images display the existence of a broad distribution of spherical crystalline GNPs with average diameter ∼6.09 nm. UV–Vis–NIR spectra reveal seven absorption bands centered at 490, 526, 551, 652, 800, 982 and 1520 nm due to the absorptions from the ground state to different excited states. Two surface plasmon resonance bands of gold (Au{sup 0}) are evidenced at 556 and 585 nm. The sizable decrease in the optical band gap (2.82–1.09 eV) with the increase of GNPs concentration from 0.025 to 0.1 mol% is attributed to the generation of higher NPs nucleation sites. The intensity parameters related to the radiative transitions within 4f{sup n} configuration of Er{sup 3+} ion are determined and analyzed using Judd–Ofelt (J–O) theory. The room temperature up-conversion emission spectra under 779 nm excitations shows three peaks centered at 520, 550 and 660 nm corresponding to the transitions from {sup 2}H{sub 11/2}, {sup 4}S{sub 3/2} and {sup 4}F{sub 9/2} excited states to {sup 4}I{sub 15/2} ground state. Significant enhancement in the luminescence intensity is primarily ascribed to surface plasmon resonance mediated strong local field effect of GNPs in the proximity Er{sup 3+} ion and radiative energy transfer. The maximum enhancement are evident for green and red bands at 0.05 mol% of Au. The stimulated

  9. Synthesis of Er and Er : Yb doped sol–gel derived silica glass and ...

    Indian Academy of Sciences (India)

    Unknown

    Materials Science Centre, †Central Research Facility, Optical Fibre Unit, Indian Institute of Technology,. Kharagpur 721 302, India. MS received 1 March 2004; revised 4 July 2004. Abstract. Er3+ and Er3+ : Yb3+ doped optical quality, crack and bubble free glasses for possible use in mak- ing laser material have been ...

  10. Optical and physical properties of sodium lead barium borate glasses doped with praseodymium ion

    Science.gov (United States)

    Lenkennavar, Susheela K.; Madhu, A.; Eraiah, B.; Kokila, M. K.

    2018-05-01

    Praseodymium doped sodium lead barium borate glasses have been prepared using single step melt quenching technique. The XRD spectrum confirms amorphous nature of glasses. The optical absorbance studies were carried out on these glasses using PekinElemer Lambda-35 Uv-Vis spectrometer in the range of 200 -1100 nm. The optical direct band gap energies were found to be in the range of 3.62 eV to 3.69 eV and indirect band gap energies were found to be in the range of 3.57 eV to 3.62eV. The refractive indices were measured by using Abbe refractometer the values are in the range of 1.620 to 1.625.

  11. Application of glass particles doped by Zn+2 as an antimicrobial and atoxic compound in LLDPE and HDPE

    International Nuclear Information System (INIS)

    Santos, M.F.; Machado, C.; Tachinski, C.G.; Júnior, J.F.; Piletti, R.; Peterson, M.; Fiori, M.A.

    2014-01-01

    This study demonstrates the potential application of glass particles doped with Zn +2 (GZn) as an atoxic, antimicrobial additive when used in conjunction with high density polyethylene (HDPE) and linear low density polyethylene (LLDPE) polymers. Toxicity tests demonstrated that these modified glass particles were nontoxic to human cells, and atomic absorption analyses demonstrated the migration of ionic species in quantities less than 2.0 ppm for both the HDPE/GZn and LLDPE/GZn compounds. Microbiological tests demonstrated the antimicrobial effect of the pure GZn compound as well as the polymeric HDPE/GZn and LLDPE/GZn compounds. In addition, at percentages of GZn higher than 2.00 wt.% and at a time of 4 h, the bactericidal performance is excellent and equal for both polymeric compounds. - Highlights: • Glass doped with Zn +2 (GZn) promoted a good bactericidal properties in LLDPE and HDPE. • LLDPE and HDPE doped with GZn have capacity of liberty ionic zinc during a time period. • GZn is not toxic to human and can be used with antimicrobial additive to polymers. • GZn has an antimicrobial effect in bacteria type Gram positive and Gram negative

  12. Thermoluminescence dosimetry properties and kinetic parameters of lithium potassium borate glass co-doped with titanium and magnesium oxides

    International Nuclear Information System (INIS)

    Hashim, S.; Alajerami, Y.S.M.; Ramli, A.T.; Ghoshal, S.K.; Saleh, M.A.; Abdul Kadir, A.B.; Saripan, M.I.; Alzimami, K.; Bradley, D.A.; Mhareb, M.H.A.

    2014-01-01

    Lithium potassium borate (LKB) glasses co-doped with TiO 2 and MgO were prepared using the melt quenching technique. The glasses were cut into transparent chips and exposed to gamma rays of 60 Co to study their thermoluminescence (TL) properties. The TL glow curve of the Ti-doped material featured a single prominent peak at 230 °C. Additional incorporation of MgO as a co-activator enhanced the TL intensity threefold. LKB:Ti,Mg is a low-Z material (Z eff =8.89) with slow signal fading. Its radiation sensitivity is 12 times lower that the sensitivity of TLD-100. The dose response is linear at doses up to 10 3 Gy. The trap parameters, such as the kinetics order, activation energy, and frequency factor, which are related to the glow peak, were determined using TolAnal software. - Highlights: • Lithium potassium borate glass doped with Ti and Mg was prepared. • The material is close to soft tissues in terms of Zeff. • The radiation sensitivity is about 12 times lower than that of TLD-100. • The signal fades about 8% in 10 days and 17% in 3 months

  13. Development and evaluation of holmium doped phosphate glass microspheres for selective internal radiotherapy

    International Nuclear Information System (INIS)

    Barros Filho, Eraldo C.; Martinelli, Jose Roberto; Squair, Peterson L; Osso Junior, Joao A.; Sene, Frank Ferrer

    2013-01-01

    Selective Internal Radiotherapy is used to treat hepatocellular carcinoma. In this treatment 90 Y -doped aluminosilicate glass microspheres are introduced in the hepatic artery and they migrate to the liver near to the tumor where they are trapped in the arterioles. The radiation β- emitted by the decay of 90 Y annihilates the cancer cells. A macroaggregate of albumin containing technetium is previously used to monitor the lung shunt and to prevent the spreading of 90 Y during the treatment. In the present work, 165 Ho- doped phosphate glass microspheres were developed aiming that application. 165 Ho has high cross section for neutron capture (64 bars) and 166 Ho decays emitting β- radiation with appropriate energy for killing cancer cells, and gamma rays with low energy which can be used to obtain images of the microspheres location and to check possible occurrence of lung shunt. Holmium also is highly paramagnetic and can be used to obtain images whereby NMR. The glass matrix consists of (P 2 O 5 ) tetrahedrons and can be produced by a relatively lower melting temperature of chemical compounds. The 31 P decays by emitting β- radiation and contributes to the absorbed dose, helping to annihilate the cancer cells. The microspheres were produced by using two methods: the flame and the gravitation falling methods to obtain microspheres with appropriate properties. (author)

  14. Microstructure and spectroscopic investigations of calcium zinc bismuth phosphate glass ceramics doped with manganese ions

    Science.gov (United States)

    Suneel Kumar, A.; Sambasiva Rao, M. V.; Chinna Ram, G.; Krishna Rao, D.

    2018-01-01

    Multi-component 10CaF2-20ZnO-(15 - x)Bi2O3-55P2O5:xMnO (0 ≤ x ≤ 2.5) glass ceramics were synthesised by melt quenching technique and heat treatment. The prepared glass ceramics were characterised by XRD, DTA, EDS and SEM. Spectroscopic studies such as optical absorption, EPR, FTIR and Raman were also carried out on these glass ceramics. The XRD and SEM studies have indicated that ceramic samples contain well defined and randomly distributed grains of different crystalline phases. The observed increase of enthalpy from DTA patterns up to 1 mol% of MnO indicates that the crystallisation starts initially from the surface of the material then gradually it is extended to the volume of the material and this influence is meagre at higher concentrations of MnO. The absorption spectra of manganese doped glass ceramics have exhibited two types of conventional bands; one due to Mn2+ ions and other due to Mn3+ ions. The EPR spectra of MnO doped glass ceramics showed a resonance signal around g2 = 2.023 with a six line hyperfine structure and another signal at about g1 = 4.314. The relative intensity and half-width of these two signals are observed to increase with the increase in the concentration of manganese ions up to 1 mol% beyond this concentration it is found to decrease. Such observation indicates the conversion of part of Mn2+ ions into Mn3+ ions in the glass ceramic matrix. The observed increase in the intensity of symmetrical structural units at the expense of asymmetrical structural units from the FTIR and Raman spectra at higher concentration of MnO indicating that Mn2+ ions occupy the network forming positions in the glass ceramic structure.

  15. Structural and spectroscopic studies on Er{sup 3+} doped boro-tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Selvaraju, K. [Department of Physics, Gandhigram Rural University, Gandhigram - 624 302 (India); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram - 624 302 (India)

    2012-04-01

    Er{sup 3+} doped boro-tellurite glasses with the chemical composition (69-x)B{sub 2}O{sub 3}-xTeO{sub 2}-15MgO-15K{sub 2}O-1Er{sub 2}O{sub 3} (where x=0, 10, 20, 30 and 40 wt%) have been prepared and their structural and spectroscopic behavior were studied and reported. The varying tellurium dioxide content in the host matrix that results, changes in structural and spectroscopic behavior around Er{sup 3+} ions are explored through XRD, FTIR, UV-VIS-NIR and luminescence measurements. The XRD pattern confirms the amorphous nature of the prepared glasses and the FTIR spectra explore the fundamental groups and the local structural units in the prepared boro-tellurite glasses. The bonding parameters ({beta}{sup Macron} and {delta}) have been calculated from the observed band positions of the absorption spectra to claim the ionic/covalent nature of the prepared glasses. The Judd-Ofelt (JO) intensity parameters {Omega}{sub {lambda}} ({lambda}=2, 4 and 6) were determined through experimental and calculated oscillator strengths obtained from the absorption spectra and their results are studied and compared with reported literature. The variation in the JO parameters {Omega}{sub {lambda}} ({lambda}=2, 4 and 6) with the change in chemical composition have been discussed in detail. The JO parameters have also been used to derive the important radiative properties like transition probability (A), branching ratio ({beta}{sub R}) and peak stimulated emission cross-section ({sigma}{sub P}{sup E}) for the excited state transitions {sup 2}H{sub 9/2}{yields}{sup 4}I{sub 15/2} and {sup 2}H{sub 11/2} and {sup 4}S3{sub /2}{yields}{sup 4}I{sub 15/2} of the Er{sup 3+} ions and the results were studied and reported. Using Davis and Mott theory, optical band gap energy (E{sub opt}) values for the direct and indirect allowed transitions have been calculated and discussed along with the Urbach energy values for the prepared Er{sup 3+} doped boro-tellurite glasses in the present study. The

  16. Novel cerium doped glass-reinforced hydroxyapatite with antibacterial and osteoconductive properties for bone tissue regeneration

    International Nuclear Information System (INIS)

    Morais, D S; Fernandes, S; Santos, J D; Lopes, M A; Gomes, P S; Fernandes, M H; Sampaio, P; Ferraz, M P; Sooraj Hussain, N

    2015-01-01

    The aim of this work was to develop a bioactive bone substitute with an effective antibacterial ability based on a cerium (Ce) doped glass-reinforced hydroxyapatite (GR-HA) composite. Developed composites were physicochemically characterized, using x-ray diffraction (XRD) analysis, SEM, energy dispersive x-ray spectroscopy (EDS), and flexural bending strength (FBS) tests. X-ray photoelectron spectroscopy (XPS) analysis was performed to analyze the oxidation state of Ce in the prepared doped glass. The antimicrobial activity of the composites was evaluated against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa; whether the cytocompatibility profile was assayed with human osteoblastic-like cells (Mg-63 cell line). The results revealed that the Ce inclusion in the GR-HA matrix induced the antimicrobial ability of the composite. In addition, Ce-doped materials reported an adequate biological behavior following seeding of osteoblastic populations, by inducing cell adhesion and proliferation. Developed materials were also found to enhance the expression of osteoblastic-related genes. Overall, the developed GR-HA-Ce composite is a prospective candidate to be used within the clinical scenario with a successful performance due to the effective antibacterial properties and capability of enhancing the osteoblastic cell response. (paper)

  17. Formation of nanostructures in Eu3+ doped glass-ceramics: an XAS study.

    Science.gov (United States)

    Pellicer-Porres, J; Segura, A; Martínez-Criado, G; Rodríguez-Mendoza, U R; Lavín, V

    2013-01-16

    We describe the results of x-ray absorption experiments carried out to deduce structural and chemical information in Eu(3+) doped, transparent, oxyfluoride glass and nanostructured glass-ceramic samples. The spectra were measured at the Pb and Eu-L(III) edges. The Eu environment in the glass samples is observed to be similar to that of EuF(3). Complementary x-ray diffraction experiments show that thermal annealing creates β-PbF(2) type nanocrystals. X-ray absorption indicates that Eu ions act as seeds in the nanocrystal formation. There is evidence of interstitial fluorine atoms around Eu ions as well as Eu dimers. X-ray absorption at the Pb-L(III) edge shows that after the thermal treatment most lead atoms form a PbO amorphous phase and that only 10% of the lead atoms remain available to form β-PbF(2) type nanocrystals. Both x-ray diffraction and absorption point to a high Eu content in the nanocrystals. Our study suggests new approaches to the oxyfluoride glass-ceramic synthesis in order to further improve their properties.

  18. Optical properties of Sm3+ -doped TeO2sbnd WO3sbnd GeO2 glasses for solid state lasers

    Science.gov (United States)

    Subrahmanyam, T.; Gopal, K. Rama; Suvarna, R. Padma; Jamalaiah, B. Chinna; Rao, Ch Srinivasa

    2018-03-01

    Sm3+ -doped oxyfluoride tellurite-tungsten (TWGSm) glasses were prepared by conventional melt quenching method. The optical properties were investigated through photoluminescence excitation, emission and luminescence decay analysis. The optical band gap energy was determined as ∼3.425 eV for 1.0 mol% of Sm3+ -doped TWGSm glass. Upon 404 nm excitation, the TWGSm glasses emit luminescence through 4G5/2 → 6H5/2 (563 nm), 4G5/2 → 6H7/2 (600 nm), 4G5/2 → 6H9/2 (645 nm) and 4G5/2 → 6H11/2 (705 nm) transitions. The Judd-Ofelt analysis was performed using absorption spectrum and obtained radiative parameters were used to estimate the laser characteristics of present glasses. The concentration of Sm3+ has been optimized as 1.0 mol% for efficient luminescence. The luminescence decay of 4G5/2 emission level was studied by monitoring the emission and excitation wavelengths at 600 and 404 nm, respectively. The experimental lifetime of 4G5/2 level was decrease with increase of Sm3+ concentration. The 1.0 mol% of Sm3+ -doped TWGSm glass could be the best choice for solid state visible lasers to emit orange luminescence.

  19. Electronic and magnetic properties of 3d-metal trioxides superhalogen cluster-doped monolayer MoS2: A first-principles study

    International Nuclear Information System (INIS)

    Li, Dan; Niu, Yuan; Zhao, Hongmin; Liang, Chunjun; He, Zhiqun

    2014-01-01

    Utilizing first-principle calculations, the structural, electronic, and magnetic properties of monolayer MoS 2 doped with 3d transition-metal (TM) atoms and 3d-metal trioxides (TMO 3 ) superhalogen clusters are investigated. 3d-metal TMO 3 superhalogen cluster-doped monolayers MoS 2 almost have negative formation energies except CoO 3 and NiO 3 doped monolayer MoS 2 , which are much lower than those of 3d TM-doped structures. 3d-metal TMO 3 superhalogen clusters are more easily embedded in monolayer MoS 2 than 3d-metal atoms. MnO 3 , FeO 3 , CoO 3 , and NiO 3 incorporated into monolayer MoS 2 are magnetic, and the total magnetic moments are approximately 1.0, 2.0, 3.0, and 4.0 μB per supercell, respectively. MnO 3 and FeO 3 incorporated into monolayer MoS 2 become semiconductors, whereas CoO 3 and NiO 3 incorporated into monolayer MoS 2 become half-metallic. Our studies demonstrate that the half-metallic ferromagnetic nature of 3d-metal TMO 3 superhalogen clusters-doped monolayer MoS 2 has a great potential for MoS 2 -based spintronic device applications. -- Highlights: •TMO 3 superhalogen clusters incorporated into monolayer MoS 2 were investigated. •TMO 3 doped structures have much lower formation energies than TM doped structures. •TMO 3 cluster-doped MoS 2 are thermodynamically favored. •Significant charge transfers between O atoms and Mo atoms in TMO 3 doped structures. •MnO 3 , FeO 3 , CoO 3 , and NiO 3 incorporated into monolayer MoS 2 are magnetic.

  20. Modifications in silver-doped silicate glasses induced by ns laser beams

    Energy Technology Data Exchange (ETDEWEB)

    Cattaruzza, E., E-mail: cattaruz@unive.it [Physical Chemistry Department, Universita Ca Foscari Venezia, via Torino 155/b, I-30172 Venezia-Mestre (Italy); Mardegan, M. [Physical Chemistry Department, Universita Ca Foscari Venezia, via Torino 155/b, I-30172 Venezia-Mestre (Italy); Trave, E. [Physical Chemistry Department, Universita Ca Foscari Venezia, Dorsoduro 2137, I-30123 Venezia (Italy); Battaglin, G. [Physical Chemistry Department, Universita Ca Foscari Venezia, via Torino 155/b, I-30172 Venezia-Mestre (Italy); Calvelli, P. [Physical Chemistry Department, Universita Ca' Foscari Venezia, Dorsoduro 2137, I-30123 Venezia (Italy); Enrichi, F. [Associazione CIVEN and Nanofab S.c.a.r.l., via delle Industrie 5, I-30175 Venezia-Marghera (Italy); Gonella, F. [Physical Chemistry Department, Universita Ca Foscari Venezia, Dorsoduro 2137, I-30123 Venezia (Italy)

    2011-04-01

    Glass layers for planar light waveguides prepared by Ag-Na ion exchange of different silicate glasses in molten salt baths are annealed and/or irradiated with a laser beam in the UV region, with different energy density values and total pulse numbers. The samples are mainly characterized by optical absorption spectroscopy, luminescence spectroscopy, and Rutherford backscattering spectrometry, in order to determine the role of irradiation parameters and of the host matrix structure in the aggregation phenomena. Photoluminescence spectroscopy gave information regarding the presence of Ag multimeric aggregates, the primal seeds for the growing (nano)crystals. The appearance of the plasmon resonance band in the optical absorption spectra proved the formation of Ag clusters and allowed the evolution steps of the clusterization process to be followed as a function of the energy deposited during the laser irradiation.

  1. Study on the water durability of zinc boro-phosphate glasses doped with MgO, Fe2O3, and TiO2

    Science.gov (United States)

    Hwang, Moon Kyung; Ryu, Bong Ki

    2016-07-01

    The water durability of zinc boro-phosphate (PZB) glasses with the composition 60P2O5-20ZnO-20B2O3- xMeO ( x = 0, 2, 4, 6 and MeO = MgO, Fe2O3, or TiO2) (mol%) was measured, and PZB glass was studied in terms of its thermal properties, density, and FTIR characteristics. The surface conditions and corrosion byproducts were analyzed using scanning electron microscopy. When MgO, Fe2O3, and TiO2 were doped into the PZB glass, Q2 was decreased and Q1 was increased in the phosphate structure, while the number of BO4 structures increased with increasing MeO content. The density of the PZB glass was increased by the addition of Fe2O3 and TiO2, while the glass transition temperature ( T g ) and dilatometric softening temperature ( T d ) were increased when additional MgO, Fe2O3, and TiO2 were added. From the weight loss analysis (95 ◦ C, 96 h), TiO2 doped glass showed the lowest weight loss (1.70 × 10 -3 g/cm2) while MgO doped glass showed the highest value (2.44 × 10 -3 g/cm2), compared with PZB glass (3.07 × 10 -3 g/cm2). These results were discussed in terms of the Me n+ ions in the glass structure, and their different coordination numbers and bonding strengths.

  2. New Er{sup 3+} doped antimony oxide based glasses: Thermal analysis, structural and spectral properties

    Energy Technology Data Exchange (ETDEWEB)

    Ouannes, K. [Faculté des Sciences et de la Technologie, Université de Biskra, BP 145 RP, 07000, Biskra (Algeria); Lebbou, K., E-mail: kheirreddine.lebbou@univ-lyon1.fr [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622, Villeurbanne (France); Walsh, Brian-M. [NASA Langley Research Center, Hampton, VA, 23681 (United States); Poulain, M. [UMR 6226- Verres et Céramiques – Campus de Beaulieu, Université de Rennes1, 35042, Rennes (France); Alombert-Goget, G.; Guyot, Y. [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622, Villeurbanne (France)

    2015-11-15

    The novel oxide glass compositions based on Sb{sub 2}O{sub 3} are elaborated and characterized, in the system (90-X)Sb{sub 2}O{sub 3}–10Na{sub 2}O–XBi{sub 2}O{sub 3} (SNB). We are interested in bismuth rates incorporated into the glass, its effect on the different physical properties that have been measured, and especially, in radiative and spectroscopic properties of erbium doped SNB glasses. Differential scanning calorimeter (DSC) measurements show an improvement of the stability factor,ΔT, of the glasses, which can indicate a reinforcement of the network. Both FTIR and Raman spectra have also been considered in terms of bismuth influence. As a function of composition, we have principally measured optical absorption, visible and infrared emission, and lifetime. The Judd–Ofelt parameters measured from the absorption spectra have been used to calculate the radiative lifetime (τ{sub r}) and the stimulated emission cross section. The spectroscopic quality factor χ = Ω{sub 4}/Ω{sub 6} = 0.73, low phonon energy of ∼600–700 cm{sup −1}, a reduced quenching effect, and a high quantum efficiency of 90% for the 1.53 μm measured emission, by pumping at 980 nm, are in favor of promising laser applications. - Highlights: • Glass belonging to Er-doped Sb{sub 2}O{sub 3}–Na{sub 2}O–Bi{sub 2}O{sub 3} (SNB) system are elaborated and characterized. • The intensity parameters Ωt were obtained via the Judd–Ofelt theory. • The optical properties were studied as a function of glass composition.

  3. Spectroscopic investigation of zinc tellurite glasses doped with Yb3 + and Er3 + ions

    Science.gov (United States)

    Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

    2016-08-01

    This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80 - x - y) TeO2 + (0.20) ZnO + xEr2O3 + yYb2O3 (x = 0, y = 0; x = 0.004, y = 0; x = 0, y = 0.05 and x = 0.004, y = 0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er3 + glasses as erbium doped fiber amplifiers at 1.55 μm in infrared emission region.

  4. Structural and luminescence properties of Mn{sup 2+} ions doped calcium zinc borophosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Ming Hua, E-mail: wanminghua819@gmail.com [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Wong, Poh Sum, E-mail: pohsumwong@gmail.com [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Hussin, Rosli, E-mail: roslihussin@utm.my [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Lintang, Hendrik O., E-mail: hendrik@ibnusina.utm.my [Catalytic Science and Technology (CST) Research Group, Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Endud, Salasiah, E-mail: salasiah@kimia.fs.utm.my [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia)

    2014-05-15

    Highlights: • FT-IR revealed that the network structures are from borate and phosphate network. • The PL spectrum exhibits a green emission band at 582 nm ({sup 4}T{sub 1g} → {sup 6}A{sub 1g}). • As the concentration of Mn{sup 2+} ions is increased, the emission band had been red shifted. • These glasses are found to have potential applications as luminescent optical materials. - Abstract: Calcium zinc borophosphate glasses (CaZnBP) doped with various concentrations of Mn{sup 2+} ions and borate and phosphate as variable were prepared using conventional melt quenching technique. The structure of obtained glasses were examined by means of use: X-ray diffraction (XRD) and fourier transform infrared (FT-IR). XRD analysis confirmed amorphous nature of glass samples. The FT-IR spectra reveals the presence of both borate and phosphate vibrational modes in the prepared glasses. The doping of Mn{sup 2+} ions (2–10 mol%) shows no significant changes in the main IR vibrational bands. Optical properties were studied by measuring the near infrared photoluminescence (PL) spectra. CaZnBP glasses exhibited intense green emission peak (582 nm) (tetrahedral symmetry), which is assigned to a transition from the upper {sup 4}T{sub 1g} → {sup 6}A{sub 1g} ground state of Mn{sup 2+} ions. As the concentration of Mn{sup 2+} ions increases, the emission band increases from 582 nm to 650 nm and exhibited a red light emission (octahedral symmetry). The decay curves of {sup 4}T{sub 1g} level were examined for all concentrations and the measured lifetimes are found to depend strongly on Mn{sup 2+} concentrations. From the emission characteristic parameters of {sup 6}A{sub 1g} (S) level, it shows that the CaZnBP glasses could have potential applications as luminescent optical materials, visible lasers and fluorescent display devices.

  5. Reactive magnetron sputtering of N-doped carbon thin films on quartz glass for transmission photocathode applications

    Science.gov (United States)

    Balalykin, N. I.; Huran, J.; Nozdrin, M. A.; Feshchenko, A. A.; Kobzev, A. P.; Sasinková, V.; Boháček, P.; Arbet, J.

    2018-03-01

    N-doped carbon thin films were deposited on a silicon substrate and quartz glass by RF reactive magnetron sputtering using a carbon target and an Ar+N2 gas mixture. During the magnetron sputtering, the substrate holder temperatures was kept at 800 °C. The carbon film thickness on the silicon substrate was about 70 nm, while on the quartz glass it was in the range 15 nm – 60 nm. The elemental concentration in the films was determined by RBS and ERD. Raman spectroscopy was used to evaluate the intensity ratios I D/I G of the D and G peaks of the carbon films. The transmission photocathodes prepared were placed in the hollow-cathode assembly of a Pierce-structure DC gun to produce photoelectrons. The quantum efficiency (QE) was calculated from the laser energy and cathode charge measured. The properties of the transmission photocathodes based on semitransparent N-doped carbon thin films on quartz glass and their potential for application in DC gun technology are discussed.

  6. Characterization of standard reference material 2944, Bi-ion-doped glass, spectral correction standard for red fluorescence

    International Nuclear Information System (INIS)

    DeRose, Paul C.; Smith, Melody V.; Anderson, Jeffrey R.; Kramer, Gary W.

    2013-01-01

    Standard Reference Material (SRM) 2944 is a cuvette-shaped, Bi-ion-doped glass, recommended for optimal use for relative spectral correction of emission from 590 nm to 805 nm and day-to-day performance verification of steady-state fluorescence spectrometers. Properties of this standard that influence its effective use or contribute to the uncertainty in its certified emission spectrum were explored here. These properties include its photostability, absorbance, dissolution rate in water, anisotropy and temperature coefficient of fluorescence intensity. The expanded uncertainties (k=2) in the certified spectrum are about 4% around the nominal peak maximum at 704 nm and increase to about 6% at the wings, using an excitation wavelength of 515 nm. -- Highlights: ► The fluorescence emission spectrum of SRM 2944 was determined for spectral correction. ► This Bi-ion-doped glass has been certified in the fluorescence region from 530 nm to 830 nm. ► Fluorescence properties of the glass were determined, e.g., anisotropy, lifetime. ► SRM 2944 is photostable under common visible lamp excitation, when UV light is not present

  7. Scintillation properties and X-ray irradiation hardness of Ce3+-doped Gd2O3-based scintillation glass

    International Nuclear Information System (INIS)

    Liu, Liwan; Shao, Chongyun; Zhang, Yu; Liao, Xili; Yang, Qiuhong; Hu, Lili; Chen, Danping

    2016-01-01

    Ce 3+ -doped Gd 2 O 3 -based scintillation glasses are prepared within an air or CO atmosphere. The effects of fluorine, lutetium, barium, and the melting atmosphere on the optical properties, scintillation properties and irradiation hardness are studied. Absorption spectra, luminescence spectra under UV and X-ray excitation, and the X-ray radiation-induced spectra are presented. The results show that the density can be increased by doping with fluorine, lutetium and barium. The luminescence intensity decreases after X-ray irradiation. Because of charge transfer quenching, fluorine and lutetium enhance the UV-excited and X-ray excited luminescence intensity, but barium decreases. Moreover, fluorine and lutetium are advantageous to irradiation hardness while barium is not. In addition, a non-reducing atmosphere provides a higher irradiation hardness than a reducing atmosphere. Fluorine-doped glass is promising to enhance luminescence intensity, promote irradiation hardness, and increase the density.

  8. White upconversion luminescence in Tm3+/Ho3+/Yb3+ triply doped K+-Na+ ion-exchanged aluminum germanate glass channel waveguide

    Science.gov (United States)

    Liu, Xiao; Chen, Baojie; Pun, Edwin Yue Bun; Lin, Hai

    2013-01-01

    Rare-earth ions doped K+-Na+ ion-exchanged aluminum germanate (NMAG) glass channel waveguides have been designed and fabricated. Under 980 nm laser pumping, an intense upconversion white light transmission trace was observed in Tm3+/Ho3+/Yb3+ triply doped NMAG glass channel waveguide and a high-brightness light spot was achieved from the output end of the fiber connected to the waveguide channel. The fluorescent colors were diverse and located within or near the white region in CIE chromaticity diagram under various pumping powers. These admirable results indicate that Tm3+/Ho3+/Yb3+ triply doped NMAG channel waveguide is a promising light source for medical and high-precision processing illumination.

  9. Violet and visible up-conversion emission in Yb{sup 3+}-Ho{sup 3+} co-doped germanium-borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yanmin, E-mail: mihuyym@163.co [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Zhang Meixin [Forensic Science Lab, Hebei University, Baoding 071002 (China); Yang Zhiping [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Fu Zuoling [Key Laboratory of Coherent Light, Atomic and Molecular Spectroscopy, College of physics, Jilin University, Ministry of Education, Changchun 130023 (China)

    2010-10-15

    The up-conversion emission properties of Yb{sup 3+}-Ho{sup 3+} co-doped germanium-borate glasses have been investigated with 980 nm excitation. The violet, blue, green and red emission bands at about 350, 485, 544 and 653 nm can be identified, respectively. Experimental results indicated that the relative intensity ratios of the peaks I{sub Red}/I{sub Green} increased with increasing B{sub 2}O{sub 3} concentration, which led to changing color of up-conversion emission from green at x=0 to yellow at x=40, to red at x=60. The violet emission at 350 nm was first reported in germanium-borate glass host and up-conversion mechanisms of the emissions were discussed. The Yb{sup 3+}-Ho{sup 3+} co-doped germanium-borate glasses could be an alternative for the generation of violet and primary colors for application in solid-state displays.

  10. Near-infrared optical properties of Yb3+-doped silicate glass waveguides prepared by double-energy proton implantation

    Science.gov (United States)

    Shen, Xiao-Liang; Zhu, Qi-Feng; Zheng, Rui-Lin; Lv, Peng; Guo, Hai-Tao; Liu, Chun-Xiao

    2018-03-01

    We report on the preparation and properties of an optical planar waveguide structure operating at 1539 nm in the Yb3+-doped silicate glass. The waveguide was formed by using (470 + 500) keV proton implantation at fluences of (1.0 + 2.0) × 1016 ions/cm2. The waveguiding characteristics including the guided-mode spectrum and the near-field image were investigated by the m-line technique and the finite-difference beam propagation method. The energy distribution for implanted protons and the refractive index profile for the proton-implanted waveguide were simulated by the stopping and range of ions in matter and the reflectivity calculation method. The proton-implanted Yb3+-doped silicate glass waveguide is a candidate for optoelectronic elements in the near-infrared region.

  11. Absorption Spectroscopy Analysis of Calcium-Phosphate Glasses Highly Doped with Monovalent Copper.

    Science.gov (United States)

    Jiménez, José A

    2016-06-03

    CaO-P2 O5 glasses with high concentrations of monovalent copper ions were prepared by a simple melt-quench method through CuO and SnO co-doping. Spectroscopic characterization was carried out by optical absorption with the aim of analyzing the effects of Cu(+) ions on the optical band-gap energies, which were estimated on the basis of indirect-allowed transitions. The copper(I) content is estimated in the CuO/SnO-containing glasses after the assessment of the concentration dependence of Cu(2+) absorption in the visible region for CuO singly doped glasses. An exponential dependence of the change in optical band gaps (relative to the host) with Cu(+) concentration is inferred up to about 10 mol %. However, the entire range is divided into two distinct linear regions that are characterized by different rates of change with respect to concentration: 1) below 5 mol %, where the linear dependence presents a relatively high magnitude of the slope; and 2) from 5-10 mol %, where a lower magnitude of the slope is manifested. With increasing concentration, the mean Cu(+) -Cu(+) interionic distance decreases, thereby decreasing the sensitivity of monovalent copper for light absorption. The decrease in optical band-gap energies is ultimately shown to follow a linear dependence with the interionic distance, suggesting the potential of the approach to gauge the concentration of monovalent copper straightforwardly in amorphous hosts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Fluorescence properties of Yb3+-Er3+ co-doped phosphate glasses containing silver nanoparticles

    Science.gov (United States)

    Martínez Gámez, Ma A.; Vallejo H, Miguel A.; Kiryanov, A. V.; Licea-Jiménez, L.; Lucio M, J. L.; Pérez-García, S. A.

    2018-04-01

    Er3+-Yb3+ co-doped phosphate glasses containing silver nitrate (SN), were fabricated. Transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS) analyses were used to evidence the nucleation and presence of silver nanoparticles (SNP). The basic parameters of the glasses were inspected by means of absorption and fluorescence spectra, and fluorescence lifetimes under excitation at 916 nm (in-band of Yb3+), and at 406 nm (in-band of surface plasmon resonance given by the presence of SNP). The spectra as well as estimates for the basic parameters defining the lasing/amplifying potential of the glasses were studied as a function of SN concentration. The experimental results indicate that by increasing the SN content an enhancement of Er3+/Yb3+ fluorescence takes place.

  13. Influence of clusters in melt on the subsequent glass-formation and crystallization of Fe–Si–B metallic glasses

    Directory of Open Access Journals (Sweden)

    Shaoxiong Zhou

    2015-04-01

    Full Text Available The liquid structure of seven representative Fe–Si–B alloys has been investigated by ab initio molecular dynamics simulation focusing on the role of clusters in terms of glass-forming ability (GFA and crystallization. It is demonstrated that the type of primary phase precipitated from amorphous state under heat treatment is determined by the relative fraction and role of various clusters in melt. The alloy melt shows higher stability and resultantly larger GFA when there is no dominant cluster or several clusters coexist, which explains the different GFAs and crystallization processes at various ratios of Si and B in the Fe–Si–B system. The close correlation among clusters, crystalline phase and GFA is also studied.

  14. Rare-Earth Oxide Ion (Tm3+, Ho3+, and U3+) Doped Glasses and Fibres for 1.8 to 4 Micrometer Coherent and Broadband Sources

    Science.gov (United States)

    2006-07-24

    oxide ( TeO2 ) , fluorine- containing silicate (SiOF2) and germanate (GeOF2) glass hosts for each dopant by characterising the spectroscopic properties...Earth Oxide Ion (Tm3+, Ho3+, And U3+) Doped Glasses And Fibres For 1.8 To 4 Micrometer Coherent And Broadband Sources 5c. PROGRAM ELEMENT NUMBER 5d...Rare-earth oxide ion (Tm3+, Ho3+, and U3+) doped glasses and fibres for 1.8 to 4 micrometer coherent and broadband sources Report prepared

  15. Highly Doped Phosphate Glass Fibers for Compact Lasers and Amplifiers: A Review

    Directory of Open Access Journals (Sweden)

    Nadia Giovanna Boetti

    2017-12-01

    Full Text Available In recent years, the exploitation of compact laser sources and amplifiers in fiber form has found extensive applications in industrial and scientific fields. The fiber format offers compactness, high beam quality through single-mode regime and excellent heat dissipation, thus leading to high laser reliability and long-term stability. The realization of devices based on this technology requires an active medium with high optical gain over a short length to increase efficiency while mitigating nonlinear optical effects. Multicomponent phosphate glasses meet these requirements thanks to the high solubility of rare-earth ions in their glass matrix, alongside with high emission cross-sections, chemical stability and high optical damage threshold. In this paper, we review recent advances in the field thanks to the combination of highly-doped phosphate glasses and innovative fiber drawing techniques. We also present the main performance achievements and outlook both in continuous wave (CW and pulsed mode regimes.

  16. Investigations on optical properties of Sm3+ ion doped boro-phosphate glasses

    Science.gov (United States)

    Vijayakumar, R.; Suthanthirakumar, P.; Karthikeyan, P.; Marimuthu, K.

    2015-06-01

    The Sm3+ doped Boro-phosphate glasses with the chemical composition 60H3BO3+20Li2CO3+10ZnO+(10-x) H6NO4P+xSm2O3 (where x= 0.1, 0.5, 1 and 2 in wt%) have been prepared by melt quenching technique. The prepared glasses were characterized through optical absorption and luminescence spectral measurements. The band gap energies corresponding to the direct and indirect allowed transitions and the Urbach's energy values were estimated from the absorption spectra. Judd-Ofelt intensity parameters have been derived to predict the radiative properties of the various emission transitions. In order to identify the emission color of the prepared glasses, the emission intensities were analyzed using CIE 1931 color chromaticity diagram. The energy transfer process takes place between Sm3+-Sm3+ ions through cross-relaxation mechanism have also been investigated and the results were discussed and reported.

  17. Application of glass particles doped by Zn{sup +2} as an antimicrobial and atoxic compound in LLDPE and HDPE

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M.F. [Post-Graduate Program in Science and Materials Engineering, Universidade do Extremo Sul Catarianese/UNESC, Av. Universitária, 1105, CEP 88806-000, Criciúma, Santa Catarina (Brazil); Machado, C.; Tachinski, C.G.; Júnior, J.F.; Piletti, R. [Laboratory of Advanced Materials and Processes, Universidade do Extremo Sul Catarianese/UNESC, iParque, Rod. Gov. Jorge Lacerda, km 4,5, CEP 88806-000, Criciúma, SC (Brazil); Peterson, M. [Post-Graduate Program in Science and Materials Engineering, Universidade do Extremo Sul Catarianese/UNESC, Av. Universitária, 1105, CEP 88806-000, Criciúma, Santa Catarina (Brazil); Laboratory of Advanced Materials and Processes, Universidade do Extremo Sul Catarianese/UNESC, iParque, Rod. Gov. Jorge Lacerda, km 4,5, CEP 88806-000, Criciúma, SC (Brazil); Fiori, M.A., E-mail: fiori@unochapeco.edu.br [Post-Graduation Program in Environmental Science, Universidade Comunitária da Região de Chapecó (Unochapecó), Chapecó, SC (Brazil); Post-Graduation Program in Technology and Management of the Innovation, Universidade Comunitária da Região de Chapecó (Unochapecó), Chapecó, SC (Brazil)

    2014-06-01

    This study demonstrates the potential application of glass particles doped with Zn{sup +2} (GZn) as an atoxic, antimicrobial additive when used in conjunction with high density polyethylene (HDPE) and linear low density polyethylene (LLDPE) polymers. Toxicity tests demonstrated that these modified glass particles were nontoxic to human cells, and atomic absorption analyses demonstrated the migration of ionic species in quantities less than 2.0 ppm for both the HDPE/GZn and LLDPE/GZn compounds. Microbiological tests demonstrated the antimicrobial effect of the pure GZn compound as well as the polymeric HDPE/GZn and LLDPE/GZn compounds. In addition, at percentages of GZn higher than 2.00 wt.% and at a time of 4 h, the bactericidal performance is excellent and equal for both polymeric compounds. - Highlights: • Glass doped with Zn{sup +2} (GZn) promoted a good bactericidal properties in LLDPE and HDPE. • LLDPE and HDPE doped with GZn have capacity of liberty ionic zinc during a time period. • GZn is not toxic to human and can be used with antimicrobial additive to polymers. • GZn has an antimicrobial effect in bacteria type Gram positive and Gram negative.

  18. Thermodynamic evidence for cluster ordering in Cu46Zr42Al7Y5 ribbons during glass transition

    DEFF Research Database (Denmark)

    Zheng, H.J.; Lv, Y.M.; Sun, Q.J.

