Luminescence properties of Yb:Nd:Tm:KY{sub 3}F{sub 10} nanophosphor and thermal treatment effects

Energy Technology Data Exchange (ETDEWEB)

Gomes, Laércio, E-mail: lgomes@ipen.br [Centro de Lasers e Aplicações, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Butantã, P.O. Box 11049, São Paulo, SP o5422-970 (Brazil); Linhares, Horácio Marconi da Silva M.D. [Centro de Lasers e Aplicações, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Butantã, P.O. Box 11049, São Paulo, SP o5422-970 (Brazil); Ichikawa, Rodrigo Uchida; Martinez, Luis Gallego [Departamento de Ciências dos Materiais, Instituto de Pesquisas Energéticas e Nucleares (Brazil); Ranieri, Izilda Marcia [Centro de Lasers e Aplicações, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Butantã, P.O. Box 11049, São Paulo, SP o5422-970 (Brazil)

2015-01-15

In this work, we present the spectroscopic properties of KY{sub 3}F{sub 10} (KY3F) nanocrystals activated with thulium and codoped with ytterbium and neodymium ions. The most important processes that lead to the thulium upconversion emissions in the blue region were identified. A time-resolved luminescence spectroscopy technique was employed to measure the luminescence decays and to determine the most important mechanisms involved in the upconversion process that populates {sup 1}G{sub 4} (Tm{sup 3+}) excited states. Analysis of the energy-transfer processes dynamics using selective pulsed-laser excitations in Yb:Nd:Tm, Nd:KY3F nanocrystals shows that the direct energy transfer from Nd{sup 3+} to Tm{sup 3+} ions is the mechanism responsible for the 78% of the blue upconversion luminescence in the Yb:Nd:Tm:KY3F when compared with the Yb:Nd:Tm:KY3F bulk crystal for an laser excitation at 802 nm. An investigation of the {sup 1}G{sub 4} level luminescence kinetic of Tm{sup 3+} in Yb/Nd/Tm system revealed that the luminescence efficiency ({sup 1}G{sub 4}) starts with a very low value (0.38%) for the synthesized nanocrystal (as grown) and strongly increases to 97% after thermal treatment at 550 °C for 6 h under argon flow. As a consequence of the thermal treatment at T=550 °C, the contributions of the (Nd×Tm) (Up{sub 1}) and (Nd×Yb×Tm) (Up{sub 2}) upconversion processes to the {sup 1}G{sub 4} luminescence are 33% (Up{sub 1}) and 67% for Up{sub 2}. Up{sub 2} process represented by Nd{sup 3+} ({sup 4}F{sub 3/2})→Yb{sup 3+} ({sup 2}F{sub 7/2}) followed by Yb{sup 3+} ({sup 2}F{sub 5/2})→Tm ({sup 3}H{sub 4})→Tm{sup 3+} ({sup 1}G{sub 4}) was previously reported as the main mechanism to produce the blue luminescence in Yb:Nd:Tm:YLiF{sub 4} and KY{sub 3}F{sub 10} bulk crystals. Results of X-ray diffraction analysis of nanopowder using the Rietveld method reveled that crystallite sizes remain unchanged (12–14 nm) after thermal treatments with T≤400 °C, while the

Sequential growth of sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles for photodynamic therapy

Energy Technology Data Exchange (ETDEWEB)

Peng, Huang-Yong; Ding, Bin-Bin; Ma, Yin-Chu [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Sun, Shi-Qi [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Tao, Wei [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Guo, Yan-Chuan [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Guo, Hui-Chen, E-mail: ghch-2004@hotmail.com [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Yang, Xian-Zhu, E-mail: yangxz@hftu.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Hai-Sheng, E-mail: shqian@hfut.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China)

2015-12-01

Graphical abstract: The monodisperse elliptical NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles have been synthesized successfully by a facile sequential growth process, which can be used as transducer for photodynamic therapy of cancer cells. - Highlights: • The NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb nanoparticles have been fabricated successfully. • The as-prepared nanoparticles show strong fluorescence excited at 980 or 808 nm. • The nanoparticles were transferred into the aqueous phase via a facile process. • Photosensitizers were loaded into the composites for photodynamic therapy. - Abstract: Upconversion (UC) nanostructures have attracted much interest for their extensive biological applications. In this work, we describe a sequential synthetic route to prepare sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles. The as-prepared products were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM, JEM 2100F), respectively. The as-prepared core–shell nanoparticles of NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb are composed of elliptical nanoparticles with a length of 80 nm and width of 42 nm, which show efficient upconversion fluorescence excited at 808 nm indicating the formation of core–shell–shell sandwiched nanostructures. In addition, the as-prepared sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles also show strong upconversion fluorescence excited at 980 nm. Amphiphilic mPEG{sub 2k}-b-PEBEP{sub 6K} copolymers (denoted as PPE) were chosen to transfer these hydrophobic UCNPs into the aqueous phase for biological application. In vitro photodynamic therapy of cancer cells show that the viability of cells incubated with the nanoparticles loaded with MC 540 was significantly lower as compared to the nanoparticles without photosensitizers exposed to NIR laser.

Effect of [Li]/[Nb] ratio on composition and defect structure of Zr:Yb:Tm:LiNbO3 crystals

Science.gov (United States)

Liu, Chunrui; Dai, Li; Wang, Luping; Shao, Yu; Yan, Zhehua; Xu, Yuheng

2018-04-01

Zr:Yb:Tm:LiNbO3 crystals with various [Li]/[Nb] ratios (0.946, 1.05, 1.20 and 1.38) were grown by the Czochralski technique. Distribution coefficients of Zr4+, Yb3+ and Tm3+ ions were analyzed by the inductively coupled plasma-atomic emission spectrometer (ICP-AES). The influence of [Li]/[Nb] ratio on the composition and defect structure of Zr:Yb:Tm:LiNbO3 crystals was investigated by X-ray diffraction and IR transmission spectrum. The results show that as the [Li]/[Nb] ratio increases in the melt, the distribution coefficients of Yb3+ and Tm3+ ions both increase while that of Zr4+ ion deceases. When the [Li]/[Nb] ratio increases to 1.20 in the melt, Zr:Yb:Tm:LiNbO3 crystal is nearly stoichiometric. In addition, when the [Li]/[Nb] ratio reaches up to 1.38, NbLi4+ are completely replaced and Li+ starts to impel the Zr4+, Yb3+ and Tm3+ into the normal Li sites.

Up-conversion mechanisms in Er{sup 3+} doped YbAG crystals

Energy Technology Data Exchange (ETDEWEB)

Kaczkan, Marcin; Borowska, Maja [Institute of Microelectronics and Optoelectronics PW, Warsaw (Poland); Malinowski, Michal [Institute of Microelectronics and Optoelectronics PW, Warsaw (Poland); Institute of Electronic Materials Technology, Warsaw (Poland); Lukasiewicz, Tadeusz; Kolodziejak, Katarzyna [Institute of Electronic Materials Technology, Warsaw (Poland)

2009-07-15

Up-conversion phenomena leading to the red, green and violet emissions in erbium doped ytterbium-aluminum garnet (YbAG) are investigated. Absorption and emission spectra and luminescence dynamics from various excited states of YbAG:Er{sup 3+} were registered. The low temperature absorption spectra were used to determine Stark levels energies of Er{sup 3+} ion in the investigated host. Emissions from the high lying excited states {sup 2}G{sub 9/2}, {sup 4}S{sub 3/2} and {sup 4}F{sub 9/2} of Er{sup 3+} were characterized under pulsed multi-photon IR excitation in the region of wavelength corresponding to the strong {sup 2}F{sub 7/2} {yields} {sup 2}F{sub 5/2} absorption transition of Yb{sup 3+} ions. Using the rate equations formalism the dynamics of the observed emissions were modeled. From the comparison of the measured and calculated decays the energy transfer rates between Yb{sup 3+} and Er{sup 3+} ions were evaluated. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Influence of Er3+/Yb3+ concentration ratio on the down-conversion and up-conversion luminescence and lifetime in GdVO4:Er3+/Yb3+ microcrystals

Directory of Open Access Journals (Sweden)

Gavrilović T.V.

2015-01-01

Full Text Available In this paper, we studied the effects of Er3+/Yb3+ concentration ratio on structural, morphological and luminescence properties of GdVO4:Er3+/Yb3+ green phosphors prepared by a high-temperature solid state method. The samples with different concentrations (between 0.5 to 2 mol% of dopant Er3+ emitting ions and different concentrations (between 5 to 20 mol% of sensitizer ions (Yb3+ were studied. The phosphors were characterized by the X-ray diffraction (XRD, scanning electron microscopy (SEM and photoluminescence spectroscopy. For all samples, XRD diffraction patterns confirmed a formation of a pure GdVO4 phase, while the SEM showed that the materials are comprised of chunks of deformed particles with an average diameter ranging from approximately 2 μm to 8 μm. Both, down-conversion and up-conversion emission spectra of GdVO4:Er3+/Yb3+ samples, under near UV and IR excitations, exhibit two strong emission bands in the green spectral region at 525 nm and 552 nm wavelengths corresponding to 2H11/2 →4I15/2 and 4S3/2 → 4I15/2 electronic transitions of Er3+ ions. The intensity of the green emission was changed by changing the Er3+/Yb3+ concentration ratio. This dual-mode luminescence makes these materials ideal as green phosphors for a wide variety of applications in the fields of bioanalysis and biomedical. [Projekat Ministarstva nauke Republike Srbije, br. 45020 i br. 172056

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

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.

Spectral-converting behaviors of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} doped YOCl phosphors

Energy Technology Data Exchange (ETDEWEB)

Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

2014-01-25

Highlights: • Luminescent materials of YOCl:Er,Yb were prepared using NH{sub 4}Cl flux. • Interesting spectral-converting behaviors were observed in the phosphors. • 980 or 1550 nm diode laser was irradiated for up-converting study. • A multi-photon process in the phosphors was calculated. -- Abstract: Luminescent materials composed of Y{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m = 0.001–0.1, n = 0.005–0.1) were prepared via a solid-state reaction using NH{sub 4}Cl flux. Photoluminescence spectra, the dependence of the luminescent intensity as a function of Er{sup 3+} content, and their CIE coordinates of the Er{sup 3+}-doped layered YOCl compounds were also investigated under near-ultraviolet (NUV) and visible lights. The spectral up-converting properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} in YOCl phosphors were elucidated under 980 and 1550 nm diode laser irradiations. This up-conversion emission spectra and the pump power dependence versus emission intensity observed in the Y{sub 0.9}Er{sub 0.1}OCl up-conversion phosphors gave rise to one- and two-photon processes. The up-conversion mechanism of Er{sup 3+} and Yb{sup 3+} ions in YOCl was described by a schematic energy-level diagram. Through the use of these up-conversion luminescent materials, the desired emitting lights throughout the orange and red regions of the spectra were achieved.

Optical properties of silica-coated Y2O3:Er,Yb nanoparticles in the presence of polyvinylpyrrolidone

International Nuclear Information System (INIS)

Fujii, Kunio; Kitamoto, Yoshitaka; Hara, Masahiko; Odawara, Osamu; Wada, Hiroyuki

2014-01-01

The optical properties of polyvinylpyrrolidone (PVP)-adsorbed and silica-coated Y 2 O 3 :Er,Yb nanoparticles produced by using PVP were studied for potential bio-applications of upconversion nanoparticles. We utilized PVP to better disperse Y 2 O 3 :Er,Yb nanoparticles in solution and to prepare silica-coated Y 2 O 3 :Er,Yb nanoparticles. The fluorescent intensity of PVP-adsorbed Y 2 O 3 :Er,Yb nanoparticles was 1.25 times higher than non-adsorbed Y 2 O 3 :Er,Yb nanoparticles, which was probably due to surface defects in Y 2 O 3 :Er,Yb nanoparticles being covered by the PVP. However, the fluorescent intensity of silica-coated Y 2 O 3 :Er,Yb nanoparticles decreased as silica layer thickness increased. This could be ascribed to the higher vibrational energy of PVP than that of the silica structure. Therefore, the optimum silica layer thickness is important in bio-applications to avoid deterioration of the optical properties of Y 2 O 3 :Er,Yb nanoparticles. - Highlights: • We prepared the silica-coated upconversion nanoparticles by using PVP. • We showed that PVP played an important role in coating nanoparticles. • PL intensity of silica-coated nanoparticles decreased as silica layer thickness increased

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 ...

Color Tunable and Upconversion Luminescence in Yb-Tm Co-Doped Yttrium Phosphate Inverse Opal Photonic Crystals.

Science.gov (United States)

Wang, Siqin; Qiu, Jianbei; Wang, Qi; Zhou, Dacheng; Yang, Zhengwen

2016-04-01

For this paper, YPO4: Tm, Yb inverse opals with the photonic band gaps at 475 nm and 655 nm were prepared by polystyrene colloidal crystal templates. We investigated the influence of photonic band gaps on the Tm-Yb upconversion emission which was in the YPO4: Tm Yb inverse opal photonic crystals. Comparing with the reference sample, significant suppression of both the blue and red upconversion luminescence of Tm3+ ions were observed in the inverse opals. The color purity of the blue emission was improved in the inverse opal by the suppression of red upconversion emission. Additionally, mechanism of upconversion emission in the inverse opal was discussed. We believe that the present work will be valuable for not only the foundational study of upconversion emission modification but also the development of new optical devices in upconversion lighting and display.

Nanosecond Q-switched operation of coupled Yb and Tm fibre lasers

Energy Technology Data Exchange (ETDEWEB)

Tsang, Yuen H [Laser Photonics Research Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Qamar, Fadi [Laser Photonics Research Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); King, Terence A [Laser Photonics Research Group, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Ko, Do-Kyeong [Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-Gu, Gwangju 500-712 (Korea, Republic of); Lee, Jongmin [Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-Gu, Gwangju 500-712 (Korea, Republic of)

2005-05-07

A small scale coupled Yb-silica and Tm-silica fibre laser system is described with output at 1.9 {mu}m and with Q-switching using an acousto-optic modulator and also by mechanical optical modulation. The Yb-fibre laser pump source exhibited strong self-pulsation with high-intensity pulses due to stimulated Brillouin scattering. But regular Q-switched pulses were generated from the Tm-fibre laser with an energy of {approx}2.4 {mu}J and duration (FWHM) of {approx}280 ns for modulation frequencies of 1-20 kHz when using acousto-optic modulation. The main effects that limit the Q-switched pulse peak power are the onset of gain-switched pulsing during the low-Q state and strong pump excited state absorption.

Spectroscopic properties of Yb3+ and Er3+ ions in heavy metal glasses

International Nuclear Information System (INIS)

Pisarski, Wojciech A.; Grobelny, Lukasz; Pisarska, Joanna; Lisiecki, Radoslaw; Ryba-Romanowski, Witold

2011-01-01

Highlights: → Heavy metal glasses doubly doped with Yb 3+ and Er 3+ were examined. → NIR luminescence at about 1530 nm and green and red up-conversion spectra were detected. → The unusual large spectral linewidth nearly close to 110 nm for 4 I 13/2 - 4 I 15/2 transition of Er 3+ ions in Yb-Er co-doped lead borate glass was obtained. → Long-lived NIR luminescence was detected in lead germanate glass. → The NIR luminescence and up-conversion phenomena strongly depend on stretching vibrations of glass host. - Abstract: Selected heavy metal glasses containing Yb 3+ and Er 3+ ions have been studied. Near-infrared luminescence spectra at 1.53 μm and up-conversion spectra of Er 3+ ions were registered under excitation of Yb 3+ ions by 975 nm diode laser line. The luminescence bands correspond to 4 I 13/2 - 4 I 15/2 (NIR), 4 S 3/2 - 4 I 15/2 (green) and 4 F 9/2 - 4 I 15/2 (red) transitions of Er 3+ , respectively. The optical transitions of rare earth ions have been examined as a function of glass host. The unusual large spectral linewidth nearly close to 110 nm for 4 I 13/2 - 4 I 15/2 transition of Er 3+ ions in Yb-Er co-doped lead borate glass was obtained, whereas long-lived NIR luminescence at 1.53 μm was detected in lead germanate glass. The NIR luminescence and up-conversion phenomena strongly depend on stretching vibrations of glass host, which was confirmed by FT-IR spectroscopy.