    2016-01-01

    This work investigated the response of Cu46Zr42Al7Y5 glass ribbons to both dynamic and static heating using differential scanning calorimeter (DSC). The DSC curve manifests three exothermic responses to dynamic heating, among which the first and the third one are the signatures of the normal sub......-Tg (Tg, glass transition temperature) relaxation and the crystallization process, respectively. The second one is attributed to a partial overlap between the endothermic response to the glass transition and the exothermic response to the formation of ordered clusters. The cluster ordering, which begins...... at the final stage of glass transition, has been verified by the differences in the activation energy of the sub-Tg relaxation, the cluster ordering and primary crystallization for both the as-spun and annealed ribbons. The cluster ordering could be driven by the large difference between the Zr–Y mixing...

  19. Eu{sup 2+}-doped OH{sup −} free calcium aluminosilicate glass: A phosphor for smart lighting

    Energy Technology Data Exchange (ETDEWEB)

    Lima, S.M., E-mail: smlima@uems.br [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, C. P. 351, CEP 79804-970 Dourados, MS (Brazil); Andrade, L.H.C.; Rocha, A.C.P. [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, C. P. 351, CEP 79804-970 Dourados, MS (Brazil); Silva, J.R.; Farias, A.M.; Medina, A.N.; Baesso, M.L. [Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900 Maringá, PR (Brazil); Nunes, L.A.O. [Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, SP (Brazil); Guyot, Y.; Boulon, G. [Laboratoire de Physico-Chimie des Matériaux Luminescents, Université de Lyon 1, UMR 5620 CNRS, 69622 Villeurbanne (France)

    2013-11-15

    In this paper, a broad emission band from Eu{sup 2+}-doped OH{sup −} free calcium aluminosilicate glass is reported. By changing the excitation wavelengths, the results showed it is possible to tune the emission from green to orange, what combined with the scattered light from the same blue LED used for excitation, provided a color rendering index of 71 and a correlated color temperature of 6550 K. Our preliminary tests indicate this material as a promising phosphor towards the development of smart lighting devices. -- Highlights: • We report a broad emission band from Eu{sup 2+}-doped OH{sup −} free calcium aluminosilicate glass. • The maximum emission peak can be tune from green to orange region. • The test with a LED provided a color rendering index of 71 and a correlated color temperature of 6550 K.

  20. A first-principles study of structure, orbital interactions and atomic oxygen and OH adsorption on Mo-, Sc- and Y-doped nickel bimetallic clusters

    International Nuclear Information System (INIS)

    Das, Nishith Kumar; Shoji, Tetsuo

    2013-01-01

    Highlights: •Mo-doped nickel clusters are energetically more stable than the Sc and Y-doped clusters (n ⩾ 10). •Mo atom exhibits center at the cluster rather than edge, while Sc and Y atom sit at the edge. •The metallic s, d orbitals are mainly dominated on the stability of nanoclusters. •The oxygen and OH adsorption energy of Mo-doped cluster are higher than those of other nanoclusters. •2p Orbitals are strongly bonds with Mo 4d, and a weakly interacts with Ni 3d, 4s and Mo 5s orbitals. -- Abstract: Density functional theory (DFT) has been used to study the stability, orbitals interactions and oxygen and hydroxyl chemisorption properties of Ni n M (1 ⩽ n ⩽ 12) clusters. A single atom doped-nickel clusters increase the stability, and icosahedral Ni 12 Mo cluster is the most stable structure. Molybdenum atom prefers to exhibit center at the cluster (n ⩾ 10) rather than edge, while Sc and Y atom remain at the edge. The Ni–Mo bond lengths are smaller than the Ni–Sc and Ni–Y. The pDOS results show that the d–d orbitals interactions are mainly dominating on the stability of clusters, while p orbitals have a small effect on the stability. The Mo-doped nanoclusters have the highest oxygen and OH chemisorption energy, and the most favorable adsorption site is on the top Mo site. The larger cluster distortion is found for the Sc- and Y-doped structures compared to other clusters. The oxygen 2p orbitals are strongly hybridizing with the Mo 4d orbitals (n < 9) and a little interaction between oxygen 2p and Ni 3d, 4s and Mo 5s orbitals. The Mo-doped clusters are significantly increased the chemisorption energies that might improve the passive film adherence of nanoalloys

  1. Luminescence investigations of rare earth doped lead-free borate glasses modified by MO (M = Ca, Sr, Ba)

    Energy Technology Data Exchange (ETDEWEB)

    Janek, Joanna, E-mail: janek.joanna@gmail.com; Sołtys, Marta; Żur, Lidia; Pietrasik, Ewa; Pisarska, Joanna; Pisarski, Wojciech A.

    2016-09-01

    Series of lead-free borate glasses with different oxide modifiers and lanthanide ions were prepared. The effect of oxide modifiers MO (M = Ca, Sr, Ba) on spectroscopic properties of trivalent Ln{sup 3+} (Ln = Eu, Er, Pr) were systematically investigated. Especially, the luminescence spectra of Ln{sup 3+}-doped lead-free borate glasses are presented and discussed in relation to the impact of selective components (CaO, SrO and BaO). Several spectroscopic parameters, such as the fluorescence intensity ratio R/O (Eu{sup 3+}) and measured luminescence lifetimes for the {sup 5}D{sub 0} (Eu{sup 3+}), {sup 4}I{sub 13/2} (Er{sup 3+}) and {sup 1}D{sub 2} (Pr{sup 3+}) excited states of lanthanide ions were analyzed in details. The research proved that spectroscopic properties of trivalent Ln{sup 3+} depend significantly on kind of presence oxide modifiers MO (M = Ca, Sr, Ba) in glass host matrices. - Highlights: • Luminescence of Ln{sup 3+}-doped borate glasses was presented and discussed. • Effect of glass modifiers on spectroscopic properties of rare earths was studied. • Measured luminescence lifetimes of Ln{sup 3+} (Ln = Eu, Er, Pr) were analyzed. • Luminescence intensity ratios R/O (Eu{sup 3+}) were determined.

  2. Magnetic cluster mean-field description of spin glasses in amorphous La-Gd-Au alloys

    International Nuclear Information System (INIS)

    Poon, S.J.; Durand, J.

    1978-03-01

    Bulk magnetic properties of splat-cooled amorphous alloys of composition La/sub 80-x/Gd/sub x/Au 20 (0 less than or equal to x less than or equal to 80) were studied. Zero-field susceptibility, high-field magnetization (up to 75 kOe) and saturated remanence were measured between 1.8 and 290 0 K. Data were analyzed using a cluster mean-field approximation for the spin-glass and mictomagnetic alloys (x less than or equal to 56). Mean-field theories can account for the experimental freezing-temperatures of dilute spin-glasses in which the Ruderman-Kittel-Kasuya-Yosida interaction is dominant. For the dilute alloys, the role of amorphousness on the magnetic interactions is discussed. By extending the mean-field approximation, the concentrated spin-glasses are represented by rigid ferromagnetic clusters as individual spin-entities interacting via random forces. Scaling laws for the magnetization M and saturation remanent magnetization M/sub rs/ are obtained and presented graphically for the x less than or equal to 32 alloys in which M/x = g(H/x*, T/x), M/sub rs/(T)/x = M/sub rs/(0)/x/ exp (-α*T/x/sup p/) where x* is the concentration of clusters, α* is a constant, and p is the freezing-temperature exponent given by T/sub M/ infinity x/sup p/. It is found that p = 1 and 1.3 for the regions 4 less than or equal to x less than or equal to 40 respectively. An attempt is also made to account for the freezing temperatures of concentrated spin glasses. The strength of the interaction among clusters is determined from high-field magnetization measurements using the Larkin-Smith method modified for clusters. It is shown that for the x < 24 alloys, the size of the clusters can be correlated to the structural short-range order in the amorphous state. More concentrated alloys are marked by the emergence of cluster percolation

  3. Towards modular bone tissue engineering using Ti-Co-doped phosphate glass microspheres: cytocompatibility and dynamic culture studies.

    Science.gov (United States)

    Peticone, Carlotta; De Silva Thompson, David; Owens, Gareth J; Kim, Hae-Won; Micheletti, Martina; Knowles, Jonathan C; Wall, Ivan

    2017-09-01

    The production of large quantities of functional vascularized bone tissue ex vivo still represent an unmet clinical challenge. Microcarriers offer a potential solution to scalable manufacture of bone tissue due to their high surface area-to-volume ratio and the capacity to be assembled using a modular approach. Microcarriers made of phosphate bioactive glass doped with titanium dioxide have been previously shown to enhance proliferation of osteoblast progenitors and maturation towards functional osteoblasts. Furthemore, doping with cobalt appears to mimic hypoxic conditions that have a key role in promoting angiogenesis. This characteristic could be exploited to meet the clinical requirement of producing vascularized units of bone tissue. In the current study, the human osteosarcoma cell line MG-63 was cultured on phosphate glass microspheres doped with 5% mol titanium dioxide and different concentrations of cobalt oxide (0%, 2% and 5% mol), under static and dynamic conditions (150 and 300 rpm on an orbital shaker). Cell proliferation and the formation of aggregates of cells and microspheres were observed over a period of two weeks in all glass compositions, thus confirming the biocompatibility of the substrate and the suitability of this system for the formation of compact micro-units of tissue. At the concentrations tested, cobalt was not found to be cytotoxic and did not alter cell metabolism. On the other hand, the dynamic environment played a key role, with moderate agitation having a positive effect on cell proliferation while higher agitation resulting in impaired cell growth. Finally, in static culture assays, the capacity of cobalt doping to induce vascular endothelial growth factor (VEGF) upregulation by osteoblastic cells was observed, but was not found to increase linearly with cobalt oxide content. In conclusion, Ti-Co phosphate glasses were found to support osteoblastic cell growth and aggregate formation that is a necessary precursor to tissue

  4. Effect of B2O3 on luminescence of erbium doped tellurite glasses.

    Science.gov (United States)

    Shen, Xiang; Nie, Qiuhua; Xu, Tiefeng; Dai, Shixun; Wang, Xunsi

    2007-02-01

    The B2O3 was introduced into the Er3+ doped TeO2-ZnO-Na2O glass to increase the phonon energy of the host. The effect of B2O3 on the non-radiative rate of the 4I11/2-->4I13/2 transition of Er3+, the lifetime of the 4I11/2 and 4I13/2 levels, the green and red upconversion emissions intensity, and the 4I13/2-->4I15/2 emission intensity was discussed. The results show that the phonon energy of boro-tellurite glass is close to that of germanate glass and is quite smaller than that of borate glass. The lifetime of 4I11/2 level and the upconversion emissions decrease with increasing B2O3 concentration. The higher OH group concentration presented in the boro-tellurite glass may shorten the lifetime of 4I13/2 level and also reduce the quantum efficiency of 4I13/2-->4I15/2 emission. The future dehydrating procedures are suggested to enhance the efficiency of amplification at 1.5 microm band.

  5. Luminescence studies on Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses for WLED applications

    Science.gov (United States)

    Vijayakumar, M.; Uma, V.; Arunkumar, S.; Marimuthu, K.

    2015-06-01

    Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses have been prepared and optically characterized using absorption, luminescence and decay measurements. The Nephelauxetic ratios (β), Bonding parameters (δ) and Judd-Ofelt (JO) intensity parameters Ωλ (λ = 2, 4 and 6) were calculated to study the nature of the environment around the RE3+ ions in the prepared glasses. The yellow to blue (Y/B) intensity ratio and the chromaticity color coordinates were calculated from the luminescence measurements. The lifetimes of the 4F9/2 excited level were measured using decay curves and is found to decrease in the Dy3+:Eu3+ co-doped glass due to the occurrence of resonant energy transfer between Dy3+-Eu3+ ions and the non-exponential decay rates have been fitted with Inokuti-Hirayama (IH) model. The decay curves are well fitted for S= 6 suggesting that the interaction between active ions for the energy transfer is of dipole-dipole nature.

  6. Antibacterial properties of copper iodide-doped glass ionomer-based materials and effect of copper iodide nanoparticles on collagen degradation.

    Science.gov (United States)

    Renné, Walter G; Lindner, Amanda; Mennito, Anthony S; Agee, Kelli A; Pashley, David H; Willett, Daniel; Sentelle, David; Defee, Michael; Schmidt, Michael; Sabatini, Camila

    2017-01-01

    This study investigated the antibacterial properties and micro-hardness of polyacrylic acid (PAA)-coated copper iodide (CuI) nanoparticles incorporated into glass ionomer-based materials, and the effect of PAA-CuI on collagen degradation. PAA-CuI nanoparticles were incorporated into glass ionomer (GI), Ionofil Molar AC, and resin-modified glass ionomer (RMGI), Vitrebond, at 0.263 wt%. The antibacterial properties against Streptococcus mutans (n = 6/group) and surface micro-hardness (n = 5/group) were evaluated. Twenty dentin beams were completely demineralized in 10 wt% phosphoric acid and equally divided in two groups (n = 10/group) for incubation in simulated body fluid (SBF) or SBF containing 1 mg/ml PAA-CuI. The amount of dry mass loss and hydroxyproline (HYP) released were quantified. Kruskal-Wallis, Student's t test, two-way ANOVA, and Mann-Whitney were used to analyze the antibacterial, micro-hardness, dry mass, and HYP release data, respectively (p glass ionomer matrix yielded significant reduction (99.999 %) in the concentration of bacteria relative to the control groups. While micro-hardness values of PAA-CuI-doped GI were no different from its control, PAA-CuI-doped RMGI demonstrated significantly higher values than its control. A significant decrease in dry mass weight was shown only for the control beams (10.53 %, p = 0.04). Significantly less HYP was released from beams incubated in PAA-CuI relative to the control beams (p glass ionomer-based materials as they greatly enhance their antibacterial properties and reduce collagen degradation without an adverse effect on their mechanical properties. The use of copper-doped glass ionomer-based materials under composite restorations may contribute to an increased longevity of adhesive restorations, because of their enhanced antibacterial properties and reduced collagen degradation.

  7. Spectroscopic investigation of zinc tellurite glasses doped with Yb(3+) and Er(3+) ions.

    Science.gov (United States)

    Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

    2016-08-05

    This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80-x-y) TeO2+(0.20) ZnO+xEr2O3+yYb2O3 (x=0, y=0; x=0.004, y=0; x=0, y=0.05 and x=0.004, y=0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er(3+) glasses as erbium doped fiber amplifiers at 1.55μm in infrared emission region. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Concentration dependent luminescence quenching of Er{sup 3+}-doped zinc boro-tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Said Mahraz, Zahra Ashur; Sahar, M.R., E-mail: mrahim057@gmail.com; Ghoshal, S.K.; Reza Dousti, M.

    2013-12-15

    Understanding the mechanism of luminescence quenching in rare earth doped tellurite glass is an important issue. The Er{sup 3+}-doped boro-tellurite glasses with compositions 30B{sub 2}O{sub 3}+10ZnO+(60−x)TeO{sub 2}+xEr{sub 2}O{sub 3} (where x=0, 0.5, 1, 1.5 and 2 mol%) were prepared by melt quenching method. Structural and optical properties of the proposed glasses were characterized using XRD, FTIR, density, UV–vis-IR absorption and PL spectroscopy. The amorphous nature of these glasses was confirmed by XRD technique. The IR-spectrum reveals five absorption bands assigned to different B–O and Te–O vibrational groups. UV–vis-IR absorption spectrum exhibits seven absorption bands at 6553, 10,244, 12,547, 15,360, 19,230, 20,661 and 22,522 cm{sup −1} corresponding to {sup 4}I{sub 13/2}, {sup 4}I{sub 11/2}, {sup 4}I{sub 9/2}, {sup 4}F{sub 9/2}, {sup 2}H{sub 11/2}, {sup 4}F{sub 7/2} and {sup 4}F{sub 3/2} excited states of Er{sup 3+} ion respectively. The optical band gap energy (E{sub opt}) corresponding to the direct and indirect allowed transitions decreased, while the Urbach energy and cut-off wavelengths are increased by the introduction of Er{sup 3+} ions. The refractive index, density and phonon cut-off edge of the samples are increased and the molar volume decreased with the further addition of dopants. The Judd–Ofelt parameter (Ω{sub 2}) decreased from 5.73 to 3.13×10{sup −20} cm{sup 2} with the increase of erbium ions concentration from 0.5 to 2 mol%. The PL spectra show green emissions for the transition from {sup 2}H{sub 11/2} and {sup 4}S{sub 3/2} excited states to {sup 4}I{sub 15/2} ground state, which show strong quenching due to the addition of Er{sup 3+} ions. -- Highlights: • Er{sup 3+}-doped zinc boro-tellurite glass has been synthesized by melt quench method. • Spectroscopic properties dependent concentration is analyzed by different techniques. • Judd–Ofelt intensity parameter (Ω{sub 2}) decreased by increase in erbium

  9. Tm3+/Yb3+ co-doped tellurite glass with silver nanoparticles for 1.85 μm band laser material

    Science.gov (United States)

    Huang, Bo; Zhou, Yaxun; Cheng, Pan; Zhou, Zizhong; Li, Jun; Jin, Wei

    2016-10-01

    Tm3+/Yb3+ co-doped tellurite glasses with different silver nanoparticles (Ag NPs) concentrations were prepared using the conventional melt-quenching technique and characterized by the UV/Vis/NIR absorption spectra, 1.85 μm band fluorescence emission spectra, transmission electron microscopy (TEM) images, differential scanning calorimeter (DSC) curves and X-ray diffraction (XRD) patterns to investigate the effects of Ag NPs on the 1.85 μm band spectroscopic properties of Tm3+ ions, thermal stability and structural nature of glass hosts. Under the excitation of 980 nm laser diode (LD), the 1.85 μm band fluorescence emission of Tm3+ ions enhances significantly in the presence of Ag NPs with average diameter of ∼8 nm and local surface Plasmon resonance (LSPR) band of ∼590 nm, which is mainly attributed to the increased local electric field induced by Ag NPs at the proximity of doped rare-earth ions on the basis of energy transfer from Yb3+ to Tm3+ ions. An improvement by about 110% of fluorescence intensity is observed in the Tm3+/Yb3+ co-doped tellurite glass containing 0.5 mol% amount of AgNO3 while the prepared glass samples possess good thermal stability and amorphous structural nature. Meanwhile, the Judd-Ofelt intensity parameters Ωt (t = 2,4,6), spontaneous radiative transition probabilities, fluorescence branching ratios and radiative lifetimes of relevant excited levels of Tm3+ ions were determined based on the Judd-Ofelt theory to reveal the enhanced effects of Ag NPs on the 1.85 μm band spectroscopic properties, and the energy transfer micro-parameters and phonon contribution ratios were calculated based on the non-resonant energy transfer theory to elucidate the energy transfer mechanism between Yb3+ and Tm3+ ions. The present results indicate that the prepared Tm3+/Yb3+ co-doped tellurite glass with an appropriate amount of Ag NPs is a promising lasing media applied for 1.85 μm band solid-state lasers and amplifiers.

  10. Magnetism in Mn-nanowires and -clusters as δ-doped layers in group IV semiconductors (Si, Ge)

    Science.gov (United States)

    Simov, K. R.; Glans, P.-A.; Jenkins, C. A.; Liberati, M.; Reinke, P.

    2018-01-01

    Mn doping of group-IV semiconductors (Si/Ge) is achieved by embedding nanostructured Mn-layers in group-IV matrix. The Mn-nanostructures are monoatomic Mn-wires or Mn-clusters and capped with an amorphous Si or Ge layer. The precise fabrication of δ-doped Mn-layers is combined with element-specific detection of the magnetic signature with x-ray magnetic circular dichroism. The largest moment (2.5 μB/Mn) is measured for Mn-wires with ionic bonding character and a-Ge overlayer cap; a-Si capping reduces the moment due to variations of bonding in agreement with theoretical predictions. The moments in δ-doped layers dominated by clusters is quenched with an antiferromagnetic component from Mn-Mn bonding.

  11. NMR in metal cluster compounds compared to glasses

    International Nuclear Information System (INIS)

    Staveren, M.P.J. van; Brom, H.B.; Jongh, L.J. de; Schmid, G.

    1991-01-01

    The field and temperature dependence of the 31 P nuclear spin lattice relaxation rate in the metal cluster compound Ru 55 (P(t-Bu) 3 ) 12 Cl 20 follows a power law: 1/T 1 ∝ T n B -m , with n = 1.5 ± 0.1 at 3.25 T and n = 1.3 ± 0.1 at 6.45 T; m ≅ 1.4. Such dependences have so far only been observed in inorganic glasses and been attributed to two level systems. The correspondence suggests that the relaxation rate is due to interaction of the P-nuclear moment with electronic spins of stochastically moving charge carriers, which are thought to be responsible for the electrical conductivity through hopping between neigboring cluster molecules. (orig.)

  12. Structure and luminescence properties of Dy2O3 doped bismuth-borate glasses

    International Nuclear Information System (INIS)

    Mugoni, Consuelo; Gatto, C.; Pla-Dalmau, A.; Siligardi, C.

    2017-01-01

    In this study heavy bismuth-borate glasses were studied as host matrices of Dy 2 O 3 rare earth, for potential application as scintillator materials in high energy physics experiments and in general radiation detection systems. Glass matrices were prepared from 20BaO-xBi 2 O 3 -(80-x)B 2 O 3 (x = 20, 30, 40 mol%) ternary systems and synthesized by the melt-quenching method at different temperatures in order to obtain high density and high transparency in the UV/Vis range. Particularly, the glass manifesting the higher transparency and with sufficiently high density was doped with Dy 2 O 3 (2.5 and 5 mol%) in order to induce the luminescence characteristics. The effects of Bi 2 O 3 and Dy 2 O 3 on density, thermal behaviour, transmission as well as luminescence properties under UV excitation, were investigated. The experimental results show that the synthesized glasses can be considered promising candidate materials as dense scintillators, due to the Dy 3+ centres emission.

  13. Experimental investigations of optical nonlinearities in semiconductor-doped glass waveguides

    International Nuclear Information System (INIS)

    Dannberg, P.; Possner, T.; Braeuer, A.; Bartuch, U.

    1988-01-01

    Both, thermal and electronic optical nonlinearities are studied in semiconductor-doped glass (SDG) waveguides which are fabricated in commercially available sharp-cut filters by Cs + -K + ion exchange. The relaxation time in photodarkened substrates is measured to be 30 ps. By means of a prism coupling set-up the saturation value of the nonlinear index change is determined. Furthermore, a high stability dual-beam interferometer is presented for the measurement of both, thermal and electronic nonlinear refractive index n 2 in planar waveguides. Conclusions about the application of SDG to opto-optical switching are given. (author)

  14. Optical and spectroscopic properties of neodymium doped cadmium-sodium borate glasses

    Science.gov (United States)

    Mohan, Shaweta; Thind, Kulwant Singh

    2017-10-01

    Neodymium doped cadmium sodium borate glasses having composition xCdO-(40-x) Na2CO3-59.5H3BO3-0.5Nd2O3; x = 10, 20 and 30 mol% were prepared by conventional melt-quenching technique. X-ray diffraction studies confirmed the amorphous nature of the prepared glasses. Conventional methods were used to determine the physical properties such as density, molar volume, refractive index, and rare earth ion concentration. The Judd-Ofelt theory was applied on the optical absorption spectra of the glasses to evaluate the three phenomenological intensity parameters Ω2, Ω4 and Ω6. The calculated intensity parameters were further used to predict the radiative transition probability (A), radiative lifetime (τR) and branching ratio (βR) for the various fluorescent levels of Nd3+ ion in the prepared glass series. The effect of the compositional changes on the spectroscopic characteristics of Nd3+ ions have been studied and reported. The value of Ω2 is found to decrease with the decrease in the sodium content and the corresponding increase in the cadmium content. This can be ascribed to the changes in the asymmetry of the ligand field at the rare earth ion site and the change in rare earth oxygen (RE-O) covalency. Florescence spectra has been used to determine the peak wavelength (λp), effective line widths (Δλeff) and stimulated emission cross-section (σp) for the 4F3/2 → 4I9/2,4I11/2,4I13/2 transitions of the Nd3+ ion. The reasonably higher values of branching ratios and stimulated emission cross-section for the prepared glasses points towards the efficacy of these glasses as laser host materials. However, the glass with more sodium content is found to show better lasing properties.

  15. Preparation and spectral analysis of a new Tb3+-doped CaO-MgO-SiO2 glass ceramics

    International Nuclear Information System (INIS)

    Cheng Jinshu; Tian Peijing; Zheng Weihong; Xie Jun; Chen Zhenxia

    2009-01-01

    Tb 3+ -doped CaO-MgO-SiO 2 glass ceramics have been prepared and characterized. The structure and optical properties of the glass ceramics were studied by XRD, SEM, Raman, and fluorescence spectra. The precipitated crystalline phase in the glass ceramics was columnar CaMgSi 2 O 6 . Raman spectra showed the introduction of rare earth nearly had no influence on the sample structure. Fluorescence measurements showed that Tb 3+ ions entered into the diopside crystalline phase and induced a much stronger emission in the glass ceramics than that in the corresponding glass. With increase of Tb 3+ content and the introduction of Gd 3+ , the fluorescence intensity of the luminescent glass ceramic increased

  16. Gamma-ray shielding effect of Gd3+ doped lead barium borate glasses

    Science.gov (United States)

    Kummathi, Harshitha; Naveen Kumar, P.; Vedavathi T., C.; Abhiram, J.; Rajaramakrishna, R.

    2018-05-01

    The glasses of the batch xPbO: 10BaO: (90-x)B2O3: 0.2Gd2O3 (x = 40,45,50 mol %) were prepared by melt-quench technique. The work emphasizes on gamma ray shielding effect on doped lead glasses. The role of Boron is significant as it acts as better neutron attenuator as compared with any other materials, as the thermal neutron cross-sections are high for Gadolinium, 0.2 mol% is chosen as the optimum concentration for this matrix, as higher the concentration may lead to further increase as it produces secondary γ rays due to inelastic neutron scattering. Shielding effects were studied using Sodium Iodide (NaI) - Scintillation Gamma ray spectrometer. It was found that at higher concentration of lead oxide (PbO) in the matrix, higher the attenuation which can be co-related with density. Infra-red (I.R.) spectra reveals that the conversion of Lose triangles to tight tetrahedral structure results in enhancement of shielding properties. The Differential Scanning Calorimeter (D.S.C.) study also reveals that the increase in glass forming range increases the stability which in-turn results in inter-conversion of BO3 to BO4 units such that the density of glass increases with increase in PbO content, resulting in much stable and efficient gamma ray shielding glasses.

  17. Phase separation, clustering, and fractal characteristics in glass: A magic-angle-spinning NMR spin-lattice relaxation study

    Science.gov (United States)

    Sen, S.; Stebbins, J. F.

    1994-07-01

    A comparative study of the 29Si spin-lattice relaxation behavior (induced by trace amounts of paramagnetic dopants in the glass) in phase-separated Li2Si4O9 and monophasic Li2Si2O5 and Na2Si2O5 glasses has been made in order to understand the nature of clustering and the resulting intermediate-range ordering. Optically clear tetrasilicate and disilicate glasses were prepared with 500 to 2000 ppm of Gd2O3, a paramagnetic dopant. The constituent structural units (Q3 and Q4 species) in all tetrasilicate glasses show strong differential relaxation following a power-law behavior. This is due to preferential partitioning of Gd3+ into the lower silica (Q3-rich) regions of these glasses, indicating the presence of Q species clusters too small to produce optical opalescence (a few nm to perhaps tens of nm). Preliminary results on 6Li spin-lattice relaxation in these glasses support this hypothesis. Differential relaxation becomes more pronounced on annealing due to growth of such clusters. No such differential relaxation was observed in the monophase disilicate glasses. For spin-lattice relaxation induced by direct dipolar coupling to paramagnetic ions, the recovery of magnetization is proportional to time as M(t)~tα where α is a function of the dimensionality D of mass distribution of the constituent Q species around the Gd3+ paramagnetic centers in the glass. For tetrasilicate glasses D~=2.62+/-0.22 and the system behaves as a mass fractal up to a length scale of 2 to 3 nm. D is thus equal to, within error, the theoretical value of 2.6 for an infinite percolation cluster of one type of Q species in another. For disilicate glasses, D~=3.06+/-0.18 which indicates a three-dimensional (and thus nonfractal) mass distribution of the constituent Q species over the same length scale.

  18. PALS investigations of matrix Vycor glass doped with molecules of luminescent dye and silver nanoparticles. Discrepancies from the ETE model

    Directory of Open Access Journals (Sweden)

    Gorgol Marek

    2015-12-01

    Full Text Available A thermal stability of three materials: undoped reference Vycor glass, glass filled with ROT-305 red dye, and silver nanoparticles was investigated by positron annihilation lifetime spectroscopy (PALS in a broad temperature range (from 93 to 473 K. The attempt of pore size calculations from the ortho-positronium lifetime data was performed using the extended Tao-Eldrup (ETE model. Below room temperature, a significant decrease in lifetime values of the longest-lived component was found for all the samples. This effect could not be explained by thermal shrinkage of the material and is probably caused by interaction of o-Ps with a Vycor glass matrix. The greatest discrepancy from the ETE model predictions was observed for the reference glass. Doping the base material with dye molecules and silver nanoparticles resulted in similar small decrease in this discrepancy. After reheating the samples to the room temperature, the PALS components returned to the initial values. In the temperature range of 293–473 K, quite good agreement between PALS results and the ETE model predictions was observed for the reference glass and the glass incorporated with dye molecules. The observed small discrepancy in this range could possibly be partly explained by thermal expansion of the material. For the glass doped with silver nanoparticles, a significant change in PALS parameters was observed in the temperature range from 403 to 473 K.

  19. Effect of MnO2 doped on physical, structure and optical properties of zinc silicate glasses from waste rice husk ash

    Science.gov (United States)

    Al-Nidawi, Ali Jabbar Abed; Matori, Khamirul Amin; Zakaria, Azmi; Mohd Zaid, Mohd Hafiz

    In this study, an investigation was conducted to explore and synthesize silicate (SiO2) glass from waste rice husk ash (RHA). MnO2 doped zinc silicate glasses with chemical formula [(ZnO)55 + (WRHA)45]100-X[MnO2]X, (where X = 0, 1, 3 and 5 wt%) was prepared by conventional melt quenching technique. The glass samples were characterized using energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, and ultraviolet-visible (UV-Vis) spectroscopy. The results revealed that by increasing the concentration of MnO2, the color of glass samples changed from colorless to brown and the density of glass increased. XRD results showed that a broad halo peak which centered on the low angle (2θ = 30°) indicated the amorphous nature of the glass. FTIR results showed basic structural units of Si-O-Si in non-bridging oxygen, Si-O and Mn-O in the glass network. FESEM result showed a decreasing porosity with an increasing MnO2 content, which was attributed to the Mn ions resort to occupy interstitial sites inside the pores of glass. Besides, the absorption intensity of glass increased and the band gap value decreased with increasing the MnO2 percentage. In this synthesized glass system of MnO2 doped zinc silicate glasses using RHA as a source of silica, the MnO2 affect most of the properties of the glass system under investigation.

  20. Preparation of Ho3+/Tm3+ Co-doped Lanthanum Tungsten Germanium Tellurite Glass Fiber and Its Laser Performance for 2.0 μm

    Science.gov (United States)

    Zhou, Dechun; Bai, Xuemei; Zhou, Hang

    2017-03-01

    Ho3+/Tm3+ co-doped 50TeO2-25GeO2-3WO3-5La2O3-3Nb2O5-5Li2O-9BaF2 glass fiber is prepared with the rod-tube drawing method of 15 μm core diameter and 125 μm inner cladding diameter applied in the 2.0 μm-infrared laser. The 2.0 μm luminescence properties of the core glass are researched and the fluorescence intensity variation for different Tm3+ doping concentration is systematically analyzed. The results show that the 2.0 μm luminescence of Ho3+ is greatly influenced by the doping concentration ratio of Ho3+ to Tm3+ and that the maximum fluorescence intensity of the core glass can be obtained and its emission cross section can reach 0.933 × 10-21 cm2 when the sensitized proportion of holmium to thulium is 0.3 to 0.7 (mol%). Simultaneously, the maximum phonon energy of the core glass sample is 753 cm-1, which is significantly lower than that of silicate, gallate and germanate glass and the smaller matrix phonon energy can be conductive to the increase 2.0 μm-band emission intensity. The continuous laser with the maximum laser output power of 0.993 W and 2051 nm -wavelength of 31.9%-slope efficiency is output within the 0.5 m glass fiber and the experiment adopts 1560 nm erbium-doped fiber laser(EDFL) as the pump source and the self-built all-fiber laser. Therefore, the glass fiber has excellent laser characteristics and it is suitable for the 2.0 μm-band laser.

  1. Electron, hole and exciton self-trapping in germanium doped silica glass from DFT calculations with self-interaction correction

    International Nuclear Information System (INIS)

    Du Jincheng; Rene Corrales, L.; Tsemekhman, Kiril; Bylaska, Eric J.

    2007-01-01

    Density functional theory (DFT) calculations were employed to understand the refractive index change in germanium doped silica glasses for the trapped states of electronic excitations induced by UV irradiation. Local structure relaxation and excess electron density distribution were calculated upon self-trapping of an excess electron, hole, and exciton in germanium doped silica glass. The results show that both the trapped exciton and excess electron are highly localized on germanium ion and, to some extent, on its oxygen neighbors. Exciton self-trapping is found to lead to the formation of a Ge E' center and a non-bridging hole center. Electron trapping changes the GeO 4 tetrahedron structure into trigonal bi-pyramid with the majority of the excess electron density located along the equatorial line. The self-trapped hole is localized on bridging oxygen ions that are not coordinated to germanium atoms that lead to elongation of the Si-O bonds and change of the Si-O-Si bond angles. We carried out a comparative study of standard DFT versus DFT with a hybrid PBE0 exchange and correlation functional. The results show that the two methods give qualitatively similar relaxed structure and charge distribution for electron and exciton trapping in germanium doped silica glass; however, only the PBE0 functional produces the self-trapped hole

  2. Thermal lens and interferometric method for glass transition and thermo physical properties measurements in Nd2O3 doped sodium zincborate glass.

    Science.gov (United States)

    Astrath, N G C; Steimacher, A; Rohling, J H; Medina, A N; Bento, A C; Baesso, M L; Jacinto, C; Catunda, T; Lima, S M; Karthikeyan, B

    2008-12-22

    In this work the time resolved thermal lens method is combined with interferometric technique, the thermal relaxation calorimetry, photoluminescence and lifetime measurements to determine the thermo physical properties of Nd(2)O(3) doped sodium zincborate glass as a function of temperature up to the glass transition region. Thermal diffusivity, thermal conductivity, fluorescence quantum efficiency, linear thermal expansion coefficient and thermal coefficient of electronic polarizability were determined. In conclusion, the results showed the ability of thermal lens and interferometric methods to perform measurements very close to the phase transition region. These techniques provide absolute values for the measured physical quantities and are advantageous when low scan rates are required.

  3. Effect of 3d-transition metal doping on the shielding behavior of barium borate glasses: a spectroscopic study.

    Science.gov (United States)

    ElBatal, H A; Abdelghany, A M; Ghoneim, N A; ElBatal, F H

    2014-12-10

    UV-visible and FT infrared spectra were measured for prepared samples before and after gamma irradiation. Base undoped barium borate glass of the basic composition (BaO 40%-B2O3 60mol.%) reveals strong charge transfer UV absorption bands which are related to unavoidable trace iron impurities (Fe(3+)) within the chemical raw materials. 3d transition metal (TM)-doped glasses exhibit extra characteristic absorption bands due to each TM in its specific valence or coordinate state. The optical spectra show that TM ions favor generally the presence in the high valence or tetrahedral coordination state in barium borate host glass. Infrared absorption bands of all prepared glasses reveal the appearance of both triangular BO3 units and tetrahedral BO4 units within their characteristic vibrational modes and the TM-ions cause minor effects because of the low doping level introduced (0.2%). Gamma irradiation of the undoped barium borate glass increases the intensity of the UV absorption together with the generation of an induced broad visible band at about 580nm. These changes are correlated with suggested photochemical reactions of trace iron impurities together with the generation of positive hole center (BHC or OHC) within the visible region through generated electrons and positive holes during the irradiation process. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Monte Carlo simulations of homogeneous upconversion in erbium-doped silica glasses

    DEFF Research Database (Denmark)

    Philipsen, Jacob Lundgreen; Bjarklev, Anders Overgaard

    1997-01-01

    Quenching of Er3+ ions by homogeneous energy-transfer upconversion in high-concentration erbium-doped silica glasses has been theoretically investigated, The results indicate that at Er3+ concentrations of 1.0-2.0·1026 m-3 or below, the kinetic limit of strong migration is not reached, and hence...... the widely accepted quadratic upconversion model is not generally valid. Nevertheless, the results offer an explanation of the experimental observations of quadratic upconversion. Furthermore, it has been shown that at a given population inversion, the quenching rate depends on the rate of exchange...

  5. Magnetism in Mn-nanowires and -clusters as δ-doped layers in group IV semiconductors (Si, Ge

    Directory of Open Access Journals (Sweden)

    K. R. Simov

    2018-01-01

    Full Text Available Mn doping of group-IV semiconductors (Si/Ge is achieved by embedding nanostructured Mn-layers in group-IV matrix. The Mn-nanostructures are monoatomic Mn-wires or Mn-clusters and capped with an amorphous Si or Ge layer. The precise fabrication of δ-doped Mn-layers is combined with element-specific detection of the magnetic signature with x-ray magnetic circular dichroism. The largest moment (2.5 μB/Mn is measured for Mn-wires with ionic bonding character and a-Ge overlayer cap; a-Si capping reduces the moment due to variations of bonding in agreement with theoretical predictions. The moments in δ-doped layers dominated by clusters is quenched with an antiferromagnetic component from Mn–Mn bonding.

  6. Up-conversion luminescence and local heating in Er{sup 3+} doped tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Y.; Rai, S.B. [Banaras Hindu University, Laser and Spectroscopy Laboratory, Physics Department, Varanasi, UP (India)

    2012-10-15

    The present article discusses the up-conversion and thermometric properties of Er doped tellurite glass on excitation with 976 nm laser radiation. Temperature has been measured using fluorescence intensity ratio variation, in 528/548 and 801/828 nm, with temperature. Temperature at laser focus spot has been estimated by comparing the intensity ratios at different laser powers with the intensity ratio at different temperatures when sample was heated externally. (orig.)

  7. Characterization of WO3-doped borophosphate glasses by optical, IR and ESR spectroscopic techniques before and after subjecting to gamma irradiation

    International Nuclear Information System (INIS)

    Ouis, M.A.; EI-Batal, H.A.; Azooz, M.A.; Abdelghany, A.M.

    2013-01-01

    Borophosphate glasses containing increasing WO 3 within the doping level (0.16-1.33%) have been prepared and investigated by UV-visible, infrared spectral measurements. These glasses have been exposed to gamma rays with a dose of 8 Mrad for studying the effect of gamma radiation on the combined studied spectra of such glasses. The optical spectrum of undoped borophosphate glass reveals strong UV absorption but with no visible bands. This strong UV absorption is related to the presence of unavoidable trace iron impurities within the chemicals used for the preparation of this borophosphate glass. The WO 3 -doped samples show two additional UV and visible bands at about 380 and 740 nm due to the presence of both W 6+ and W 5+ ions in noticeable content. The calculated induced spectra reveal the appearance of an ultraviolet band at 320 nm and two visible bands centered at 390 and 540 nm which are related to the combined presence of W 6+ and W 5+ ions. The FTIR spectra show vibrational bands due to characteristic constitutional phosphate and borate groups but the phosphate groups are predominant due to the high P 2 O 5 content (50%). The effect of the addition of WO 3 with the dopant level reveals limited changes in the IR spectra. Electron spin resonance (ESR) spectra show specified signals in the high WO 3 content glass but on gamma irradiation the signals are disappeared. This result confirms the decrease of the W 5+ ions by photochemical oxidation to paired W 6+ ions. This result is also observed in optical absorption of WO 3 doped glasses after gamma irradiation through the disappearance of the visible band at 740 nm. (author)

  8. Investigation of thermal stability and spectroscopic properties in Er3+ doped bismuth-boron-germanium glasses

    International Nuclear Information System (INIS)

    Nie Qiuhua; Lu Longjun; Dai Shixun; Xu Tiefeng; Shen Xiang; Zhang Xudong; Liang Xiaowei; Zhang Xianghua

    2007-01-01

    A series of Er 3+ -doped 50Bi 2 O 3 -(50-x)B 2 O 3 -xGeO 2 +0.5 wt% Er 2 O 3 (x=0, 5, 10, 15, 20 mol%) glasses were prepared. The thermal stability, absorption spectra, emission spectra and lifetime of the 4 I 13 / 2 level of Er 3+ ions were measured and studied. It is found that the absorption cross-section of Er 3+ , emission intensity and lifetime of the 4 I 13 / 2 level of Er 3+ increase with increasing GeO 2 content in the glass composition, while the fluorescence full-width at half-maximum (FWHM) at 1.5 μm of Er 3+ is about 79 nm in x=20 mol% glass sample under 970 nm pump. The obtained data suggest that this system glass can be used as a candidate host material for potential broadband optical amplifiers

  9. A fundamental self-generated quenching center for lanthanide-doped high-purity solids

    International Nuclear Information System (INIS)

    Auzel, F.