Photoluminescence characterization of porous YAG: Yb{sup 3+}–Er{sup 3+} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Desirena, H., E-mail: hagdes@cio.mx [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico); Diaz-Torres, L.A. [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico); Rodríguez, R.A. [Centro Universitario de Los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico); Meza, O. [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48, Centro Historico 72570, Puebla (Mexico); Salas, P. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Apartado Postal 1-1010, Querétaro 76000, Querétaro México (Mexico); Angeles-Chávez, C. [Instituto Mexicano del Petróleo, Ciudad México, D.F. 07730, México (Mexico); Tobar, E.H.; Castañeda-Contreras, J. [Centro Universitario de Los Lagos, Universidad de Guadalajara, Lagos de Moreno, Jalisco (Mexico); De la Rosa, E., E-mail: elder@cio.mx [Centro de Investigaciones en Óptica, A. P. 1-948, León 37150, Guanajuato (Mexico)

2014-09-15

Yb{sup 3+}/Er{sup 3+} codoped yttrium aluminium garnet (YAG) porous nanocrystals were prepared by glycolate method assisted with poly-vinyl alcohol (PVA) and urea. The typical cubic structure for YAG was confirmed from XRD with crystallite average size of ∼40 nm, calculated from Scherrer formula and corroborated by TEM. Strong green and red upconversion emissions are observed readily with the naked eyes, and the color coordinates were obtained from emission spectra. A theoretical model to calculate CIE coordinate as a function of donor (Yb{sup 3+}) and acceptors (Er{sup 3+}) concentration is proposed. The eye-safe near infrared emitted signal and fluorescence lifetime were also measured and results show lifetime as large as 8.5 ms. The maximum energy transfer efficiency from Yb{sup 3+} to Er{sup 3+} was 72% for 20 mol% of Yb{sub 2}O{sub 3}. The proposed mechanisms for signal emitted are explained in terms of direct and energy back transfer processes, and cross relaxation. - Highlights: • Strong upconversion emission were observed in YAG:Er{sup 3+}–Yb{sup 3+} samples. • Color emission can be tuned from green to red by choosing properly the Yb{sup 3+} concentration. • The experimental colour coordinates match very well with the proposed theoretical model. • Cross relaxation and energy back transfer are mainly responsible for the red emission. • Fluorescence lifetime of {sup 4}I{sub 13/2} level increase with the Yb{sup 3+} concentration.

Luminescence dosemeter of the Al{sub 2}O{sub 3}:Er,Yb

Energy Technology Data Exchange (ETDEWEB)

Goncalves, Katia A.; Ventieri, Alexandre; Bitencourt, Jose F.S. [Universidade de Sao Paulo (EP/USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Eletrica; Mittani, Juan C.R.; Tatumi, Sonia H. [Faculdade de Tecnologia de Sao Paulo (CEETEPS), SP (Brazil)

2011-07-01

The present work deals with the thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) properties of {alpha}-Al{sub 2}O{sub 3}: Er,Yb obtained by sol gel process. Nanocrystals formations composed by Er{sub 2}O{sub 3}, Yb{sub 2}O{sub 3} and Yb{sub 3}Al{sub 5}O{sub 12} were observed by TEM images, EDS, electron beam diffraction and RXD, located at the surface of the alumina grains. The sample codoped with 1mol% of Er and 2 mol% of Yb supplied the best results for TL and OSL responses. The growth of the intensity of dosimetric TL peak at 205 deg C was linear with gamma radiation doses and the same behavior was observed in OSL growth curve. The luminescence fading of the sample after a dose of 5 Gy was found initially for a period of 30 days and minimum detectable dose measured for TL was 60.78 mGy and for OSL was 13.09 mGy. (author)

Energy transfer processes in Yb{sup 3+}-Tm{sup 3+} co-doped sodium alumino-phosphate glasses with improved 1.8 {mu}m emission

Energy Technology Data Exchange (ETDEWEB)

Camargo, Andrea S S de; Terra, Idelma A A; Nunes, Luiz Antonio de O; Li, M Siu [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, 13560-970, Sao Carlos-SP (Brazil)], E-mail: andreasc@ifsc.usp.br

2008-06-25

Sodium alumino-phosphate glasses co-doped with Yb{sup 3+} and Tm{sup 3+} ions have been prepared with notably low OH{sup -} content, and characterized from the viewpoint of their spectroscopic properties. In these glasses, Yb{sup 3+} acts as an efficient sensitizer of excitation energy at 0.98 {mu}m-which can be provided by high power and low cost diode lasers, and subsequently undergoes non-resonant energy transfer to Tm{sup 3+} ions ({sup 2}F{sub 5/2}, {sup 3}H{sub 6} {yields} {sup 2}F{sub 7/2}, {sup 3}H{sub 5}). Through this process, the emitting level {sup 3}F{sub 4} is rapidly populated, generating improved emission at 1.8 {mu}m ({sup 3}F{sub 4} {yields} {sup 3}H{sub 6}). In order to guarantee the efficiency of such favorable energy transfer, energy losses via multiphonon decay, Yb-Yb radiative trapping, and non-radiative transfer to OH{sup -} groups were evaluated, and minimized when possible. The dipole-dipole energy transfer microscopic parameters corresponding to Yb{sup 3+} {yields} Tm{sup 3+}, Yb{sup 3+} {yields} Yb{sup 3+} and Tm{sup 3+} {yields} Tm{sup 3+} transfers, calculated by the Foerster-Dexter model, are C{sub Yb-Tm} = 2.9 x 10{sup -40} cm{sup 6} s{sup -1}, C{sub Yb-Yb} = 42 x 10{sup -40} cm{sup 6} s{sup -1} and C{sub Tm-Tm} = 43 x 10{sup -40} cm{sup 6} s{sup -1}, respectively.

Theoretical modelling of dual-wavelength pumped Yb3+–Tm3+ co-doped silica fibre laser

International Nuclear Information System (INIS)

Fu, Yuqing; Chen, Jianguo

2010-01-01

Numerical simulations have, for the first time to our knowledge, been carried out to characterize the Yb 3+ –Tm 3+ co-doped silica fibre laser (YTFL), defined by a fibre grating and an end mirror, by using the rate equations, which take into consideration both the energy transfer processes from Yb 3+ to Tm 3+ ions and the cross-relaxation processes among different Tm 3+ ions. A dual-wavelength pumping scheme with one at 805 nm and the other at 975 nm is used to pump the YTFL. We have investigated the wavelength-dependent output power of the YTFL, from 1750 to 2200 nm, which takes its maximum output power at ∼ 1800 nm. The effect of the cross-relaxation processes in the Tm 3+ -doped silica fibre laser has been studied. The results indicate that these processes are beneficial to the laser and should be considered in the theoretical modelling. The influence of the Yb 3+ concentration on the characteristics of the YTFL has also been analysed and the results show that Yb 3+ dopants can improve the output power and slope efficiency of the laser

Spectral variations and energy transfer processes on both Er 3+ ion concentration and excitation densities in Yb 3+-Er 3+ codoped LaF3 materials

International Nuclear Information System (INIS)

Zhang Jisen; Qin Weiping; Zhao Dan; Degejihu; Zhang Jishuang; Wang Yan; Cao Chunyan

2007-01-01

In comparison with the up-conversion spectra of Yb 3+ -Er 3+ codopded systems reported previously, the interesting intensity changes of up-conversion luminescence between the violet, the blue, the green and the red on the both Er 3+ ion concentration and excitation density with 978 nm laser diodes as an excitation source were observed in Yb 3+ -Er 3+ codopded LaF 3 powders. In order to clarify the change mechanisms, the up-conversion spectra of LaF 3 : 10 mol% Yb 3+ , 0.5 mol% Er 3+ and LaF 3 : 10 mol% Yb 3+ , 1 mol% Er 3+ were investigated and the results indicated that the cross-relaxation processes between Er 3+ ions and the thermal population of the 2 H 11/2 level play significant roles

Microwave hydrothermal synthesis and upconversion properties of Yb3+/Er3+ doped YVO4 nanoparticles.

Science.gov (United States)

Kshetri, Yuwaraj K; Regmi, Chhabilal; Kim, Hak-Soo; Lee, Soo Wohn; Kim, Tae-Ho

2018-05-18

Yb 3+ and Er 3+ doped YVO 4 (Yb 3+ /Er 3+ :YVO 4 ) nanoparticles with highly efficient near-infrared to visible upconversion properties have been synthesized by microwave hydrothermal process. Uniform-sized Yb 3+ /Er 3+ :YVO 4 nanoparticles were synthesized within 1 h at 140 °C which is relatively faster than the conventional hydrothermal process. Under 980 nm laser excitation, strong green and less strong red emissions are observed which are attributed to 2 H 11/2 , 4 S 3/2 to 4 I 15/2 and 4 F 9/2 to 4 I 15/2 transitions of Er 3+ respectively. The emission intensity is found to depend strongly on the concentration of Yb 3+ . The quadratic dependence of upconversion intensity on the excitation power indicates that the upconversion process is governed by two-photon absorption process.

Microwave hydrothermal synthesis and upconversion properties of Yb3+/Er3+ doped YVO4 nanoparticles

Science.gov (United States)

Kshetri, Yuwaraj K.; Regmi, Chhabilal; Kim, Hak-Soo; Wohn Lee, Soo; Kim, Tae-Ho

2018-05-01

Yb3+ and Er3+ doped YVO4 (Yb3+/Er3+:YVO4) nanoparticles with highly efficient near-infrared to visible upconversion properties have been synthesized by microwave hydrothermal process. Uniform-sized Yb3+/Er3+:YVO4 nanoparticles were synthesized within 1 h at 140 °C which is relatively faster than the conventional hydrothermal process. Under 980 nm laser excitation, strong green and less strong red emissions are observed which are attributed to 2H11/2, 4S3/2 to 4I15/2 and 4F9/2 to 4I15/2 transitions of Er3+ respectively. The emission intensity is found to depend strongly on the concentration of Yb3+. The quadratic dependence of upconversion intensity on the excitation power indicates that the upconversion process is governed by two-photon absorption process.

A broadening temperature sensitivity range with a core-shell YbEr@YbNd double ratiometric optical nanothermometer

Science.gov (United States)

Marciniak, L.; Prorok, K.; Francés-Soriano, L.; Pérez-Prieto, J.; Bednarkiewicz, A.

2016-02-01

The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle based optical nano-thermometer under single ~808 nm wavelength photo-excitation from around ΔT = 150 K to over ΔT = 300 K (150-450 K). Such engineered nanocrystals are suitable for remote optical temperature measurements in technology and biotechnology at the sub-micron scale.The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle

A comprehensive phononics of phonon assisted energy transfer in the Yb3+ aided upconversion luminescence of Tm3+ and Ho3+ in solids

International Nuclear Information System (INIS)

Debnath, Radhaballabh; Bose, Saptasree

2015-01-01

The theory of phonon assisted energy transfer is being widely used to explain the Yb 3+ ion aided normal and upconversion emission of various rare earth ions in different Yb 3+ co-doped solids. The reported phonon dynamics in many of these studies are either incomplete or erroneous. Here we report Yb 3+ aided upconversion luminescence properties of Tm 3+ and Ho 3+ in (Yb 3+ /Tm 3+ ) and (Yb 3+ /Ho 3+ ) co-doped two BaO–tellurite glasses and explain their phononics in the light of Dexter's theory by proposing a comprehensive scheme. The approach is valid for other systems of different phonon structures. - Highlights: • Yb 3+ aided upconversion luminescence properties of Tm 3+ and Ho 3+ in (Yb 3+ /Tm 3+ ) and (Yb 3+ /Ho 3+ ) co-doped two BaO–tellurite glasses, are reported. • Phonon assisted energy transfer in these systems are explained in the light of Dexter's theory by proposing a comprehensive scheme of phononics. • The approach is valid for other systems of different phonon structures

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.

Fabrication and evaluation of chitosan/NaYF4:Yb3+/Tm3+ upconversion nanoparticles composite beads based on the gelling of Pickering emulsion droplets

International Nuclear Information System (INIS)

Yan, Huiqiong; Chen, Xiuqiong; Shi, Jia; Shi, Zaifeng; Sun, Wei; Lin, Qiang; Wang, Xianghui; Dai, Zihao

2017-01-01

The rare earth ion doped upconversion nanoparticles (UCNPs) synthesized by hydrophobic organic ligands possess poor solubility and low fluorescence quantum yield in aqueous media. To conquer this issue, NaYF 4 :Yb 3+ /Tm 3+ UCNPs, synthesized by a hydrothermal method, were coated with F127 and then assembled with chitosan to fabricate the chitosan/NaYF 4 :Yb 3+ /Tm 3+ composite beads (CS/NaYF 4 :Yb 3+ /Tm 3+ CBs) by Pickering emulsion system. The characterization results revealed that the as-synthesized NaYF 4 :Yb 3+ /Tm 3+ UCNPs with an average size of 20 nm exhibited spherical morphology, high crystallinity and characteristic emission upconversion fluorescence with an overall blue color output. The NaYF 4 :Yb 3+ /Tm 3+ UCNPs were successfully conjugated on the surface of chitosan beads by the gelling of emulsion droplets. The resultant CS/NaYF 4 :Yb 3+ /Tm 3+ CBs showed good upconversion luminescent property, drug-loading capacity, release performance and excellent biocompatibility, exhibiting great potentials in targeted drug delivery and tissue engineering with potential tracking capability and lasting release performance. - Highlights: • NaYF 4 :Yb 3+ /Tm 3+ UCNPs were coated by F127 to improve aqueous dispersibility. • NaYF 4 :Yb 3+ /Tm 3+ UCNPs were assembled with chitosan to fabricate the composite beads (CMs). • Pickering emulsions stabilized by UCNPs exhibited uniform and satisfactory emulsion droplets. • The CMs prepared by the gelling of emulsion droplet preserved upconversion luminescent property. • The resultant CMs showed good drug-loading capacity, release performance and biocompatibility.

Synthesis, Structural Characterization and Up-Conversion Luminescence Properties of NaYF4:Er3+,Yb3+@MOFs Nanocomposites

Science.gov (United States)

Giang, Lam Thi Kieu; Marciniak, Lukasz; Huy, Tran Quang; Vu, Nguyen; Le, Ngo Thi Hong; Binh, Nguyen Thanh; Lam, Tran Dai; Minh, Le Quoc

2017-10-01

This paper describes a facile synthesis of NaYF4:Er3+,Yb3+ nanoparticles embraced in metal-organic frameworks (MOFs), known as NaYF4:Er3+, Yb3+@MOFs core/shell nanostructures, by using iron(III) carboxylate (MIL-100) and zeolitic imidazolate frameworks (ZIF-8). Morphological, structural and optical characterization of these nanostructures were investigated by field emission-scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, and up-conversion luminescence measurements. Results showed that spherical-shaped NaYF4:Er3+,Yb3+@MIL-100 nanocomposites with diameters of 150-250 nm, and rod-shaped NaYF4:Er3+,Yb3+@ZIF-8 nanocomposites with lengths of 300-550 nm, were successfully synthesized. Under a 980-nm laser excitation at room temperature, the NaYF4:Er3+,Yb3+@MOFs nanocomposites exhibited strong up-conversion luminescence with two emission bands in the green part of spectrum at 520 nm and 540 nm corresponding to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+ ions, respectively, and a red emission band at 655 nm corresponding to the 4F9/2 → 4I15/2 transition of Er3+ ions. The above properties of NaYF4:Er3+,Yb3+@MOFs make them promising candidates for applications in biotechnology.

Investigation of upconversion luminescence in antimony–germanate double-clad two cores optical fiber co-doped with Yb{sup 3+}/Tm{sup 3+} and Yb{sup 3+}/Ho{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Zmojda, J.; Kochanowicz, M.; Miluski, P.; Dorosz, J. [Bialystok University of Technology, Wiejska 45 Street, 15-351 Bialystok (Poland); Pisarska, J.; Pisarski, W.A. [Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice (Poland); Dorosz, D., E-mail: d.dorosz@pb.edu.pl [Bialystok University of Technology, Wiejska 45 Street, 15-351 Bialystok (Poland)

2016-02-15

In the paper double-clad optical fiber with two off-set cores co-doped with 1Yb{sub 2}O{sub 3}–0.1Tm{sub 2}O{sub 3} and 1Yb{sub 2}O{sub 3}–0.5Ho{sub 2}O{sub 3} has been investigated. Antimony–germanate glass was melted as a matrix for active cores. The concentration of lanthanides and their ratio have been optimized to achieve maximum upconversion emission intensity at 478 nm ({sup 1}G{sub 4}→{sup 3}H{sub 6}) and 650 nm ({sup 1}G{sub 4}→{sup 3}F{sub 4}) in glasses doped with Tm{sup 3+} ions and 545 nm and 655 nm, corresponding to the {sup 5}F{sub 5}→{sup 5}I{sub 8} and {sup 5}F{sub 4}→{sup 5}I{sub 8} transitions in holmium ions. The energy transfer efficiency in glasses used as optical fiber cores was η{sub Tm}=56% (0.1 mol% Tm{sub 2}O{sub 3}) and η{sub Ho}=85% (0.5 mol% Ho{sub 2}O{sub 3}), respectively. As a result of excitation of the fabricated optical fiber (λ{sub exc}=976 nm), a UC luminescence spectra was obtained. Superposition of three emission bands at the wavelengths of 481 nm (Tm{sup 3+}: blue), 545 nm (Ho{sup 3+}:green) and 665 nm (Tm{sup 3+}, Ho{sup 3+}: red) from two separated cores was measured. Influence of fiber length and excitation power on the color coordinates (CIE-1931) have been also investigated. - Highlights: • Antimony-germanate glasses co-doped with Yb{sup 3+}/Tm{sup 3+} and Yb{sup 3+}/Ho{sup 3+} were presented. • UC luminescence in double-clad, two off-set core co-doped with Yb{sup 3+}/Tm{sup 3+} and Yb{sup 3+}/Ho{sup 3+} optical fiber was presented. • The chromatic coordinates shift in the blue region at CIE scheme as a function of pump power and length of optical fiber was observed.