    2002-01-01

    An intrinsic self-generated quenching center for lanthanide-doped high-purity solids is presented for transitions, which cannot be quenched by cross-relaxation. This center, in fact a cluster-like pair of active centers, is shown to come from a particular multiphonon-assisted energy transfer between them. Being due to the vibronic properties of the host it cannot be suppressed. Its role in lanthanide first excited states self-quenching is analyzed and a simple mathematical expression is derived. This law is compared with experimental results for self-quenching in Er-doped fluorophosphate glasses

  10. Processing and optical characterization of lead calcium titanate borosilicate glass doped with germanium

    Science.gov (United States)

    Gautam, C. R.; Das, Sangeeta; Gautam, S. S.; Madheshiya, Abhishek; Singh, Anod Kumar

    2018-04-01

    In this study, various compositions of lead calcium titanate borosilicate glass doped with a fixed amount of germanium were synthesized using the rapid melt quench technique. The amorphous nature of the synthesized glass was confirmed by X-ray diffraction and scanning electron microscopy analyses. The structural and optical properties were deduced using Raman, Fourier transform infrared (FTIR), and ultraviolet-visible (UV-Vis) spectroscopy. FTIR spectroscopy confirmed the presence of borate groups in triangular and tetrahedral coordination. Infrared and Raman analyses detected the vibrational bonds of Gesbnd Osbnd Ge, Bsbnd Osbnd Ge, Sisbnd Osbnd Ge, Sisbnd Osbnd Si, and Pbsbnd Osbnd Ge. The energy band gaps were evaluated for the prepared glass samples based on Tauc plots of the UV-Vis spectra. The calculated values of the optical band gap decreased from 2.91 to 2.85 eV as the PbO content increased from x = 0.0 to x = 0.7. Furthermore, the Urbach energy was studied based on the UV-Vis results to confirm the disordered structure of the glass. The calculated densities of the glass samples (1.5835 g/cm3 to 3.9184 g/cm3) increased as the concentration of PbO increased, whereas they decreased with the molar volume.

  11. Optical properties of Dy3+ doped bismuth boro-tellurite glasses for WLED applications

    Science.gov (United States)

    Karthikeyan, P.; Marimuthu, K.

    2016-05-01

    The Dy3+ doped bismuth boro-tellurite glasses with the chemical composition (79.5-x) B2O3+xTeO2+10Bi2O3+10PbF2+0.5Dy2O3 (where x = 10, 20, 30 and 40 in wt%) have been prepared by melt quenching technique. The optical properties of the prepared glasses have been studied through absorption and emission spectral measurements. The bonding parameters, optical band gap energy, Urbach's energy and Judd-Ofelt (JO) intensity parameters (Ωλ, λ = 2, 4 and 6) were calculated from the absorption spectra. The radiative properties like transition probability (A), stimulated emission cross-section (σPE) and branching ratios (βR) were calculated from the emission spectra using JO theory. The strong emissions in the visible region, large stimulated emission cross-section and higher branching ratio values observed for the title glasses are found to be suitable for lasers and WLED applications.

  12. Quantum efficiency and excited-state relaxation dynamics in neodymium-doped phosphate laser glasses

    International Nuclear Information System (INIS)

    Caird, J.A.; Ramponi, A.J.; Staver, P.R.

    1991-01-01

    Radiometrically calibrated spectroscopic techniques employing an integrating-sphere detection system have been used to determine the fluorescence quantum efficiencies for two commercially available Nd 3+ -doped phosphate laser glasses, LG-750 and LG-760. Quantum efficiencies and fluorescence lifetimes were measured for samples with various neodymium concentrations. It is shown that the effects of concentration quenching are accurately described when both resonant nonradiative excitation hopping (the Burshtein model) and annihilation by cross relaxation are accounted for by Foerster--Dexter dipole--dipole energy-transfer theory. The Foerster--Dexter critical range for nonradiative excitation hopping was found to be R DD =11 A, while the critical range for cross relaxation was close to R DA =4 A in these glasses. The quantum efficiency at low Nd 3+ concentrations was (92±5)%, implying a nonradiative relaxation rate of 210±150 s -1 for isolated ions. Improved values for the radiative lifetimes and the stimulated emission cross sections for these glasses were also deduced from the measurements

  13. Organic solution-processible electroluminescent molecular glasses for non-doped standard red OLEDs with electrically stable chromaticity

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Xiaoman; Zuo, Weiwei; Liu, Yingliang, E-mail: liuylxn@sohu.com; Zhang, Zhenru; Zeng, Cen; Xu, Shengang; Cao, Shaokui, E-mail: caoshaokui@zzu.edu.cn

    2015-10-15

    Highlights: • The D–A–D electroluminescent molecular glasses are synthesized. • Non-doped red electroluminescent film is fabricated by spin-coating. • Red OLED shows stable wavelength, luminous efficiency and chromaticity. • CIE1931 coordinate is in accord with standard red light in PAL system. - Abstract: Organic light-emitting molecular glasses (OEMGs) are synthesized through the introduction of nonplanar donor and branched aliphatic chain into electroluminescent emitters. The target OEMGs are characterized by {sup 1}H NMR, {sup 13}C NMR, IR, UV–vis and fluorescent spectra as well as elemental analysis, TG and DSC. The results indicated that the optical, electrochemical and electroluminescent properties of OEMGs are adjusted successfully by the replacement of electron-donating group. The non-doped OLED device with a standard red electroluminescent emission is achieved by spin-coating the THF solution of OEMG with a triphenylamine moiety. This non-doped red OLED device takes on an electrically stable electroluminescent performance, including the stable maximum electroluminescent wavelength of 640 nm, the stable luminous efficiency of 2.4 cd/A and the stable CIE1931 coordinate of (x, y) = (0.64, 0.35), which is basically in accord with the CIE1931 coordinate (x, y) = (0.64, 0.33) of standard red light in PAL system.

  14. Effect of MnO2 doped on physical, structure and optical properties of zinc silicate glasses from waste rice husk ash

    Directory of Open Access Journals (Sweden)

    Ali Jabbar Abed Al-Nidawi

    Full Text Available In this study, an investigation was conducted to explore and synthesize silicate (SiO2 glass from waste rice husk ash (RHA. MnO2 doped zinc silicate glasses with chemical formula [(ZnO55 + (WRHA45]100-X[MnO2]X, (where X = 0, 1, 3 and 5 wt% was prepared by conventional melt quenching technique. The glass samples were characterized using energy dispersive X-ray fluorescence (EDXRF, X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, Fourier transform infrared (FTIR spectroscopy, and ultraviolet–visible (UV–Vis spectroscopy. The results revealed that by increasing the concentration of MnO2, the color of glass samples changed from colorless to brown and the density of glass increased. XRD results showed that a broad halo peak which centered on the low angle (2θ = 30° indicated the amorphous nature of the glass. FTIR results showed basic structural units of Si-O-Si in non-bridging oxygen, Si-O and Mn-O in the glass network. FESEM result showed a decreasing porosity with an increasing MnO2 content, which was attributed to the Mn ions resort to occupy interstitial sites inside the pores of glass. Besides, the absorption intensity of glass increased and the band gap value decreased with increasing the MnO2 percentage. In this synthesized glass system of MnO2 doped zinc silicate glasses using RHA as a source of silica, the MnO2 affect most of the properties of the glass system under investigation. Keywords: Rice husk, Manganese dioxide, Glass, Zinc silicate, Sintering, Optical properties

  15. Mid-infrared emission and Raman spectra analysis of Er(3+)-doped oxyfluorotellurite glasses.

    Science.gov (United States)

    Chen, Fangze; Xu, Shaoqiong; Wei, Tao; Wang, Fengchao; Cai, Muzhi; Tian, Ying; Xu, Shiqing

    2015-04-10

    This paper reports on the spectroscopic and structural properties in Er(3+)-doped oxyfluorotellurite glasses. The compositional variation accounts for the evolutions of Raman spectra, Judd-Ofelt parameters, radiative properties, and fluorescent emission. It is found that, when maximum phonon energy changes slightly, phonon density plays a crucial role in quenching the 2.7 μm emission generated by the Er(3+):(4)I11/2→(4)I13/2 transition. The comparative low phonon density contributes strong 2.7 μm emission intensity. The high branching ratio (18.63%) and large emission cross section (0.95×10(-20)  cm(2)) demonstrate that oxyfluorotellurite glass contained with 50 mol.% TeO2 has potential application in the mid-infrared region laser.

  16. Geometric, stability, and electronic properties of gold-doped Pd clusters (Pd{sub n}Au, n = 3~20)

    Energy Technology Data Exchange (ETDEWEB)

    Huan, Hao; Chen, Yan; Wang, Tao; Ye, Xiang, E-mail: yexiang@shnu.edu.cn [Shanghai Normal University, Department of Physics (China); Gu, Xiao, E-mail: gx@cqu.edu.cn [Chongqing University, Department of Applied Physics (China)

    2016-11-15

    The structure, stability, and electronic properties of Pd{sub n}Au (n = 3~20) clusters are studied by density functional theory. The results show that the clusters studied here prefer three-dimensional structures even with very small atom number. It is found that the binding energies of Pd{sub n}Au clusters are higher than the corresponding pure Pd{sub n} clusters with the same atom number. Most Pd{sub n}Au clusters studied here are magnetic with magnetic moments ranging from 1.0 to 7.0 μ{sub B.} The dissociation energies of Pd atoms are lower than the doped gold atom, that is the doped Au atom will increase the mother clusters stability and activity.

  17. Influence of single and binary doping of strontium and lithium on in vivo biological properties of bioactive glass scaffolds

    Science.gov (United States)

    Khan, Pintu Kumar; Mahato, Arnab; Kundu, Biswanath; Nandi, Samit K.; Mukherjee, Prasenjit; Datta, Someswar; Sarkar, Soumya; Mukherjee, Jayanta; Nath, Shalini; Balla, Vamsi K.; Mandal, Chitra

    2016-01-01

    Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG) porous scaffolds have been checked in vitro and in vivo. BAG scaffolds were prepared by conventional glass melting route and subsequently, scaffolds were produced by evaporation of fugitive pore formers. After thorough physico-chemical and in vitro cell characterization, scaffolds were used for pre-clinical study. Soft and hard tissue formation in a rabbit femoral defect model after 2 and 4 months, were assessed using different tools. Histological observations showed excellent osseous tissue formation in Sr and Li + Sr scaffolds and moderate bone regeneration in Li scaffolds. Fluorochrome labeling studies showed wide regions of new bone formation in Sr and Li + Sr doped samples as compared to Li doped samples. SEM revealed abundant collagenous network and minimal or no interfacial gap between bone and implant in Sr and Li + Sr doped samples compared to Li doped samples. Micro CT of Li + Sr samples showed highest degree of peripheral cancellous tissue formation on periphery and cortical tissues inside implanted samples and vascularity among four compositions. Our findings suggest that addition of Sr and/or Li alters physico-chemical properties of BAG and promotes early stage in vivo osseointegration and bone remodeling that may offer new insight in bone tissue engineering. PMID:27604654

  18. UV emission properties of thulium-doped fluorozirconate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Piramidowicz, R., E-mail: r.piramidowicz@elka.pw.edu.p [Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw (Poland); Telekomunikacja Polska Research and Development Centre, Obrzezna 7, 02-691 Warsaw (Poland); Bok, A.; Klimczak, M.; Malinowski, M. [Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw (Poland)

    2009-12-15

    In this work, we present our latest results on UV emission in bulk ZBLAN glasses doped with thulium ions, broadening knowledge of the short-wavelength optical properties of this system. We examined a set of samples with different activator concentrations (2500, 10,000, 25,000 and 50,000 ppm) in respect of absorption and short-wavelength emission properties. The concentration-dependant spectra of UV emission from the {sup 1}I{sub 6}+{sup 3}P{sub 0} and {sup 1}D{sub 2} levels and fluorescence dynamics profiles have been recorded and carefully examined under direct (one-photon) excitation, enabling discussion of fluorescence quenching mechanisms and determination of appropriate cross-relaxation rates. According to authors' best knowledge, the three-photon red-to-UV up-conversion has been reported for the first time under excitation of a laser diode.

  19. Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

    International Nuclear Information System (INIS)

    Vasileva, A.A.; Nazarov, I.A.; Olshin, P.K.; Povolotskiy, A.V.; Sokolov, I.A.; Manshina, A.A.

    2015-01-01

    Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium–phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass. - Graphical abstract: Formation of silver NPs on the surface of 0.5Ag 2 O–0.4P 2 O 5 –0,1Nb 2 O 5 glass induced by CW laser irradiation. - Highlights: • The structure of 0.5Ag 2 O–0.1Nb 2 O 5 –0.4P 2 O 5 and 0.55Ag 2 O–0.45P 2 O 5 glasses was investigated by Raman spectroscopy. • Fs laser writing induces formation of silver NPs in investigated glasses. • Surface plasmon resonance in the absorption spectra confirms the formation of NP. • The possibility of CW laser induced formation of silver NPs on the surface of sample with niobium is shown

  20. Alpha self irradiation effects in nuclear borosilicate glass

    International Nuclear Information System (INIS)

    Peuget, S.; Roudil, D.; Deschanels, X.; Jegou, C.; Broudic, V.; Bart, J.M.

    2004-01-01

    The properties of actinide glasses are studied in the context of high-level waste management programs. Reprocessing high burnup fuels in particular will increase the minor actinide content in the glass package, resulting in higher cumulative alpha decay doses in the glass, and raising the question of the glass matrix behavior and especially its containment properties. The effect of alpha self-irradiation on the glass behavior is evaluated by doping the glass with a short-lived actinide ( 244 Cm) to reach in several years the alpha dose received by the future glass packages over several thousand years. 'R7T7' borosilicate glasses were doped with 3 different curium contents (0.04, 0.4 and 1.2 wt% 244 CmO 2 ). The density and mechanical properties of the curium-doped glasses were characterized up to 2. 10 18 α/g, revealing only a slight evolution of the macroscopic behavior of R7T7 glass in this range. The leaching behavior of curium-doped glass was also studied by Soxhlet tests. The results do not show any significant evolution of the initial alteration rate with the alpha dose. (authors)

  1. Spectroscopic and radiative properties study of Nd3+ doped cadmium-phosphate glasses

    International Nuclear Information System (INIS)

    Mahmoud, K.H.

    2010-01-01

    A spectroscopic investigation is performed on Nd 3+ doped cadmium-phosphate glasses. The Judd-Ofelt analysis is applied to the glass system in order to evaluate their potential as both glass laser and amplifier materials. The phenomenological Judd-Ofelt parameters Ω (2) , Ω (4) , and Ω (6) are determined, their values are 4.80x10 -20 , 6.18x10 -20 , and 7.14x10 -20 cm -2 , respectively. The quality factor for glass system is 0.86. Predicted radiative decay rates and branching ratios of transitions from Nd 3+4 F 3/2 state to the 4 I J manifolds are determined and analyzed. The calculated lifetime of the 4 F 3/2 metastable state of Nd 3+ is 31 μs. The results showed that 4 F 3/2 to 4 I 11/2 transition, with fluorescence at 1056 nm, has the most potential for laser application. Photoluminescence up-conversion under excitation at 488 nm laser light exhibits three emission bands of Nd 3+ ions at 541 (green), 601 (orange), and 677 nm (red). These emission bands are assigned to 4 G 7/2 → 4 I 9/2 , 4 G 7/2 → 4 I 11/2 , and 4 G 7/2 → 4 I 13/2 transitions, respectively. Analysis of luminescence spectra enhances the use of glass system in optical displays, lasers, and optical memory devices.

  2. Thermal, structural and spectroscopic investigations on Eu{sup 3+} doped boro-tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Selvaraju, K. [Department of Physics, Gandhigram Rural University, Gandhigram 624 302 (India); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram 624 302 (India); Seshagiri, T.K.; Godbole, S.V. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Fundamental O-H, (BO{sub 3}){sup -} vibrations and B-O-B linkages in borate network explored. Black-Right-Pointing-Pointer The covalent nature of the Eu{sup 3+} ions with surrounding ligands have been confirmed. Black-Right-Pointing-Pointer B3TMK glass is found to be the best optical candidate for laser working at 612 nm. - Abstract: Eu{sup 3+} doped boro-tellurite glasses with the chemical composition (69 - x)B{sub 2}O{sub 3}-xTeO{sub 2}-15Mg{sub 2}O-15K{sub 2}O-1Eu{sub 2}O{sub 3} (where x = 0, 10, 20, 30 and 40 wt%) have been synthesized and its thermal, structural and spectroscopic behavior were studied and reported. The thermal behavior of the Eu{sup 3+} doped boro-tellurite glasses were explored through DTA thermograms. The presence of varying tellurium dioxide results in structural and spectroscopic changes around Eu{sup 3+} ions and are explored through XRD, FTIR, UV-vis, Luminescence and lifetime measurements. The XRD pattern confirms the amorphous nature and the FTIR spectra reveal the formation of the local structural units BO{sub 3} and BO{sub 4} in the prepared glasses. The bonding parameters (-bar {beta} and {delta}) have been calculated based on the observed band positions of the absorption spectra. The Judd-Ofelt (JO) parameters were determined from the absorption and luminescence spectra and the results are presented. The variation in the JO intensity parameters {Omega}{sub {lambda}} ({lambda} = 2, 4 and 6) and the hypersensitive band positions with the change in chemical composition have been discussed in detail. The JO parameters have been used to derive important radiative properties like transition probabilities (A), branching ratios ({beta}{sub R}) and peak stimulated emission cross section ({sigma}E/P) for the {sup 5}D{sub 0} {yields} {sup 7}F{sub J} (J = 1, 2, 3 and 4) transitions of the Eu{sup 3+} ions. The varying optical properties of the prepared glasses with the change in tellurium dioxide have

  3. Investigations on structural and optical behavior of Er3+ doped lead boro-tellurite glasses

    Science.gov (United States)

    Karthikeyan, P.; Suthanthirakumar, P.; Vijayakumar, R.; Marimuthu, K.

    2015-06-01

    Er3+ doped lead boro-tellurite glasses with the chemical composition (30-x)B2O3+30TeO2+23MgO+17PbF2+xEr2O3 (where x=0.05, 0.25, 0.5, and 1 in wt%) were synthesized by melt quenching technique. The structural and optical behaviors have been investigated through FTIR, absorption and emission spectral analysis. The UV-vis- NIR absorption spectra were used to calculate the bonding parameters (β ¯, δ), Judd-Ofelt intensity parameters (Ωλ, λ = 2, 4 and 6), Optical band gap and Urbach's energy of the prepared glasses. The radiative properties such as transition probability (AR), stimulated emission cross-section (σPE ), branching ratios (βR) were calculated from the luminescence spectra. The optical properties of the prepared glasses with varying Er3+ ion concentration have been studied and reported in the present work.

  4. Adsorption of RuSex (x =1–5) cluster on Se-doped graphene: First principle calculations

    International Nuclear Information System (INIS)

    Üzengi Aktürk, O.; Tomak, M.

    2015-01-01

    Highlights: • Electronic properties of adsorption of RuSe x (x =1–5) cluster on Se-doped graphene are investigated. • It is found that RuSe, RuSe 4 , RuSe 5 adsorbate make substrate metallic. • RuSe 2 makes it half metallic and RuSe 3 makes semiconductor. - Abstract: We have investigated the adsorption of RuSe x (x =1–5) cluster on Se-doped graphene. The change of the adsorption energy with the number of Se atoms and magnetization values are investigated. Electronic properties of adsorption of RuSe x (x =1–5) cluster on Se-doped graphene are investigated. The highest adsorption energy belongs to RuSe adsorbate. The biggest magnetization value belongs to RuSe 2 adsorbate. This adsorbate makes the substrate half metallic. This property is important in electronic device applications. It is observed that substitutional Se atom changes the electronic properties of graphene. This substitution makes graphene metallic. While RuSe, RuSe 4 , RuSe 5 adsorbate make substrate metallic, RuSe 3 makes it semiconducting. Generally, it is found that there is a charge transfer from the substrate to clusters within the Löwdin analysis. This is in line with the charge difference results

  5. Cyan-white-red luminescence from europium doped Al2O3-La2O3-SiO2 glasses.

    Science.gov (United States)

    Yang, Hucheng; Lakshminarayana, G; Zhou, Shifeng; Teng, Yu; Qiu, Jianrong

    2008-04-28

    Aluminum-lanthanum-silicate glasses with different Eu doping concentration have been synthesized by conventional melt-quenching method at 1680 degrees C in reductive atmosphere. Under 395nm excitation, samples with low Eu doping concentration show mainly the cyan broad emission at 460nm due to 4f(6)5d(1)-4f(7) transition of Eu(2+); and the samples with higher Eu doping concentration show mainly some narrow emissions with maximum at 616nm due to (5)D(0)-(7)F(j) (J=0, 1, 2, 3, 4) transitions of Eu(3+). Cyan-white-red tunable luminescence under 395nm excitation has been obtained by changing the Eu doping concentration.

  6. Thermal analyzes of phosphate glasses doped with Yb{sup 3+} and ZnTe nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, A.M.; Bell, M.J.V. [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, MG (Brazil); Anjos, V., E-mail: virgilio@fisica.ufjf.br [Laboratório de Espectroscopia de Materiais, Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, MG (Brazil); Pinheiro, A.S.; Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física da Universidade Federal de Uberlândia, CP 593, CEP 38400-902 Uberlândia, MG (Brazil)

    2016-01-15

    This work studies the thermal properties of a glass matrix called PZABP doped with ZnTe and co-doped with Yb{sup 3+} with nominal composition 60P{sub 2}O{sub 5}, 15ZnO, 5Al{sub 2}O{sub 3}, 10BaO, and 10 PbO (mol%). The presence of ZnTe results in the formation of nanocrystals which are evidenced by optical absorption, X-Ray Diffraction (XRD) and Raman scattering. Thermal lens and Volumetric Heat Capacity techniques were used to investigate thermal diffusivity (D), thermal conductivity (K) and optical path variation with temperature (ds/dT). The outcomes indicate high values for the thermal diffusivity and a relatively small thermal conductivity, i.e., around 2.6×10{sup −3} cm{sup 2}/s and 3.4×10{sup −3} W cm{sup −1} K{sup −1}, respectively. On the other hand, a low ds/dT value, 1.0×10{sup −6} K{sup −1}, was obtained as required for an active laser medium. Moreover, it has been observed that the matrix allows high concentration of dopants without compromising its thermal properties. As a result, PZABP glasses may be pointed out as a promising material to applications in high power photonics devices. - Highlights: • UV transparentglass matrix (PZABP) is used for Yb{sup 3+}doping. • Bulk like and quantum dots like crystals of ZnTe were grown. • Thermal properties point out PZABP as a material to high power photonics devices.

  7. Electronic polarizability, optical basicity and interaction parameter for Nd2O3 doped lithium-zinc-phosphate glasses

    Science.gov (United States)

    Algradee, M. A.; Sultan, M.; Samir, O. M.; Alwany, A. Elwhab B.

    2017-08-01

    The Nd3+-doped lithium-zinc-phosphate glasses were prepared by means of conventional melt quenching method. X-ray diffraction results confirmed the glassy nature of the studied glasses. The physical parameters such as the density, molar volume, ion concentration, polaron radius, inter-ionic distance, field strength and oxygen packing density were calculated using different formulae. The transmittance and reflectance spectra of glasses were recorded in the wavelength range 190-1200 nm. The values of optical band gap and Urbach energy were determined based on Mott-Davis model. The refractive indices for the studied glasses were evaluated from optical band gap values using different methods. The average electronic polarizability of the oxide ions, optical basicity and an interaction parameter were investigated from the calculated values of the refractive index and the optical band gap for the studied glasses. The variations in the different physical and optical properties of glasses with Nd2O3 content were discussed in terms of different parameters such as non-bridging oxygen and different concentrations of Nd cation in glass system.

  8. Cross Relaxation in rare-earth-doped oxyfluoride glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lakshminarayana, G.; Weis, Eric M. [Materials Science and Technology Division (MST-7), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lira, A.C. [Unidad Académica Profesional Nezahualcóyotl, Universidad Autónoma del Estado de México, Av. Bordo de Xochiaca s/n, Nezahualcóyotl, Estado de Mexico 57000, México (Mexico); Caldiño, Ulises [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, México D.F. 09340 (Mexico); Williams, Darrick J. [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hehlen, Markus P., E-mail: hehlen@lanl.gov [Materials Science and Technology Division (MST-7), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-07-15

    The excited-state relaxation dynamics of Tb{sup 3+}, Sm{sup 3+}, and Eu{sup 3+} doped into a 50SiO{sub 2}–20Al{sub 2}O{sub 3}–10Na{sub 2}O–20LaF{sub 3} (mol%) oxyfluoride glass are studied. Multiphonon relaxation of the primary emitting states in Tb{sup 3+} ({sup 5}D{sub 3} and {sup 5}D{sub 4}), Sm{sup 3+} ({sup 4}G{sub 5/2}), and Eu{sup 3+} ({sup 5}D{sub 0}) was found to be negligible in the present host. The relaxation of Tb{sup 3+} ({sup 5}D{sub 4}) and Eu{sup 3+} ({sup 5}D{sub 0}) is dominated by radiative decay. For Tb{sup 3+} ({sup 5}D{sub 3}) and Sm{sup 3+} ({sup 4}G{sub 5/2}) in contrast, radiative relaxation is in competition with several non-radiative cross-relaxation processes. This competition was found to be particularly pronounced for the {sup 5}D{sub 3} excited state in Tb{sup 3+}, where a 124-fold decrease of the ({sup 5}D{sub 3}→{sup 7}F{sub 5})/({sup 5}D{sub 4}→{sup 7}F{sub 5}) emission intensity ratio and a ∼10-fold shortening of the {sup 5}D{sub 3} lifetime was observed upon increasing the Tb{sup 3+} concentration from 0.01% to 1%. The Tb{sup 3+} concentration dependence of {sup 5}D{sub 3} also points to some degree of ion aggregation in the “as quenched” glasses. A Judd–Ofelt intensity analysis was performed for Sm{sup 3+} and used to estimate the relative magnitude of {sup 4}G{sub 5/2} cross-relaxation processes. Four cross-relaxation processes in particular were identified to account for 92% of the total {sup 4}G{sub 5/2} non-radiative decay, and a 11% quantum efficiency was estimated for the {sup 4}G{sub 5/2} excited state. Non-exponentiality in the {sup 5}D{sub 0} decay of Eu{sup 3+} is evidence for several Eu{sup 3+} coordination environments in the glass host that manifest in different {sup 5}D{sub 0} decay constants because of the hypersensitivity of the {sup 5}D{sub 0}→{sup 7}F{sub 2} transition. -- Highlights: ► Tb{sup 3+}, Sm{sup 3+}, and Eu{sup 3+} were doped into a LaF{sub 3}-rich oxyfluoride glass. ► The

  9. Gas-generated thermal oxidation of a coordination cluster for an anion-doped mesoporous metal oxide.

    Science.gov (United States)

    Hirai, Kenji; Isobe, Shigehito; Sada, Kazuki

    2015-12-18

    Central in material design of metal oxides is the increase of surface area and control of intrinsic electronic and optical properties, because of potential applications for energy storage, photocatalysis and photovoltaics. Here, we disclose a facile method, inspired by geochemical process, which gives rise to mesoporous anion-doped metal oxides. As a model system, we demonstrate that simple calcination of a multinuclear coordination cluster results in synchronic chemical reactions: thermal oxidation of Ti8O10(4-aminobenzoate)12 and generation of gases including amino-group fragments. The gas generation during the thermal oxidation of Ti8O10(4-aminobenzoate)12 creates mesoporosity in TiO2. Concurrently, nitrogen atoms contained in the gases are doped into TiO2, thus leading to the formation of mesoporous N-doped TiO2. The mesoporous N-doped TiO2 can be easily synthesized by calcination of the multinuclear coordination cluster, but shows better photocatalytic activity than the one prepared by a conventional sol-gel method. Owing to an intrinsic designability of coordination compounds, this facile synthetic will be applicable to a wide range of metal oxides and anion dopants.

  10. First principles studies of the electronic properties and catalytic activity of single-walled carbon nanotube doped with Pt clusters and chains

    International Nuclear Information System (INIS)

    Hayes, Kayla E.; Lee, Hee-Seung

    2012-01-01

    Highlights: ► Electronic and magnetic properties of (5, 5)-SWNT doped with Pt clusters and chains. ► Pt-doping can change metallic (5, 5)-SWNT to semiconducting CNT. ► Oxygen adsorption on Pt-doped (5, 5)-SWNT is barrierless process. ► Pt-doping reduces the activation barrier of oxygen dissociation reaction. ► Adsorbed oxygen has 2 O 2 - – character. - Abstract: We report the results of density functional theory calculations on the electronic structures, geometrical parameters, and magnetic properties of a wide variety of Pt clusters/chains adsorbed on metallic (5,5) single-walled carbon nanotube (SWNT). It was found that the electronic band structures of Pt/CNT systems are very sensitive to the small changes in the geometries of Pt clusters and chains. In some cases, metallic (5, 5)-SWNT becomes a small-gap semiconducting nanotube with adsorbed Pt clusters and chains. We also investigated the dissociation of molecular oxygen on the (5, 5)-SWNT doped with a single Pt atom via the nudged elastic band (NEB) method. The NEB results showed that the activation barrier is lowered even with a single Pt atom compared to that of pristine SWNT. It was found that the electronic structure of molecular oxygen adsorbed on Pt-doped CNT resembles that of 2 O 2 - , which should facilitate the dissociation process.

  11. Eu-doped ZnO-HfO2 hybrid nanocrystal-embedded low-loss glass-ceramic waveguides

    Science.gov (United States)

    Ghosh, Subhabrata; N, Shivakiran Bhaktha B.

    2016-03-01

    We report on the sol-gel fabrication, using a dip-coating technique, of low-loss Eu-doped 70SiO2 -(30-x) HfO2-xZnO (x = 2, 5, 7 and 10 mol%) ternary glass-ceramic planar waveguides. Transmission electron microscopy and grazing incident x-ray diffraction experiments confirm the controlled growth of hybrid nanocrystals with an average size of 3 nm-25 nm, composed of ZnO encapsulated by a thin layer of nanocrystalline HfO2, with an increase of ZnO concentration from x = 2 mol% to 10 mol% in the SiO2-HfO2 composite matrix. The effect of crystallization on the local environment of Eu ions, doped in the ZnO-HfO2 hybrid nanocrystal-embedded glass-ceramic matrix, is studied using photoluminescence spectra, wherein an intense mixed-valence state (divalent as well as trivalent) emission of Eu ions is observed. The existence of Eu2+ and Eu3+ in the SiO2-HfO2-ZnO ternary matrix is confirmed by x-ray photoelectron spectroscopy. Importantly, the Eu{}2+,3+-doped ternary waveguides exhibit low propagation losses (0.3 ± 0.2 dB cm-1 at 632.8 nm) and optical transparency in the visible region of the electromagnetic spectrum, which makes ZnO-HfO2 nanocrystal-embedded SiO2-HfO2-ZnO waveguides a viable candidate for the development of on-chip, active, integrated optical devices.

  12. Enhanced Laser Cooling of Rare-Earth-Ion-Doped Glass Containing Nanometer-Sized Metallic Particles

    International Nuclear Information System (INIS)

    Jia Youhua; Zhong Biao; Yin Jianping

    2009-01-01

    The enhanced laser cooling performance of rare-earth-ions-doped glasses containing small particles is predicted. This is achieved by the enhancement of local field around rare earth ions, owing to the surface plasmon resonance of small metallic particles. The role of energy transfer between ions and the particle is theoretical discussed. Depending on the particle size and the ion emission quantum efficiency, the enhancement of the absorption and the fluorescence is predicted. Moreover, taking Yb 3+ -doped ZBLAN as example, the cooling power and heat-light converting efficiency are calculated. It is finally concluded that the absorption and the fluorescence are greatly enhanced in these composite materials, the cooling power is increased compared to the bulk material. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  13. Application of Judd-Ofelt Theory Upon Chlofluorophosphate Glass ...

    African Journals Online (AJOL)

    A series of erbium doped glasses chlorofluorophosphates were prepared and characterized. The absorption spectra were analyzed to determine the Judd-Ofelt parameters. The optical performance of these doped glasses suggesting the relevance of these glasses for optical fiber/ wave guide lasers and optical amplifiers.

  14. Application of Cu{sub 2}O-doped phosphate glasses for bandpass filter

    Energy Technology Data Exchange (ETDEWEB)

    Elhaes, H. [Physics Department, Faculty of Women for Arts, Science and Education, Ain Shams University, 11757 Cairo (Egypt); Attallah, M., E-mail: m_atallah94@yahoo.com [Basic Science Department, Higher Technological Institute, 10th of Ramadan City (Egypt); Elbashar, Y.; El-Okr, M. [Physics Department, Faculty of Science, Al Azhar University, Cairo (Egypt); Ibrahim, M. [Spectroscopy Department, National Research Centre, 12311 Dokki, Cairo (Egypt)

    2014-09-15

    Phosphate glasses doped with copper ions having general composition 42P{sub 2}O{sub 5}–39ZnO–(18−x) Na{sub 2}O–1CaO–xCu{sub 2}O [x=2, 4, 6, 8, 10 mol%] were prepared using a conventional melt-quench technique. Physical and chemical properties of the glasses were investigated using X-ray diffraction technique and UV–visible optical absorption. The density was measured by Archimedes' method, and molar volume (V{sub M}) was calculated. It is found that density and molar volume show opposite trend by increasing Cu{sub 2}O content. Absorbance and transmittance at the normal incidence are measured by a spectrophotometer in the spectral range of 190–1100 nm. Analyses of the obtained results were considered in the frame of current theories. Absorption data were used for absorption coefficient, the optical band gap (E{sub opt}), the cutoff in UV and IR bands to the bandpass filter, which confirmed the optical properties of this type of filter. E{sub opt} values for different glass samples are found to decrease with increasing Cu{sub 2}O content.

  15. Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

    Energy Technology Data Exchange (ETDEWEB)

    Vasileva, A.A., E-mail: anvsilv@gmail.com [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation); Nazarov, I.A. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg (Russian Federation); Olshin, P.K.; Povolotskiy, A.V. [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation); Sokolov, I.A. [St.Petersburg State Polytechnical University, St.Petersburg (Russian Federation); LTD “AtomTjazhMash”, St.Petersburg (Russian Federation); Manshina, A.A. [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation)

    2015-10-15

    Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium–phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass. - Graphical abstract: Formation of silver NPs on the surface of 0.5Ag{sub 2}O–0.4P{sub 2}O{sub 5}–0,1Nb{sub 2}O{sub 5} glass induced by CW laser irradiation. - Highlights: • The structure of 0.5Ag{sub 2}O–0.1Nb{sub 2}O{sub 5}–0.4P{sub 2}O{sub 5} and 0.55Ag{sub 2}O–0.45P{sub 2}O{sub 5} glasses was investigated by Raman spectroscopy. • Fs laser writing induces formation of silver NPs in investigated glasses. • Surface plasmon resonance in the absorption spectra confirms the formation of NP. • The possibility of CW laser induced formation of silver NPs on the surface of sample with niobium is shown.

  16. Investigations on optical properties of Sm{sup 3+} ion doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, R.; Suthanthirakumar, P.; Karthikeyan, P.; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute – Deemed University, Gandhigram – 624302 (India)

    2015-06-24

    The Sm{sup 3+} doped Boro-phosphate glasses with the chemical composition 60H{sub 3}BO{sub 3}+20Li{sub 2}CO{sub 3}+10ZnO+(10−x) H{sub 6}NO{sub 4}P+xSm{sub 2}O{sub 3} (where x= 0.1, 0.5, 1 and 2 in wt%) have been prepared by melt quenching technique. The prepared glasses were characterized through optical absorption and luminescence spectral measurements. The band gap energies corresponding to the direct and indirect allowed transitions and the Urbach’s energy values were estimated from the absorption spectra. Judd-Ofelt intensity parameters have been derived to predict the radiative properties of the various emission transitions. In order to identify the emission color of the prepared glasses, the emission intensities were analyzed using CIE 1931 color chromaticity diagram. The energy transfer process takes place between Sm{sup 3+}−Sm{sup 3+} ions through cross-relaxation mechanism have also been investigated and the results were discussed and reported.

  17. Identification of ε-Fe{sub 2}O{sub 3} nano-phase in borate glasses doped with Fe and Gd

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, O.S.; Ivantsov, R.D. [L.V. Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk (Russian Federation); Edelman, I.S., E-mail: ise@iph.krasn.ru [L.V. Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk (Russian Federation); Petrakovskaja, E.A. [L.V. Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk (Russian Federation); Velikanov, D.A. [L.V. Kirensky Institute of Physics, Siberian Branch of RAS, 660036 Krasnoyarsk (Russian Federation); Siberian Federal University, 660036 Krasnoyarsk (Russian Federation); Zubavichus, Y.V. [NRC “Kurchatov Institute”, 123182 Moscow (Russian Federation); Zaikovskii, V.I. [Boreskov Institute of Catalysis, Siberian Branch of RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Stepanov, S.A. [Vavilov State Optical Institute, All-Russia Research Center, 192371 Petersburg (Russian Federation)

    2016-03-01

    A new type of magnetic nanoparticles was revealed in borate glasses co-doped with low contents of iron and gadolinium. Structure and magnetic properties of the particles differ essentially from that of the α-Fe{sub 2}O{sub 3}, γ-Fe{sub 2}O{sub 3}, or Fe{sub 3}O{sub 4} nanoparticles which were detected earlier in similar glass matrices. Transmission electron microscopy including STEM-HAADF and EDX, synchrotron radiation-based XRD, static magnetic measurements, magnetic circular dichroism, and electron magnetic resonance studies allow referring the nanoparticles to the iron oxide phase-ε-Fe{sub 2}O{sub 3}. Analysis of the data set has shown that it is Gd atoms that govern the process of nanoparticles’ nucleation and its incorporation into the particles in different proportions can be used to adjust their magnetic and magneto-optical characteristics. - Highlights: • Alumina-potassium-borate glasses co-doped with Fe and Gd are studied. • Magnetic nanoparticles with structure close to ε-Fe{sub 2}O{sub 3} are shown to arise in glasses • Magnetic hysteresis loops and EMR evidence on the ferromagnetic and paramagnetic nano-phases coexistence. • Magnetic circular dichroism for ε-Fe{sub 2}O{sub 3} is studied for the first time.