Tunable multicolor and white-light upconversion luminescence in Yb3+/Tm3+/Ho3+ tri-doped NaYF4 micro-crystals.

Science.gov (United States)

Lin, Hao; Xu, Dekang; Teng, Dongdong; Yang, Shenghong; Zhang, Yueli

2015-09-01

NaYF4 micro-crystals with various concentrations of Yb(3+) /Tm(3+) /Ho(3+) were prepared successfully via a simple and reproducible hydrothermal route using EDTA as the chelating agent. Their phase structure and surface morphology were studied using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD patterns revealed that all the samples were pure hexagonal phase NaYF4. SEM images showed that Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 were hexagonal micro-prisms. Upconversion photoluminescence spectra of Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 micro-crystals with various dopant concentrations under 980 nm excitation with a 665 mW pump power were studied. Tunable multicolor (purple, purplish blue, yellowish green, green) and white light were achieved by simply adjusting the Ho(3+) concentration in 20%Yb(3+)/1%Tm(3+)/xHo(3+) tri-doped NaYF4 micro-crystals. Furthermore, white-light emissions could be obtained using different pump powers in 20%Yb(3+)/1%Tm(3+)/1%Ho(3+) tri-doped NaYF4 micro-crystals at 980 nm excitation. The pump power-dependent intensity relationship was studied and relevant energy transfer processes were discussed in detail. The results suggest that Yb(3+)/Tm(3+) Ho(3+) tri-doped NaYF4 micro-crystals have potential applications in optoelectronic devices such as photovoltaic, plasma display panel and white-light-emitting diodes. Copyright © 2014 John Wiley & Sons, Ltd.

Fabrication and evaluation of chitosan/NaYF4:Yb3+/Tm3+ upconversion nanoparticles composite beads based on the gelling of Pickering emulsion droplets.

Science.gov (United States)

Yan, Huiqiong; Chen, Xiuqiong; Shi, Jia; Shi, Zaifeng; Sun, Wei; Lin, Qiang; Wang, Xianghui; Dai, Zihao

2017-02-01

The rare earth ion doped upconversion nanoparticles (UCNPs) synthesized by hydrophobic organic ligands possess poor solubility and low fluorescence quantum yield in aqueous media. To conquer this issue, NaYF 4 :Yb 3+ /Tm 3+ UCNPs, synthesized by a hydrothermal method, were coated with F127 and then assembled with chitosan to fabricate the chitosan/NaYF 4 :Yb 3+ /Tm 3+ composite beads (CS/NaYF 4 :Yb 3+ /Tm 3+ CBs) by Pickering emulsion system. The characterization results revealed that the as-synthesized NaYF 4 :Yb 3+ /Tm 3+ UCNPs with an average size of 20nm exhibited spherical morphology, high crystallinity and characteristic emission upconversion fluorescence with an overall blue color output. The NaYF 4 :Yb 3+ /Tm 3+ UCNPs were successfully conjugated on the surface of chitosan beads by the gelling of emulsion droplets. The resultant CS/NaYF 4 :Yb 3+ /Tm 3+ CBs showed good upconversion luminescent property, drug-loading capacity, release performance and excellent biocompatibility, exhibiting great potentials in targeted drug delivery and tissue engineering with potential tracking capability and lasting release performance. Copyright © 2016 Elsevier B.V. All rights reserved.

1.8 μm luminescent properties and energy transfer of Yb{sup 3+}/Tm{sup 3+} co-doped α-NaYF{sub 4} single crystals

Energy Technology Data Exchange (ETDEWEB)

Feng, Zhigang [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Xia, Haiping, E-mail: hpxcm@nbu.edu.cn [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Wang, Cheng; Zhang, Zhixiong; Jiang, Dongsheng; Zhang, Jian; He, Shinan; Tang, Qingyang; Sheng, Qiguo; Gu, Xuemei; Zhang, Yuepin [Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang, 315211 (China); Chen, Baojiu [Department of Physics, Dalian Maritime University, Dalian, Liaoning Province, 116026 (China); Jiang, Haochuan, E-mail: jianghaochuan@nimte.ac.cn [Ningbo Institute of Materials Technology and Engineering, The Chinese Academy of Sciences, Ningbo, Zhejiang, 315211 (China)

2016-09-25

This paper reports on successful preparation of α-NaYF{sub 4} single crystals co-doped with ∼1.9 mol% Tm{sup 3+} and various concentrations (3.85 mol%, 7.69 mol%, 11.54 mol%, 15.38 mol%) of Yb{sup 3+} by using a flux-Bridgman method. The fluorescence decay curve was measured to investigate the luminescent properties of the Yb{sup 3+}/Tm{sup 3+} co-doped α-NaYF{sub 4}, and the energy transfer process from Yb{sup 3+} to Tm{sup 3+}; the J-O intensity parameters of Tm{sup 3+} were further calculated and analyzed according to the absorption spectra. Results show that, an intense 1.8 μm emission was achieved with Yb{sup 3+} as sensitizer for Tm{sup 3+} in the α-NaYF{sub 4} single crystal under the excitation of 980 nm LD (Laser Diode) because of the strong energy transfer from Yb{sup 3+} to Tm{sup 3+}. The maximum emission intensity at 1.8 μm is obtained at about 15.38 mol% doping concentration of Yb{sup 3+} when the concentration of Tm{sup 3+} ions is fixed at ∼1.90 mol% in the current research. Moreover, the calculated maximum value of emission cross section at 1.8 μm is 1.63 × 10{sup −20} cm{sup 2} for 3.85 mol% Yb{sup 3+}/1.9 mol% Tm{sup 3+} sample, and the obtained energy transfer rate (W{sub ET}) and energy transfer efficiency (η) are 1543 s{sup −1} and 83.8%, respectively. Our analysis of the fluorescence dynamics indicates that electric dipole-dipole interaction is dominant for the energy transfer from Yb{sup 3+} ions to Tm{sup 3+} ions by using Inokuti-Hirayama’s model. - Highlights: • The Tm{sup 3+}/Yb{sup 3+} co-doped α-NaYF{sub 4} single crystals were grown by Bridgman method. • The 1.8 μm emission intensity is obtained at 15.38 mol% Yb{sup 3+}/1.90 mol% Tm{sup 3+} sample. • The maximum value of emission cross section at 1.8 μm is 1.63 × 10{sup −20} cm{sup 2}. • The energy transfer rate is 1543 s{sup −1} and energy transfer efficiency is 83.8%. • The physical mechanism for energy transfer from Yb{sup 3+} to Tm{sup 3+} ions

Spectroscopic investigations of OH- influence on near-infrared fluorescence quenching of Yb3+/Tm3+ co-doped sodium-metaphosphate glasses

International Nuclear Information System (INIS)

Terra, I.A.A.; Camargo, A.S.S. de; Terrile, M.C.; Nunes, L.A.O.

2008-01-01

Energy transfer processes were studied in two sets of Yb 3+ and Tm 3+ co-doped sodium-metaphosphate glasses, prepared in air and nitrogen atmospheres. Using Foerster, Dexter, and Miyakawa theoretical models, the energy transfer parameters were calculated. The main ion-ion energy transfer processes analyzed were energy migration among Yb 3+ ions, cross-relaxations between Yb 3+ and Tm 3+ ions, and interactions with OH - radicals. The results indicated that Yb→Tm energy transfer favors 1.8 μm emissions, and there is no evidence of concentration quenching up to 2% Tm 2 O 3 doping. As expected, samples prepared in nitrogen atmosphere present higher fluorescence quantum efficiency than those prepared in air, and this feature is specially noted in the near-infrared region, where the interaction with the OH - radicals is more pronounced

Bifunctional NaYF4:Er3+/Yb3+ submicron rods, implemented in quantum dot sensitized solar cell(Conference Presentation)

Science.gov (United States)

Guerrero, J. Pablo; Cerdán Pasarán, Andrea; López-Luke, Tzarara; Ramachari, D.; Esparza, Diego; De la Rosa Cruz, Elder; Romero Arellano, Victor Hugo

2016-09-01

In this work are presented the results obtained with solar cells sensitized with quantum dots of cadmium sulphide (CdS) incorporating luminescent materials (NaYF4:Yb/Er). The study revealed that through using a bifunctional layer of NaYF4:Yb/Er submicron rods, the infrared radiation is absorbed in 980nm to generate luminescence in the visible region to 530nm, under the UP-conversion process, in the same way simultaneously, NaYF4:Yb/Er layer causes scattering toward the quantum dots, the emission and scattering generated by this material is reabsorbed by the QD-CdS, and these in turn are absorbing in its range of solar radiation absorption, Thus generates an increase in the electron injection into the semiconductor of TiO2. The results of a cell incorporating NaYF4: Yb/Er at 0.07M shown photoconversion efficiencies of 3.39% improving efficiency with respect to the reference solar cell without using NaYF4: Yb/Er of 1.99%. The obtained values of current and voltage showed a strong dependence of the percentage of NaYF4 Yb/Er, and the mechanism of incorporation of this material.