  18. The Effect of Remelting on the Physical Properties of Borotellurite Glass Doped with Manganese

    Science.gov (United States)

    Hashim, Syed Putra Hashim Syed; Sidek, Haji Abdul Aziz; Halimah, Mohamed Kamari; Matori, Khamirul Amin; Yusof, Wan Mohamad Daud Wan; Zaid, Mohd Hafiz Mohd

    2013-01-01

    A systematic set of borotellurite glasses doped with manganese (1–x) [(B2O3)0.3(TeO2)0.7]-xMnO, with x = 0.1, 0.2, 0.3 and 0.4 mol%, were successfully synthesized by using a conventional melt and quench-casting technique. In this study, the remelting effect of the glass samples on their microstructure was investigated through density measurement and FT-IR spectra and evaluated by XRD techniques. Initial experimental results from XRD evaluation show that there are two distinct phases of glassy and crystallite microstructure due to the existence of peaks in the sample. The different physical behaviors of the studied glasses were closely related to the concentration of manganese in each phase. FTIR spectra revealed that the addition of manganese oxide contributes the transformation of TeO4 trigonal bipyramids with bridging oxygen (BO) to TeO3 trigonal pyramids with non-bridging oxygen (NBO). PMID:23296276

  19. The Effect of Remelting on the Physical Properties of Borotellurite Glass Doped with Manganese

    Directory of Open Access Journals (Sweden)

    Syed Putra Hashim Syed Hashim

    2013-01-01

    Full Text Available A systematic set of borotellurite glasses doped with manganese (1–x [(B2O30.3(TeO20.7]-xMnO, with x = 0.1, 0.2, 0.3 and 0.4 mol%, were successfully synthesized by using a conventional melt and quench-casting technique. In this study, the remelting effect of the glass samples on their microstructure was investigated through density measurement and FT-IR spectra and evaluated by XRD techniques. Initial experimental results from XRD evaluation show that there are two distinct phases of glassy and crystallite microstructure due to the existence of peaks in the sample. The different physical behaviors of the studied glasses were closely related to the concentration of manganese in each phase. FTIR spectra revealed that the addition of manganese oxide contributes the transformation of TeO4 trigonal bipyramids with bridging oxygen (BO to TeO3 trigonal pyramids with non-bridging oxygen (NBO.

  20. Structures, stabilities, and electronic properties for rare-earth lanthanum doped gold clusters

    International Nuclear Information System (INIS)

    Zhao, Ya-Ru

    2015-01-01

    The structures, stabilities, and electronic properties of rare-earth lanthanum doped gold La 2 Au n (n = 1-9) and pure gold Au n (n ≤ 11) clusters have been investigated by using density functional theory. The optimized geometries show that the lowest energy structures of La 2 Au n clusters favour the 3D structure at n ≥ 3. The lanthanum atoms can strongly enhance the stabilities of gold clusters and tend to occupy the most highly coordinated position. By analysing the gap, vertical ionization potential, and chemical hardness, it is found that the La 2 Au 6 isomer possesses higher stability for small-sized La 2 Au n clusters (n = 1-9). The charges in the La 2 Au n clusters transfer from La atoms to the Au n host. In addition, Wiberg bond indices analysis reveals that the intensity of different bonds of La 2 Au n clusters exhibits a sequence of La-La bond > La-Au bond > Au-Au bond.

  1. Performance of magneto-optical glass in optical current transducer application

    International Nuclear Information System (INIS)

    Shen, Yan; Lu, Yunhe; Liu, Zhao; Yu, Xueliang; Zhang, Guoqing; Yu, Wenbin

    2015-01-01

    First, a theoretical analysis was performed on the effect of temperature on the performance of the sensing element of paramagnetic rare earth-doped magneto-optical glass material that can be used in an optical current transducer application. The effect comprises two aspects: the linear birefringence and the Verdet constant. On this basis, rare earth-doped glass temperature characteristics were studied, and the experimental results indicated that the linear birefringence of rare earth-doped glass increased with increasing temperature, while its magneto-optical sensitivity decreased. Comparative experiments performed for various concentrations of rare earth dopant in the glass revealed that changes in the dopant concentration had no significant effect on the performance of magneto-optical glass. At last, a comparison between rare earth-doped magneto-optical and diamagnetic dense flint glass showed that the sensitivity of the former was six times that of the latter, although the temperature stability of the former was poorer. - Highlights: • Theoretical analysis on the effects of temperature on RE glass. • Rare earth doping leads to higher magneto-optical sensitivity. • The sensitivity of the RE glass is six times that of the dense flint glass

  2. Spectroscopic investigation on europium doped heavy metal borate glasses for red luminescent application

    Energy Technology Data Exchange (ETDEWEB)

    Hegde, Vinod; Wagh, Akshatha; Kamath, Sudha D. [Manipal University, Department of Physics, Manipal Institute of Technology, Manipal (India); Hegde, Hemanth [Manipal University, Department of Chemistry, Manipal Institute of Technology, Manipal (India); Vishwanath, C.S.D. [Sri Venkateswara University, Department of Physics, Tirupati (India)

    2017-05-15

    The present study explores a new borate family glasses based on 10ZnO-5Na{sub 2}O-10Bi{sub 2}O{sub 3}-(75 - x) B{sub 2}O{sub 3}-xEu{sub 2}O{sub 3} (x = 0, 0.1, 0.5, 1, 1.5, 2, 3 mol%) composition, synthesized by rapid melt quench technique. Prepared glasses were subjected to the density and refractive index measurements and their values were used to calculate other physical properties of the glass matrix as a function of Eu{sup 3+} concentration. XRD confirmed amorphous nature of the glasses. FTIR spectra in the absorption mode were recorded in the 400-4000 cm{sup -1} region to identify different functional groups in the glass matrix. Deconvoluted FTIR spectra showed increase in BO{sub 4} units with rise in europium content which confirmed the 'network strengthener' role of europium ions by creating bridging oxygens (BOs). Optical properties were investigated for their luminescence behavior through various spectroscopic techniques such as UV-Vis-NIR absorption, excitation, emission, decay profiles, and color measurements at room temperature. Lasing properties of the glasses like total radiative life time, branching ratio, emission cross section, and optical gain were obtained from the calculated Judd-Ofelt (Ω{sub 2},Ω{sub 4}) intensity parameters. From the measured values of emission, cross sections, branching ratios, life times, strong photoluminescence features, and CIE chromaticity coordinates, 0.5 mol% of Eu{sup 3+} ions doped ZnNaBiB glasses showed optimum performance and are potential candidate for red light generation at 613 nm. (orig.)

  3. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Omar, R. S., E-mail: ratnasuffhiyanni@gmail.com; Wagiran, H., E-mail: husin@utm.my; Saeed, M. A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru (Malaysia)

    2016-01-22

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B{sub 2}O{sub 3} − 20 CaO – 10 MgO-(y) Dy{sub 2}O{sub 3} with 0.05  mol % ≤ y ≤ 0.7  mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy{sub 2}O{sub 3} concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used.

  4. Optical properties of Er{sup 3+}-doped strontium barium niobate nanocrystals obtained by thermal treatment in glass

    Energy Technology Data Exchange (ETDEWEB)

    Haro-Gonzalez, P. [Dep. of Fisica Fundamental Experimental, Electronica y Sistemas, Universidad de La Laguna Avda Astrofisico Franscisco Sanchez, 38206 La Laguna, S/C de Tenerife (Spain)], E-mail: patharo@ull.es; Lahoz, F. [Dep. of Fisica Fundamental Experimental, Electronica y Sistemas, Universidad de La Laguna Avda Astrofisico Franscisco Sanchez, 38206 La Laguna, S/C de Tenerife (Spain); Gonzalez-Platas, J. [Dep. of Fisica Fundamental II, Universidad de La Laguna, 38206 La Laguna, S/C de Tenerife (Spain); Caceres, J.M. [Dep. of Edafologia y Geologia, Universidad de La Laguna, 38206 La Laguna, S/C de Tenerife (Spain); Gonzalez-Perez, S. [Dep. of Fisica Fundamental Experimental, Electronica y Sistemas, Universidad de La Laguna Avda Astrofisico Franscisco Sanchez, 38206 La Laguna, S/C de Tenerife (Spain); Marrero-Lopez, D. [Dep. of Quimica Inorganica, Universidad de La Laguna, 38206 La Laguna, S/C de Tenerife (Spain); Capuj, N. [Dep. of Fisica Basica, Universidad de La Laguna, 38206 La Laguna, S/C de Tenerife (Spain); Martin, I.R. [Dep. of Fisica Fundamental Experimental, Electronica y Sistemas, Universidad de La Laguna Avda Astrofisico Franscisco Sanchez, 38206 La Laguna, S/C de Tenerife (Spain)

    2008-05-15

    Measurements of the optical properties of Er{sup 3+} ions in strontium barium niobate glass and glass ceramics have been carried out. The glasses have been fabricated using a melt-quenching method, and the glass ceramic samples have been obtained from the glass precursor by a thermal treatment. The ceramic samples formed by a glassy phase, and a crystalline phase contains nanocrystals of Sr{sub 1-x}Ba{sub x}Nb{sub 2}O{sub 6} (SBN) doped with Er{sup 3+} ions with a mean size of {approx}50 nm, as confirmed with XRD. Green up-conversion emission has been obtained under excitation at 800 nm, and the temporal evolution of this emission has been reported with the purpose of determining the involved up-conversion mechanism. These optical measures have confirmed that the Er{sup 3+} ions have been incorporated into the SBN matrix, after a thermal treatment, which produced an increment of the up-conversion efficiency.

  5. Influences of oxygen gas flow rate on electrical properties of Ga-doped ZnO thin films deposited on glass and sapphire substrates

    International Nuclear Information System (INIS)

    Makino, Hisao; Song, Huaping; Yamamoto, Tetsuya

    2014-01-01

    The Ga-doped ZnO (GZO) films deposited on glass and c-plane sapphire substrates have been comparatively studied in order to explore the role of grain boundaries in electrical properties. The influences of oxygen gas flow rates (OFRs) during the deposition by ion-plating were examined. The dependences of carrier concentration, lattice parameters, and characteristic of thermal desorption of Zn on the OFR showed common features between glass and sapphire substrates, however, the Hall mobility showed different behavior. The Hall mobility of GZO films on glass increased with increasing OFR of up to 15 sccm, and decreased with further increasing OFR. On the other hand, the Hall mobility of GZO films on c-sapphire increased for up to 25 sccm. The role of grain boundary in polycrystalline GZO films has been discussed. - Highlights: • Ga-doped ZnO films were deposited on glass and c-sapphire by ion-plating. • The epitaxial growth on c-sapphire was confirmed by X-ray diffraction. • Dependence of Hall mobility showed different tendency between glass and sapphire. • Grain boundaries influence transport properties at high O 2 gas flow rate

  6. Highly matched spectrum needed for photosynthesis in Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Weirong; Gao, Huiping [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute for Computational Materials Science, Henan University, Kaifeng 475004 (China); Mao, Yanli, E-mail: ylmao@henu.edu.cn [School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute for Computational Materials Science, Henan University, Kaifeng 475004 (China)

    2015-11-05

    A series of oxyfluoride glass ceramics containing CaF{sub 2} nano-crystals tri-doped with Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} ions were prepared by high temperature melting method and subsequent heat treatment. The structural properties were examined by X-ray diffraction measurements. The absorption, excitation, and emission spectra of the glass ceramics were investigated. Difference in erbium emission spectra between glass and glass ceramics had been studied. The emission bands originating from the {sup 4}F{sub 9/2} state of Er{sup 3+} were enhanced when the CaF{sub 2} nano-crystal created. By down-converting the ultraviolet wavelength region (280∼400 nm) light and up-converting the near-infrared wavelength region (900∼1100 nm) light, the glass ceramics can also emit strong reddish orange emission. The emission spectra consisting of bluish violet (400∼500 nm) and reddish orange (640∼680 nm) bands match well with the action spectrum of photosynthesis and absorption spectra of chlorophylls. Our materials will be favored to promote the development of glass greenhouses for green plant. - Highlights: • Ce{sup 3+}/Er{sup 3+}/Yb{sup 3+} tri-doped oxyfluoride glass ceramics were prepared by high temperature melting method. • 668 nm red emission was obtained under 320 nm, 380 nm and 980 nm excitation, respectively. • The emission of samples matched well with the spectrum for photosynthesis.

  7. Enhanced Visible Light Photocatalytic Activity of V2O5 Cluster Modified N-Doped TiO2 for Degradation of Toluene in Air

    Directory of Open Access Journals (Sweden)

    Fan Dong

    2012-01-01

    Full Text Available V2O5 cluster-modified N-doped TiO2 (N-TiO2/V2O5 nanocomposites photocatalyst was prepared by a facile impregnation-calcination method. The effects of V2O5 cluster loading content on visible light photocatalytic activity of the as-prepared samples were investigated for degradation of toluene in air. The results showed that the visible light activity of N-doped TiO2 was significantly enhanced by loading V2O5 clusters. The optimal V2O5 loading content was found to be 0.5 wt.%, reaching a removal ratio of 52.4% and a rate constant of 0.027 min−1, far exceeding that of unmodified N-doped TiO2. The enhanced activity is due to the deposition of V2O5 clusters on the surface of N-doped TiO2. The conduction band (CB potential of V2O5 (0.48 eV is lower than the CB level of N-doped TiO2 (−0.19 V, which favors the photogenerated electron transfer from CB of N-doped TiO2 to V2O5 clusters. This function of V2O5 clusters helps promote the transfer and separation of photogenerated electrons and holes. The present work not only displays a feasible route for the utilization of low cost V2O5 clusters as a substitute for noble metals in enhancing the photocatalysis but also demonstrates a facile method for preparation of highly active composite photocatalyst for large-scale applications.

  8. Spectroscopic studies of Dy3 + ion doped tellurite glasses for solid state lasers and white LEDs

    Science.gov (United States)

    Himamaheswara Rao, V.; Syam Prasad, P.; Mohan Babu, M.; Venkateswara Rao, P.; Satyanarayana, T.; Luís F., Santos; Veeraiah, N.

    2018-01-01

    Rare earth ion Dy3 +-doped tellurite glasses were synthesised in the system of (75-x)TeO2-15Sb2O3-10WO3-xDy2O3 (TSWD glasses). XRD and FTIR characterizations were used to find the crystalline and structural properties. The intensities of the electronic transitions and the ligand environment around the Dy3 + ion were determined using the Judd-Ofelt (J-O) theory on the absorption spectra of the glasses. The measured luminescence spectra exhibit intense emissions at 574 and 484 nm along with less intense emissions around 662 and 751 nm. Various radiative properties of the 4F9/2 excited level of Dy3 + ion were calculated for the glasses. Decay profiles were measured to find the life times and quantum efficiencies. Yellow to blue intensity ratio (Y/B), CIE chromaticity coordinates and correlated color temperature (CCT) values are calculated using the emission spectra to evaluate the emitted light. The obtained results suggest the utility of the glasses for potential yellow laser and white LED's applications.

  9. Behavior of 99Tc in doped-glass/basalt hydrothermal interaction tests

    International Nuclear Information System (INIS)

    Coles, D.G.; Apted, M.J.

    1984-01-01

    The release of polyvalent radionuclides from a nuclear waste repository located in basalt may be sensitively related to the redox potential (Eh) imposed by the basalt. A series of tests are reported here, evaluating the effect of basalt on the concentrations of 99 Tc released into solution from a borosilicate glass waste form. Crushed PNL 76-68 glass, doped with 0.7 mg 99 Tc/g glass, was reacted with reference basalt groundwater under oxic hydrothermal conditions in a sampling autoclave, both alone and in the presence of crushed basalt. The steady state fluid concentrations of 99 Tc and various table species were determined from samples obtained at the test conditions of 200 0 C, 30 MPa, and a initial solution to solid mass ratio of 10 for both tests. In the glass + groundwater test, the 99 Tc concentration rose rapidly to about 50 mg/L after only 200 hr of run time and remained at a value between 50 and 60 mg/L throughout the duration of the test. For the basalt + glass + groundwater test, the 99 Tc concentration rose to an initial value of about 2.5 mg/L. At about 700 hr, the 99 Tc concentration began to drop rapidly until a value near the analytical detection limit (approximately 0.005 mg/L) was reached after a test duration of 1400 hr. It is concluded that the presence of basalt in these hydrothermal experiments reduces the concentration of 99 Tc in solution by nearly four orders of magnitude, probably by control of solution Eh and subsequent precipitation of a solid containing a reduced form of technetium. Reaction mechanisms are discussed that can account for these observations. 17 references, 1 figure

  10. Cluster formation of network-modifier cations in cesium silicate glasses

    Science.gov (United States)

    Jardón-Álvarez, Daniel; Sanders, Kevin J.; Phyo, Pyae; Baltisberger, Jay H.; Grandinetti, Philip J.

    2018-03-01

    Natural abundance 29Si two-dimensional magic-angle flipping (2D MAF) NMR spectra were measured in a series of ten cesium silicate glass compositions xCs2O.(1 - x)SiO2, where x is 0.067, 0.113, 0.175, 0.179, 0.218, 0.234, 0.263, 0.298, 0.31, and 0.36. The Q3 shielding anisotropy decreases with increasing Cs content—interpreted as an increase in the non-bridging oxygen (NBO) bond length from increasing Cs coordination (clustering) around the NBO. The 29Si 2D MAF spectra for four glass compositions x = 0.218, 0.234, 0.263, 0.298 exhibit a second co-existing and distinctly smaller shielding anisotropy corresponding to a significantly longer Si-NBO length arising from a higher degree of Cs clustering around the NBO. This second Q3 site appears at a Cs2O mole fraction close to the critical mole fraction of x = 0.24 associated with the percolation threshold of non-bridging oxygen in random close packing of oxygen, thus suggesting that the longer Si-NBO length is associated with an infinite size spanning cluster while the sites with larger anisotropies are associated with shorter Si-NBO lengths and belong to finite size clusters. The equilibrium constant of the Q3 disproportionation reaction was determined as k3 = 0.005, indicating a Qn anionic species distribution close to a binary model as expected for a low field strength modifier such as cesium. It is also found that evolution of the isotropic Q4 and line shapes with increasing Cs content are consistent with a random connectivity model between Qn of differing number of bridging oxygen, n.

  11. Emission tunability and local environment in europium-doped OH{sup −}-free calcium aluminosilicate glasses for artificial lighting applications

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Aline M.; Sandrini, Marcelo; Viana, José Renato M.; Baesso, Mauro L.; Bento, Antônio C.; Rohling, Jurandir H. [Departamento de Física, Universidade Estadual de Maringá, Av Colombo, 5790, 87020-900, Maringá, PR (Brazil); Guyot, Yannick [Laboratoire de Physico–Chimie des Matériaux Luminescents, Université de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, UMR 5620 CNRS 69622 (France); De Ligny, Dominique [Department of Materials Science and Engineering, University of Erlangen Nürnberg, Martens str. 5, 91058, Erlangen (Germany); Nunes, Luiz Antônio O. [Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador São-Carlense400, 13566-590, São Carlos, SP (Brazil); Gandra, Flávio G. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil); Sampaio, Juraci A. [Lab Ciências Físicas, Universidade Estadual Norte Fluminense, 28013-602, Campos Dos Goytacazes, RJ (Brazil); Lima, Sandro M.; Andrade, Luis Humberto C. [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul-UEMS, Dourados, MS, C. P. 351, CEP 79804-970 (Brazil); and others

    2015-04-15

    The relationship between emission tunability and the local environment of europium ions in OH{sup −}-free calcium aluminosilicate glasses was investigated, focusing on the development of devices for artificial lighting. Significant conversion of Eu{sup 3+} to Eu{sup 2+} was obtained by means of melting the glasses under a vacuum atmosphere and controlling the silica content, resulting in broad, intense, and tunable luminescence ranging from blue to red. Electron spin resonance and X-ray absorption near edge structure measurements enabled correlation of the luminescence behavior of the material with the Eu{sup 2+}/Eu{sup 3+} concentration ratio and changes in the surrounding ions' crystal field. The coordinates of the CIE 1931 chromaticity diagram were calculated from the spectra, and the contour maps showed that the light emitted from Eu{sup 2+} presented broad bands and enhanced color tuning, ranging from reddish-orange to blue. The results showed that these Eu doped glasses can be used for tunable white lighting by combining matrix composition and the adjustment of the pumping wavelength. - Highlights: • Eu{sup 2+}-doped OH{sup −} free calcium aluminosilicate glass as a new source for white lighting. • Correlation between emission tunability and local environment of europium ions. • Significant reduction of Eu{sup 3+} to Eu{sup 2+} by melting the glasses under vacuum atmosphere. • Broad, intense and tunable luminescence ranging from blue to red.

  12. 1887 nm lasing in Tm3+-doped TeO2-BaF2-Y2O3 glass microstructured fibers

    Science.gov (United States)

    Wang, Shunbin; Yao, Chuanfei; Jia, Zhixu; Qin, Guanshi; Qin, Weiping

    2017-04-01

    In this paper, we demonstrate ∼2 μm lasing in Tm3+-doped fluorotellurite microstructured fibers. The Tm3+-doped fibers are based on TeO2-BaF2-Y2O3 glasses and fabricated by using a rod-in-tube method. Under the pump of a 1570 nm Er3+-doped fiber laser, lasing at 1887 nm is obtained in a ∼42.5 cm long Tm3+-doped fiber with a threshold pump power of 94 mW. As the pump power increases to 780 mW, the obtained maximum unsaturated power reaches up to ∼408 mW with a slop efficiency of ∼58.1%. This result indicates that the Tm3+-doped fluorotellurite fibers are promising gain media for ∼2 μm fiber lasers.

  13. Structural and luminescence studies of Ho{sup 3+}-doped zinc-aluminium-sodium-phosphate (ZANP) glasses

    Energy Technology Data Exchange (ETDEWEB)

    Brahmachary, K.; Rajesh, D.; Ratnakaram, Y. C., E-mail: ratnakaramsvu@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati-517502 (India)

    2015-06-24

    Trivalent holmium doped zinc-aluminium-sodium-phosphate (ZANP) glasses were prepared by conventional melt-quenching technique and characterized for their structural and luminescence properties. The amorphous nature, elemental analysis and thermal stability of the glasses were studied by using X-ray diffraction, energy dispersive spectrum and differential scanning calorimetry analysis, respectively. The absorption and fluorescence spectra have been recorded at room temperature. Based on the absorption spectra, the Judd-Ofelt parameters and radiative parameters such as spontaneous transition probabilities (A{sub R}), branching ratios (β{sub R}), radiative lifetimes (τ{sub R}) were calculated and discussed. From the emission spectra emission peak positions (λ{sub P}), effective bandwidths (Δλ{sub eff}) and stimulated emission cross-sections (σ{sub P}) were calculated for the observed emission transitions,{sup 5}S{sub 2} ({sup 5}F{sub 4}→{sup 5}I{sub 8}) and {sup 5}F{sub 5}→{sup 5}I{sub 8} in all the glass samples. The stimulated emission cross-section is higher for ZANPHo10 glass matrix and so it may be useful for laser excitation.

  14. Structural and luminescence behavior of Er(3+) ions doped Barium tellurofluoroborate glasses.

    Science.gov (United States)

    Annapoorani, K; Maheshvaran, K; Arunkumar, S; Suriya Murthy, N; Marimuthu, K

    2015-01-25

    Er(3+) doped Barium tellurofluoroborate glasses (BTFBxE) with the chemical composition (30-x)TeO2+30B2O3+20BaO+20BaF+xEr2O3 (where x=0.01, 0.05, 0.1, 0.5, 1.0 and 2.0 in wt%) were prepared following the melt quenching technique. The different vibrational modes of borates and tellurites in the prepared glasses were explored through FTIR and Raman spectra. The optical absorption spectra have been used to determine the ionic/covalent nature of the metal-ligand bond in the prepared glasses with the help of Nephelauxetic ratio (β) and bonding parameter (δ) studies. The optical band gap of direct and indirect allowed transitions were determined from Tauc's plot and the variations of band gap energy with structural arrangements were discussed. The Urbach energy values were determined and the relatively lower values of the Urbach's energy reveal the minimal degree of disorderness in the prepared glasses. The oscillator strengths (fexp and fcal) and Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6) were calculated with the application of JO theory and the trends of the JO intensity parameters are found to be Ω2>Ω6>Ω4 for all the prepared glasses with a minimum variation in Ω2 intensity parameter values. A bright green emission was observed from the (2)H11/2+(4)S3/2→ (4)I15/2 transition and the radiative properties such as transition probability (A), stimulated emission cross-section (σP(E)), branching ratio (βr) and radiative lifetime (τ) were calculated using the JO parameters. The suitability of the prepared glasses for the fabrication of photonic devices were also discussed and reported in the present work. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Laser-induced dendritic microstructures on the surface of Ag+-doped glass

    International Nuclear Information System (INIS)

    Nahal, A.; Mostafavi-Amjad, J.; Ghods, A.; Khajehpour, M. R. H.; Reihani, S. N. S.; Kolahchi, M. R.

    2006-01-01

    Fractal dendritic silver microstructures are observed on the surface of the Ag + -doped glasses as a result of a photothermal interaction with a focused multiline cw high-power (P max =8 W) Ag + laser beam. It is found that evolution of the structures depends on the exposure time and also on the concentration of the silver ions in the sample. The fractal dimension of the generated dendritic microstructures increases with the exposure time. Instability of the contact line of the molten silver flow toward the periphery of the interaction area is discussed as a result of the temperature gradient, due to the Gaussian intensity distribution across the laser beam

  16. Concentration dependent spectroscopic properties of Dy3+ ions doped boro-phosphate glasses

    Science.gov (United States)

    Mariyappan, M.; Marimuthu, K.

    2016-05-01

    Dy3+ ions doped boro-phosphate glasses have been synthesized by melt quenching method and characterized through FTIR, absorption and luminescence spectral measurements. The presence of various stretching and bending vibrations of different borate and phosphate groups were identified from the FTIR spectra. In order to examine the electronic band structure of the studied glasses, Optical energy gap (Eopt) and Urbach energy (ΔE) values were estimated from the absorption spectra. The Judd-Ofelt (JO) intensity parameters were calculated to examine the symmetry of the ligand environment around the Dy3+ ions site. The emission spectra exhibit two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponding to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively. The emission spectra were characterized through Commission International d'Eclairage (CIE) 1931 chromaticity diagram to explore its suitability for WLED applications.

  17. Optical and luminescence properties of Dy3+ doped sodium silicate glass

    Science.gov (United States)

    Srisittipokakun, N.; Kaewkhao, J.

    2017-07-01

    The aim of the present work is to study the optical and luminescence properties of Dy2O3 doped Na2O-BaO-Bi2O3-SiO2 glasses. The Dy3+ ion is chosen as dopant because it emits three visible bands, blue (470-485 nm; 4F9/2→6H15/2), yellow (570-580 nm; 4F9/2→6H13/2) and red (640-655 nm; 4F9/2→6H11/2) luminescence and finds its applications in the fields of laser, white LEDs, telecommunication technology and display devices. NaBaBiSiDy glasses with the compositions of (30-x)SiO2: 10Bi2O3: 30Na2O: 30BaO: xDy2O3 where x=0.0, 0.1, 0.5, 1.0, 1.5 and 2.0 mol% were prepared by melt-quenching technique and characterized by using density, optical absorption photoluminescence (PL) and decay rate measurements as function of different concentrations. The density (ρ), molar volume (VM) and refractive index obtained were found to increase with increase in the concentration of Dy2O3 in the glass matrix. The chromaticity coordinates were calculated from emission spectra and analyzed with CIE color diagram and appear in the white light region under ultraviolet excitation.

  18. Structural and luminescence properties of samarium doped lead alumino borate glasses

    Science.gov (United States)

    Mohan, Shaweta; Kaur, Simranpreet; Singh, D. P.; Kaur, Puneet

    2017-11-01

    The study reports the effect of samarium concentration on the physical, structural and spectroscopic characteristics of samarium doped lead alumino borate glasses having composition 20PbO-(10-x)Al2O3-70B2O3-xSm2O3; x = 0.1, 0.5, 1.0 and 2.0 mol %. The glasses were fabricated by conventional melt-quenching technique and then characterized by XRD, FTIR, optical absorption and fluorescence spectra. X-ray diffraction studies confirmed the amorphous nature of the prepared glasses. FTIR spectra indicate the presence of BO3, BO4, AlO6 and a few other structural groups. Various physical properties such as density, molar volume, refractive index, rare earth ion concentration, boron-boron distance and polarizability etc. were determined using conventional methods and standard formulae. The Judd-Ofelt theory was applied on the optical absorption spectra of the glasses to evaluate the three phenomenological intensity parameters Ω2, Ω4 and Ω6. The value of Ω2 was found to be highest for glass with 1 mol% Sm2O3 and attributed to the asymmetry of the ligand field at the rare earth ion site and the rare earth oxygen (Sm-O) covalency. The calculated intensity parameters and fluorescence spectra were further used to predict the radiative transition probability (A), radiative lifetime (τR), branching ratio (βR), peak wavelength (λp), effective line widths (Δλeff) and stimulated emission cross-section (σ) for the characteristic 4G5/2 → 6H5/2, 6H7/2 and 6H9/2 transitions of the Sm3+ ion. Concentration quenching was observed for 2 mol% concentration of Sm2O3 and ascribed to energy transfer through various cross-relaxation channels between Sm3+ ions. Reasonably high values of branching ratios and stimulated emission cross-section for the prepared glasses points towards their utility in the development of visible lasers emitting in the reddish-orange spectral region. However, the glass with 1 mol% Sm2O3 was found to show better radiative properties.

  19. Enhanced 1.32 μm fluorescence and broadband amplifying for O-band optical amplifier in Nd3+-doped tellurite glass

    Science.gov (United States)

    Zhou, Zi-zhong; Zhou, Ming-han; Su, Xiu-e.; Cheng, Pan; Zhou, Ya-xun

    2017-01-01

    WO3 oxides with relatively high phonon energy and different concentrations were introduced into the Nd3+-doped tellurite-based glasses of TeO2-ZnO-Na2O to improve the 1.32 μm band fluorescence emission. The absorption spectra, Raman spectra, 1.32 μm band fluorescence spectra and differential scanning calorimeter (DSC) curves were measured, together with the Judd-Ofelt intensity parameters, stimulated emission and gain parameters were calculated to evaluate the effects of WO3 amount on the glass structure and spectroscopic properties of 1.32 μm band fluorescence. It is shown that the introduction of an appropriate amount of WO3 oxide can effectively improve the 1.32 μm band fluorescence intensity through the enhanced multi-phonon relaxation (MPR) processes between the excited levels of Nd3+. The results indicate that the prepared Nd3+-doped tellurite glass with an appropriate amount of WO3 oxide is a potential gain medium applied for the O-band broad and high-gain fiber amplifier.

  20. Laser-induced radial birefringence and spin-to-orbital optical angular momentum conversion in silver-doped glasses

    International Nuclear Information System (INIS)

    Amjad, Jafar Mostafavi; Khalesifard, Hamid Reza; Slussarenko, Sergei; Karimi, Ebrahim; Santamato, Enrico; Marrucci, Lorenzo

    2011-01-01

    Samples of Ag + /Na + ion-exchanged glass that have been subject to intense laser irradiation may develop novel optical properties, as a consequence of the formation of patterns of silver nanoparticles and other structures. Here, we report the observation of a laser-induced permanent transverse birefringence, with the optical axis forming a radial pattern, as revealed by the spin-to-orbital angular momentum conversion occurring in a probe light beam. The birefringence pattern can be modeled well as resulting from thermally-induced stresses arising in the silver-doped glass during laser exposure, although the actual mechanism leading to the permanent anisotropy is probably more complex.

  1. Photoluminescence and lasing in whispering gallery mode glass microspherical resonators

    Energy Technology Data Exchange (ETDEWEB)

    Ristić, D. [Ruđer Bošković Institute, Division of Materials Physics, Laboratory for Molecular Physics, Bijenička c. 54, Zagreb (Croatia); Center of Excellence for Advanced Materials and Sensing Devices, Research unit New Functional Materials, Bijenička c. 54, Zagreb (Croatia); Berneschi, S.; Camerini, M. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Farnesi, D.; Pelli, S. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Trono, C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Chiappini, A.; Chiasera, A.; Ferrari, M. [CSMFO Group, Istituto di Fotonica e Nanotecnologie, IFN-CNR, Via alla Cascata 56/C, 38050 Povo-Trento (Italy); Lukowiak, A. [Institute of Low Temperature and Structure Research, PAS, ul. Okolna 2, Wroclaw 50-950 (Poland); Dumeige, Y.; Féron, P. [Laboratoire d' Optronique, (CNRS-UMR 6082-Foton), ENSSAT, 6 rue de Kérampont, 22300 Lannion (France); Righini, G.C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Soria, S., E-mail: s.soria@ifac.cnr.it [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Conti, G. Nunzi [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy)

    2016-02-15

    We report experimental results regarding the development of Er{sup 3+}-doped glass microspherical cavities for the fabrication of compact sources at 1.55 μm. We investigate several different approaches in order to fabricate the microspheres including direct melting of Er{sup 3+}-doped glass powders, synthesis of Er{sup 3+}-doped monolithic microspheres by drawing Er{sup 3+}-doped glass, and coating of silica microspheres with an Er{sup 3+}-doped sol–gel layer. Details of the different fabrication processes are presented together with the photoluminescence characterization in free space configuration of the microspheres and of the glass precursor. We have analyzed the photoluminescence spectra of the whispering gallery modes of the microspheres excited using evanescent coupling and we demonstrate tunable laser action in a wide range of wavelengths around 1.55 μm. As much as 90 μW of laser output power was measured in Er{sup 3+}-doped glass microspheres. - Highlights: • Different approaches in microsphere fabrication and various types of post-processing. • Trimming of photorefractive glass microsphere lasers with UV light. • Peak power record of 90 μW by pumping at 1480 nm.

  2. Bright white upconversion luminescence from Er3+/Tm3+/Yb3+-doped titanate-based glasses prepared by aerodynamic levitation method

    Science.gov (United States)

    Zhang, Minghui; Yu, Jianding; Jiang, Wan; Liu, Yan; Ai, Fei; Wen, Haiqin; Jiang, Meng; Yu, Huimei; Pan, Xiuhong; Tang, Meibo; Gai, Lijun

    2017-10-01

    Aerodynamic levitation method was employed to prepare Er3+/Tm3+/Yb3+-doped titanate-based glasses. DTA results show that the glass performs high thermal stability with the glass transition temperature of 799 °C. The interaction among rare earth ions has been discussed by adjusting the relative concentration. Er3+ ions can quench the upconversion luminescence of Tm3+ ions. Tm3+ ions play a strong role in quenching the emissions of Er3+ and Tm3+ when the content of Tm3+ ions is greater than or equal 0.05. From the view of the ratio of red emission to green emission, Tm3+ ions can improve the red emission of Er3+ ions to some extent in contrast with the green emissions of Er3+ ions. 980 nm incident laser can be efficiently absorbed by Yb3+ ions. The relative intensity of red, green, and blue upconversion luminescence has been tuned to obtain white light. The composition with white upconversion luminescence of the color coordinate (0.291, 0.3292) has been found. Moreover, white upconversion luminescence mechanism is a two-photon process of ET, ESA, and cooperative sensitization. Rare earth ions doped titanate-based glasses with bright upconversion luminescence perform potential applications in color display, back light, et al.

  3. Laser- and gamma-induced transformations of optical spectra of indium-doped sodium borate glass

    CERN Document Server

    Kopyshinsky, O V; Zelensky, S E; Danilchenko, B A; Shakhov, O P

    2003-01-01

    The optical absorption and luminescence properties of indium-doped sodium borate glass irradiated by gamma-rays and by powerful UV lasers within the impurity-related absorption band are investigated experimentally. It is demonstrated that both the laser- and gamma-irradiation cause similar transformations of optical spectra in the UV and visible regions. The changes of the spectra observed are described with the use of a model which includes three types of impurity centres formed by differently charged indium ions.

  4. Effect of cadmium doping on some properties of glass-insulated bismuth-based microwires

    International Nuclear Information System (INIS)

    Meglei, D.; Dyntu, M.

    2011-01-01

    Full text: According to the literature, semiconductor converters based on films and wire crystals are widely used in present-day microelectronics. However, the production of efficient semiconductor converters requires crystals of high structural perfection with a given composition and desired electrical and mechanical properties. In this work, we describe the study of the perfection of the microstructure and mechanical properties of glass-insulated microwires based on Bi doped with cadmium (Cd) and the technique of preparation of micro resistors suitable for instrumentation applications. Microscopic studies of ground, polished, and chemically etched microwires doped with cadmium showed that they have smooth cylindrical surfaces in the entire range of diameters. Sizes of defects in the form of micropores, microcracks, dislocations, and twins on their surface are much smaller than those of pure bismuth microwire. It is also found that the tendency to twinning and the number and size of surface defects decrease with decreasing diameters; at the same time, their homogeneity increases. The tensile strength of the studied microwires with glass insulation is high for all tested diameters and ranges within 33.274.1 kg/mm with respect to internal diameters of 5.6 21.2 m; in addition, they withstand a breaking force up to 130 g and more, whereas the samples of pure bismuth microwires withstood a force up to 80 g. It is also found that the tensile strength of cadmium doped microwires is significantly higher than that of undoped samples. The bending strength as a measure of elasticity was determined using a special installation according to the critical bending radius of the sample at which the sample integrity is violated. The results of bending tests showed that, with increasing diameter of the doped samples, the critical radius linearly increases; that is, in this case, the elasticity increases with decreasing diameter. Metallographic analysis revealed that cadmium in the

  5. Reddish-orange, neutral and warm white emissions in Eu3+, Dy3+ and Dy3+/Eu3+ doped CdO-GeO2-TeO2 glasses

    Science.gov (United States)

    Rodríguez-Carvajal, David A.; Meza-Rocha, A. N.; Caldiño, U.; Lozada-Morales, R.; Álvarez, E.; Zayas, Ma. E.

    2016-11-01

    Eu3+, Dy3+ and Dy3+/Eu3+ doped CdO-GeO2-TeO2 glasses were prepared using the melt-quenching process and analyzed by X-diffraction, Raman spectroscopy, excitation and emission spectra, and emission decay time profiles. The lack of X ray diffraction peaks revealed that all samples are amorphous. Vibrational modes associated with Tesbnd Osbnd Te and Gesbnd Osbnd Ge related bonds and molecular oxygen were detected by Raman spectroscopy. The luminescence characteristics were studied upon excitations that correspond with the emission of InGaN (370-420 nm) based LEDs. The Eu3+ singly doped glass displayed reddish-orange global emission, with x = 0.601 and y = 0.349 CIE1931 chromaticity coordinates, upon 393 nm excitation. Neutral emission with x = 0.373 and y = 0.412 CIE1931 chromaticity coordinates and correlated color temperature (CCT) of 4400 K, was achieved in the Dy3+ singly doped glass excited at 388 nm. The Dy3+/Eu3+ co-doped glass exhibited warm, neutral and soft warm white emissions with CCT values of 3435, 4153 and 2740 K, under excitations at 382, 388 and 393 nm, respectively, depending mainly on the Dy3+ and Eu3+ relative excitation. The Dy3+ excitation bands observed in the Dy3+/Eu3+ glass by monitoring the 611 nm Eu3+ emission, suggest that Dy3+ → Eu3+ energy transfer takes place, despite the fact that the Dy3+ emission decays in the Dy3+ and Dy3+/Eu3+ doped glass, remain without changes. The shortening of Eu3+ decay in presence of Dy3+ was attributed to an Eu3+ → Dy3+ non-radiative energy transfer process, which according with the Inokuti-Hirayama model might be dominated through an electric quadrupole-quadrupole interaction, with efficiency and probability of 5.5% and 51.6 s-1, respectively.