Photon up-converting (Yb,Er){sub 2}O{sub 3} thin films by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Tuomisto, Minnea [Department of Chemistry, University of Turku (Finland); Doctoral Programme in Physical and Chemical Sciences, University of Turku Graduate School (UTUGS), Turku (Finland); Giedraityte, Zivile; Karppinen, Maarit [Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University (Finland); Lastusaari, Mika [Department of Chemistry, University of Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf), Turku (Finland)

2017-06-15

We report up-converting (Yb,Er){sub 2}O{sub 3} thin films grown with the atomic layer deposition (ALD) technique. The films are crystalline and show a homogeneous morphology with a roughness less than 1 nm for 40 nm thick films. High-intensity near-infrared (NIR) to green and red two-photon up-conversion emission is obtained with 974 nm excitation through an absorption by Yb{sup 3+}, followed by a Yb{sup 3+}-Er{sup 3+} energy transfer and emission from Er{sup 3+}. The ALD technique promises to be excellent for producing up-converting films for many applications such as near-infrared radiation absorbing layers for solar cells and sensors in point-of-care biomedical diagnostics. Schematic picture of the ALD-grown (Yb,Er){sub 2}O{sub 3} thin film including the up-conversion emission spectra. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

NIR to visible frequency upconversion in Er3+ and Yb3+ codoped ZrO2 phosphor

International Nuclear Information System (INIS)

Singh, Vijay; Kim, Sang Hwan; Rai, Vineet Kumar; Al-Shamery, Katharina; Haase, Markus

2013-01-01

The ZrO 2 :Er 3+ codoped with Yb 3+ phosphor powders have been prepared by the urea combustion route. Formation of the compounds ZrO 2 :Er 3+ and ZrO 2 :Er 3+ , Yb 3+ was confirmed by XRD. The frequency upconversion emissions in the green and red regions upon excitation with a CW diode laser at ∝978 nm are reported. Codoping with Yb 3+ enhances the emission intensities of the triply ionized erbium in the green and red spectral regions by about ∝130 and ∝820 times respectively. The emission properties of the ZrO 2 :Er 3+ phosphor powders are discussed on the basis of excited state absorption, energy transfer, and cross-relaxation energy transfer mechanisms. (orig.)

Co-operative energy transfer in Yb3+-Er3+ co-doped SrGdxOy upconverting phosphor

Science.gov (United States)

Kumar, Ashwini; Pathak, Trilok K.; Dhoble, S. J.; . Terblans, J. J.; Swart, H. C.

2018-04-01

Upconversion nanoparticles (UCNPs) have shown considerable interest in many fields; however, low upconversion efficiency of UCNPs is still the most severe limitation of their applications. Yb3+ and Er3+ co-doped SrGd4O7/Gd2O3(SGO) upconversion (UC) phosphors were synthesized by a modified co-precipitation process. The UC properties were investigated by direct excitation with a 980 nm laser. It was observed that the as prepared materials showed relatively strong green emission, while upon the incorporation of the Er3+ ion, there was an increase in the upconversion luminescence intensity for the red component. The effect of different doping concentration of Er3+on the emission spectra and X-ray diffraction patterns of the UC materials have also been studied. The luminescence lifetimes and Commission Internationale de L'Eclairage coordinates for these as prepared samples were determined to understand the energy transfer (ET) mechanisms occurring between Yb3+ and Er3+ in the SGO host matrix. The UC luminescence intensity as a function of laser pump power was monitored and it was confirmed that the UC process in SGO:Yb3+/Er3+is a two-photon absorption process. The findings reported here are expected to provide a better approach for understanding of the ET mechanisms in the oxide based Yb3+/Er3+ co-doped UC phosphors. This study might be helpful in precisely defined applications where optical transitions are essential criterion and this can be easily achieved by smart tuning of the emission properties of Yb3+/Er3+ co-doped UC phosphors.

Energy transfer upconversion in Er3+-Tm3+ codoped sodium silicate glass

Science.gov (United States)

Kumar, Vinod; Pandey, Anurag; Ntwaeaborwa, O. M.; Swart, H. C.

2018-04-01

Er3+/Tm3+ doped and codoped Na2O-SiO2-ZnO (NSZO) glasses were prepared by the conventional melt-quenching method. The amorphous nature of the prepared glasses was confirmed by the X-ray diffraction analysis. The optical absorption spectrum displayed several peaks, which correspond to Er3+ and Tm3+ dopant ions embedded into the NSZO glass. Both dopants experienced upconversion emission under 980 nm excitation. Efficient energy transfer from Er3+ to Tm3+ was observed in the co-doped samples to enhance the near infrared emission of the Tm3+ ions.

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.

Optical bistability in Er-Yb codoped phosphate glass microspheres at room temperature

NARCIS (Netherlands)

Warda, Jonathan M.; O'Shea, Danny G.; Shortt, Brian J.; Chormaic, Sile Nic

2007-01-01

We experimentally demonstrate optical bistability in Er(3+)-Yb(3+) phosphate glass microspheres at 295 K. Bistability is associated with both Er(3+) fluorescence and lasing behavior, and chromatic switching. The chromatic switching results from an intrinsic mechanism exploiting the thermal coupling

Resonantly cladding-pumped Yb-free Er-doped LMA fiber laser with record high power and efficiency.

Science.gov (United States)

Zhang, Jun; Fromzel, Viktor; Dubinskii, Mark

2011-03-14

We report the results of our power scaling experiments with resonantly cladding-pumped Er-doped eye-safe large mode area (LMA) fiber laser. While using commercial off-the-shelf LMA fiber we achieved over 88 W of continuous-wave (CW) single transverse mode power at ~1590 nm while pumping at 1532.5 nm. Maximum observed optical-to-optical efficiency was 69%. This result presents, to the best of our knowledge, the highest power reported from resonantly-pumped Yb-free Er-doped LMA fiber laser, as well as the highest efficiency ever reported for any cladding-pumped Er-doped laser, either Yb-co-doped or Yb-free.

Blue and red emission in wide band gap BaZrO{sub 3}:Yb{sup 3+},Tm{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Borja-Urby, R. [Centro de Investigaciones en Optica, A. C., C. P. 37150 Leon, Gto. (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Centro de Investigaciones en Optica, A. C., C. P. 37150 Leon, Gto. (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A. P. 1-1010, Queretaro 76000 (Mexico); Vega-Gonzalez, M. [Centro de Geociencias-Universidad Nacional Autonoma de Mexico, A. P. 1-1010, Queretaro 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Cd. Mexico D.F. 07730 (Mexico)

2010-10-25

Under NIR excitation at 967 intense blue and red photoluminescence (PL) emissions are observed at room temperature in codoped Tm{sup 3+}-Yb{sup 3+} barium zirconate (BaZrO{sub 3}:Yb,Tm) powders. Powders were prepared by a simple hydrothermal method, and present a wide band gap that depends on the total rare earth content due to the degree of disorder induced in the BaZrO{sub 3} lattice by the substitution of the rare earth ions. Rietveld refinements of the XRD patterns indicated the presence of primary nanocrystallites with sizes between 50 and 70 nm depending on the Tm{sup 3+} content. Scanning transmission electron microscopy (STEM) shows that these primary particles self-aggregated in larger secondary particles which present a regular morphology with sizes around 1 {mu}m. The intense blue and red PL emissions in BaZrO{sub 3} powders under 967 nm excitation are governed by energy transfer processes from Yb{sup 3+} ions to Tm{sup 3+} ions and crossrelaxation among Tm{sup 3+} ions.