  6. New fluorophosphate glasses co-doped with Eu{sup 3+} and Tb{sup 3+} as candidates for generating tunable visible light

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, T.B. de, E-mail: thiago.branquinho-de-queiroz@uni-bayreuth.de [Physics Institute of São Carlos, University of São Paulo, 13566-590 São Carlos, SP (Brazil); Theoretical Physics IV, University of Bayreuth, 95440 Bayreuth (Germany); Botelho, M.B.S. [Physics Institute of São Carlos, University of São Paulo, 13566-590 São Carlos, SP (Brazil); University of Brasilia, 70910-900 Brasilia, DF (Brazil); Gonçalves, T.S.; Dousti, M. Reza [Physics Institute of São Carlos, University of São Paulo, 13566-590 São Carlos, SP (Brazil); Camargo, A.S.S. de, E-mail: andreasc@ifsc.usp.br [Physics Institute of São Carlos, University of São Paulo, 13566-590 São Carlos, SP (Brazil)

    2015-10-25

    A series of optically active Eu{sup 3+} and Tb{sup 3+} doped fluorophosphate glasses with compositions (BaF{sub 2}){sub 0.25}(SrF{sub 2}){sub 0.25}(AlF{sub 3}){sub 0.10}[Al(PO{sub 3}){sub 3}]{sub 0.20}(YF{sub 3}){sub 0.20-x}(EuF{sub 3} and/or TbF{sub 3}){sub x} (x = 0 to 0.04) was prepared and characterized by optical spectroscopy. While embedded in the oxyfluoride host, the cited rare earth (RE) ions exhibit improved spectroscopic properties such as longer excited state lifetimes than in oxide glasses and intense emissions in the red ({sup 5}D{sub 0} → {sup 7}F{sub 2}, Eu{sup 3+}), green and blue ({sup 5}D{sub 4} → {sup 7}F{sub 5} and {sup 5}D{sub 3},{sup 5}G{sub 6} → {sup 7}F{sub 5},{sup 7}F{sub 4}, Tb{sup 3+}) spectral regions. Based on this fact, co-doped samples can be designed with appropriate concentrations of these two ions and generate tunable and white light upon excitation with suitable wavelengths, dispensing the need for a third blue emitting RE ion. Four co-doped samples with equal amounts of EuF{sub 3} and TbF{sub 3} and total concentration of 0.3, 0.5, 1.0 and 1.5 mol% were tested. Their CIE chromaticity coordinates were calculated for various excitation wavelengths in the region from 350 to 360 nm allowing tuned emission from blue to red. The long lifetime values of the emitting levels in these co-doped samples (τ ≈ 3.1 ms for Eu{sup 3+5}D{sub 0}, and τ ≈ 4.0 ms for Tb{sup 3+5}D{sub 4}), associated with fairly high quantum yields (Q.Y. = 5–12%) of the samples indicate that these materials could be efficiently pumped by high power LEDs around 355 nm. - Highlights: • Fluorophosphate glasses doped with Eu{sup 3+} and Tb{sup 3+} and excellent optical properties. • Tunable visible emission and white emission in co-doped samples. • Rare earth bonding preference to fluoride rather than phosphate ions.

  7. Influence of Cr doping on the stability and structure of small cobalt oxide clusters

    Energy Technology Data Exchange (ETDEWEB)

    Tung, Nguyen Thanh; Lievens, Peter; Janssens, Ewald, E-mail: ewald.janssens@fys.kuleuven.be [Laboratory of Solid-State Physics and Magnetism, KU Leuven, B-3001 Leuven (Belgium); Tam, Nguyen Minh; Nguyen, Minh Tho [Department of Chemistry, KU Leuven, B-3001 Leuven (Belgium)

    2014-07-28

    The stability of mass-selected pure cobalt oxide and chromium doped cobalt oxide cluster cations, Co{sub n}O{sub m}{sup +} and Co{sub n−1}CrO{sub m}{sup +} (n = 2, 3; m = 2–6 and n = 4; m = 3–8), has been investigated using photodissociation mass spectrometry. Oxygen-rich Co{sub n}O{sub m}{sup +} clusters (m ⩾ n + 1 for n = 2, 4 and m ⩾ n + 2 for n = 3) prefer to photodissociate via the loss of an oxygen molecule, whereas oxygen poorer clusters favor the evaporation of oxygen atoms. Substituting a single Co atom by a single Cr atom alters the dissociation behavior. All investigated Co{sub n−1}CrO{sub m}{sup +} clusters, except CoCrO{sub 2}{sup +} and CoCrO{sub 3}{sup +}, prefer to decay by eliminating a neutral oxygen molecule. Co{sub 2}O{sub 2}{sup +}, Co{sub 4}O{sub 3}{sup +}, Co{sub 4}O{sub 4}{sup +}, and CoCrO{sub 2}{sup +} are found to be relatively difficult to dissociate and appear as fragmentation product of several larger clusters, suggesting that they are particularly stable. The geometric structures of pure and Cr doped cobalt oxide species are studied using density functional theory calculations. Dissociation energies for different evaporation channels are calculated and compared with the experimental observations. The influence of the dopant atom on the structure and the stability of the clusters is discussed.

  8. Thermal, structural and spectroscopic properties of Pr3+-doped lead zinc borate glasses modified by alkali metal ions

    Directory of Open Access Journals (Sweden)

    M.V. Sasi kumar

    2017-07-01

    Full Text Available This paper offers a study on Pr3+-doped alkali and mixed-alkali borate glasses prepared by the melt quenching technique and characterized by thermal, structural and spectroscopic studies. The amorphous nature of the glassy systems was identified based on X-ray diffraction. The thermal behaviour of glasses was studied using differential thermal analysis (DTA. The functional groups contained in the glasses were identified by Fourier transform infrared spectroscopy (FTIR. Spectral intensities were evaluated from the absorption spectra and used for calculating J–O intensity parameters, Ωλ (λ = 2, 4 and 6. Further, these parameters were used for calculating different radiative properties. The best radiative state was identified as the laser transition state among the various states. Emission analysis was performed for this state by calculating the branching ratios and stimulated emission cross sections (σp for all the prepared glasses. These studies suggest that borate glasses are useful for visible fluorescence.

  9. Influence of silver nanoparticles on the spectroscopic properties of Sm3+ doped boro-phosphate glasses

    Science.gov (United States)

    Suthanthirakumar, P.; Marimuthu, K.

    2016-05-01

    The Sm3+ doped novel boro-phosphate glasses containing silver nanoparticles (NPs) (SmBPxA) have been prepared following the melt quenching technique and their structural and spectroscopic behavior were studied through HR-TEM, optical absorption and photoluminescence spectral measurements. The TEM analysis validates the existence of Ag NPs with an average diameter of ~8 nm. The Surface plasmon resonance (SPR) band of silver NPs was found at around 600 nm from the absorption spectrum of the Sm3+ ions free glass sample. The optical band gap energy (Eopt) corresponding to the direct and indirect allowed transitions and the Urbach energy (ΔE) values were determined from the absorption spectral measurements. The luminescence intensity is found to get enhance when the Ag NPs were embedded along with the Sm3+ ions in the prepared glasses due to the local electric field effect around the rare earth (RE) ion site produced by the SPR of Ag NPs.

  10. Gamma rays shielding and sensing application of some rare earth doped lead-alumino-phosphate glasses

    Science.gov (United States)

    Kaur, Preet; Singh, Devinder; Singh, Tejbir

    2018-03-01

    Seven rare earth (Sm3+, Eu3+ and Nd3+) doped lead alumino phosphate glasses were prepared. The protective and sensing measures from gamma rays were analysed in terms of parameters viz. density (ρ), refractive index, energy band gap (Eg), mean free path (mfp), effective atomic number (Zeff) and buildup factors (energy absorption EABF as well as exposure buildup factor EBF). The energy dependent parameters (mfp, Zeff, EABF and EBF) were investigated in the energy region from 15 keV to 15 MeV. EABF and EBF values were observed to be maximum in the intermediate energy region. Besides, the EABF and EBF values for the prepared samples are shown to have strong dependence on chemical composition of the glass at lower energy, whereas, it is almost independent of chemical composition in higher energy region. The prepared glass samples are found to have potential applications in radiation shielding as well as radiation sensing, which further find numerous applications in the field of medicine and industry.

  11. Optical Properties of Malachite Green Dye Doped SiO2 Glasses: Effect of Transition Metal (Fe-I Used as a Codopant

    Directory of Open Access Journals (Sweden)

    Dulen Bora

    2014-01-01

    Full Text Available Enhanced luminescence properties of Malachite Green (MG (oxalate in Fe-MG codoped SiO2 glasses compared to its values in MG doped SiO2 glasses are reported here. The enhancement is chiefly attributed to a resonance nonradiative energy transfer between Fe and MG. The quantum yield of Malachite Green (MG, in presence of Iron, trapped in sol-gel derived SiO2 glass increases by an order of ~103 compared to that in low viscous solvent while a lifetime of 3.29 ns is reported.

  12. Spectroscopic investigations on Pr3+ ions doped lead telluro-borate glasses for photonic applications

    Science.gov (United States)

    Suthanthirakumar, P.; Mariyappan, M.; Marimuthu, K.

    2018-04-01

    A new series of Lead telluro-borate glasses doped with different concentrations of Pr3+ ions (xPLTB) were prepared by melt quenching technique and their structural and spectroscopic properties were investigated by recording XRD, FTIR, optical absorption and luminescence spectral measurements. XRD measurements confirm the amorphous nature and the FTIR spectra reveal the presence of different vibrational modes of borate and tellurite networks in the prepared glasses. The bonding parameter values (δ) obtained from the absorption band positions indicates that the bonding between Pr3+ ions and their surrounding ligands is of ionic in nature. The optical band gap (Eopt) corresponding to the direct and indirect allowed transitions were determined with the framework of tauc's plot. From the luminescence spectra, important radiative parameters such as stimulated emission cross-section (σPE) , branching ratios (βR) and radiative lifetime (τR) were calculated for the dominant emission transition 3P0→3H4 (blue) in order to suggest the suitability of the studied glasses for suitable photonic applications.

  13. Fabrication and characterization of Er+3 doped SiO2/SnO2 glass-ceramic thin films for planar waveguide applications

    Science.gov (United States)

    Guddala, S.; Chiappini, A.; Armellini, C.; Turell, S.; Righini, G. C.; Ferrari, M.; Narayana Rao, D.

    2015-02-01

    Glass-ceramics are a kind of two-phase materials constituted by nanocrystals embedded in a glass matrix and the respective volume fractions of crystalline and amorphous phase determine the properties of the glass-ceramics. Among these properties transparency is crucial in particular when confined structures, such as, dielectric optical waveguides, are considered. Moreover, the segregation of dopant rare-earth ions, like erbium, in low phonon energy crystalline medium makes these structures more promising in the development of waveguide amplifiers. Here we are proposing a new class of low phonon energy tin oxide semiconductor medium doped silicate based planar waveguides. Er3+ doped (100-x) SiO2-xSnO2 (x= 10, 20, 25 and 30mol%), glass-ceramic planar waveguide thin films were fabricated by a simple sol-gel processing and dip coating technique. XRD and HRTEM studies indicates the glass-ceramic phase of the film and the dispersion of ~4nm diameter of tin oxide nanocrystals in the amorphous phase of silica. The spectroscopic assessment indicates the distribution of the dopant erbium ions in the crystalline medium of tin oxide. The observed low losses, 0.5±0.2 dB/cm, at 1.54 μm communication wavelength makes them a quite promising material for the development of high gain integrated optical amplifiers.

  14. THE GRISM LENS-AMPLIFIED SURVEY FROM SPACE (GLASS). IV. MASS RECONSTRUCTION OF THE LENSING CLUSTER ABELL 2744 FROM FRONTIER FIELD IMAGING AND GLASS SPECTROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Schmidt, K. B.; Jones, T. A. [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States); Hoag, A.; Huang, K.-H.; Bradac, M. [Department of Physics, University of California, Davis, CA 95616 (United States); Treu, T. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547 (United States); Brammer, G. B.; Ryan, R. E. Jr. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD, 21218 (United States); Vulcani, B. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study (UTIAS), the University of Tokyo, Kashiwa, 277-8582 (Japan); Amorín, R.; Castellano, M.; Fontana, A.; Merlin, E. [INAF—Osservatorio Astronomico di Roma Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Trenti, M., E-mail: xinwang@physics.ucsb.edu [School of Physics, The University of Melbourne, VIC 3010 (Australia)

    2015-09-20

    We present a strong and weak lensing reconstruction of the massive cluster Abell 2744, the first cluster for which deep Hubble Frontier Fields (HFF) images and spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) are available. By performing a targeted search for emission lines in multiply imaged sources using the GLASS spectra, we obtain five high-confidence spectroscopic redshifts and two tentative ones. We confirm one strongly lensed system by detecting the same emission lines in all three multiple images. We also search for additional line emitters blindly and use the full GLASS spectroscopic catalog to test reliability of photometric redshifts for faint line emitters. We see a reasonable agreement between our photometric and spectroscopic redshift measurements, when including nebular emission in photometric redshift estimations. We introduce a stringent procedure to identify only secure multiple image sets based on colors, morphology, and spectroscopy. By combining 7 multiple image systems with secure spectroscopic redshifts (at 5 distinct redshift planes) with 18 multiple image systems with secure photometric redshifts, we reconstruct the gravitational potential of the cluster pixellated on an adaptive grid, using a total of 72 images. The resulting mass map is compared with a stellar mass map obtained from the deep Spitzer Frontier Fields data to study the relative distribution of stars and dark matter in the cluster. We find that the stellar to total mass ratio varies substantially across the cluster field, suggesting that stars do not trace exactly the total mass in this interacting system. The maps of convergence, shear, and magnification are made available in the standard HFF format.

  15. The Grism Lens-amplified Survey from Space (GLASS). IV. Mass Reconstruction of the Lensing Cluster Abell 2744 from Frontier Field Imaging and GLASS Spectroscopy

    Science.gov (United States)

    Wang, X.; Hoag, A.; Huang, K.-H.; Treu, T.; Bradač, M.; Schmidt, K. B.; Brammer, G. B.; Vulcani, B.; Jones, T. A.; Ryan, R. E., Jr.; Amorín, R.; Castellano, M.; Fontana, A.; Merlin, E.; Trenti, M.

    2015-09-01

    We present a strong and weak lensing reconstruction of the massive cluster Abell 2744, the first cluster for which deep Hubble Frontier Fields (HFF) images and spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) are available. By performing a targeted search for emission lines in multiply imaged sources using the GLASS spectra, we obtain five high-confidence spectroscopic redshifts and two tentative ones. We confirm one strongly lensed system by detecting the same emission lines in all three multiple images. We also search for additional line emitters blindly and use the full GLASS spectroscopic catalog to test reliability of photometric redshifts for faint line emitters. We see a reasonable agreement between our photometric and spectroscopic redshift measurements, when including nebular emission in photometric redshift estimations. We introduce a stringent procedure to identify only secure multiple image sets based on colors, morphology, and spectroscopy. By combining 7 multiple image systems with secure spectroscopic redshifts (at 5 distinct redshift planes) with 18 multiple image systems with secure photometric redshifts, we reconstruct the gravitational potential of the cluster pixellated on an adaptive grid, using a total of 72 images. The resulting mass map is compared with a stellar mass map obtained from the deep Spitzer Frontier Fields data to study the relative distribution of stars and dark matter in the cluster. We find that the stellar to total mass ratio varies substantially across the cluster field, suggesting that stars do not trace exactly the total mass in this interacting system. The maps of convergence, shear, and magnification are made available in the standard HFF format.

  16. Ruby coloured lead glasses by generation of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gil, C. [Fundacion Centro Nacional del Vidrio, Pocillo, 1, 40100 La Granja de San Ildefonso (Segovia) (Spain); Villegas, M.A. [Centro Nacional de Investigaciones Metalurgicas (CENIM), Spanish Council for Scientific Research (CSIC), Avda. Gregorio del Amo, 8, 28040 Madrid (Spain)]. E-mail: mavillegas@cenim.csic.es

    2004-11-15

    Both yellow and red superficial ruby lead crystal glasses have been obtained by Ag{sup +} ion-exchange. For red ruby colouring lead glass substrates were previously doped with reducing oxides (arsenic, antimony, cerium and tin). The best experimental conditions for silver ion-exchange were determined. The optical absorption behaviour of the samples was studied to point out the influence of the parameters involved in the ion-exchange process. Moreover, other parameters affecting the final colouring of the glasses (kind of dopant, dopant concentration, etc.) were also analysed. The dopant percentage added to the lead crystal glass is the most important factor for developing superficial red ruby colouring. Antimony oxide doped lead glass ion-exchanged with silver showed the most intense red ruby colouring, even for a doping concentration lower than those of arsenic oxide doped samples able to enhance similar colour. Spectral saturation appeared for the highest doping concentration and for the most severe ion-exchange conditions. Chromatic coordinates were calculated from the corresponding transmission visible spectra. The colour purity showed by the samples obtained satisfies the ornamental requirements that motivated this research.

  17. Upconversion studies of Er3+/Yb3+ doped SrO.TiO2 borosilicate glass ceramic system

    International Nuclear Information System (INIS)

    Maheshwari, Aditya; Om Prakash; Kumar, Devendra; Rai, S.B.

    2011-01-01

    Upconversion behaviour has been studied in various matrices and fine powders of SrTiO 3 by previous workers. In present work, Er 3+ /Yb 3+ were doped in appropriate ratio in SrO.TiO 2 borosilicate glass ceramic system to study the upconversion phenomenon. Dielectric properties of this class of glass ceramic system have been extensively investigated by Thakur et al. It has been observed that both upconversion efficiency and dielectric constant increases with transformation of glass into glass ceramic. Therefore, present investigation is based upon the study of optical as well as the electrical properties of same glass ceramic system. In order to prepare different crystalline matrices, two different Er 3+ /Yb 3+ :SrO.TiO 2 borosilicate glasses with same amount of Er 2 O 3 and Yb 2 O 3 were prepared by melt quench method. Glasses were transparent with light-wine colour. Glass ceramics were prepared from the glasses by heat treatment based on DTA (Differential thermal analysis) results. Glass ceramics were fully opaque with brownish-cream colour. Powder X-ray diffraction (XRD) patterns confirmed that two different crystalline matrices, Sr 3 Ti 2 O 7 , Ti 10 O 19 and SrTiO 3 , TiO 2 were present in two glass ceramic samples respectively. Luminescence properties of glass and glass ceramic samples with 976nm laser irradiation showed that the intensities of the green and red emission increased multiple times in glass ceramic than that of the glass. Possible mechanisms responsible for upconversion eg. Energy Transfer (ET) and Excited State Absorption (ESA), were studied through laser pumping power log dependence

  18. Energy transfer and cross-relaxation in Tb3+-doped borosilicate glasses

    International Nuclear Information System (INIS)

    Kim, Jung Hwan; Sol, Jung Sik

    1990-01-01

    Energy transfer in Tb 3+ -doped borosilicate glasses has been studied by the analysis of fluorescence intensities and lifetimes of 5 D 3 and 5 D 4 states as a function of Tb 3+ concentration. It is shown that as the Tb 3+ concentration is increased the cross-relaxation produces high population of the 5 D 4 state at the expense of 5 D 3 . It is also found that this interaction is predominantly dipole-dipole transition with critical distance of 13 A. The critical distance for energy transfer 5 D 4 5 D 3 which is responsible for the quenching of 5 D 4 emission at high concentration of Tb 3+ ions is 4.5 A. (Author)

  19. Study of upconversion fluorescence property of novel Er3+/Yb3+ co-doped tellurite glasses.

    Science.gov (United States)

    Xu, Tie-Feng; Li, Guang-Po; Nie, Qiu-Hua; Shen, Xiang

    2006-06-01

    Er3+/Yb3+ co-doped TeO2-B2O3-Nb2O5-ZnO (TBN) glasses were prepared. The absorption spectra and upconversion luminescence spectra of TBN glasses were measured and analyzed. The upconversion emission bands centered at 530, 546 and 658 nm were observed under the excitation at 975 nm, corresponding to the transitions of 2H11/2-->4I15/2, 4S3/2-->4I15/2 and 4F9/2-->4I15/2 respectively. The ratio of red emission to green emission increases with an increasing of Yb3+ ions concentration. According to the quadratic dependence on excitation power, the possible upconversion mechanisms and processes were discussed.

  20. Structural and luminescence studies on Dy3+ doped lead boro-telluro-phosphate glasses

    Science.gov (United States)

    Selvi, S.; Venkataiah, G.; Arunkumar, S.; Muralidharan, G.; Marimuthu, K.

    2014-12-01

    This paper reports results obtained on the structural and luminescence properties of Dy3+doped lead boro-telluro-phosphate glasses prepared following the melt quenching technique. FTIR spectra exhibit the presence of B-O vibrations, P-O-P symmetric vibrations and Te-O stretching modes of TeO3 and TeO6 units. The metal-ligand bond was identified through UV-vis-NIR absorption spectra and to determine the band tailing parameter, direct and indirect band gap energy of the prepared glasses. The Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6), experimental and theoretical oscillator strengths were also determined and reported. Luminescence measurements were made to determine the transition probability (A), stimulated emission cross-section (σPE) and branching ratio (βR) for the transitions that include 4F9/2→6H11/2, 6H13/2 and 6H15/2 bands. The effect of Dy3+ ion concentration on the intensity ratio of yellow to blue emission bands has also been studied and reported. The lifetime corresponding to the 4F9/2 level of the title glasses has been found to decrease with the increase in Dy3+ ion concentration. The chromaticity coordinates (x,y) have been estimated from the luminescence spectra and the suitability of title glasses for white light applications has been analyzed using CIE chromaticity diagram. The variation of optical properties with the concentration of dysprosium oxide content in the glasses have been studied and reported.

  1. Luminescence of Eu(3+) doped SiO2 Thin Films and Glass Prepared by Sol-gel Technology

    Science.gov (United States)

    Castro, Lymari; Jia, Weiyi; Wang, Yanyun; Santiago, Miguel; Liu, Huimin

    1998-01-01

    Trivalent europium ions are an important luminophore for lighting and display. The emission of (5)D0 to (7)F2 transition exhibits a red color at about 610 nm, which is very attractive and fulfills the requirement for most red-emitting phosphors including lamp and cathode ray phosphorescence materials. Various EU(3+) doped phosphors have been developed, and luminescence properties have been extensively studied. On the other hand, sol-gel technology has been well developed by chemists. In recent years, applications of this technology to optical materials have drawn a great attention. Sol-gel technology provides a unique way to obtain homogeneous composition distribution and uniform doping, and the processing temperature can be very low. In this work, EU(3+) doped SiO2 thin films and glasses were prepared by sol-gel technology and their spectroscopic properties were investigated.

  2. Electronic polarizability, optical basicity and interaction parameter for Nd{sub 2}O{sub 3} doped lithium-zinc-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Algradee, M.A.; Sultan, M.; Samir, O.M.; Alwany, A.E.B. [Ibb University, Department of Physics, Faculty of Science, Ibb (Yemen)

    2017-08-15

    The Nd{sup 3+}-doped lithium-zinc-phosphate glasses were prepared by means of conventional melt quenching method. X-ray diffraction results confirmed the glassy nature of the studied glasses. The physical parameters such as the density, molar volume, ion concentration, polaron radius, inter-ionic distance, field strength and oxygen packing density were calculated using different formulae. The transmittance and reflectance spectra of glasses were recorded in the wavelength range 190-1200 nm. The values of optical band gap and Urbach energy were determined based on Mott-Davis model. The refractive indices for the studied glasses were evaluated from optical band gap values using different methods. The average electronic polarizability of the oxide ions, optical basicity and an interaction parameter were investigated from the calculated values of the refractive index and the optical band gap for the studied glasses. The variations in the different physical and optical properties of glasses with Nd{sub 2}O{sub 3} content were discussed in terms of different parameters such as non-bridging oxygen and different concentrations of Nd cation in glass system. (orig.)

  3. Thermoluminescence and optically stimulated luminescence properties of Dy3+-doped CaO-Al2O3-B2O3-based glasses

    Science.gov (United States)

    Yahaba, T.; Fujimoto, Y.; Yanagida, T.; Koshimizu, M.; Tanaka, H.; Saeki, K.; Asai, K.

    2017-02-01

    We developed Dy3+-doped CaO-Al2O3-B2O3 based glasses with Dy concentrations of 0.5, 1.0, and 2.0 mol% using a melt-quenching technique. The as-synthesized glasses were applicable as materials exhibiting thermoluminescence (TL) and optically stimulated luminescence (OSL). The optical and radiation response properties of the glasses were characterized. In the photoluminescence (PL) spectra, two emission bands due to the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions of Dy3+ were observed at 480 and 580 nm. In the OSL spectra, the emission band due to the 4F9/2 → 6H15/2 transition of Dy3+ was observed. Excellent TL and OSL responses were observed for dose ranges of 0.1-90 Gy. In addition, TL fading behavior was better than that of OSL in term of the long-time storage. These results indicate that the Dy3+-doped CaO-Al2O3-B2O3-based glasses are applicable as TL materials.

  4. Upconversion dynamics in Yb3+-Ho3+-doped fluoroindate glasses

    International Nuclear Information System (INIS)

    Martin, I.R.; Rodriguez, V.D.; Lavin, V.; Rodriguez-Mendoza, U.R.

    1998-01-01

    The mechanisms and dynamics of the upconversion emissions in Yb 3+ -Ho 3+ -doped fluoroindate glasses by exciting at 975 nm have been analysed. The upconversion efficiencies have been measured as a function of temperature in the range from 12 to 295 K. The temporal evolution of the 545- and 650-nm upconversion emissions obtained under flash excitation at 975 nm in codoped samples with 2.25 mol.% of Yb 3+ and 0.75 mol.% of Ho 3+ cannot be described using the energy migration model. This indicates that at this concentration of Yb 3+ the rapid migration regimen between these ions has not been reached. A model is proposed in order to explain the temporal evolution of these emissions taking into account energy migration between donors and backtransfer processes. (orig.)

  5. Spectroscopy and near infrared upconversion of Er{sup 3+}-doped TZNT glasses

    Energy Technology Data Exchange (ETDEWEB)

    Venkata Krishnaiah, K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Marques-Hueso, J. [Institute of Sensors, Signals and Systems & Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Suresh, K.; Venkataiah, G. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Richards, B.S. [Light Technology Institute (LTI), Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe (Germany); Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Jayasankar, C.K., E-mail: ckjaya@yahoo.com [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India)

    2016-01-15

    In this paper we report on the near infrared (NIR) upconversion (UC) and spectroscopic properties of erbium (Er{sup 3+})-doped TeO{sub 2}–ZnO–Nb{sub 2}O{sub 5}–TiO{sub 2} (TZNT) oxide glasses. Judd–Ofelt theory has been applied to investigate the intensity parameters (Ω{sub λ}, λ=2, 4 and 6) which are used to derive radiative properties of the fluorescent levels. The different glasses present high refractive indices, low dispersion and Abbe numbers, as determined by variable angle spectroscopic ellipsometry. Under 980 nm excitation, the NIR emission profile and full width at half maximum have been studied in a broad range of Er{sup 3+} concentrations (0.01–3.0 mol%). On the other side, NIR UC has been obtained by exciting at 1523 nm, showing an increase of the intensity with Er{sup 3+} ion density in the studied range. The decay curves of the {sup 4}I{sub 13/2} level exhibit single exponential nature for all the different concentrations. The lifetime of the {sup 4}I{sub 13/2} level has been found to decrease (3.73–1.20 ms) after an initial increase (3.65–3.73 ms) with increasing of Er{sup 3+} ion concentration. The TZNT samples show broadband UC emission at 1.0 µm, which match with the band gap of silicon. This reveals that the investigated glasses could find application in photonics, for example non-linear optics and photovoltaic’s. - Highlights: • The Er{sup 3+}:TZNT glasses have been synthesized and optically characterized. • Refractive index and Abbe number of the TZNT glasses were measured by Ellipsometry. • Near infrared emission (1400–1600 nm) has been obtained under 980 nm excitation. • Near infrared upconversion at 980 nm has been investigated under 1523 nm excitation.

  6. Femtosecond laser direct writing of gratings and waveguides in high quantum efficiency erbium-doped Baccarat glass

    International Nuclear Information System (INIS)

    Vishnubhatla, K C; Kumar, R Sai Santosh; Rao, D Narayana; Rao, S Venugopal; Osellame, R; Ramponi, R; Bhaktha, S N B; Mattarelli, M; Montagna, M; Turrell, S; Chiappini, A; Chiasera, A; Ferrari, M; Righini, G C

    2009-01-01

    The femtosecond laser direct writing technique was employed to inscribe gratings and waveguides in high quantum efficiency erbium-doped Baccarat glass. Using the butt coupling technique, a systematic study of waveguide loss with respect to input pulse energy and writing speed was performed to achieve the best waveguide with low propagation loss (PL). By pumping at 980 nm, we observed signal enhancement in these active waveguides in the telecom spectral region. The refractive index change was smooth and we estimated it to be ∼10 -3 . The high quantum efficiency (∼80%) and a best PL of ∼0.9 dB cm -1 combined with signal enhancement makes Baccarat glass a potential candidate for application in photonics.

  7. Study of absorption and IR-emission of Er3+, Dy3+, Tm3+ doped high-purity tellurite glasses

    Science.gov (United States)

    Motorin, S. E.; Dorofeev, V. V.; Galagan, B. I.; Sverchkov, S. E.; Koltashev, V. V.; Denker, B. I.

    2018-04-01

    A study of high-purity TeO2-ZnO based tellurite glasses doped with Er3+, Dy3+ or Tm3+ that could be used as laser media in the 2-3 μm spectral range is presented. The glasses are prepared by melting the oxides mixture inside a silica glass reactor in an atmosphere of purified oxygen. The low level of hydroxyl groups absorption allowed to measure correctly the luminescence decay characteristics of the dopants. The rare-earth ions absorption bands, the luminescence spectra and kinetic characteristics of emission from the levels 4I11/2, 4I13/2 of Er3+, 6H13/2 of Dy3+ and 3H4, 3H5, 3F4 of Tm3+ ions are investigated. The results confirm the high potential of tellurite glasses as an active media for bulk, planar waveguide and fiber lasers.

  8. Red luminescence from Eu3+-doped TeO2-WO3-GeO2 glasses for solid state lasers

    Science.gov (United States)

    Subrahmanyam, Tallam; Gopal, Kotalo Rama; Suvarna, Reniguntla Padma; Jamalaiah, Bungala Chinna

    2018-05-01

    Eu3+-doped oxyfluoro tellurite (TWGEu) glasses were prepared by conventional melt quenching method. The optical band gap energy and covalence between Eu3+ and O2-/F- ions were determined from optical absorption spectra. Using the 5D0 → 7F1,2,4 emission transitions, the Ω2 and Ω4 intensity parameters were determined. These intensity parameters were used to evaluate the radiative parameters such as emission probability rate (AR), luminescence branching ratio (βR) and radiative life time (τR) of 5D0 → 7FJ transitions. The laser characteristic parameters such as stimulated emission cross-section, gain bandwidth and quantum efficiency were determined. The luminescence decay profiles of 5D0 emission level were well fitted to single exponential function for all the concentrations. The experimental results show that the 0.5 mol% of Eu3+-doped TWGEu glass could be the best choice to design red laser sources.

  9. CoO-doped MgO-Al2O3-SiO2-colored transparent glass-ceramics with high crystallinity

    Science.gov (United States)

    Tang, Wufu; Zhang, Qian; Luo, Zhiwei; Yu, Jingbo; Gao, Xianglong; Li, Yunxing; Lu, Anxian

    2018-02-01

    To obtain CoO-doped MgO-Al2O3-SiO2 (MAS)-colored transparent glass-ceramics with high crystallinity, the glass with the composition 21MgO-21Al2O3-54SiO2-4B2O3-0.2CoO (in mol %) was prepared by conventional melt quenching technique and subsequently thermal treated at several temperatures. The crystallization behavior of the glass, the precipitated crystalline phases and crystallinity were analyzed by X-ray diffraction (XRD). The microstructure of the glass-ceramics was characterized by field emission scanning electron microscopy (FSEM). The transmittance of glass-ceramic was measured by UV spectrophotometer. The results show that a large amount of α-cordierite (indianite) with nano-size was precipitated from the glass matrix after treatment at 1020 °C for 3 h. The crystallinity of the transparent glass-ceramic reached up to 97%. Meanwhile, the transmittance of the glass-ceramic was 74% at 400 nm with a complex absorption band from 450 nm to 700 nm. In addition, this colored transparent glass-ceramic possessed lower density (2.469 g/cm3), lower thermal expansion coefficient (1.822 × 10-6 /℃), higher Vickers hardness (9.1 GPa) and higher bending strength (198 MPa) than parent glass.

  10. Concentration dependent spectroscopic properties of Dy{sup 3+} ions doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mariyappan, M.; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute - Deemed University, Gandhigram – 624 302 (India)

    2016-05-23

    Dy{sup 3+} ions doped boro-phosphate glasses have been synthesized by melt quenching method and characterized through FTIR, absorption and luminescence spectral measurements. The presence of various stretching and bending vibrations of different borate and phosphate groups were identified from the FTIR spectra. In order to examine the electronic band structure of the studied glasses, Optical energy gap (E{sub opt}) and Urbach energy (ΔE) values were estimated from the absorption spectra. The Judd-Ofelt (JO) intensity parameters were calculated to examine the symmetry of the ligand environment around the Dy{sup 3+} ions site. The emission spectra exhibit two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponding to the {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} transitions respectively. The emission spectra were characterized through Commission International d’Eclairage (CIE) 1931 chromaticity diagram to explore its suitability for WLED applications.

  11. Structural and optical studies on Eu3+ doped boro-tellurite glasses

    Science.gov (United States)

    Maheshvaran, K.; Veeran, P. K.; Marimuthu, K.

    2013-03-01

    Eu3+ doped boro-tellurite glasses (69 - x)B2O3 + xTeO2 + 15Na2CO3 + 15NaF + 1Eu2O3 (where x = 0, 10, 20, 30 and 40 wt%) have been prepared and their structural and optical properties were studied through XRD, FTIR, absorption, luminescence and decay time measurements. The FTIR spectra reveal the presence of B-O-B bond bending vibrations and Te-O-Te or O-Te-O linkage bending vibrations in the prepared glasses. The absorption spectral measurements were used to calculate the bonding parameters (β¯, δ). The direct, indirect allowed band gap (Eopt), band tail parameter (B) and Urbach energy (ΔE) values of the prepared glasses have also been determined from the absorption spectral measurements. The phonon sideband is observed from the excitation spectra on the higher energy side of the 7F0 → 5D2 transition. The phonon energy (hω) and the electron-phonon coupling constant (g) were also derived from the phonon sideband spectra. Through the luminescence spectra, Judd-Ofelt (JO) intensity parameters (Ωλ, λ = 2, 4 and 6) and the luminescence intensity ratio (R) have been determined. The JO parameters have also been used to calculate the radiative properties like transition probability (A), stimulated emission cross-section (σPE), radiative lifetime (τrad), and branching ratios (βR) for the 5D0 → 7FJ (J = 0, 1, 2, 3 and 4) emission transitions of the Eu3+ ions. The experimental lifetime of the 5D0 level is found to be single exponential for all the prepared glasses. The obtained results were discussed and reported in the present work.

  12. The effect of excitation intensity variation and silver nanoparticle codoping on nonlinear optical properties of mixed tellurite and zinc oxide glass doped with Nd2O3 studied through ultrafast z-scan spectroscopy

    Science.gov (United States)

    Moreira, L.; Falci, R. F.; Darabian, H.; Anjos, V.; Bell, M. J. V.; Kassab, L. R. P.; Bordon, C. D. S.; Doualan, J. L.; Camy, P.; Moncorgé, R.

    2018-05-01

    The research on Nd3+ doped new solid-state laser hosts with specific thermo-mechanical and optical properties is very active. Nd3+ doped tellurite glasses are suitable for these applications. They have high linear and nonlinear refraction index, wide transmittance range. The TeO2-ZnO (TZO) glass considered in the present work combines all those features and the nonlinear optical properties can be used for the development of Kerr-lens mode-locked sub picosecond lasers. Recently the laser performance of Nd3+ doped TZO glass and was reported and laser slope efficiency of 21% was observed. We investigate how the intensity variation and the silver nanoparticles codoping affects the nonlinear optical properties of Nd3+ doped TZO glasses. Intensity dependent nonlinear refraction indices coefficients at 750, 800 and 850 nm were observed. The nonlinear optical features were obtained through ultrafast single beam z-scan technique with excitations at 750, 800 and 850 nm and are up to two orders of magnitude higher than those reported in the literature.

  13. Characterization of radiative properties of Nd{sub 2}O{sub 3} doped phosphate and silicate glasses for solid state laser

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, P., E-mail: pnandi@barc.gov.in; Shukla, R., E-mail: pnandi@barc.gov.in; Goswami, M., E-mail: pnandi@barc.gov.in [Glass and Advanced Materials Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Sudarsan, V. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India)

    2014-04-24

    Nd{sub 2}O{sub 3} doped calcium aluminium phosphate and calcium aluminium silicate glasses prepared to compare their absorption and emission properties. Radiative lifetime of the excited state {sup 4}F{sub 3/2} derived by Judd-Ofelt theory applied to the absorption spectra. Using the photoluminescence spectrometer the steady state emission and relaxation time from excited energy level recorded under green light excitation. Phosphate glass has higher emission cross-section, higher radiative lifetime but less quantum efficiency due to non-radiative quenching through hydroxyl ions compared to silicate glass for Nd{sup 3+}:{sup 4}F{sub 3/2}→{sup 4}I{sub 9/2} emission.

  14. Radio- and photoluminescence properties of Ce/Tb co-doped glasses with huntite-like composition

    Science.gov (United States)

    Lorenzi, Roberto; Golubev, Nikita V.; Ziaytdinova, Mariyam Z.; Jarý, Vítězslav; Babin, Vladimir; Malashkevich, Georgii E.; Paleari, Alberto; Sigaev, Vladimir N.; Fasoli, Mauro; Nikl, Martin

    2018-04-01

    Optical properties of yttria-aluminoborate (YAB) glasses with general composition 10(CexTbyY(1-x-y))-30Al2O3-60B2O3 are investigated and compared with data available on YAB crystals with huntite-like structure. Ce doped samples show optical features ascribable to preferential location of rare earth ions in sites with specific geometry similar to that observed in crystalline structures. Samples prepared with Tb ions as emission activator and Ce ions as sensitizer have been studied within the framework of non-radiative energy transfer. The resulting Förster radius is of 4.6 ± 0.5 Å comparable with that observed in Ce/Tb co-doped YAl3(BO3)4 crystals. The investigated materials possess radio- and photoluminescence emission efficiencies and performances comparable to that of crystalline counterparts with the advantage of having easiness of preparation and workability typical of glassy systems.

  15. In Vitro Bioactivity and Antimicrobial Tuning of Bioactive Glass Nanoparticles Added with Neem (Azadirachta indica) Leaf Powder

    Science.gov (United States)

    Prabhu, M.; Ruby Priscilla, S.; Kavitha, K.; Manivasakan, P.; Rajendran, V.; Kulandaivelu, P.

    2014-01-01

    Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications. PMID:25276834

  16. In vitro bioactivity and antimicrobial tuning of bioactive glass nanoparticles added with neem (Azadirachta indica) leaf powder.

    Science.gov (United States)

    Prabhu, M; Ruby Priscilla, S; Kavitha, K; Manivasakan, P; Rajendran, V; Kulandaivelu, P

    2014-01-01

    Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications.

  17. Magnetic, electrical transport and electron spin resonance studies of Fe-doped manganite LaMn0.7Fe0.3O3+δ

    International Nuclear Information System (INIS)

    Liu, X.J.; Li, Z.Q.; Yu, A.; Liu, M.L.; Li, W.R.; Li, B.L.; Wu, P.; Bai, H.L.; Jiang, E.Y.

    2007-01-01

    We have investigated the magnetic, electrical transport and electron spin resonance (ESR) properties of polycrystalline Fe-doped manganite LaMn 0.7 Fe 0.3 O 3+ δ prepared by sol-gel method. A typical cluster-glass feature is presented by DC magnetization and AC susceptibility measurements and a sharp but shallow memory effect was observed. Symmetrical Lorentzian lines of the Mn/Fe spectra were detected above 120 K, where the sample is a paramagnetic (PM) insulator. When the temperature decreases from 120 K, magnetic clusters contributed from ferromagnetic (FM) interaction between Mn 3+ and Mn 3+ /Fe 3+ ions develop and coexist with PM phase. At lower temperature, these FM clusters compete with antiferromagnetic (AFM) ones between Fe 3+ ions, which are associated with a distinct field-cooled (FC) effect in characteristic of cluster-glass state

  18. Nd3+-doped lanthanum lead boro-tellurite glass for lasing and amplification applications

    Science.gov (United States)

    Madhu, A.; Eraiah, B.; Manasa, P.; Srinatha, N.