Y2O3:Yb/Er nanotubes: Layer-by-layer assembly on carbon-nanotube templates and their upconversion luminescence properties

International Nuclear Information System (INIS)

Huang, Weishi; Shen, Jianfeng; Wan, Lei; Chang, Yu; Ye, Mingxin

2012-01-01

Graphical abstract: Well-shaped Y 2 O 3 :Yb/Er nanotubes have been successfully synthesized on a large scale via layer-by-layer assembly on carbon nanotubes templates followed by a subsequent heat treatment process. The as-prepared Y 2 O 3 :Yb/Er nanotubes show a strong red emission corresponding to the 4 F 9/2 – 4 I 15/2 transition of the Er 3+ ions under excitation at 980 nm. Display Omitted Highlights: ► Well-shaped Y 2 O 3 :Yb/Er nanotubes have been successfully synthesized. ► CNTs were used as templates for Y 2 O 3 :Yb/Er nanotubes. ► LBL assembly and calcination were used for preparation of Y 2 O 3 :Yb/Er nanotubes. ► The as-prepared Y 2 O 3 :Yb/Er nanotubes show a strong red emission. -- Abstract: Well-shaped Y 2 O 3 :Yb/Er nanotubes have been successfully synthesized on a large scale via layer-by-layer (LBL) assembly on carbon nanotubes (CNTs) templates followed by a subsequent heat treatment process. The crystal structure, element analysis, morphology and upconversion luminescence properties were characterized. XRD results demonstrate that the diffraction peaks of the samples calcinated at 800 °C or above can be indexed to the pure cubic phase of Y 2 O 3 . SEM images indicate that a large quantity of uniform and rough nanotubes with diameters of about 30–60 nm can be observed. The as-prepared Y 2 O 3 :Yb/Er nanotubes show a strong red emission corresponding to the 4 F 9/2 – 4 I 15/2 transition of the Er 3+ ions under excitation at 980 nm, which have potential applications in such fields as nanoscale devices, molecular catalysts, nanobiotechnology, photonics and optoelectronics.

Intrinsic Bistability and Critical Slowing in Tm3+/Yb3+ Codoped Laser Crystal with the Photon Avalanche Mechanism

International Nuclear Information System (INIS)

Li, Li; Li-Xue, Chen; Xin-Lu, Zhang

2009-01-01

We present theoretically a novel intrinsic optical bistability (IOB) in the Tm 3+ /Yb 3+ codoped system with a photon avalanche mechanism. Numerical simulations based on the rate equation model demonstrate distinct IOB hysteresis and critical slowing dynamics around the avalanche thresholds. Such an IOB characteristic in Tm 3+ /Yb 3+ codoped crystal has potential applications in solid-state bistable optical displays and luminescence switchers in visible-infrared spectra. (fundamental areas of phenomenology (including applications))

Synthesis and characterization of KY3F10 and KY3F10:Yb:Nd:Tm crystals for optical applications

International Nuclear Information System (INIS)

Linhares, Horacio Marconi da Silva Dantas

2009-01-01

In this work, crystals of KY 3 F 10 pure and doped with Yb, Nd and Tm were grown aiming at the attainment of blue emission via Tm 3+ ions up conversion. It was established the best conditions to synthesis and purification of KY 3 F 10 . Crystals doped with 1.3 mol% Nd, 0.5 mol% Tm and some concentrations of Yb (5, 10, 20, 30 and 40 mol%) were obtained by slow cooling of the charge from the melt, using an usual conventional synthesis system and in a reactive HF atmosphere. It was taken into account parameters as cooling rate and different configurations of boats to conditioning the materials. The limit of Yb concentration to obtain a unique cubic phase was determined as 30mol%, for the cooling rates used in this work. The physical and chemical characterizations of the samples were performed by X-ray diffraction, differential thermal analysis, inductively coupled plasma-optical emission spectroscopy (ICP-OES), scanning electron microscopy, optical absorption and emission. An initial spectroscopic study was performed to verify the effect of the Yb 3+ concentration regarding the blue emission efficiency in the KY 3 F 10 :Yb:Nd:Tm. When the Nd 3+ is pumped at 797 nm, it was determined that the suitable Yb concentrations are between 10 and 20 mol% to obtain blue emission at 480 nm, and between 20 and 30 mol% to obtain emission at 450 nm. It was observed that two emissions bands in the UV (350 and 360nm) enhanced proportionally with the Yb 3+ concentration. (author)

Energy levels, oscillator strengths, line strengths, and transition probabilities in Si-like ions of La XLIII, Er LIV, Tm LV, and Yb LVI

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhan-Bin, E-mail: chenzb008@qq.com [College of Science, National University of Defense Technology, Changsha, Hunan 410073 (China); Ma, Kun [School of Information Engineering, Huangshan University, Huangshan 245041 (China); Wang, Hong-Jian [Chongqing Key Laboratory for Design and Control of Manufacturing Equipment, Chongqing Technology and Business University, Chongqing 40067 (China); Wang, Kai, E-mail: wangkai@hbu.edu.cn [Hebei Key Lab of Optic-electronic Information and Materials, The College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Liu, Xiao-Bin [Department of Physics, Tianshui Normal University, Tianshui 741001 (China); Zeng, Jiao-Long [College of Science, National University of Defense Technology, Changsha, Hunan 410073 (China)

2017-01-15

Detailed calculations using the multi-configuration Dirac–Fock (MCDF) method are carried out for the lowest 64 fine-structure levels of the 3s{sup 2}3p{sup 2}, 3s{sup 2}3p3d, 3s3p{sup 3}, 3s3p{sup 2}3d, 3s{sup 2}3d{sup 2}, and 3p{sup 4} configurations in Si-like ions of La XLIII, Er LIV, Tm LV, and Yb LVI. Energies, oscillator strengths, wavelengths, line strengths, and radiative electric dipole transition rates are given for all ions. A parallel calculation using the many-body perturbation theory (MBPT) method is also carried out to assess the present energy levels accuracy. Comparisons are performed between these two sets of energy levels, as well as with other available results, showing that they are in good agreement with each other within 0.5%. These high accuracy results can be used to the modeling and the interpretation of astrophysical objects and fusion plasmas. - Highlights: • Energy levels and E1 transition rates of Si-like ions are presented. • Breit interaction and Quantum Electrodynamics effects are discussed. • Present results should be useful in the astrophysical application and plasma modeling.

Effect of silica surface coating on the luminescence lifetime and upconversion temperature sensing properties of semiconductor zinc oxide doped with gallium(III) and sensitized with rare earth ions Yb(III) and Tm(III).

Science.gov (United States)

Li, Yuemei; Li, Yongmei; Wang, Rui; Zheng, Wei

2018-02-26

Optical sensing of temperature by measurement of the ratio of the intensities of the 700 nm emission and the 800 nm emission of Ga(III)-doped ZnO (GZO) nanoparticles (NPs) and of GZO NPs coated with a silica shell are demonstrated at 980 nm excitation. It is found that the relative sensitivity of SiO 2 @Yb/Tm/GZO is 6.2% K -1 at a temperature of 693 K. This is ~3.4 times higher than that of Yb/Tm/GZO NPs. Obviously, the SiO 2 shell structure decreases the rate of the nonradiative decay. The decay time of the 800 nm emission of the Yb/Tm/GZO NPs (15 mol% Ga; 7 mol% Yb; 0.5 mol% Tm) displays a biexponential decay with a dominant decay time of 148 μs and a second decay time of ~412 μs. The lifetime of the Yb/Tm/GZO NPs at 293 K, and of the SiO 2 @Yb/Tm/GZO NPs are ~412 μs. Both the Yb/Tm/GZO and SiO 2 @Yb/Tm/GZO can be used up to 693 K. These results indicate that the SiO 2 shell on the Yb/Tm/GZO is beneficial in terms of sensitivity and resolution. Graphical abstract The enhancement the decay time and thermal sensitivity in the SiO 2 @Yb/Tm/GZO shell@core structure have been studied compared to the Ga(III)-doped Yb/Tm-doped ZnO (Yb/Tm/GZO). The SiO 2 @Yb/Tm/GZO have good thermal accuracy up to 693 °C.

Enhancing photovoltaic performance of dye-sensitized solar cell by rare-earth doped oxide of Lu2O3:(Tm3+, Yb3+)

International Nuclear Information System (INIS)

Li Qingbei; Lin Jianming; Wu Jihuai; Lan Zhang; Wang Yue; Peng Fuguo; Huang Miaoliang

2011-01-01

Highlights: → Tm 3+ /Yb 3+ codoped oxide is introduced into the TiO 2 film in dye-sensitized solar cell. → The RE improves light harvest via conversion luminescence and increases photocurrent. → The RE elevates the oxide film energy level and increases the cell photovoltage. → The cell efficiency is increased by 11.1% compared to the cell lacking of RE doping. - Abstract: In order to increase of the photocurrent, photovoltage and energy conversion efficiency of dye-sensitized solar cell (DSSC), rare-earth doped oxide of Lu 2 O 3 :(Tm 3+ , Yb 3+ ) is prepared and introduced into the TiO 2 film in the DSSC. As a luminescence medium, Lu 2 O 3 :(Tm 3+ , Yb 3+ ) improves incident light harvest via a conversion luminescence process and increases photocurrent; as a p-type dopant, the rare-earth ions elevate the energy level of the oxide film and increase the photovoltage. Under a simulated solar light irradiation of 100 mW cm -2 , the light-to-electric energy conversion efficiency of the DSSC with Lu 2 O 3 :(Tm 3+ , Yb 3+ ) doping reaches 6.63%, which is increased by 11.1% compared to the DSSC without Lu 2 O 3 :(Tm 3+ , Yb 3+ ) doping.