    2018-01-01

    Nd3+-doped lanthanum lead boro-tellurite glass samples were prepared by conventional melt quenching method and their structural, thermal, fluorescence, and decay times of the glasses were investigated. Prepared glass samples exhibits amorphous nature and shows good thermal stability in the temperature range of 100-800 °C. Judd-Ofelt (JO) analysis was carried out and the intensity parameters (Ωλ = 2, 4, 6) also spontaneous radiative probability and stimulated-.emission cross-sections were estimated. The magnitude of Ωλ confirms the covalency nature. The near infrared emission spectra were measured by 808 nm excitation in which the emission intensity is found to be high at 1060 nm for the 4F3/2 → 4F11/2 transition. The stimulated cross section, effective band width and branching ratios are found to be 8.910 × 10-20 cm2, 21.57 nm and 53.72 % respectively, for 4F3/2 → 4F11/2 transition. The derived gain bandwidth, figure of merit, threshold and saturation intensity found to be comparable to some of the glass systems. Furthermore, the time decay rate found to decrease from 100 μs to 27 μs when the concentration increased from 0.1 to 3.0 mol% of Nd3+ ions and also all follow the single exponential behaviour which is attributed to the self quenching effect due to the cross-relaxation channels.

  19. Enhancement of Dielectric Breakdown Strength and Energy Conversion Efficiency of Niobate Glass-Ceramics by Sc2O3 Doping

    Science.gov (United States)

    Xiao, Shi; Xiu, Shaomei; Yang, Ke; Shen, Bo; Zhai, Jiwei

    2018-01-01

    Niobate glass-ceramics K2O-SrO-Nb2O5-B2O3-Al2O3-SiO2 (KSN-BAS) doped with different amounts of Sc2O3 have been prepared through a melt quenching/controlled crystallization method, and the influence of the Sc2O3 content on their phase composition, microstructure, dielectric performance, and charge-discharge properties investigated. X-ray powder diffraction results showed that the peak positions of the KSr2Nb5O15 phase shifted to higher angle and the glass-ceramic microstructures were significantly improved by Sc2O3 addition. Based on these results, 0.5 mol.% Sc2O3 doping was found to achieve remarkable enhancement in energy storage density, which reached 9.63 ± 0.39 J/cm3 at dielectric breakdown strength of 1450.38 ± 29.01 kV/cm with high conversion efficiency of ˜ 92.1%. For pulsed power applications, discharge speed of 17 ns and power density of 0.48 MW/cm3 were obtained in the glass-ceramic with 0.5 mol.% Sc2O3. These results could provide a new design strategy for high-performance dielectric capacitors.

  20. Luminescent properties of Tb3+- doped TeO2-WO3-GeO2 glasses for green laser applications

    Science.gov (United States)

    Subrahmanyam, T.; Rama Gopal, K.; Padma Suvarna, R.; Jamalaiah, B. C.; Vijaya Kumar, M. V.

    2018-06-01

    Different concentrations of Tb3+ -doped oxyfluoro tellurite (TWGTb) glasses were prepared by conventional melt quenching technique and characterized for green laser applications. The Judd-Ofelt theory was applied to evaluate various spectroscopic and radiative parameters. The TWGTb glasses exhibit 5D3 → 7F5-3 and 5D4 → 7F6-0 transitions when excited at 316 nm radiation. The variation of intensity of 5D4 → 7F5 (Green) and 5D3 → 7F4 (Blue) transitions and the green to blue (IG/IB) intensity ratios were studied as a function of Tb3+ ions concentration. The laser characteristic parameters such as effective bandwidth (Δλeff), stimulated emission cross-section (σe), gain bandwidth (σe × Δλeff) and optical gain (σe × τR) were determined using the three phenomenological Judd-Ofelt intensity parameters. The fluorescence decay profiles of 5D4 metastable level exhibit single-exponential nature for all the samples. Based on the experimental results we suggest that the 1.0 mol% of Tb3+ -doped TWGTb glass could be a suitable laser host material to emit intense green luminescence at 545 nm.

  1. Investigations on optical properties of Eu3+ ion doped magnesium telluroborate glasses for red laser applications

    Science.gov (United States)

    Arunkumar, S.; Annapoorani, K.; Marimuthu, K.

    2018-04-01

    Eu3+ doped Magnesium telluroborate glasses were prepared with the chemical composition (40-x)H3BO3+35 TeO2+15MgCO3+10MgF2+xEu2O3 (where x = 0.1, 0.5, 1.0 and 2.0 in wt%) following the melt quenching technique and labeled as MTB0.1Eu, MTB0.5Eu, MTB1.0Eu and MTB2.0Eu respectively. The absorption spectra exhibit seven peaks in the visible and NIR region. Five emission peaks corresponding to the 5D0→7FJ (J=0, 1, 2, 3, 4) transitions were observed while exciting at 465 nm. The luminescence intensity ratio (R) and Ω2 parameter values were found to be higher for the MTB0.5Eu glass thus indicates the higher asymmetry around the Eu3+ ions site compared to other prepared glasses. The CIE color chromaticity coordinates of the present glasses are found to lie in the prominent red region in the chromaticity diagram. The stimulated emission cross-section value of the MTB0.5Eu glass was found to be higher pertaining to the 5D0 → 7F2 transition compared to the other prepared glasses and reported literature thus suggests its suitability for red laser applications.

  2. Immobilisation of radwastes in glass containers and products formed thereby

    International Nuclear Information System (INIS)

    Macedo, P.B.; Simmons, C.J.; Lagakos, N.; Simmons, J.H.; Tran, D.C.

    1980-01-01

    A method of preventing the dissemination of toxic material to the environment comprises forming an admixture of toxic material and glass packing in a hollow doped glass container of high silica content, or forming the admixture in a first container and then depositing at least a portion of the admixture in a hollow doped glass container of high silica content. The glass container is then heated to collapse its walls and to seal the container so that the toxic material is entrapped and sealed within the collapsed doped glass container. The thermal expansion coefficient of the container may be decreased prior to use by exchanging hydrogen ion in pores thereof with other cations followed by collapsing the pores. (author)

  3. Silver nanocluster formation in ion-exchanged glasses by annealing, ion beam and laser beam irradiation: An EXAFS study

    International Nuclear Information System (INIS)

    Battaglin, G.; Cattaruzza, E.; Gonella, F.; Polloni, R.; D'Acapito, F.; Colonna, S.; Mattei, G.; Maurizio, C.; Mazzoldi, P.; Padovani, S.; Sada, C.; Quaranta, A.; Longo, A.

    2003-01-01

    Extended X-ray absorption fine structure analysis is used to determine the silver local environment in silicate glasses doped by the Ag-alkali ion-exchange process, followed by different treatments, namely, ion irradiation, thermal annealing in reducing atmosphere, laser irradiation. The obtained results indicate that metal nanocluster composites with different cluster structures may be formed with these multistep methodologies, pointing out the role of the preparation parameters in giving rise to different features. Lattice parameters and cluster diameter were determined by grazing incidence X-ray diffraction

  4. Novel online security system based on rare-earth-doped glass microbeads

    Science.gov (United States)

    Officer, Simon; Prabhu, G. R.; Pollard, Pat; Hunter, Catherine; Ross, Gary A.

    2004-06-01

    A novel fluorescent security label has been produced that could replace numerous conventional fluorescent dyes in document security. This label utilizes rare earth ions doped in a borosilicate glass matrix to produce sharp spectral fluorescence peaks with characteristic long lifetimes due to the rare earth ions. These are subsequently detected by an online detection system based on fluorescence and the long lifetimes to avoid any interference from other fluorophores present in the background. Security is further enhanced by the interaction of the rare earth ions with each other and the effect of the host on the emission spectra and therefore the number of permutations that could be produced. This creates a very secure label with various applications for the security market.

  5. Lanthanum lead boro-tellurite glasses doped with samarium trioxide for luminescent devices application

    Science.gov (United States)

    Madhu, A.; Eraiah, B.

    2018-04-01

    Boro-tellurite based glasses (10La2O3-(20-x) TeO2-30PbO-40B2O3-xSm2O3) (x = 0, 0.5, 1.0 and 2.0 mol %) doped with different concentrations of Sm3+ ions has been investigated. The optical properties have been studied through spectroscopic measurements such as absorption and luminescence. Absorption spectra reveals nine peaks due to 6H5/2→6P3/2, 4I3/2+4F5/2+4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2, and 6H13/2 transitions. Luminescence spectra under the excitation of 403 nm display four emission bands due to 4G5/2→6H5/2, 6H7/2, 6H9/2 and 6H11/2 transitions of Sm3+ ions. Among them 6H7/2 bright orange -red is more intense which proves that the present glasses are potential candidates for luminescent device applications in visible range as well as optical fibre communication since its refractive index is 1.65 high compared to other glasses.

  6. Characterization and spectroscopic studies of multi-component calcium zinc bismuth phosphate glass ceramics doped with iron ions

    Science.gov (United States)

    Kumar, A. Suneel; Narendrudu, T.; Suresh, S.; Ram, G. Chinna; Rao, M. V. Sambasiva; Tirupataiah, Ch.; Rao, D. Krishna

    2018-04-01

    Glass ceramics with the composition 10CaF2-20ZnO-(15-x)Bi2O3-55P2O5:x Fe2O3(0≤x≤2.5) were synthesized by melt-quenching technique and heat treatment. These glass ceramics were characterized by XRD and SEM. Spectroscopic studies such as optical absorption, EPR were also carried out on these glass ceramics. From the absorption spectra the observed bands around 438 and 660nm are the octahedral transitions of Fe3+ (d5) ions and another band at about 536 nm is the tetrahedral transition of Fe3+ (d5) ions. The absorption spectrum also consist of a band around 991 nm and is attributed to the octahedral transition of Fe2+ ions. The EPR spectra of the prepared glass ceramics have exhibited two resonance signals one at g1=4.32 and another signal at g2=2.008. The observed decrease in band gap energy up to 2 mol% Fe2O3 doped glass ceramics is an evidence for the change of environment around iron ions and ligands from more covalent to less covalent (ionic) and induces higher concentration of NBOs which causes the depolymerization of the glass ceramic network.

  7. Visible and near infrared up-conversion luminescence in Yb3+/Tm3+ co-doped yttria-alumino-silicate glass based optical fibers

    International Nuclear Information System (INIS)

    Halder, Arindam; Chandra Paul, Mukul; Wadi Harun, Sulaiman; Kumar Bhadra, Shyamal; Bysakh, Sandip; Das, Shyamal; Pal, Mrinmay

    2013-01-01

    We report blue light up-conversion (UC) emission in Yb–Tm co-doped nano-phase separated yttria-alumino-silicate (YAS) glass based D-shaped with low-index cladding optical fibers. Y 2 O 3 creates an environment of nano structured YAS glass phases with Yb and Tm rich zone into the core glass which confirmed from TEM analyses. This kind of glass host assists in distributing of Yb and Tm rich zone uniformly throughout the core region. Yb and Tm doped regions exist mainly into nano YAS phases, defined as RE rich nano YAS-RE phases. All samples exhibit UC luminescence peaks at 483 nm, 650 nm and 817 nm for Tm 3+ and 1044 nm for Yb 3+ under excitation by 975 nm laser light. In such type of nano-engineered glass–ceramic based host, almost all the Yb ions transferred its energy to the nearer Tm ions. In particular 483 nm emission is attributed to 1 G 4 → 3 H 6 transition through a three step resonance energy transfer (ET) from excited Yb 3+ . The highest emission intensity is obtained with a concentration of 0.5 wt% Tm 3+ and 2.0 wt% Yb 3+ . The ET between Yb 3+ and Tm 3+ is increased with increase of Yb 3+ concentration with respect to Tm 3+ . The experimental fluorescence life-times of Tm 3+ upconversion emission at visible wavelengths into such kind of fiber is reported under 975 nm pump excitation. The present study is important for development of an efficient tunable 483 nm fluorescence light source. -- Highlights: • We report nano-phase separated YAS glass host based Yb–Tm co-doped optical fibers. • Almost all the Yb transferred its energy to the neighboring Tm ions. • We report strong UC luminescence peaks at 483 nm and 817 nm wavelengths. • We report third ET coefficient as 1.6723 Hz for such kind of Yb–Tm codoped fiber. • We report suitable fiber as an efficient tunable 483 nm fluorescence light source

  8. Influence of silver nanoparticles on the spectroscopic properties of Sm{sup 3+} doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Suthanthirakumar, P.; Marimuthu, K., E-mail: emari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram - 624 302 (India)

    2016-05-23

    The Sm{sup 3+} doped novel boro-phosphate glasses containing silver nanoparticles (NPs) (SmBPxA) have been prepared following the melt quenching technique and their structural and spectroscopic behavior were studied through HR-TEM, optical absorption and photoluminescence spectral measurements. The TEM analysis validates the existence of Ag NPs with an average diameter of ~8 nm. The Surface plasmon resonance (SPR) band of silver NPs was found at around 600 nm from the absorption spectrum of the Sm{sup 3+} ions free glass sample. The optical band gap energy (E{sub opt}) corresponding to the direct and indirect allowed transitions and the Urbach energy (ΔE) values were determined from the absorption spectral measurements. The luminescence intensity is found to get enhance when the Ag NPs were embedded along with the Sm{sup 3+} ions in the prepared glasses due to the local electric field effect around the rare earth (RE) ion site produced by the SPR of Ag NPs.

  9. Thermal effects on light emission in Yb3+ -sensitized rare-earth doped optical glasses

    International Nuclear Information System (INIS)

    Gouveia, E.A.; Araujo, M.T. de; Gouveia-Neto, A.S.

    2001-01-01

    The temperature effect upon infrared-to-visible frequency upconversion fluorescence emission in off-resonance infrared excited Yb 3+ -sensitized rare-earth doped optical glasses is theoretically and experimentally investigated. We have examined samples of Er3+/Yb 3+ -codoped Ga 2 S 3 :La 2 O 3 chalcogenide glasses and germanosilicate optical fibers, and Ga2O3:La 2 O 3 chalcogenide and fluoroindate glasses codoped with Pr 3+ /Yb 3+ , excited off-resonance at 1.064μm. The experimental results revealed thermal induced enhancement in the visible upconversion emission intensity as the samples temperatures were increased within the range of 20 deg C to 260 deg C. The fluorescence emission enhancement is attributed to the temperature dependent multiphonon-assisted anti-Stokes excitation process of the ytterbium-sensitizer. A theoretical approach that takes into account a sensitizer temperature dependent effective absorption cross section, which depends upon the phonon occupation number in the host matrices, has proven to agree very well with the experimental data. As beneficial applications of the thermal enhancement, a temperature tunable amplifier and a fiber laser with improved power performance are presented. (author)

  10. Optical properties of lithium magnesium borate glasses doped with Dy3+ and Sm3+ ions

    International Nuclear Information System (INIS)

    Yasser Saleh Mustafa Alajerami; Suhairul Hashim; Wan Muhamad Saridan Wan Hassan; Ahmad Termizi Ramli; Azman Kasim

    2012-01-01

    Several studies showed the interesting properties of trivalent lanthanide ions when doped in various types of glasses. Optical and physical properties of lithium magnesium borate glasses doped with Dy 3+ then with Sm 3+ ions were determined by measuring their absorption and luminescence spectra in the visible region. The absorption spectra of Dy 3+ showed eight absorption bands with hypersensitive transition at 1265 nm ( 6 H 15/2 → 6 F 11/2 - 6 H 9/2 ) and three PL emission bands at 588 nm ( 4 F 9/2 → 6 H 15/2 ), 660 nm ( 4 F 9/2 → 6 H 13/2 ) and 775 nm ( 4 F 9/2 → 6 H 11/2 ). Regarding the Sm3 + , nine absorption bands were observed with hypersensitive transition at 1237 nm ( 6 H 5/2 - 6 F 7/2 ); the PL spectrum showed four prominent peaks at 4 G 5/2 → 6 H 5/2 (yellow color), 4 G 5/2 → 6 H 7/2 (bright orange color), 4 G 5/2 → 6 H 9/2 (orange reddish color) and 4 G 5/2 → 6 H 11/2 (red color), respectively. Finally, a series of physical parameters such as the oscillator strengths, refractive index, ions concentration, Polaron radius and other parameters were calculated for each dopant.

  11. Upconversion properties of Er3+/Yb3+ co-doped TeO2-TiO2-K2O glasses.

    Science.gov (United States)

    Su, Fangning; Deng, Zaide

    2006-01-01

    The Er3+/Yb3+ co-doped TeO2-TiO2-K2O glasses were prepared by conventional melting procedures, and their upconversion spectra were performed. The dependence of luminescence intensity on the ratio of Yb3+/Er3+ was studied, and the relationship between green upconversion luminescence intensity and Er3+ concentration is discussed in detail. The 546 nm green upconversion luminescence intensity is optimised in the studied glasses either when the Yb3+/Er3+ ratio is 25/1 and Er3+ concentration is 0.1 mol%, or when the Yb3+/Er3+ ratio is 10/1 and Er3+ concentration is 0.15 mol%. These glasses could be one of the potential candidates for LD pumping microchip solid-state lasers.

  12. Segregation and Clustering Effects on Complex Boron Redistribution in Strongly Doped Polycrystalline-Silicon Layers

    International Nuclear Information System (INIS)

    Abadli, S.; Mansour, F.

    2011-01-01

    This work deals with the investigation of the complex phenomenon of boron (B) transient enhanced diffusion (TED) in strongly implanted silicon (Si) layers. It concerns the instantaneous influences of the strong B concentrations, the Si layers crystallization, the clustering and the B trapping/segregation during thermal post-implantation annealing. We have used Si thin layers obtained from disilane (Si2H6) by low pressure chemical vapor deposition (LPCVD) and then B implanted with a dose of 4 x 1015 atoms/cm2 at an energy of 15 keV. To avoid long redistributions, thermal annealing was carried out at relatively low-temperatures (700, 750 and 800 'deg'C) for various short-times ranging between 1 and 30 minutes. To investigate the experimental secondary ion mass spectroscopy (SIMS) doping profiles, a redistribution model well adapted to the particular structure of Si-LPCVD layers and to the effects of strong-concentrations has been established. The good adjustment of the simulated profiles with the experimental SIMS profiles allowed a fundamental understanding about the instantaneous physical phenomena giving and disturbing the TED process in strongly doped Si-LPCVD layers. It was found that boron TED is strongly affected by the simultaneous complex kinetics of clustering, crystallization, trapping and segregation during annealing. The fast formation of small Si-B clusters enhances the B diffusivity whereas the evolution of the clusters and segregation reduce this enhancement. (author)

  13. Synthesis and properties of ZnTe and Eu3+ ion co-doped glass nanocomposites

    International Nuclear Information System (INIS)

    Rahaman Molla, Atiar; Tarafder, Anal; Dey, Chirantan; Karmakar, Basudeb

    2014-01-01

    In this study, ZnTe (II-VI) semiconductor and Eu +3 -ion co-doped borosilicate glass has been prepared in the SiO 2 -K 2 O-CaO-BaO-B 2 O 3 glass system followed by controlled heat-treatment to produce glass nanocomposites. Glass transition temperature and crystallization peak temperature have been evaluated using DSC analysis. Dilatometric studies were carried out to evaluate thermal expansion co-efficient, glass transition temperature, and dilatometric softening temperature and found to be 10.7 × 10 −6 /K, 580° C and 628° C, respectively. TEM micrographs demonstrate formation of nano sized crystallites of less than 50 nm. The ZnTe crystal formation also established through selected area electron diffraction (SAED) analysis and high resolution images obtained through TEM studies. With increasing heat treatment time, optical transmission cut-off wavelength (λ cut-off ) shifted towards higher wavelength. Excitation spectra were recorded by monitoring emission at 613 nm corresponding to the 5 D 0 → 7 F 2 transition. An intense 394 nm excitation band corresponding to the 7 F 0 → 5 L 6 transition was observed. Emission spectra were then recorded by exciting the glass samples at 394 nm. When the glass is heat-treated for 30 min at 610° C, a 6-fold increase in the intensity of the red emission at 612 nm has been observed, which is attributed to the segregation of Eu 3+ ions into the low phonon energy ZnTe crystallites and as the size of the nanocrystals is smaller than the size of the exciton, quantum confinement effect is visible. Further increase in heat-treatment duration led to decrease in luminescence intensity due to the growth of larger size crystals. 5 D 1 → 7 F 0 transition is visible only in the samples heat-treated for 30 min and 1 h, which is a characteristic of presence of Eu 3+ ions in the low phonon energy ZnTe crystal sites. The micro hardness of the precursor glass and glass nanocomposites was evaluated; base glass shows

  14. Mid-IR and far-IR investigation of AgI-doped silver diborate glasses

    International Nuclear Information System (INIS)

    Hudgens, J.J.; Martin, S.W.

    1996-01-01

    The structures of xAgI+(1-x)Ag 2 O·2B 2 O 3 glasses, where 0.2≤x≤0.6, have been investigated using mid- and far-infrared spectroscopy. The mid-IR spectra revealed that in those glasses prepared using AgNO 3 as the starting material for Ag 2 O, the BO 4 - /BO 3 ratio is constant with increasing amounts of AgI as would be expected form the proposed behavior of AgI in these glasses. However, a survey of the literature revealed those glasses prepared from pure Ag 2 O show a strong linear dependence of the BO 4 - /BO 3 ratio on AgI content. Most probably, in those glasses prepared with Ag 2 O the Ag 2 O/B 2 O 3 ratio changes with AgI content due to the decomposition of Ag 2 O during melting. This different behavior is associated with AgNO 3 decomposing to Ag 2 O with heating followed by incorporation into the glassy network. For Ag 2 O used directly, it is proposed that it decomposes to Ag metal and O 2 (gas) with heating before it can be incorporated into the borate network. This latter behavior decreases with increasing AgI in the batch composition because AgI lowers the liquidus temperature of the melt considerably. The far-IR analysis of the AgI-doped silver diborate glasses suggests that there are three coordination environments for the Ag + ions; one with iodide anions and the other two with oxygen ions. It is proposed that the separate oxygen coordination environments for the Ag + ions arise from one with bridging oxygens of BO 4 - units, and the other with nonbridging oxygens on BO 3 - units. Furthermore, it is proposed that the Ag + ions in the iodide-ion environments progressively agglomerate into disordered regions of AgI, but do not form structures similar to α-AgI. (Abstract Truncated)

  15. Luminescence properties of Dy3+ doped lithium zinc borosilicate glasses for photonic applications

    Directory of Open Access Journals (Sweden)

    N. Jaidass

    2018-03-01

    Full Text Available Different concentrations of Dy3+ ions doped lithium zinc borosilicate glasses of chemical composition (30-x B2O3 - 25 SiO2 -10 Al2O3 -30 LiF - 5 ZnO - x Dy2O3 (x = 0, 0.1, 0.5, 1.0 and 2.0 mol% were prepared by the melt quenching technique. The prepared glasses were investigated through X-ray diffraction, optical absorption, photoluminescence and decay measurements. Intensities of absorption bands expressed in terms of oscillator strengths (f were used to determine the Judd-Ofelt (J-O intensity parameters Ωλ (λ = 2, 4 and 6. The evaluated J-O parameters were used to determine the radiative parameters such as transition probabilities (AR, total transition probability rate (AT, radiative lifetime (τR and branching ratios (βR for the excited 4F9/2 level of Dy3+ ions. The chromaticity coordinates determined from the emission spectra were found to be located in the white light region of CIE chromaticity diagram. Keywords: Condensed matter physics, Engineering, Materials science

  16. Influence of Glass Property Restrictions on Hanford HLW Glass Volume

    International Nuclear Information System (INIS)

    Kim, Dong-Sang; Vienna, John D.

    2001-01-01

    A systematic evaluation of Hanford High-Level Waste (HLW) loading in alkali-alumino-borosilicate glasses was performed. The waste feed compositions used were obtained from current tank waste composition estimates, Hanford's baseline retrieval sequence, and pretreatment processes. The waste feeds were sorted into groups of like composition by cluster analysis. Glass composition optimization was performed on each cluster to meet property and composition constraints while maximizing waste loading. Glass properties were estimated using property models developed for Hanford HLW glasses. The impacts of many constraints on the volume of HLW glass to be produced at Hanford were evaluated. The liquidus temperature, melting temperature, chromium concentration, formation of multiple phases on cooling, and product consistency test response requirements for the glass were varied one- or many-at-a-time and the resultant glass volume was calculated. This study shows clearly that the allowance of crystalline phases in the glass melter can significantly decrease the volume of HLW glass to be produced at Hanford.

  17. Optical absorption and emission characteristics of Pr{sup 3+}-doped RTP glasses

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, D.V.R. [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Jamalaiah, B.C. [Department of Physics, Sree Vidyanikethan Engineering College, Tirupati (India); Sasikala, T. [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Rama Moorthy, L., E-mail: lrmphysics@yahoo.co.i [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Jayasimhadri, M.; Jang, Kiwan; Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon (Korea, Republic of); Yi, Soung Soo [Department of Photonics, Silla University, Pusan 617-736 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Pusan 608-737 (Korea, Republic of)

    2010-02-15

    Judd-Ofelt (J-O) parameters are calculated for Pr{sup 3+}ions doped alkaline earth potassium titanium phosphate (RTP, where R=Mg, Ca, Sr) glasses. The best fit for the oscillator strengths has been obtained by omitting the {sup 3}H{sub 4}->{sup 3}P{sub 2} hypersensitive transition. In all the three glasses, the J-O parameters follow the same trend as OMEGA{sub 2}OMEGA{sub 6}. These J-O intensity parameters are then used to compute the radiative properties such as the radiative transition probabilities (A{sub R}), branching ratios (beta{sub R}) and radiative lifetimes (tau{sub R}) for the observed fluorescence bands. The fluorescence spectra obtained upon 445 nm excitation exhibited an intense emission band centered at 484 nm ({sup 3}P{sub 0}->{sup 3}H{sub 4}), four medium intense bands at 525 nm ({sup 3}P{sub 1}->{sup 3}H{sub 5}), 598 nm ({sup 1}D{sub 2}->{sup 3}H{sub 4}), 608 nm ({sup 3}P{sub 0}->{sup 3}H{sub 6}) and 641 nm ({sup 3}P{sub 0}->{sup 3}F{sub 2}) and one weak band at 669 nm ({sup 3}P{sub 1}->{sup 3}F{sub 3}). The experimental branching ratios (beta{sub exp}) obtained from steady state fluorescence are compared with the calculated values. The decay curves measured from the {sup 3}P{sub 0} excited metastable state are found to be single exponential in all the glasses. The gain bandwidths (sigma{sub e}xDELTAlambda{sub P}) and optical gain (sigma{sub e}xtau{sub m}) parameters suggest that the RTP glasses could be used for laser active materials to emit intense blue emission at 484 nm.

  18. Analysis of energy transfer process based emission spectra of erbium doped germanate glasses for mid-infrared laser materials

    International Nuclear Information System (INIS)

    Cai, Muzhi; Wei, Tao; Zhou, Beier; Tian, Ying; Zhou, Jiajia; Xu, Shiqing; Zhang, Junjie

    2015-01-01

    Highlights: • Er 3+ doped germanate glass with good thermal stability were prepared. • Ionic boding nature was proved by bonding parameter calculation. • Mid-infrared fluorescent behaviors and energy transfer were investigated. • Rate equation and Dexter’s theory were utilized to elucidate 2.7 μm emission. - Abstract: Er 3+ activated germanate glass with good thermal stability was prepared. Bonding parameters have been calculated and the nature of ionic bonding of the germanate glass has been determined. Mid-infrared fluorescence was observed and corresponding radiative properties were investigated. For Er 3+ : 4 I 11/2 → 4 I 13/2 transition, high spontaneous radiative transition probability (30.09 s −1 ), large emission cross section ((14.84 ± 0.10) × 10 −21 cm 2 ) and superior gain performance were obtained from the prepared glass. Besides, energy transfer processes concerning the 2.7 μm emission were also discussed in detail. According to simplified rate equation and Dexter’s theory, energy transfer microscopic parameters were computed to elucidate observed 2.7 μm emissions. Results demonstrate that the prepared germanate glass possessing excellent spectroscopic properties might be an attractive candidate for mid-infrared laser or amplifier

  19. Effects of ionizing radiations on the optical properties of ionic copper-activated sol-gel silica glasses

    Science.gov (United States)

    Al Helou, Nissrine; El Hamzaoui, Hicham; Capoen, Bruno; Ouerdane, Youcef; Boukenter, Aziz; Girard, Sylvain; Bouazaoui, Mohamed

    2018-01-01

    Studying the impact of radiations on doped silica glasses is essential for several technological applications. Herein, bulk silica glasses, activated with various concentrations of luminescent monovalent copper (Cu+), have been prepared using the sol-gel technique. Thereafter, these glasses were subjected to X- or γ-rays irradiation at 1 MGy(SiO2) accumulated dose. The effect of these ionizing radiations on the optical properties of these glasses, as a function of the Cu-doping content, were investigated using optical absorption and photoluminescence spectroscopies. Before any irradiation, the glass with the lowest copper concentration exhibits blue and green luminescence bands under UV excitation, suggesting that Cu+ ions occupy both cubic and tetragonal symmetry sites. However, at higher Cu-doping level, only the green emission band exists. Moreover, we showed that the hydroxyl content decreases with increasing copper doping concentration. Both X and γ radiation exposures induced visible absorption due to HC1 color centers in the highly Cu-doped glasses. In the case of the lower Cu-doped glass, the Cu+ sites with a cubic symmetry are transformed into sites with tetragonal symmetry.

  20. Structural and luminescence studies on Dy{sup 3+} doped lead boro–telluro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Selvi, S. [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India); Venkataiah, G. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Arunkumar, S.; Muralidharan, G. [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India)

    2014-12-01

    This paper reports results obtained on the structural and luminescence properties of Dy{sup 3+}doped lead boro−telluro-phosphate glasses prepared following the melt quenching technique. FTIR spectra exhibit the presence of B−O vibrations, P−O−P symmetric vibrations and Te−O stretching modes of TeO{sub 3} and TeO{sub 6} units. The metal–ligand bond was identified through UV−vis−NIR absorption spectra and to determine the band tailing parameter, direct and indirect band gap energy of the prepared glasses. The Judd−Ofelt (JO) intensity parameters (Ω{sub 2}, Ω{sub 4} and Ω{sub 6}), experimental and theoretical oscillator strengths were also determined and reported. Luminescence measurements were made to determine the transition probability (A), stimulated emission cross-section (σ{sub P}{sup E}) and branching ratio (β{sub R}) for the transitions that include {sup 4}F{sub 9/2}→{sup 6}H{sub 11/2}, {sup 6}H{sub 13/2} and {sup 6}H{sub 15/2} bands. The effect of Dy{sup 3+} ion concentration on the intensity ratio of yellow to blue emission bands has also been studied and reported. The lifetime corresponding to the {sup 4}F{sub 9/2} level of the title glasses has been found to decrease with the increase in Dy{sup 3+} ion concentration. The chromaticity coordinates (x,y) have been estimated from the luminescence spectra and the suitability of title glasses for white light applications has been analyzed using CIE chromaticity diagram. The variation of optical properties with the concentration of dysprosium oxide content in the glasses have been studied and reported.

  1. Stable glass-ceramic sealants for solid oxide fuel cells: Influence of Bi{sub 2}O{sub 3} doping

    Energy Technology Data Exchange (ETDEWEB)

    Goel, Ashutosh; Ferreira, Jose M.F. [Department of Ceramics and Glass Engineering, University of Aveiro, CICECO, 3810-193 Aveiro (Portugal); Pascual, Maria J. [Instituto de Ceramica y Vidrio (CSIC), Kelsen 5, Campus de Cantoblanco, 28049 Madrid (Spain)

    2010-07-15

    Diopside (CaMgSi{sub 2}O{sub 6}) based glass-ceramics in the system SrO-CaO-MgO-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-La{sub 2}O{sub 3}-Bi{sub 2}O{sub 3}-SiO{sub 2} have been synthesized for sealing applications in solid oxide fuel cells (SOFC). The parent glass composition in the primary crystallization field of diopside has been doped with different amounts of Bi{sub 2}O{sub 3} (1, 3, 5 wt.%). The sintering behavior by hot-stage microscopy (HSM) reveals that all the investigated glass compositions exhibit a two-stage shrinkage behavior. The crystallization kinetics of the glasses has been studied by differential thermal analysis (DTA) while X-ray diffraction adjoined with Rietveld-R.I.R. analysis have been employed to quantify the amount of crystalline and amorphous phases in the glass-ceramics. Diopside and augite crystallized as the primary crystalline phases in all the glass-ceramics. The coefficient of thermal expansion (CTE) of the investigated glass-ceramics varied between (9.06-10.14) x 10{sup -6} K{sup -1} after heat treatment at SOFC operating temperature for a duration varying between 1 h and 200 h. Further, low electrical conductivity, good joining behavior and negligible reactivity with metallic interconnects (Crofer22 APU and Sanergy HT) in air indicate that the investigated glass-ceramics are suitable candidates for further experimentation as sealants in SOFC. (author)

  2. Spectroscopic identification of rare earth elements in phosphate glass

    Science.gov (United States)

    Devangad, Praveen; Tamboli, Maktum; Muhammed Shameem, K. M.; Nayak, Rajesh; Patil, Ajeetkumar; Unnikrishnan, V. K.; Santhosh, C.; Kumar, G. A.

    2018-01-01

    In this work, rare earth-doped phosphate glasses were synthesized and characterized using three different spectroscopic techniques. The absorption spectra of the prepared praseodymium (Pr) and samarium (Sm) doped glasses, recorded by a UV-VIS-NIR spectrophotometer, show the characteristic absorption bands of these elements. To confirm this inference, laser-induced fluorescence spectra of Pr and Sm were obtained at a laser excitation of 442 nm. Their emission bands are reported here. The elemental analysis of these samples was carried out using a laser-induced breakdown spectroscopy (LIBS) system. Characteristic emission lines of Pr and Sm have been identified and reported by the recorded LIBS spectra of glass samples. Results prove that using these three complimentary spectroscopic techniques (absorption, fluorescence and LIBS), we can meaningfully characterize rare earth-doped glass samples.

  3. Hydrogen storage in N- and B-doped graphene decorated by small platinum clusters: A computational study

    Science.gov (United States)

    Chen, I.-Nan; Wu, Shiuan-Yau; Chen, Hsin-Tsung

    2018-05-01

    In this work, we perform density functional theory (DFT) calculations to investigate the hydrogen adsorption on Pt4 cluster supported on pristine, B-, and N-doped graphene sheets. It is found that the doping B or N atom in the graphene could enhance the interaction between the Pt4 cluster and the supporting substrate. The first H2 molecule is found to be dissociative chemisorption on the three substrates. Further, dissociative and molecular adsorption of multiple H2 molecules are co-adsorbed on the three substrates. In addition, the interaction between Pt4(H2)x and the substrate is illustrated for the stability of Pt4(H2)x on the substrate. AIMD simulation is also performed to verify the stability and hydrogen storage. Accordingly, the B-graphene is predicted to be the most potential materials for hydrogen storage among these three materials.

  4. On the induction of homogeneous bulk crystallization in Eu-doped calcium aluminosilicate glass by applying simultaneous high pressure and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Muniz, R. F., E-mail: robsonfmuniz@yahoo.com.br [Institut Lumière Matière, UMR 5306 CNRS-Université Lyon 1, Université de Lyon, 69622 Villeurbanne (France); Departamento de Física, Universidade Estadual de Maringá, 87020900, Maringá, PR (Brazil); Ligny, D. de [Department of Materials Science, Glass and Ceramics, University of Erlangen Nürnberg, Martensstr. 5, 91058 Erlangen (Germany); Le Floch, S.; Martinet, C.; Guyot, Y. [Institut Lumière Matière, UMR 5306 CNRS-Université Lyon 1, Université de Lyon, 69622 Villeurbanne (France); Rohling, J. H.; Medina, A. N.; Sandrini, M.; Baesso, M. L. [Departamento de Física, Universidade Estadual de Maringá, 87020900, Maringá, PR (Brazil); Andrade, L. H. C.; Lima, S. M. [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, C.P. 351, Dourados, MS (Brazil)

    2016-06-28

    From initial calcium aluminosilicate glass, transparent glass-ceramics have been successfully synthesized under simultaneous high pressure and temperature (SHPT). Possible homogeneous volumetric crystallization of this glassy system, which was not achieved previously by means of conventional heat treatment, has been put in evidence with a SHPT procedure. Structural, mechanical, and optical properties of glass and glass-ceramic obtained were investigated. Raman spectroscopy and X-ray diffraction allowed to identify two main crystalline phases: merwinite [Ca{sub 3}Mg(SiO{sub 4}){sub 2}] and diopside [CaMgSi{sub 2}O{sub 6}]. A Raman scanning profile showed that the formation of merwinite is quite homogeneous over the bulk sample. However, the sample surface also contains significant diopside crystals. Instrumented Berkovich nanoindentation was applied to determine the effect of SHPT on hardness from glass to glass-ceramic. For Eu-doped samples, the broadband emission due to 4f{sup 6}5d{sup 1} → 4f{sup 7} transition of Eu{sup 2+} was studied in both host systems. Additionally, the {sup 5}D{sub 0} → {sup 7}F{sub J} transition of Eu{sup 3+} was used as an environment probe in the pristine glass and the glass-ceramic.

  5. Structure determination of AgPO3 and (AgPO3)0.5(AgI)0.5 glasses by neutron diffraction and small angle neutron scattering

    International Nuclear Information System (INIS)

    Tachez, M.; Mercier, R.; Malugani, J.P.; Chieux, P.

    1987-01-01

    Neutron diffraction and small angle neutron scattering (SANS) were performed on AgPO 3 and (AgPO 3 ) 0.5 (AgI) 0.5 glasses. AgPO 3 glass is made up of long chains of PO 4 tetrahedra joined together by Ag atoms. When silver iodide is added, the radial distribution function shows a large peak at 2.83 A, due to Ag-I interactions. AgI does not modify the network forming unit. The existence of small clusters is confirmed by analysing the coordination number of Ag-I pairs obtained by subtracting the experimental structure function of the AgPO 3 glass from that of the corresponding AgI-doped glasses. A rough estimation of their size is given by SANS experiments. Not all the AgI pairs are involved in AgI cluster units. The compatibility of the results obtained with recent structural investigations by non diffractometric techniques is examined. 23 refs.; 5 figs.; 3 tabs

  6. Thermal properties and optical transition probabilities of Tm3 + doped TeO2-WO3 glass.

    Science.gov (United States)

    Cenk, S; Demirata, B; Oveçoglu, M L; Ozen, G

    2001-10-01

    Glasses with the composition of (1 - x)TeO2 + (x)WO3, where x = 0.15, 0.25 and 0.3 were prepared and, their thermal and absorption measurements were carried out. Differential thermal analysis (DTA) curves taken in the 23-600 degrees C temperature range with a heating rate of 10 degrees C/min reveal a change in the value of the glass transition temperature, Tg, while crystallization was not observed for the glasses containing a WO3 content of more than 15 mol%. All the glasses were found to be moisture-resistant. The absorption bands corresponding to the absorption of the 1G4, 3F2, 3F3 and 3F4, 3H5 and 3H4 levels from the 3H6 ground level of the Tm3+ ion were observed in the optical absorption spectra. Integrated absorption cross-sections of each band except that of 3H5 level was found to vary with the glass composition. Judd-Ofelt analysis was carried out for the samples doped with 1.0 mol% Tm2O3. The omega2 parameter shows the strongest dependence on the host composition and it increases with the increasing WO3 amount. The value of omega4 increases rather slowly while the value of omega6 is practically independent of the composition. The strong dependence of the parameter omega2 indicates that this parameter is related to the structural change and the symmetry of the local environment of the Tm3+ ions in this glass.

  7. A full-configuration-interaction nuclear orbital approach and application for small doped He clusters

    Energy Technology Data Exchange (ETDEWEB)

    Lara-Castells, M. P. de, E-mail: delara@iff.csic.es; Aguirre, N. F., E-mail: delara@iff.csic.es; Delgado-Barrio, G., E-mail: delara@iff.csic.es; Villarreal, P., E-mail: delara@iff.csic.es [Instituto de Física Fundamental (CSIC), Serrano 123, 28006 Madrid (Spain); Mitrushchenkov, A. O. [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée (France)

    2015-01-22

    An efficient full-configuration-interaction 'nuclear orbital' treatment was developed as a benchmark quantum-chemistry-like method to calculate, ground and excited, fermionic 'solvent' wave-functions and applied to {sup 3}He{sub N} clusters with atomic or molecular impurities [J. Chem. Phys. (Communication) 125, 221101 (2006)]. The main difficulty in handling doped {sup 3}He{sub N} clusters lies in the Fermi-Dirac nuclear statistics, the wide amplitudes of the He-dopant and He-He motions, and the hard-core He-He interaction at short distances. This paper overviews the theoretical approach and its recent applications to energetic, structural and spectroscopic aspects of different dopant-{sup 3}He{sub N} clusters. Preliminary results by using the latest version of the FCI-NO computational implementation, to bosonic Cl{sub 2}(X)-({sup 4}He){sub N} clusters, are also shown.

  8. Four-wave mixing of Nd3+-doped crystals and glasses

    International Nuclear Information System (INIS)

    Powell, R.C.; Payne, S.A.; Chase, L.L.; Wilke, G.D.

    1990-01-01

    Degenerate four-wave-mixing measurements have been performed on a wide variety of Nd 3+ -doped oxide and fluoride glasses and crystals. Crossed beams from a cw argon-ion laser were used to excite the Nd 3+ ions directly and establish population gratings. Absolute measurements of the signal strengths were made, and their magnitudes were found to be sensitively influenced by the composition of the host. A theoretical model was developed to interpret the results, and it was found that the dominant contribution to the signal is associated with the difference in polarizability of the Nd 3+ ions in the metastable state versus the ground state. The magnitude of the observed change in the polarizability indicates that the 4f→5d transitions are responsible for this effect, and as a result, the value of the left-angle 4f|r|5d right-angle radial integral sensitively affects the calculated polarizability change

  9. Effect of concentration variation on 2.0 µm emission of Ho3+-doped SiO2-Al2O3-Na2CO3-SrF2-CaF2 oxyfluorosilicate glasses

    Science.gov (United States)

    Gelija, Devarajulu; Borelli, Deva Prasad Raju

    2018-02-01

    The concentration variation of Ho3+ ion-doped SiO2-Al2O3-Na2CO3-SrF2-CaF2 glasses has been prepared by conventional melt quenching method. The thermal stability of 1 mol % of Ho3+-doped oxyfluorosilicate glass has been calculated using the differential thermal analysis (DTA) spectra. The phenomenological Judd-Ofelt intensity parameters Ωλ ( λ = 2, 4 and 6) were calculated for all concentrations of Ho3+ ions. The luminescence spectra in visible region of Ho3+ ion-doped glasses were recorded under the excitation wavelength of 452 nm. The spectra consists of several intense emission bands (5F4, 5S2) → 5I8 (547 nm), 5F3 → 5I8 (647 nm), 5F5 → 5I7 (660 nm) and (5F4, 5S2) → 5I7 (750 nm) in the range 500-780 nm. The fluorescence emission at ˜2.0 µm (5I7 → 5I8) was observed under the excitation of 488 nm Ar-ion laser. The stimulated emission cross section for 5I7 → 5I8 transition (˜2.0 µm) varies from 8.46 to 9.52 × 10-21 cm2, as calculated by the Fuchtbauer-Ladenburg (FL) theory. However, Mc-Cumber theory was used to calculate emission cross section values about 4.24-5.75 × 10-21 cm2 for the 5I7 → 5I8 transition in all concentrations of Ho3+-doped oxyfluorosilicate glasses. Therefore, these results reveal that the 0.5 mol % of Ho3+-doped oxyfluorosilicate glasses, exhibiting higher emission cross section, has potentially been used for laser applications at ˜ 2.0 µm.

  10. Optical absorption and spectroscopic properties of thulium doped (TeO{sub 2})(Nb{sub 2}O{sub 5})(TiO{sub 2}) glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kabalci, Idris [Department of Physics Education, Education Faculty, Harran University, Sanliurfa (Turkey); Tay, Turgay [Department of Chemistry, Science Faculty, Anadolu University, Eskisehir (Turkey); Oezen, Goenuel [Department of Physics, Science and Arts Faculty, Istanbul Technical University, Istanbul (Turkey)

    2011-09-15

    A type of thulium doped tellurite based optical glasses was prepared through conventional melt quenching technique. In the experiments, the effect of different Tm{sup 3+} ion concentration and glass composition on optical properties of (TeO{sub 2}){sub (1-x-y)}(Nb{sub 2}O{sub 5}){sub (x)}(TiO{sub 2}){sub (y)} (x=0.05, 0.10, 0.15, and 0.20 mol) glasses have been investigated by using UV-VIS-NIR optical spectrophotometry measurements in a wavelength range 400-2000 nm. Considering absorption measurements for the 1.0mol% Tm{sup 3+} doped of (TeO{sub 2}){sub 0.9}(Nb{sub 2}O{sub 5}){sub 0.05}(TiO{sub 2}){sub 0.05} glass, {sup 1}G{sub 4}, {sup 3}F{sub 2}, {sup 3}F{sub 3}, {sup 3}F{sub 4}, {sup 3}H{sub 5}, and {sup 3}H{sub 4} absorption bands were observed from the {sup 3}H{sub 6} ground level, at 463, 660, 687, 793, 1211 and 1700 nm wavelengths, respectively. Furthermore, spontaneous emission probabilities, and the radiative lifetimes for the 4f-4f transitions of the Tm{sup 3+} ions were calculated. The spectral intensities were determined in terms of Judd-Ofelt parameters ({omega}{sub 2}, {omega}{sub 4}, {omega}{sub 6}). Luminescence analysis was realized for the different Tm{sup 3+} ion concentration (0.002, 0.005 and 0.01mol) at room temperature. The luminescence band intensity of the {sup 3}F{sub 4}{yields}{sup 3}H{sub 4} transition was measured as a function of Tm{sup 3+} ion concentration (0.002, 0.005 and 0.01mol). Furthermore, luminescence data of the thulium doped glass samples were used to determine the compositional dependence of the emission cross sections at 1470 nm (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Spin-Glass Transition and Giant Paramagnetism in Heavily Hole-Doped Bi2Sr2Co2Oy

    Science.gov (United States)

    Hsu, Hung Chang; Lee, Wei-Li; Lin, Jiunn-Yuan; Young, Ben-Li; Kung, Hsiang-Hsi; Huang, Jian; Chou, Fang Cheng

    2014-02-01

    Hole-doped single crystals of misfit-layered cobaltate Bi2-xPbxSr2-zCo2Oy (x = 0-0.61, y = 8.28-8.62, and z = 0.01-0.22) have been successfully grown using the optical floating-zone method. Heavier hole doping has been achieved through both Pb substitution in the Bi site and the more effective Sr vacancy formation. The Co4+ : Co3+ ratio can be raised significantly from its original ˜1 : 1 to 4.5 : 1, as confirmed by iodometric titration. A spin-glass transition temperature of Tg ˜ 70 K is confirmed by ac susceptibility measurement when the Co4+ : Co3+ ratio becomes higher than 2 : 1, presumably owing to the significantly increased probability of triangular geometrical frustration among antiferromagnetically coupled localized Co4+ spins.

  12. The effects of gamma irradiation on the elastic properties of soda lime glass doped with cerium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Laopaiboon, R.; Laopaiboon, J.; Pencharee, S. [Glass Technology Excellent Center (GTEC), Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 (Thailand); Nontachat, S. [Department of Radiotherapy, Ubon Ratchathani Cancer Centre, Ubon Ratchathani, 34190 (Thailand); Bootjomchai, C., E-mail: cherdsak_per@hotmail.co.th [Glass Technology Excellent Center (GTEC), Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 (Thailand)

    2016-05-05

    Soda lime glass doped with cerium oxide was prepared using a conventional melt quenching technique. The density and molar volume of the glass samples were measured. Ultrasonic wave velocities of the glass samples were carried out using a pulse echo technique. The density and ultrasonic velocities were used for determining elastic moduli of the glass samples, both before and after irradiation with gamma rays at 1 kGy. The results revealed that the influence of gamma irradiation caused the matrix structure of the glass samples to be damaged by creating displacements, electronic defects and/or breaks in the network bonds, leading to the formation of non-bridging oxygens (NBOs). Elastic properties were investigated under the influence of gamma irradiation. The results also revealed that the structures of the glass samples were distorted by irradiation. Damage by irradiation created the NBOs and/or the transformation of main glass network structures from Q{sub 4} to Q{sub 3}. Evidence of these results was acquired from FTIR spectra. The results of FTIR supported the results and were obtained from ultrasonic velocities. In addition, the elastic properties obtained from experiments were compared with theoretical values calculated from the Makishima and Mackenzie model (M–M model). - Highlights: • Results show good agreement between experimental and theoretical of elastic moduli. • Influence of irradiation created a distorted network structure. • Transformation of network structure from Ref. Q{sub 4} to Q{sub 3} after irradiation. • FTIR result is good evidence of the result is obtained from ultrasonic technique.

  13. Luminescent properties of Eu{sup 3+}-doped glass ceramics containing BaCl{sub 2} nanocrystals under NUV excitation for White LED

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Han; Mo, Zhaojun, E-mail: mzjmzj163@163.com; Zhang, Xiaosong; Yuan, Linlin; Yan, Ming; Li, Lan, E-mail: lilan@tjut.edu.cn

    2016-07-15

    Eu{sup 3+} doped fluorozirconate glass ceramics containing BaCl{sub 2} nanocrystals were successfully fabricated by melt quenching method, and their structural and luminous properties were investigated. The existence of BaCl{sub 2} nanocrystals in the glass ceramics plays an important role on the improvement of luminescent properties. The emission intensity in glass ceramics was remarkably enhanced, which attributes to the phonon energy decrease by Eu{sup 3+} ions into BaCl{sub 2} nanocrystals. Meanwhile, the extended average fluorescence decay lifetime from 4.60 ms to 5.42 ms and the decreased Red/Orange ratio and spark splitting of {sup 7}F{sub 1} energy level also confirmed this view. Additionally, the excitation spectra showed that glass ceramics could be effectively excited by NUV light. The CIE chromaticity coordinates of glass ceramics (GC320) were calculated as (0.611, 0.371), which was close to the NTSC standard values for red (0.67, 0.33). The results suggested that the glass ceramics may be used as potential red phosphors under UV light excitation for white light-emitting diodes.

  14. Manganese activated phosphate glass for dosimetry

    International Nuclear Information System (INIS)

    Regulla, D.

    1975-01-01

    A measuring element comprises a metaphosphate glass doped with manganese as an activator. The manganese activated metaphosphate glass can detect and determine radiation doses in the range between milliroentgens and more than 10 megaroentgens. (auth)

  15. UV-visible, infrared and Raman spectroscopic and thermal studies of tungsten doped lead borate glasses and the effect of ionizing gamma irradiation

    International Nuclear Information System (INIS)

    El-Kheshen, Amany A.; El-Batal, Fatma H.; Marzouk, Samir Y.

    2008-01-01

    Ultraviolet-visible, infrared and Raman spectroscopy together with thermal properties were measured for undoped and WO 3 - doped (up to 10%) lead borate glasses. Also, the effect of gamma irradiation was followed by UV-visible measurements. The UV visible spectrum of the undoped glass reveals before irradiation intense ultraviolet bands due to the combined effects of trace iron impurities (Fe 3+ ) and Pb 2+ ions which remain unchanged with the addition of WO 3 . Infrared and Raman measurements show characteristic bands due to borate group and the possible sharing of lead-oxygen and tungsten-oxygen groups. The studied glasses show obvious resistance to gamma irradiation. The thermal and density data are correlated with the introduction of highly polarizable and heavy (W 6+ ) ions and to the change in structural arrangement with varying glass composition. (author)

  16. The Effect of Indium Content on the Atomic Environment and Cluster Stability of GeSe4Inx=10,15 Glasses

    Directory of Open Access Journals (Sweden)

    Georgios S. E. Antipas

    2015-01-01

    Full Text Available The atomic environments of two chalcogenide glasses, with compositions GeSe4In10 and GeSe4In15, were studied via Reverse Monte Carlo and Density Functional Theory. Indium content demoted Ge–Se bonding in favor of Se-In while the contribution of Se–Se in the first coordination shell order was faint. Upon transition to the richer In glass, there was formation of rich Ge-centered clusters at radial distances further than 4 Å from the RMC box center, which was taken to signify a reduction of Ge–Se interactions. Cluster coordination by Se promoted stability while, very conclusively, In coordination lowered cluster stability by intervening in the Ge–Se and Se–Se networks.

  17. Optical transitions of Ho(3+) in oxyfluoride glasses and upconversion luminescence of Ho(3+)/Yb(3+)-codoped oxyfluoride glasses.

    Science.gov (United States)

    Feng, Li; Wu, Yinsu

    2015-05-05

    Optical properties of Ho(3+)-doped SiO2-BaF2-ZnF2 glasses have been investigated on the basis of the Judd-Ofelt theory. Judd-Ofelt intensity parameters, radiative transition probabilities, fluorescence branching ratios and radiative lifetimes have been calculated for different glass compositions. Upconversion emissions were observed in Ho(3+)/Yb(3+)-codoped SiO2-BaF2-ZnF2 glasses under 980nm excitation. The effects of composition, concentration of the doping ions, and excitation pump power on the upconversion emissions were also systematically studied. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. EUROPIUM ION INFLUENCE ON THE FORMATION OF Ag-NANOPARTICLES IN FLUORINE PHOSPHATE GLASSES

    Directory of Open Access Journals (Sweden)

    R. O. Pysh'ev

    2015-05-01

    Full Text Available The paper deals with research of formation characteristics of silver nanoparticles in fluorophosphate glasses 0.25 Na2O - 0.5 P2O5 - 0.10 Ga2O3 - 0.075 AlF3 - 0.025 NaF - 0.05 ZnF2 doped with EuF3 (0.8 and 4 wt.% and without them. The synthesis was carried out in closed glassy carbon crucibles in argon atmosphere. Nanoparticles were formed after a low temperature process of Ag+ → Na+ ion-exchange (320 °C and subsequent heat treatment. It was shown that in the initial glasses doped with EuF3, rare earth ions exist in two valence forms (Eu2+ and Eu3+ in dynamic equilibrium and the concentration of Eu2+ increases proportionally to the total concentration of fluoride. It was shown that sizes of molecular clusters or metal nanoparticles depend on the concentration of europium fluoride and duration of ion exchange. The metallic Ag-nanoparticles sizes were defined for different times of heat treatment and ion exchange. The possibility of the stimulating growth of nanoparticles through the introduction of additional EuF3 in the glass was proved. The possibility of obtaining nanoparticles without the heat treatment in glasses with a high concentration of EuF3 was shown. Chemical mechanism for the formation of Ag-nanoparticles during the ion exchange was suggested.

  19. Nd3+-doped heavy metal oxide based multicomponent borate glasses for 1.06 μm solid-state NIR laser and O-band optical amplification applications

    Science.gov (United States)

    Lakshminarayana, G.; Kaky, Kawa M.; Baki, S. O.; Lira, A.; Meza-Rocha, A. N.; Falcony, C.; Caldiño, U.; Kityk, I. V.; Méndez-Blas, A.; Abas, A. F.; Alresheedi, M. T.; Mahdi, M. A.

    2018-04-01

    Nd3+-doped glasses in the composition (50-x) B2O3-10 PbO-10 BaO-10 Al2O3-10 ZnO-10 Na2O-(x) Nd2O3 (x = 0.0, 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, and 2.0 mol %) were fabricated using melt quenching method. Upon 592 nm visible and 808 nm LD excitations, the luminescence spectra show a strong 4F3/2 → 4I11/2 (1.06 μm) emission transition, and two less intense 4F3/2 → 4I9/2 (0.89 μm) and 4F3/2 → 4I13/2 (1.331 μm) emission transitions. The intensity of such emissions increases up to 0.5 mol % Nd3+, and above this doping level, quenching occurs. For 0.5 mol % Nd3+-doped glass, following Judd-Ofelt intensity parameters and emission spectrum, AR, τR, βR and βexp, including Δλeff,σem(λp), (σem × (Δλeff)) and (σem × (τrad)), are derived for Nd3+ ion 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 fluorescence transitions. The highest σem(λp) for the 1.06 and 1.331 μm fluorescence bands are found to be 6.216 × 10-20 and 2.295 × 10-20cm2, respectively. The 4F3/2 level lifetimes are found to decrease with an increase in Nd2O3 content and the decay curves of the glass up to 1.5 mol % Nd3+ exhibit single exponential nature. From 'τexp' of the Nd3+: 4F3/2 level, quantum efficiency (η), (σem × (τexp)), and saturation intensity (IS) are 48.87%, 51.09 × 10-25 cm2s and 3.67 × 108 W/m2, respectively, for the 0.5 mol % Nd3+-doped glass. Higher thermal stability, very low χ, high AR, large βexp., moderate τR, large gain bandwidth and high optical gain values indicate that 0.5 mol % Nd3+-doped glass could be a potential gain medium for solid-state NIR lasers at 1.06 μm. Moreover, for the 1.331 μm emission, large Δλeff and the theoretical gain coefficient value of 1.579 dB/cm, evaluated with an excited Nd3+ ion fractional factor of 0.6, indicate that this glass might be a promising candidate in developing O-band optical fiber amplifiers.

  20. Thermal stability and Judd-Ofelt analysis of optical properties of Sm3+-doped sodium tellurite glasses

    Science.gov (United States)

    Mawlud, Saman Q.; Ameena, Mudhafar M.; Sahar, Md. Rahim; Mahraz, Zahra A. Said; Ahmed, Kasim Fawzy

    2017-09-01

    Series of glasses based on (70-x) TeO2 - 20Na2O - xSm2O3 (x=0, 0.3, 0.6, 1, 1.2, 1.5 mol%) have been prepared using melt-quenching technique. The nature of the glass has been confirmed using X-ray diffraction; it is found that the glass samples are amorphous in nature. The thermal stability of the glass has been determined by means of Differential Thermal Analysis (DTA). From the DTA curve, the glass transition temperature (Tg), crystallization temperature (Tc) and melting temperature (Tm) have been identified and thermal stability is also calculated. The absorption properties of these samples are obtained by using UV-Visible-NIR spectrometer, the recorded absorption spectra exhibit nine absorption transition bands peaks corresponding to the transitions from ground level 6H5/2→6P3/2, 4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2 and 6F1/2. The emission characteristic of this glass is characterized using Photoluminescence (PL) spectroscopy at excited wavelength 404 nm, the emission spectra consisted of four emission bands at 561.95 nm, 598.69 nm, 643.77 nm and 704.56 nm which were assigned as a transition 4G5/2→6H5/2, 6H7/2, 6H9/2 and 6H11/2 respectively. From f-f intensity model the experimental oscillator strengths, fexp and theoretical oscillator strength fcal were calculated. Using Judd-Ofelt theory and fit process of least square, the phenomenological intensity parameters Ωλ (λ=2,4,6) were obtained, In order to evaluate potential applications of Sm3+ ions in telluride glasses, the spectroscopic parameters: transition probability AR, branching ratio Br, radiative life time τr, emission pick cross section σλ for each band were calculated. The comparative studies with other Sm3+ doped different glasses showed that present glasses could be a potential candidate for lasers.

  1. Analysis of energy transfer process based emission spectra of erbium doped germanate glasses for mid-infrared laser materials

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Muzhi; Wei, Tao; Zhou, Beier; Tian, Ying; Zhou, Jiajia; Xu, Shiqing, E-mail: shiqingxu@cjlu.edu.cn; Zhang, Junjie, E-mail: jjzhang@cjlu.edu.cn

    2015-03-25

    Highlights: • Er{sup 3+} doped germanate glass with good thermal stability were prepared. • Ionic boding nature was proved by bonding parameter calculation. • Mid-infrared fluorescent behaviors and energy transfer were investigated. • Rate equation and Dexter’s theory were utilized to elucidate 2.7 μm emission. - Abstract: Er{sup 3+} activated germanate glass with good thermal stability was prepared. Bonding parameters have been calculated and the nature of ionic bonding of the germanate glass has been determined. Mid-infrared fluorescence was observed and corresponding radiative properties were investigated. For Er{sup 3+}:{sup 4}I{sub 11/2}→{sup 4}I{sub 13/2} transition, high spontaneous radiative transition probability (30.09 s{sup −1}), large emission cross section ((14.84 ± 0.10) × 10{sup −21} cm{sup 2}) and superior gain performance were obtained from the prepared glass. Besides, energy transfer processes concerning the 2.7 μm emission were also discussed in detail. According to simplified rate equation and Dexter’s theory, energy transfer microscopic parameters were computed to elucidate observed 2.7 μm emissions. Results demonstrate that the prepared germanate glass possessing excellent spectroscopic properties might be an attractive candidate for mid-infrared laser or amplifier.

  2. Photoluminescence properties of Er{sup 3+}-doped alkaline earth titanium phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, D.V.R.; Babu, A. Mohan [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Jamalaiah, B.C. [Department of Physics, Sree Vidyanikethan Engineering College, Tirupati, 517 102 (India); Moorthy, L. Rama, E-mail: lrmphysics@yahoo.co.i [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Jayasimhadri, M.; Jang, Kiwan; Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Yi, Soung Soo [Department of Photonics, Silla University, Pusan 617-736 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Pusan 608-737 (Korea, Republic of)

    2010-02-18

    Er{sup 3+}-doped alkaline earth titanium phosphate (RTP) glasses with molar composition of 24 (NaPO{sub 3}){sub 6} + 30 KH{sub 2}PO{sub 4} + 25 TiO{sub 2} + 20 RCl{sub 2} + 1 Er{sub 2}O{sub 3} were prepared by melt quenching technique. Judd-Ofelt intensity parameters ({Omega}{sub 2,4,6}) were determined from the experimental oscillator strengths (f{sub exp}) of absorption bands. From these parameters spontaneous emission probabilities (A{sub R}), luminescence branching ratios ({beta}{sub R}) and radiative lifetimes ({tau}{sub R}) have been calculated. Visible and near infrared photoluminescence spectra has been recorded by exciting the samples at 380 and 970 nm respectively. An intense broad emission band at 1.53 {mu}m was observed corresponding to {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} transition. McCumber theory has been applied to determine the emission cross-sections ({sigma}{sub e}) of the {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} transition using the absorption cross-sections ({sigma}{sub a}). The lifetimes of {sup 4}S{sub 3/2} level were measured for the glasses by exciting the samples at 540 nm wavelength and the quantum efficiencies were also determined.

  3. Reduction Mechanisms of Cu2+-Doped Na2O-Al2O3-SiO2 Glasses during Heating in H2 Gas.

    Science.gov (United States)

    Nogami, Masayuki; Quang, Vu Xuan; Ohki, Shinobu; Deguchi, Kenzo; Shimizu, Tadashi

    2018-01-25

    Controlling valence state of metal ions that are doped in materials has been widely applied for turning optical properties. Even though hydrogen has been proven effective to reduce metal ions because of its strong reducing capability, few comprehensive studies focus on practical applications because of the low diffusion rate of hydrogen in solids and the limited reaction near sample surfaces. Here, we investigated the reactions of hydrogen with Cu 2+ -doped Na 2 O-Al 2 O 3 -SiO 2 glass and found that a completely different reduction from results reported so far occurs, which is dominated by the Al/Na concentration ratio. For Al/Na glass body. For Al/Na > 1, on the other hand, the reduction of Cu 2+ ions occurred simultaneously with the formation of OH bonds, whereas the reduced Cu metal moved outward and formed a metallic film on glass surface. The NMR and Fourier transform infrared results indicated that the Cu 2+ ions were surrounded by Al 3+ ions that formed AlO 4 , distorted AlO 4 , and AlO 5 units. The diffused H 2 gas reacted with the Al-O - ···Cu + units, forming Al-OH and metallic Cu, the latter of which moved freely toward glass surface and in return enhanced H 2 diffusion.

  4. Structural and optical investigations on Dy{sup 3+} doped boro-tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Maheshvaran, K. [Department of Physics, Gandhigram Rural University, Gandhigram 624 302 (India); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram 624 302 (India)

    2011-07-07

    Highlights: > The structural and optical properties have been studied through XRD, FTIR, absorption, luminescence and decay time measurements. > The prepared glasses posses ionic nature and the ionic nature gradually increases when the tellurium di-oxide content increases in the host matrix. > The radiative properties such as radiative transition probability (A), radiative lifetime ({tau}{sub rad}), stimulated emission cross section ({sigma}{sub P}{sup E}) and branching ratios ({beta}{sub R}) are calculated for the {sup 4}F{sub 9/2} {yields} {sup 6}H{sub 15/2}, {sup 6}H{sub 13/2} and {sup 6}H{sub 11/2} transitions. > The decay curve of the {sup 4}F{sub 9/2} level of Dy{sup 3+}:BXTD glasses is well fitted for single exponential. > The stimulated emission cross section for the Dy{sup 3+}:B3TD glass possess higher value and therefore it is suggested for suitable laser applications. - Abstract: Dy{sup 3+} doped boro-tellurite glasses were prepared by following melt quenching technique with the chemical composition (69 - x)H{sub 3}BO{sub 3} + xTeO{sub 2} + 15Mg{sub 2}CO{sub 3} + 15K{sub 2}CO{sub 3} + 1Dy{sub 2}O{sub 3} (where x = 0, 10, 20, 30 and 40 wt%) by varying the tellurium dioxide content. The structural and optical properties have been studied through XRD, FTIR, absorption, luminescence and decay time measurements. The XRD pattern has been used to confirm the amorphous nature of the prepared glasses. The FTIR spectra reveals the presence of B-O vibrations and Te-O stretching modes of TeO{sub 3} and TeO{sub 6} units in the prepared glasses. The UV-vis-NIR absorption spectra were used to calculate the oscillator strength, bonding parameters ({beta}-bar and {delta}) and Judd-Ofelt intensity parameters ({Omega}{sub {lambda},} {lambda} = 2, 4 and 6). The radiative transition probability (A), stimulated emission cross section ({sigma}{sub P}{sup E}) and the experimental, calculated branching ratios ({beta}{sub R}) have been calculated from the luminescence spectra

  5. Effect of concentration variation on 2.0 μm emission of Ho3+-doped SiO2-Al2O3-Na2CO3-SrF2-CaF2 oxyfluorosilicate glasses

    International Nuclear Information System (INIS)

    Gelija, Devarajulu; Borelli, Deva Prasad Raju

    2018-01-01

    The concentration variation of Ho 3+ ion-doped SiO 2 -Al 2 O 3 -Na 2 CO 3 -SrF 2 -CaF 2 glasses has been prepared by conventional melt quenching method. The thermal stability of 1 mol % of Ho 3+ -doped oxyfluorosilicate glass has been calculated using the differential thermal analysis (DTA) spectra. The phenomenological Judd-Ofelt intensity parameters Ω λ (λ = 2, 4 and 6) were calculated for all concentrations of Ho 3+ ions. The luminescence spectra in visible region of Ho 3+ ion-doped glasses were recorded under the excitation wavelength of 452 nm. The spectra consists of several intense emission bands ( 5 F 4 , 5 S 2 ) → 5 I 8 (547 nm), 5 F 3 → 5 I 8 (647 nm), 5 F 5 → 5 I 7 (660 nm) and ( 5 F 4 , 5 S 2 ) → 5 I 7 (750 nm) in the range 500-780 nm. The fluorescence emission at ∝ 2.0 μm ( 5 I 7 → 5 I 8 ) was observed under the excitation of 488 nm Ar-ion laser. The stimulated emission cross section for 5 I 7 → 5 I 8 transition (∝ 2.0 μm) varies from 8.46 to 9.52 x 10 -21 cm 2 , as calculated by the Fuchtbauer-Ladenburg (FL) theory. However, Mc-Cumber theory was used to calculate emission cross section values about 4.24-5.75 x 10 -21 cm 2 for the 5 I 7 → 5 I 8 transition in all concentrations of Ho 3+ -doped oxyfluorosilicate glasses. Therefore, these results reveal that the 0.5 mol % of Ho 3+ -doped oxyfluorosilicate glasses, exhibiting higher emission cross section, has potentially been used for laser applications at ∝ 2.0 μm. (orig.)

  6. Ytterbium-Phosphate Glass for Microstructured Fiber Laser

    Directory of Open Access Journals (Sweden)

    Ryszard Stępień

    2014-06-01

    Full Text Available In the paper, we report on the development of a synthesis and melting method of phosphate glasses designed for active microstructured fiber manufacturing. Non-doped glass synthesized in a P2O5-Al2O3-BaO-ZnO-MgO-Na2O oxide system served as the matrix material; meanwhile, the glass was doped with 6 mol% (18 wt% of Yb2O3, as fiber core. The glasses were well-fitted in relation to optical (refractive index and thermal proprieties (thermal expansion coefficient, rheology. The fiber with the Yb3+-doped core, with a wide internal photonic microstructure for a laser pump, as well as with a high relative hole size in the photonic outer air-cladding, was produced. The laser built on the basis of this fiber enabled achieving 8.07 W of output power with 20.5% slope efficiency against the launched pump power, in single-mode operation M2 = 1.59, from a 53 cm-long cavity.

  7. Molecular adsorption of hydrogen peroxide on N- and Fe-doped titania nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Mohajeri, Afshan, E-mail: amohajeri@shirazu.ac.ir; Dashti, Nasimeh Lari

    2017-06-15

    Highlights: • The stability and electronic properties of N/Fe-doped (TiO{sub 2}){sub n} clusters with n = 5,6 were studied. • The adsorption H{sub 2}O{sub 2} on the surface of doped clusters has been investigated. • This is the first report of H{sub 2}O{sub 2} adsorption onto the (TiO{sub 2}){sub n} cluster in the presence of metal and non-metal dopants. • The effect of N and Fe dopants on interaction strength was studied. - Abstract: Titanium dioxide (titania) nanoparticles have been extensively investigated for photocatalytic applications such as the decomposition and adsorption of pollutant and undesirable compound in air and waste water. In this context, the present article reports the molecular adsorption of hydrogen peroxide on the surface of doped titania clusters. Density functional theory calculations were performed to investigate the structures and electronic properties of two nanoscale (TiO{sub 2}){sub n} clusters (n = 5,6) modified by nitrogen and iron dopants. The relative stability of all possible N-doped and Fe-doped isomers has been compared with each other and with the parent cluster. It was found that the Fe-doped clusters are in general more stable than the N-doped counterparts. Moreover, after N/Fe doping an enhanced in the magnetization of the clusters is observed. In the second part, we have investigated different modes of H{sub 2}O{sub 2} adsorption on the lowest-energy isomers of doped clusters. In almost all the cases, the adsorptions on the doped clusters are found to be less exothermic than on the corresponding undoped parent cluster. Our results highlight the essential role of charge transfer into the interaction between H{sub 2}O{sub 2} and doped (TiO{sub 2}){sub n} clusters, especially for Fe-doped clusters.

  8. Yb3+ sensitized Tm3+ upconversion in tellurite lead oxide glass.

    Science.gov (United States)

    Mohanty, Deepak Kumar; Rai, Vineet Kumar; Dwivedi, Y

    2012-04-01

    Triply ionized thulium/thulium--ytterbium doped/codoped TeO2-Pb3O4 (TPO) glasses have been fabricated by classical quenching method. The upconversion emission spectra in the Tm3+/Tm3+-Yb3+ doped/codoped glasses upon excitation with a diode laser lasing at ∼980 nm has been studied. Effect of the addition of the Yb3+ on the upconversion emission intensity in the visible and near infrared regions of the Tm3+ doped in TPO glass has been studied and the processes involved explored. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Fabrication and characterization of chromium-doped nanophase separated yttria-alumina-silica glass-based optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Debjit; Dhar, Anirban; Das, Shyamal; Paul, Mukul C. [Fiber Optics and Photonics Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India); Kir' yanov, Alexander V. [Centro de Investigaciones en Optica, Guanajuato (Mexico); Bysakh, Sandip [Electron Microscopic Section, Material Characterization Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India)

    2015-08-15

    The basic material and optical properties of chromium-doped nanophase-separated yttria-alumina-silica (YAS) glass based optical preforms and fibers, fabricated through the modified chemical vapor deposition process in conjunction with solution doping technique under suitable thermal annealing conditions are reported. The size of the phase-separated particles within the core of the annealed preform is around 20-30 nm which is significantly reduced to around 5.0 nm in the drawn fiber. The absorption spectra of fibers drawn from the annealed and non-annealed preform samples revealed the presence of Cr{sup 4+}, Cr{sup 3+}, and Cr{sup 6+} specie. Numerically, extinction of absorption drops ∝3-3.5 times for the annealed sample as a result of nano-phase restructuration during annealing process. Intense broadband emission (within 500-800 nm) in case of the annealed preform sample is observed as compared to the non-annealed one and is associated with the presence of Cr{sup 3+} ions in nanostructured environment inside the YAS core glass. The final fibers show broadband emission ranging from 900 to 1400 nm under pumping at 1064 nm which is attributed mainly to the presence of Cr{sup 3+}/Cr{sup 4+} ions. The fabricated fibers seem to be a potential candidate for the development of fiber laser sources for the visible and near-infra ranges and for effective Q-switching units for ∝1-1.1 μm all-fiber ytterbium lasers. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Density-functional study of the structures and properties of holmium-doped silicon clusters HoSi n (n = 3-9) and their anions.

    Science.gov (United States)

    Hou, Liyuan; Yang, Jucai; Liu, Yuming

    2017-04-01

    The structures and properties of Ho-doped Si clusters, including their adiabatic electron affinities (AEAs), simulated photoelectron spectra (PESs), stabilities, magnetic moments, and charge-transfer characteristics, were systematically investigated using four density-functional methods. The results show that the double-hybrid functional (which includes an MP2 correlation component) can accurately predict the ground-state structure and properties of Ho-doped Si clusters. The ground-state structures of HoSi n (n = 3-9) are sextuplet electronic states. The structures of these Ho-doped Si clusters (aside from HoSi 7 ) are substitutional. The ground-state structures of HoSi n - are quintuplet electronic states. Their predicted AEAs are in excellent agreement with the experimental ones. The mean absolute error in the theoretical AEAs of HoSi n (n = 4-9) is only 0.04 eV. The simulated PESs for HoSi n - (n = 5-9) are in good agreement with the experimental PESs. Based on its simulated PES and theoretical AEA, we reassigned the experimental PES of HoSi 4 - and obtained an experimental AEA of 2.2 ± 0.1 eV. The dissociation energies of Ho from HoSi n and HoSi n - (n = 3-9) were evaluated to test the relative stabilities of the clusters. HOMO-LUMO gap analysis indicated that doping the Si clusters with the rare-earth metal atom significantly increases their photochemical reactivity. Natural population analysis showed that the magnetic moments of HoSi n (n = 3-9) and their anions derive mainly from the Ho atom. It was also found that the magnetic moments of Ho in the HoSi n clusters are larger than the magnetic moment of an isolated Ho atom.

  11. Magnetic nanoparticles formed in glasses co-doped with iron and larger radius elements

    Energy Technology Data Exchange (ETDEWEB)

    Edelman, I.; Ivanova, O.; Ivantsov, R.; Velikanov, D.; Zabluda, V. [L.V. Kirensky Institute of Physics SB RAS, 660036 Krasnoyarsk (Russian Federation); Zubavichus, Y.; Veligzhanin, A. [NRC ' Kurchatov Institute,' 123182 Moscow (Russian Federation); Zaikovskiy, V. [Boreskov Institute of Catalysis, Siberian Branch of RAS, 630090 Novosibirsk (Russian Federation); Stepanov, S. [S.I. Vavilov State Optical Institute, St. Petersburg (Russian Federation); Artemenko, A. [ICMCB, UPR CNRS 9048, 33608 Pessac cedex (France); Curely, J.; Kliava, J. [LOMA, UMR 5798 Universite Bordeaux 1-CNRS, 33405 Talence cedex (France)

    2012-10-15

    A new type of nanoparticle-containing glasses based on borate glasses co-doped with low contents of iron and larger radius elements, Dy, Tb, Gd, Ho, Er, Y, and Bi, is studied. Heat treatment of these glasses results in formation of magnetic nanoparticles, radically changing their physical properties. Transmission electron microscopy and synchrotron radiation-based techniques: x-ray diffraction, extended x-ray absorption fine structure, x-ray absorption near-edge structure, and small-angle x-ray scattering, show a broad distribution of nanoparticle sizes with characteristics depending on the treatment regime; a crystalline structure of these nanoparticles is detected in heat treated samples. Magnetic circular dichroism (MCD) studies of samples subjected to heat treatment as well as of maghemite, magnetite, and iron garnet allow to unambiguously assign the nanoparticle structure to maghemite, independently of co-dopant nature and of heat treatment regime used. Different features observed in the MCD spectra are related to different electron transitions in Fe{sup 3+} ions gathered in the nanoparticles. The static magnetization in heat treated samples has non-linear dependence on the magnetizing field with hysteresis. Zero-field cooled magnetization curves show that at higher temperatures the nanoparticles occur in superparamagnetic state with blocking temperatures above 100 K. Below ca. 20 K, a considerable contribution to both zero field-cooled and field-cooled magnetizations occurs from diluted paramagnetic ions. Variable-temperature electron magnetic resonance (EMR) studies unambiguously show that in as-prepared glasses paramagnetic ions are in diluted state and confirm the formation of magnetic nanoparticles already at earlier stages of heat treatment. Computer simulations of the EMR spectra corroborate the broad distribution of nanoparticle sizes found by 'direct' techniques as well as superparamagnetic nanoparticle behaviour demonstrated in the

  12. Magnetic nanoparticles formed in glasses co-doped with iron and larger radius elements

    International Nuclear Information System (INIS)

    Edelman, I.; Ivanova, O.; Ivantsov, R.; Velikanov, D.; Zabluda, V.; Zubavichus, Y.; Veligzhanin, A.; Zaikovskiy, V.; Stepanov, S.; Artemenko, A.; Curély, J.; Kliava, J.

    2012-01-01

    A new type of nanoparticle-containing glasses based on borate glasses co-doped with low contents of iron and larger radius elements, Dy, Tb, Gd, Ho, Er, Y, and Bi, is studied. Heat treatment of these glasses results in formation of magnetic nanoparticles, radically changing their physical properties. Transmission electron microscopy and synchrotron radiation-based techniques: x-ray diffraction, extended x-ray absorption fine structure, x-ray absorption near-edge structure, and small-angle x-ray scattering, show a broad distribution of nanoparticle sizes with characteristics depending on the treatment regime; a crystalline structure of these nanoparticles is detected in heat treated samples. Magnetic circular dichroism (MCD) studies of samples subjected to heat treatment as well as of maghemite, magnetite, and iron garnet allow to unambiguously assign the nanoparticle structure to maghemite, independently of co-dopant nature and of heat treatment regime used. Different features observed in the MCD spectra are related to different electron transitions in Fe 3+ ions gathered in the nanoparticles. The static magnetization in heat treated samples has non-linear dependence on the magnetizing field with hysteresis. Zero-field cooled magnetization curves show that at higher temperatures the nanoparticles occur in superparamagnetic state with blocking temperatures above 100 K. Below ca. 20 K, a considerable contribution to both zero field-cooled and field-cooled magnetizations occurs from diluted paramagnetic ions. Variable-temperature electron magnetic resonance (EMR) studies unambiguously show that in as-prepared glasses paramagnetic ions are in diluted state and confirm the formation of magnetic nanoparticles already at earlier stages of heat treatment. Computer simulations of the EMR spectra corroborate the broad distribution of nanoparticle sizes found by “direct” techniques as well as superparamagnetic nanoparticle behaviour demonstrated in the magnetization

  13. Magnetic nanoparticles formed in glasses co-doped with iron and larger radius elements

    Science.gov (United States)

    Edelman, I.; Ivanova, O.; Ivantsov, R.; Velikanov, D.; Zabluda, V.; Zubavichus, Y.; Veligzhanin, A.; Zaikovskiy, V.; Stepanov, S.; Artemenko, A.; Curély, J.; Kliava, J.

    2012-10-01

    A new type of nanoparticle-containing glasses based on borate glasses co-doped with low contents of iron and larger radius elements, Dy, Tb, Gd, Ho, Er, Y, and Bi, is studied. Heat treatment of these glasses results in formation of magnetic nanoparticles, radically changing their physical properties. Transmission electron microscopy and synchrotron radiation-based techniques: x-ray diffraction, extended x-ray absorption fine structure, x-ray absorption near-edge structure, and small-angle x-ray scattering, show a broad distribution of nanoparticle sizes with characteristics depending on the treatment regime; a crystalline structure of these nanoparticles is detected in heat treated samples. Magnetic circular dichroism (MCD) studies of samples subjected to heat treatment as well as of maghemite, magnetite, and iron garnet allow to unambiguously assign the nanoparticle structure to maghemite, independently of co-dopant nature and of heat treatment regime used. Different features observed in the MCD spectra are related to different electron transitions in Fe3+ ions gathered in the nanoparticles. The static magnetization in heat treated samples has non-linear dependence on the magnetizing field with hysteresis. Zero-field cooled magnetization curves show that at higher temperatures the nanoparticles occur in superparamagnetic state with blocking temperatures above 100 K. Below ca. 20 K, a considerable contribution to both zero field-cooled and field-cooled magnetizations occurs from diluted paramagnetic ions. Variable-temperature electron magnetic resonance (EMR) studies unambiguously show that in as-prepared glasses paramagnetic ions are in diluted state and confirm the formation of magnetic nanoparticles already at earlier stages of heat treatment. Computer simulations of the EMR spectra corroborate the broad distribution of nanoparticle sizes found by "direct" techniques as well as superparamagnetic nanoparticle behaviour demonstrated in the magnetization studies.

  14. Impact effects of gamma irradiation on the optical and FT infrared absorption spectra of some Nd3+-doped soda lime phosphate glasses

    Science.gov (United States)

    Marzouk, M. A.; Elkashef, I. M.; Elbatal, H. A.

    2018-04-01

    The main aim of the present work is to study by two collective optical and FTIR spectral measurements some prepared Nd2O3-doped soda lime phosphate glasses before and after gamma irradiation with dose (9 Mrad). The spectral data reveal two strong UV absorption peaks which are correlated with unavoidable trace iron impurities beside extended additional characteristic bands due to Nd3+ ions. Gamma irradiation on the undoped glass produces slight decrease of the intensity of the UV absorption and the generation of an induced visible band and these effects are controlled with two photochemical reduction of some Fe3+ ions to Fe2+ ions together with the formation of nonbridging oxygen hole center (NBOHC) or phosphorous oxygen hole center (POHC). The impact effect of gamma irradiation on the spectra of Nd2O3-doped glasses is limited due to suggested shielding behavior of neodymium ions. FT-infrared spectra show vibrational modes due to main Q2-Q3 phosphate groups and the response of gamma irradiation of the IR spectra is low and the limited variations are related to suggested changes in some bond angles and bond lengths which cause the observed decrease to the intensities of some IR bands.

  15. Mechanical stability of a Cm-doped celsian glass-ceramic

    International Nuclear Information System (INIS)

    Routbort, J.L.; Offermann, P.; Matzke, H.

    1983-01-01

    Radiation damage due to a α-decay of actinides will modify the material used to store nuclear wastes. For example, ionization-induced processes can fragment the oxide bonds of a glass thereby creating gas bubbles. Phase decomposition, swelling, and disordering of crystalline phases are other possibilities. The self-irradiation damage could also affect the fracture properties of the storage materials. Spontaneous failure and fragmentation of some brittle materials have been observed during storage. The fracture toughness, K/sub Ic/, of a material is of technological and scientific interest. The ease with which a material can be handled and transported depends partially on K/sub Ic/. The resistance to fracture caused by unavoidable thermoelastic stresses is determined by K/sub Ic/. Cracking may, in the presence of water, lead to accelerated material degradation since the amount of leaching is proportional to the available surface area under non-stagnant conditions. This is especially important when the storage time is expected to be very long. From a scientific viewpoint, K/sub Ic/ is a fundamental parameter which characterizes the stress intensity factor at the onset of rapid crack growth resulting in failure. The Hertzian indentation technique was used to measure the fracture properties of a celsian glass-ceramic (B1-3) developed for high-level waste storage. Spontaneous failure due to radiation was not observed, on the contrary, the self-radiation damage caused by recoiling Pu atoms resulting from α-decay of a Cm-244 doped sample to a dose of congruent to 1.5 x 10 19 α-decays/cm 3 increases K/sub Ic/ by at least 25%. This increase in toughness is probably caused by the internal stresses which result from disordering due to the radiation damage. This is confirmed by the broadening of the x-ray spectra as the result of self-radiation

  16. The effect of La2O3 in Tm3+-doped germanate-tellurite glasses for ~2 μm emission

    OpenAIRE

    Peng, Ya-Pei; Yuan, Xinqiang; Zhang, Junjie; Zhang, Long

    2014-01-01

    A germanate-tellurite glass (GeO2-TeO2-K2O-Nb2O5-La2O3) with thulium doping has been investigated for application as a laser material around 2.0 μm regions. Under the 808 nm laser diode pumped, intense 1.8 μm emission is obtained. Based on the absorption spectra, radiative properties are predicted using Judd-Ofelt theory. The maximum value of emission cross-section of Tm3+ around 1.8 μm can reach 1.46 × 10−20 cm2, which indicated that the germanate-tellurite glass may provide high gain as a g...

  17. Helium behaviour in nuclear glasses

    International Nuclear Information System (INIS)

    Fares, T.

    2011-01-01

    The present thesis focuses on the study of helium behavior in R7T7 nuclear waste glass. Helium is generated by the minor actinides alpha decays incorporated in the glass matrix. Therefore, four types of materials were used in this work. These are non radioactive R7T7 glasses saturated with helium under pressure, glasses implanted with 3 He + ions, glasses doped with curium and glasses irradiated in nuclear reactor. The study of helium solubility in saturated R7T7 glass has shown that helium atoms are inserted in the glass free volume. The results yielded a solubility of about 10 16 at. cm -3 atm. -1 . The incorporation limit of helium in this type of glass has been determined; its value amounted to about 2*10 21 at. cm -3 , corresponding to 2.5 at.%. Diffusion studies have shown that the helium migration is controlled by the single population dissolved in the glass free volume. An ideal diffusion model was used to simulate the helium release data which allowed to determine diffusion coefficients obeying to the following Arrhenius law: D = D 0 exp(-E a /kBT), where D 0 = 2.2*10 -2 and 5.4*10 -3 cm 2 s -1 and E a = 0.61 eV for the helium saturated and the curium doped glass respectively. These results reflect a thermally activated diffusion mechanism which seems to be not influenced by the glass radiation damage and helium concentrations studied in the present work (up to 8*10 19 at. g -1 , corresponding to 0.1 at.%). Characterizations of the macroscopic, structural and microstructural properties of glasses irradiated in nuclear reactor did not reveal any impact associated with the presence of helium at high concentrations. The observed modifications i.e. a swelling of 0.7 %, a decrease in hardness by 38 %, an increase between 8 and 34 % of the fracture toughness and a stabilization of the glass structure under irradiation, were attributed to the glass nuclear damage induced by the irradiation in reactor. Characterizations by SEM and TEM of R7T7 glasses implanted

  18. Absorption, fluorescence and second harmonic generation in Cr3+-doped BiB3O6 glasses

    Science.gov (United States)

    Kuznik, W.; Fuks-Janczarek, I.; Wojciechowski, A.; Kityk, I. V.; Kiisk, V.; Majchrowski, A.; Jaroszewicz, L. R.; Brik, M. G.; Nagy, G. U. L.

    2015-06-01

    Synthesis, spectral properties and photoinduced nonlinear optical effects of chromium-doped BiB3O6 glass are studied in the present paper. Absorption, excitation and time resolved luminescence spectra are presented and luminescence decay behavior is discussed. Detailed analysis of the obtained spectra (assignment of the most prominent spectral features in terms of the corresponding Cr3+ energy levels, crystal field strength Dq, Racah parameters B and C) was performed. A weak photostimulated second harmonic generation signal was found to increase drastically due to poling by proton implantation in the investigated sample.

  19. Field-induced cluster spin glass and inverse symmetry breaking enhanced by frustration

    Science.gov (United States)

    Schmidt, M.; Zimmer, F. M.; Magalhaes, S. G.

    2018-03-01

    We consider a cluster disordered model to study the interplay between short- and long-range interactions in geometrically frustrated spin systems under an external magnetic field (h). In our approach, the intercluster long-range disorder (J) is analytically treated to get an effective cluster model that is computed exactly. The clusters follow a checkerboard lattice with first-neighbor (J1) and second-neighbor (J2) interactions. We find a reentrant transition from the cluster spin-glass (CSG) state to a paramagnetic (PM) phase as the temperature decreases for a certain range of h. This inverse symmetry breaking (ISB) appears as a consequence of both quenched disorder with frustration and h, that introduce a CSG state with higher entropy than the polarized PM phase. The competitive scenario introduced by antiferromagnetic (AF) short-range interactions increases the CSG state entropy, leading to continuous ISB transitions and enhancing the ISB regions, mainly in the geometrically frustrated case (J1 =J2). Remarkably, when strong AF intracluster couplings are present, field-induced CSG phases can be found. These CSG regions are strongly related to the magnetization plateaus observed in this cluster disordered system. In fact, it is found that each field-induced magnetization jump brings a CSG region. We notice that geometrical frustration, as well as cluster size, play an important role in the magnetization plateaus and, therefore, are also relevant in the field-induced glassy states. Our findings suggest that competing interactions support ISB and field-induced CSG phases in disordered cluster systems under an external magnetic field.

  20. Study on upconversion luminescence and thermal properties of Ho{sup 3+}/Yb{sup 3+} co-doped La{sub 2}O{sub 3}–TiO{sub 2}–ZrO{sub 2} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Minghui; Wen, Haiqin [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Yu, Huimei [Analysis and Testing Center of Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Ai, Fei [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Shao, Hui [School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212003 (China); Pan, Xiuhong; Tang, Meibo; Yu, Jianding; Gai, Lijun [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Liu, Yan, E-mail: liuyan@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China)

    2016-07-05

    Bulk Ho{sup 3+}/Yb{sup 3+} co-doped La{sub 2}O{sub 3}–TiO{sub 2}–ZrO{sub 2} glass spheres were fabricated by aerodynamic levitation method. High concentration of Yb{sup 3+} ions was successfully doped in glasses. The effects of Yb{sup 3+} concentration on mechanical properties, Raman, absorption spectra, thermal stability, and glass forming ability were studied systematically. Green, red, and infrared emissions centered at 550, 662, and 758 nm were obtained at 980 nm excitation. Yellow light from glass spheres can be easily observed by naked eyes. As Yb{sup 3+} concentration increases, the upconversion luminescence can be improved obviously. The upconversion luminescence mechanism is a two-photon process of energy transfer, excited state absorption, and energy back transfer. The emission intensity can be enhanced in the samples with high Yb{sup 3+} concentration, since the absorption for the incident laser and the energy transfer efficiency are increased, and the nonradiative relaxation probability is reduced. The light color referring to the ratio for red to green emissions can be tuned by Yb{sup 3+} concentration. Ho{sup 3+}/Yb{sup 3+} co-doped La{sub 2}O{sub 3}–TiO{sub 2}–ZrO{sub 2} glasses show promising comprehensive properties and are helpful to speed the application of upconversion luminescence materials. - Highlights: • Ho{sup 3+}/Yb{sup 3+} doped titanate glasses are prepared by containerless processing. • The effects of Yb{sup 3+} on thermal and mechanical properties have been studied. • High concentration of Yb{sup 3+} is favorable to upconversion luminescence. • The mechanisms are energy transfer, excited state absorption, energy back transfer.

  1. Photoinduced electron transfer and solvation in iodide-doped acetonitrile clusters.

    Science.gov (United States)

    Ehrler, Oli T; Griffin, Graham B; Young, Ryan M; Neumark, Daniel M

    2009-04-02

    We have used ultrafast time-resolved photoelectron imaging to measure charge transfer dynamics in iodide-doped acetonitrile clusters I(-)(CH(3)CN)(n) with n = 5-10. Strong modulations of vertical detachment energies were observed following charge transfer from the halide, allowing interpretation of the ongoing dynamics. We observe a sharp drop in the vertical detachment energy (VDE) within 300-400 fs, followed by a biexponential increase that is complete by approximately 10 ps. Comparison to theory suggests that the iodide is internally solvated and that photodetachment results in formation of a diffuse electron cloud in a confined cavity. We interpret the initial drop in VDE as a combination of expansion of the cavity and localization of the excess electron on one or two solvent molecules. The subsequent increase in VDE is attributed to a combination of the I atom leaving the cavity and rearrangement of the acetonitrile molecules to solvate the electron. The n = 5-8 clusters then show a drop in VDE of around 50 meV on a much longer time scale. The long-time VDEs are consistent with those of (CH(3)CN)(n)(-) clusters with internally solvated electrons. Although the excited-state created by the pump pulse decays by emission of a slow electron, no such decay is seen by 200 ps.

  2. Dy:Eu doped CaBAl glasses for white light applications

    Science.gov (United States)

    Lodi, T. A.; Sandrini, M.; Medina, A. N.; Barboza, M. J.; Pedrochi, F.; Steimacher, A.

    2018-02-01

    The combination of Eu3+ and Dy3+ in co-doped glassy materials provides interesting applicability for white light emission devices. In this work, Dy:Eu doped Calcium Boroaluminate (CaBAl) glasses were prepared by conventional melting quenching, with 3 wt% of Dy2O3 and Eu2O3 content varying from 0 to 3 wt%, and results of absorption spectra, photoluminescence and photoluminescence lifetime are discussed in terms of Eu2O3 content. The photoluminescence of the samples was studied under excitation of 365 and 405 nm light source. The 365 nm excitation shows favor to the Dy3+ ion emission. The results of photoluminescence lifetime at 575 nm (Dy3+) shows a decrease due to Eu2O3 addition, which suggests an energy transfer from Dy3+ (donor) to the Eu3+ (acceptor). On the other hand, under excitation of 405 nm, the photoluminescence lifetime at 575 nm (Dy3+) shows no significant changes due to Eu2O3 amount, which indicates that the energy transfer from Dy3+ to Eu3+ (under λexc = 405 nm) is negligible. However, the results of photoluminescence under 405 nm excitation present a white yellowish emission in the CIE diagram, which shifts to red with Eu2O3 addition. The combination of a Blue LED (BL) emission with the emission of the samples was also studied in the CIE diagram, in order to improve light emission and to obtain ideal White Light (WL). The results show that by modifying the emission intensity of BL, it is possible to achieve a route for smart lighting, close to the circadian light cycle.

  3. Enhanced visible light photocatalytic properties of Fe-doped TiO2 nanorod clusters and monodispersed nanoparticles

    International Nuclear Information System (INIS)

    Liu, Y.; Wei, J.H.; Xiong, R.; Pan, C.X.; Shi, J.

    2011-01-01

    In order to get photocatalysts with desired morphologies and enhanced visible light responses, the Fe-doped TiO 2 nanorod clusters and monodispersed nanoparticles were prepared by modified hydrothermal and solvothermal method, respectively. The microstructures and morphologies of TiO 2 crystals can be controlled by restraining the hydrolytic reaction rates. The Fe-doped photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis absorption spectroscopy (UV-vis), N 2 adsorption-desorption measurement (BET), and photoluminescence spectroscopy (PL). The refinements of the microstructures and morphologies result in the enhancement of the specific surface areas. The Fe 3+ -dopants in TiO 2 lattices not only lead to the significantly extending of the optical responses from UV to visible region but also diminish the recombination rates of the electrons and holes. The photocatalytic activities were evaluated by photocatalytic decomposition of formaldehyde in air under visible light illumination. Compared with P25 (TiO 2 ) and N-doped TiO 2 nanoparticles, the Fe-doped photocatalysts show high photocatalytic activities under visible light.

  4. Investigations on luminescence behavior of Er3+/Yb3+ co-doped boro-tellurite glasses

    Science.gov (United States)

    Maheshvaran, K.; Arunkumar, S.; Venkata Krishnaiah, K.; Marimuthu, K.

    2015-01-01

    Er3+/Yb3+ co-doped boro-tellurite glasses with the chemical composition 30TeO2+(24 - x)B2O3 + 15SrO + 10BaO + 10Li2O + 10LiF + 1Er2O3 + xYb2O3 (where x = 0, 0.1, 0.5, 1 and 2 in wt%) have been prepared and their luminescence behavior were studied and reported. Absorption spectral measurements have been used to derive the Judd-Ofelt (JO) intensity parameters from the experimental and calculated oscillator strength values following the JO theory. The various lasing parameters such as stimulated emission cross-section (σEp), experimental and calculated branching ratios (βR) and radiative lifetime (τcal) for the 2H9/2 → 4I15/2, 4S3/2 → 4I15/2 and 4I13/2 → 4I15/2 emission transitions were determined using the JO intensity parameters. The absorption and emission cross-section values for the 4I13/2 → 4I15/2 emission band have been calculated using McCumbar theory and the Gain cross-section for the 4I13/2 → 4I15/2 emission transition also obtained. The upconversion emission mechanism have been studied through various energy transfer processes and the intensity of the upconversion emission transitions are found to increase with the increase in Yb3+ ion concentration. The luminescence decay curves corresponding to the 4I13/2 → 4I15/2 transition of the Er3+/Yb3+ co-doped boro-tellurite glasses under 980 nm excitation wavelength have also been studied and reported in the present work.

  5. Formation of black glass to be used in solar collectors as absorbent and CuO and Fe{sub 2}O{sub 3}'s effect on this glass

    Energy Technology Data Exchange (ETDEWEB)

    Colak, Sadiye Cetinkaya; Birdogan, Selcuk; Aral, Ertunc; Kilic, Gokhan [Eskisehir Osmangazi University, Faculty of Science and Arts, Physics Department, Meselik, 26480 Eskisehir (Turkey)

    2009-06-15

    Solar energy has the highest potential among novel and renewable energies. In order for solar energy to be used it should first be collected. In this study, a black glass was formed by doping silicate glass with Co{sub 3}O{sub 4} at a high concentration to be used as absorbent, and in addition, this black glass was also doped with CuO and Fe{sub 2}O{sub 3}. Optical absorptions, electrical conductivities, thermal diffusion coefficients, SEM images and EDX spectra of all glasses were obtained and effects of transition metal oxides on glass were examined. (author)

  6. Tunable white light generation from Ce{sup 3+}-Tb{sup 3+}-Mn{sup 2+} doped metaphosphate glass for LED and solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Debarati; Biswas, K.; Balaji, S. [CSIR-Network of Institute for Solar Energy (NISE) (India); Glass Division, Glass Science and Technology Section, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S.C. Mullick Road, Kolkata 700032 (India); Annapurna, K., E-mail: annapurnak@cgcri.res.in [CSIR-Network of Institute for Solar Energy (NISE) (India); Glass Division, Glass Science and Technology Section, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S.C. Mullick Road, Kolkata 700032 (India)

    2017-03-15

    Alkali free Ba-Al metaphosphate glasses doped with Ce, Tb and Mn are prepared and their concentration is tuned to achieve white light emission for production of LEDs and luminescent concentrator for Si-PV applications. The occurrence of a redox reaction among dopant ions (Ce{sup 4+}, Tb{sup 3+}→Ce{sup 3+}, Tb{sup 4+}) is observed from the absorption spectra while there is no change in oxidation state of Mn{sup 2+} ions. This is confirmed from ESR studies. Emission spectra indicated effective downshifting of radiation from near visible to green and red region of the spectrum. On tuning the concentration of Tb{sup 3+} and Mn{sup 2+}, bright white light emission (CIE coordinates: x=3.32, y=3.33) corresponding to CCT of 5900 K is obtained. This white light produced has been further tuned to different hues by varying the excitation wavelength of this triply doped glass.

  7. Broadband ˜2μm emission in Tm3+/Ho3+ co-doped TeO2-WO3-La2O3 glass

    Science.gov (United States)

    Li, Kefeng; Wang, Guonian; Zhang, Junjie; Hu, Lili

    2010-10-01

    In this work, we report the infrared emission properties of Tm 3+/Ho 3+ co-doped TeO 2-WO 3-La 2O 3 (TWL) glass under 808 nm laser excitation. A broad and flat emission from 1600 to 2200 nm corresponding to the Tm 3+ ( 3F 4→ 3H 6) and Ho 3+ ( 5I 7→ 5I 8) emissions is observed. The full width at half maximum (FWHM) of this broadband increases up to a value of ˜370 nm with an optimal [Tm 3+]/[Ho 3+] concentration ratio. The energy transfer processes of Tm 3+↔Ho 3+ are analyzed and the results show that energy transfer between Tm 3+ and Ho 3+ plays an important role in the luminescence mechanism. The OH - influence on the broadband emission is also discussed. These results indicate that Tm 3+-Ho 3+ co-doped TWL glass could be a promising material for widely tunable laser or broadband amplifier applications.

  8. Doping influence by some transition elements on the irradiation effects in nuclear waste glasses; Influence du dopage par certains elements de transition sur les effets d'irradiation dans des verres d'interet nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Florent, Olivier

    2006-06-15

    High-level waste glasses are submitted to auto-irradiation. Modelling it using external irradiations on simple glasses revealed defects production and non negligible structural changes. This thesis aims at determining the impact of a more complex composition on these effects, especially the influence of adding polyvalent transition metals. Silicate, soda-lime and alumino-borosilicate glasses are doped with different iron, chromium and manganese concentrations then {beta} irradiated at different doses up to 10{sup 9} Gy. Non doped glasses show an increase of their density and polymerisation coupled with a molecular oxygen and point defects production. Adding 0.16 mol% Fe decreases the amount of defects by 85 % and all irradiation effects. A Fe{sup 3+} reduction is also observed by EPR, optical absorption and indirectly by Raman spectroscopy. A higher than 0.32 mol% Fe concentration causes complete blockage of the evolution of polymerisation, density and defect production. The same results are obtained on chromium or manganese doped glasses. An original in situ optical absorption device shows the quick decrease of Fe{sup 3+} amount to a 25 % lower level during irradiation. Stopping irradiation causes a lower decrease of 65 %, suggesting a dynamic (h{sup 0}/e-) consuming equilibrium. He{sup +} and Kr{sup 3+} ions and {gamma} irradiated glasses tend to confirm these phenomena for all kind of irradiation with electronic excitations. (author)

  9. Application of glass particles doped by Zn(+2) as an antimicrobial and atoxic compound in LLDPE and HDPE.

    Science.gov (United States)

    Santos, M F; Machado, C; Tachinski, C G; Júnior, J F; Piletti, R; Peterson, M; Fiori, M A

    2014-06-01

    This study demonstrates the potential application of glass particles doped with Zn(+2) (GZn) as an atoxic, antimicrobial additive when used in conjunction with high density polyethylene (HDPE) and linear low density polyethylene (LLDPE) polymers. Toxicity tests demonstrated that these modified glass particles were nontoxic to human cells, and atomic absorption analyses demonstrated the migration of ionic species in quantities less than 2.0ppm for both the HDPE/GZn and LLDPE/GZn compounds. Microbiological tests demonstrated the antimicrobial effect of the pure GZn compound as well as the polymeric HDPE/GZn and LLDPE/GZn compounds. In addition, at percentages of GZn higher than 2.00wt.% and at a time of 4h, the bactericidal performance is excellent and equal for both polymeric compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Optical properties of Nd3+ doped barium lithium fluoroborate glasses for near-infrared (NIR) emission

    Science.gov (United States)

    Mariselvam, K.; Arun Kumar, R.; Suresh, K.

    2018-04-01

    The neodymium doped barium lithium fluoroborate (Nd3+: BLFB) glasses with the chemical composition (70-x) H3BO3 - 10 Li2CO3 - 10 BaCO3- 5 CaF2-5 ZnO - x Nd2O3 (where x = 0.05, 0.1, 0.25, 0.5, 1, 2 in wt %) have been prepared by the conventional melt quenching technique and characterised through optical absorption, near infrared emission and decay-time measurements. The x-ray diffraction studies confirm the amorphous nature of the prepared glasses. The optical absorption spectra and emission spectra were recorded in the wavelength ranges of 190-1100 nm. The optical band gap (Eg) and Urbach energy (ΔE) values were calculated from the absorption spectra. The Judd-Ofelt intensity parameters were determined from the systematic analysis of the absorption spectrum of neodymium ions in the prepared glasses. The emission spectra exhibited three prominent peaks at 874, 1057, 1331 nm corresponding to the 4F3/2 → 4I9/2, 11/2, 13/2 transitions levels respectively in the near infrared region. The emission intensity of the 4F3/2 → 4I11/2 transition increases with the increase in neodymium concentration up to 0.5 wt% and the concentration quenching mechanism was observed for 1 wt% and 2 wt% concentrations. The lifetime of the 4F3/2 level was found to decrease with increasing Nd3+ ion concentration. The nature of energy transfer process was a single exponential curve which was studied for all the glasses and analysed.

  11. Physical and optical properties of calcium sulfate ultra-phosphate glass-doped Er2O3

    Science.gov (United States)

    Aliyu, Aliyu Mohammed; Hussin, R.; Deraman, Karim; Ahmad, N. E.; Danmadami, Amina M.; Yamusa, Y. A.

    2018-03-01

    The influence of erbium on physical and optical properties of calcium sulfate ultra-phosphate glass was investigated using conventional melt quench process. Selected samples of composition 20CaSO4 (80 - x) P2O5- xEr2O3 with 0.1 ≤x ≤ 0.9 mol.% were prepared and assessed. X-ray diffraction (XRD) techniques were used to confirm the amorphous nature of the said samples. The structural units of phosphate-based glass were assessed from Raman spectra as ultra-(Q3), meta-(Q2), pyro-(Q1) and orthophosphate (Q0) units. Depolymerization process of the glasses was testified for higher calcium oxide content and UV-visible for optical measurement. Thermal analysis have been investigated by means of thermogravimetric analysis. The results show the decomposition of materials in the temperature range of 25∘C-1000∘C. Er3+ absorption spectra were measured in the range of 400-1800nm. PL measurement was carried out in order to obtain the excitation and emission spectra of the samples. The emission spectra excited at 779nm comprises of 518nm, 550nm and 649nm of transition 4F9/2, 4S3/2 and 2H11/2 excited states to 4I15/2 ground state. In physical properties, the density calculated using Archimedes method is inversely proportional to molar volume with increase in Er3+ ions. Optical bandgap (Eg) were determined using Tauc’s plots for direct transitions where Eg (direct) decreases with increase in erbium content. The refractive index increases with decreasing molar volume; this may have a tendency for larger optical bandgap. The result obtained from the glass matrix indicates that erbium oxide-doped calcium sulfate ultra-phosphate may give important information for wider development of functional glasses.

  12. STRUCTURE FEATURES OF THE SODIUM-GERMANATE GLASSES DOPED WITH YTTERBIUM ERBIUM RETRIEVED FROM RAMAN SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    I. M. Sevastianova

    2016-09-01

    Full Text Available Subject of Research.The paper deals with study of Raman spectra and luminescence spectra in the visible region of the sodium-germanate glass: 49 GeO2 – 13 Na2O – 27 Yb2O3 – 11 La2O3 - 0,25 Er2O3 and presents research results. In addition, this glass is doped with 5 mol% of the following components MgO, BaO, Al2O3, PbO, Nb2O5, TiO2, SiO2, P2O5 in order to study the effect of these additives on the structure of the glassy matrix and the anti-Stokes luminescence spectra of erbium ions. Method. Raman scatteringspectra were recorded by Renishaw inVia Raman Microscope. Excitation source is a helium neon laser (λ= 633 nm with power equal to 50Wt. Anti-Stokes luminescence of erbium ions was registered in spectral region of 450–750 nm at room temperature (excitation laser wavelength is 975 nm, power is 1Wt. Main Results. It was shown that the structure of the initial glass does not change with the introduction of niobium as Nb2O5 in any coordination plays a role of network forming, building a single mixed grid with tetrahedrons [GeO4]. Introduction of the second glass former P2O5 leads to loosening germanate structure due to the appearance of the phosphate sublattice. This leads to a redistribution of the relative intensity of up-conversion luminescence bands with maxima at 540 and 670 nm compared with the initial glass. Introduction of additives PbO, MgO, Al2O3, TiO2 results in a multicenter structure. In case of titanium oxide addition it leads to a change in the relative intensities of the erbium luminescence.

  13. Spectroscopic properties and energy transfer analysis of Tm3+-doped BaF2-Ga2O3-GeO2-La2O3 glass.

    Science.gov (United States)

    Yu, Shenglei; Yang, Zhongmin; Xu, Shanhui

    2010-05-01

    This paper reports on the spectroscopic properties and energy transfer analysis of Tm(3+)-doped BaF(2)-Ga(2)O(3)-GeO(2)-La(2)O(3) glasses with different Tm(2)O(3) doping concentrations (0.2, 0.5, 2.0, 2.5, 3.0, 3.5, 3.5, 4.0 wt%). Mid-IR fluorescence intensities in the range of 1,300 nm-2,200 nm have been measured when excited under an 808 nm LD for all the samples with the same pump power. Energy level structure and Judd-Ofelt parameters have been calculated based on the absorption spectra of Tm(3+), cross-relaxation rates and multi-phonon relaxation rates have been estimated with different Tm(2)O(3) doping concentrations. The maximum fluorescence intensity at around 1.8 mum has been obtained in Tm(2)O(3)-3 wt% sample and the maximum value of calculated stimulated emission cross-section of Tm(3+) in this sample is about 0.48 x 10(-20) cm(2) at 1,793 nm, and there is not any crystallization peak in the DSC curve of this sample, which indicate the potential utility of Tm(3+)-doped BaF(2)-Ga(2)O(3)-GeO(2)- La(2)O(3) glass for 2.0-microm optical fiber laser.

  14. Effect of heat treatment on the structural and optical properties of tellurite glasses doped erbium

    Energy Technology Data Exchange (ETDEWEB)

    Jlassi, I., E-mail: ifa.jlassi@fst.rnu.tn [Laboratoire de Physico-Chimie des Materiaux Mineraux et leurs Applications, Centre National de Recherches en Sciences des Materiaux, B.P. 95 Hammam-Lif 2050 (Tunisia); Elhouichet, H. [Laboratoire de Physico-Chimie des Materiaux Mineraux et leurs Applications, Centre National de Recherches en Sciences des Materiaux, B.P. 95 Hammam-Lif 2050 (Tunisia); Departement de Physique, Faculte des Sciences de Tunis, Campus ElManar 2092 (Tunisia); Hraiech, S.; Ferid, M. [Laboratoire de Physico-Chimie des Materiaux Mineraux et leurs Applications, Centre National de Recherches en Sciences des Materiaux, B.P. 95 Hammam-Lif 2050 (Tunisia)

    2012-03-15

    The 75TeO{sub 2}-20ZnO-4Na{sub 2}CO{sub 3}-1Er{sub 2}O{sub 3} (in molar ratio) glass system was prepared by the conventional melt-quenching method. As such, the samples prepared were investigated by differential scanning calorimetry (DSC), X-ray diffractrometry (XRD), Raman spectroscopy and infrared luminescence. DSC analyses were carried out on our glass at different heating rates between 5 and 20 Degree-Sign C/min. The result of the annealing temperature on the spectroscopic properties of Er{sup 3+} in tellurite glasses was discussed. The activation energy, for surface crystallization, was determined graphically from a Kissinger-type plot and had a value about 897.2 kJ/mol. Crystalline phases for both {alpha}-TeO{sub 2}, {gamma}-TeO{sub 2} and Zn{sub 2}Te{sub 3}O{sub 8} system were determined by the XRD method and were confirmed by Raman spectroscopy characterizations after heat treatment. The effect of heat treatment on absorption spectra and luminescence properties in the tellurite glass was also investigated. With heat treatment, the ultraviolet absorption edge presented a redshift. As a result, the Judd-Ofelt (J-O) intensity parameters ({Omega}{sub 2}, {Omega}{sub 4}, {Omega}{sub 6}) were determined. The spontaneous emission probabilities of some relevant transitions, the branching ratio and the radiative lifetimes of several excited states of Er{sup 3+} were predicted using intensity J-O parameters. The near infrared emission that corresponds to Er{sup 3+}: {sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2} can be significantly enhanced after heat treatment. Notably, it is found that the luminescence lifetime in the present system is much longer than that in most other glasses and glass ceramics. A comparative study on luminescence performance suggests that the obtained glass ceramic is a promising material for Er{sup 3+} doped fiber amplifiers. - Highlights: Black-Right-Pointing-Pointer Tellurite glasses were prepared by conventional melt-quenching method. Black

  15. Structure and crystallization of SiO2 and B2O3 doped lithium disilicate glasses from theory and experiment.

    Science.gov (United States)

    Erlebach, Andreas; Thieme, Katrin; Sierka, Marek; Rüssel, Christian

    2017-09-27

    Solid solutions of SiO 2 and B 2 O 3 in Li 2 O·2SiO 2 are synthesized and characterized for the first time. Their structure and crystallization mechanisms are investigated employing a combination of simulations at the density functional theory level and experiments on the crystallization of SiO 2 and B 2 O 3 doped lithium disilicate glasses. The remarkable agreement of calculated and experimentally determined cell parameters reveals the preferential, kinetically controlled incorporation of [SiO 4 ] and [BO 4 ] at the Li + lattice sites of the Li 2 O·2SiO 2 crystal structure. While the addition of SiO 2 increases the glass viscosity resulting in lower crystal growth velocities, glasses containing B 2 O 3 show a reduction of both viscosities and crystal growth velocities. These observations could be rationalized by a change of the chemical composition of the glass matrix surrounding the precipitated crystal phase during the course of crystallization, which leads to a deceleration of the attachment of building units required for further crystal growth at the liquid-crystal interface.

  16. Thermal analyses, spectral characterization and structural interpretation of Nd3+/Er3+ ions co-doped TeO2-ZnCl2 glasses system

    Science.gov (United States)

    Ahmed, Kasim F.; Ibrahim, Saeed O.; Sahar, Md. R.; Mawlud, Saman Q.; Khizir, Hersh A.

    2017-09-01

    The Nd3+/Er3+ ions co-doped in the system of zinc-tellurite with the composition of (70-2x)TeO2-30ZnCl2-xNd2O3-xEr2O3 concentration from 1.0 to 3.0 mol% (x=1, 2 and 3) glasses were prepared by using conventional melt-quenching technique. The amorphous nature of the glass been confirmed by using X-RAY Diffraction Spectroscopy. Thermal characteristic were determined using a DTA. The obtained results discussed in terms of the glass structure. The glass structure studied by means of FTIR. Seven significant vibrational peaks around 471, 687, 742, 768, 1632, 2833 and 3378 cm-1 which correspond to the structural bonding of the glass are observed in a range of 400-4000cm-1. The peaks observed are consistent with the stretching and bending vibrations of the Te-O, TeO4 trigonal bipyramids, TeO3 trigonal pyramids, Te-O-Te and OH linkages respectively.

  17. Electronic and magnetic properties of 3d transition metal-doped strontium clusters: Prospective magnetic superatoms

    International Nuclear Information System (INIS)

    Chauhan, Vikas; Sen, Prasenjit

    2013-01-01

    Highlights: • Structural, electronic and magnetic properties of TM-Sr clusters are studied using DFT methods. • CrSr 9 and MnSr 10 have enhanced stability in the CrSr n and MnSrn series. • These two clusters behave as magnetic superatoms. • A qualitative understanding of the magnetic coupling between two superatom units is offered. • Reactivity of these superatoms to molecular oxygen also studied. - Abstract: Structural, electronic and magnetic properties of 3d transition metal doped strontium clusters are studied using first-principles electronic structure methods based on density functional theory. Clusters with enhanced kinetic and thermodynamic stability are identified by studying their hardness, second order energy difference and adiabatic spin excitation energy. CrSr 9 and MnSr 10 are found to have enhanced stability. They retain their structural identities in assemblies, and are classified as magnetic superatoms. A qualitative understanding of the magnetic coupling between two cluster units is arrived at. Reactivity of these superatoms with O 2 molecule is also studied. Prospects for using these magnetic superatoms in applications are discussed

  18. CuO, MnO2 and Fe2O3 doped biomass ash as silica source for glass production in Thailand

    Directory of Open Access Journals (Sweden)

    N. Srisittipokakun

    Full Text Available In this research, glass productions from rice husk ash (RHA and the effect of BaO, CuO, MnO2 and Fe2O3 on physical and optical properties were investigated. All properties were compared with glass made from SiO2 using same preparations. The results show that a higher density and refractive index of BaO, CuO, MnO2 and Fe2O3 doped in RHA glasses were obtained, compared with SiO2 glasses. The optical spectra show no significant difference between both glasses. The color of CuO glasses show blue from the absorption band near 800 nm (2B1g → 2B2g due to Cu2+ ion in octahedral coordination with a strong tetragonal distortion. The color of MnO2 glasses shows brown from broad band absorption at around 500 nm. This absorption band is assigned to a single allowed 5Eg → 5T2g transition which arises from the Mn3+ ions (3d4 configuration in octahedral symmetry. The yellow color derives from F2O3 glass due to the homogeneous distribution of Fe3+ (460 nm and Fe2+ (1050 nm ions in the glass matrices. Glass production from RHA is possible and is a new option for recycling waste from biomass power plant systems and air pollution reduction. Keywords: Rice husk ash, Glass, Optical, Physical

  19. Mid-infrared emissions of Pr{sup 3+}-doped GeS{sub 2}–Ga{sub 2}S{sub 3}–CdI{sub 2} chalcohalide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chunfeng [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Guo, Haitao, E-mail: guoht_001@opt.ac.cn [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Xu, Yantao; Hou, Chaoqi; Lu, Min [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); He, Xin [School of Applied Physics and Materials, Wuyi University, Jiangmen, Guangdong 529020 (China); Wang, Pengfei; Li, Weinan [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Peng, Bo, E-mail: bpeng@opt.ac.cn [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China)

    2014-12-15

    Graphical abstract: ∼4.6 μm mid-infrared fluorescence emission from Pr{sup 3+} in the sulfide glass is successfully observed at room temperature excited by a 2.01 μm Tm{sup 3+}:YAG ceramic laser system. - Highlights: • Serial Pr{sup 3+}-doped GeS{sub 2}–Ga{sub 2}S{sub 3}–CdI{sub 2} chalcohalide glasses were synthesized. • ∼4.6 μm mid-infrared fluorescence from Pr{sup 3+} was observed at room temperature. • The compositional dependence of luminescence properties was studied. • Radiative properties have been determined using the Judd–Ofelt theory. - Abstract: For elucidation of the glass composition’s influence on the spectroscopic properties in the chalcohalide system and the discovery of a new material for applications in mid-infrared fiber-lasers, a serial Pr{sup 3+}-doped (100 − x)(0.8GeS{sub 2}·0.2Ga{sub 2}S{sub 3})xCdI{sub 2} (x = 5, 10, 15 and 20) chalcohalide glasses were prepared. ∼4.6 μm mid-infrared fluorescence emission from Pr{sup 3+} in the sulfide glass is successfully observed at room temperature excited by a 2.01 μm Tm{sup 3+}:YAG ceramic laser system, and the effective line-width of fluorescence band is 106–227 nm. Intense compositional dependence of mid-infrared emissions is found. The radiative rates of Pr{sup 3+} ions in these glasses were calculated by using the Judd–Ofelt theory.

  20. The effect of La2O3 in Tm3+-doped germanate-tellurite glasses for ~2 μm emission

    Science.gov (United States)

    Peng, Ya-Pei; Yuan, Xinqiang; Zhang, Junjie; Zhang, Long

    2014-06-01

    A germanate-tellurite glass (GeO2-TeO2-K2O-Nb2O5-La2O3) with thulium doping has been investigated for application as a laser material around 2.0 μm regions. Under the 808 nm laser diode pumped, intense 1.8 μm emission is obtained. Based on the absorption spectra, radiative properties are predicted using Judd-Ofelt theory. The maximum value of emission cross-section of Tm3+ around 1.8 μm can reach 1.46 × 10-20 cm2, which indicated that the germanate-tellurite glass may provide high gain as a good medium for efficient 1.8 μm laser system.