Synthesis of novel branched β-NaLuF4: Yb/Er upconversion luminescence material and investigation of its optical properties

Science.gov (United States)

Ding, Yanli; Yang, Tonghui; Yin, Naiqiang; Shu, Fangjie; Zhao, Ying; Zhang, Xiaodan

2018-05-01

Branched β-NaLuF4: Yb/Er was synthesized using a simple hydrothermal method by controlling the NaF/Ln molar ratio. In contrast to the β-NaYF4: Yb/Er hexagonal disks, the branched β-NaLuF4: Yb/Er has stronger emission intensity. The integrated intensities of green and red emission bands were as 6.2 and 3.3 times as that of NaYF4, respectively. The branched β-NaLuF4: Yb/Er has the smaller unit cell volume, the higher absorption intensity around 980 nm and the lower crystal field symmetry than NaYF4, which made a significant contribution to the stronger upconversion (UC) fluorescence emissions. The results indicate that the branched β-NaLuF4: Yb/Er is an excellent UC luminescence material. The current research has a great potential in improving near-infrared conversion efficiency of solar cells.

Preparation and luminescence properties of LaPO{sub 4}:Er,Yb nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Jung, Ha-Kyun [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejeon 305-600 (Korea, Republic of)]. E-mail: hakyun@krict.re.kr; Oh, Jae-Suk [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejeon 305-600 (Korea, Republic of); Seok, Sang-Il [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejeon 305-600 (Korea, Republic of); Lee, Tack-Hyuck [Department of Chemistry, Paichai University, Daejeon 302-735 (Korea, Republic of)

2005-09-15

For possible applications as optical amplification materials in telecommunications, LaPO{sub 4}:Er,Yb nanoparticles were synthesized in a solution system and their properties were investigated by various spectroscopic techniques. The prepared nanoparticles are single-phased and present the monazite structure, the particle size being about 5 nm with a narrow size distribution. Also, it was confirmed by EA and FT-IR analyses that the surface of nanoparticles is coated with the solvent molecules used in the synthesis reaction, which possibly prevents them from agglomerating. In the NIR region, the emission of the LaPO{sub 4}:Er particles is very weak due to an efficient quenching of the {sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2} emission by the hydroxyl groups adsorbed on the surface of the nanoparticles. On the other hand, the co-doping of Yb{sup 3+} as a sensitizer in the nanoparticles resulted in the increase of the emission intensity at 1539 nm due to the effective energy transfer from Yb{sup 3+} to Er{sup 3+}. In addition, the synthesized nanoparticles have exhibited good dispersibility into a polymer matrix and effective luminescence in the NIR region.

Hydrothermal synthesis and upconversion luminescent properties of YVO4:Yb3+,Er3+ nanoparticles

International Nuclear Information System (INIS)

Liang, Yanjie; Chui, Pengfei; Sun, Xiaoning; Zhao, Yan; Cheng, Fuming; Sun, Kangning

2013-01-01

Graphical abstract: YVO 4 :Yb 3+ ,Er 3+ nanoparticles have been successfully prepared via a facile hydrothermal technique in the presence of citric acid as a complexing agent followed by a subsequent heat treatment process. The PL intensity of the sample increases with the increase of annealing temperature and excitation power. Under the excitation of a 980 nm diode laser, the samples show bright green luminescence. Highlights: ► YVO 4 :Yb 3+ ,Er 3+ nanoparticles were prepared by a hydrothermal approach. ► Bright green luminescence is observed under the excitation of a 980 nm laser diode. ► The PL intensity increases with the increase of annealing temperature. ► Energy transfer properties between Yb 3+ ion and Er 3+ ion were analyzed. -- Abstract: In this paper, YVO 4 :Yb 3+ ,Er 3+ nanoparticles have been successfully prepared via a facile hydrothermal technique in the presence of citric acid as a complexing agent followed by a subsequent heat treatment process. The nanostructures, morphologies and upconversion luminescent properties of the as-prepared YVO 4 :Yb 3+ ,Er 3+ upconverting nanoparticles were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescent (PL) spectra. XRD results indicate that all the diffraction peaks of samples can be well indexed to the tetragonal phase of YVO 4 . TEM images demonstrate that the samples synthesized hydrothermally consist of granular-like nanoparticles ranging in size from about 30 to 50 nm. After being calcined at 500–800 °C for 2 h, the grain sizes of nanoparticles increase slightly. Additionally, the as-prepared nanoparticles show bright green luminescence corresponding to the 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 transitions of Er 3+ ions under the excitation of a 980 nm diode laser, which might find potential applications in fields such as phosphor powders, infrared detection and display devices

The effects of energy transfer on the Er{sup 3+} 1.54 {mu}m luminescence in nanostructured Y{sub 2}O{sub 3} thin films with heterogeneously distributed Yb{sup 3+} and Er{sup 3+} codopants

Energy Technology Data Exchange (ETDEWEB)

Hoang, J.; Chang, J. P. [Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095 (United States); Schwartz, Robert N.; Wang, Kang L. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States)

2012-09-15

We report the effects of heterogeneous Yb{sup 3+} and Er{sup 3+} codoping in Y{sub 2}O{sub 3} thin films on the 1535 nm luminescence. Yb{sup 3+}:Er{sup 3+}:Y{sub 2}O{sub 3} thin films were deposited using sequential radical enhanced atomic layer deposition. The Yb{sup 3+} energy transfer was investigated for indirect and direct excitation of the Yb {sup 2}F{sub 7/2} state using 488 nm and 976 nm sources, respectively, and the trends were described in terms of Forster and Dexter's resonant energy transfer theory and a macroscopic rate equation formalism. The addition of 11 at. % Yb resulted in an increase in the effective Er{sup 3+} photoluminescence (PL) yield at 1535 nm by a factor of 14 and 42 under 488 nm and 976 nm excitations, respectively. As the Er{sub 2}O{sub 3} local thickness was increased to greater than 1.1 A, PL quenching occurred due to strong local Er{sup 3+}{r_reversible} Er{sup 3+} excitation migration leading to impurity quenching centers. In contrast, an increase in the local Yb{sub 2}O{sub 3} thickness generally resulted in an increase in the effective Er{sup 3+} PL yield, except when the Er{sub 2}O{sub 3} and Yb{sub 2}O{sub 3} layers were separated by more than 2.3 A or were adjacent, where weak Yb{sup 3+}{r_reversible} Er{sup 3+} coupling or strong Yb{sup 3+}{r_reversible} Yb{sup 3+} interlayer migration occurred, respectively. Finally, it is suggested that enhanced luminescence at steady state was observed under 488 nm excitation as a result of Er{sup 3+}{yields} Yb{sup 3+} energy back transfer coupled with strong Yb{sup 3+}{r_reversible} Yb{sup 3+} energy migration.

Highly efficient upconversion luminescence in hexagonal NaYF4:Yb3+, Er3+ nanocrystals synthesized by a novel reverse microemulsion method

Science.gov (United States)

Gunaseelan, M.; Yamini, S.; Kumar, G. A.; Senthilselvan, J.

2018-01-01

A new reverse microemulsion system is proposed for the first time to synthesize NaYF4:Yb,Er nanocrystals, which demonstrated high upconversion emission in 550 and 662 nm at 980 nm diode laser excitation. The reverse microemulsion (μEs) system is comprised of CTAB and oleic acid as surfactant and 1-butanol co-surfactant and isooctane oil phase. The surfactant to water ratio is able to tune the microemulsion droplet size from 14 to 220 nm, which eventually controls the crystallinity and particulate morphology of NaYF4:Yb,Er. Also, the microemulsion precursor and calcination temperature plays certain role in transforming the cubic NaYF4:Yb,Er to highly luminescent hexagonal crystal structured upconversion material. Single phase hexagonal NaYF4:YbEr nanorod prepared by water-in-oil reverse microemulsion (μEs) gives intense red upconversion emission. Both nanosphere and nanorod shaped NaYF4:Yb,Er was obtained, but nanorod morphology resulted an enhanced upconversion luminescence. The structural, morphological, thermal and optical luminescence properties of the NaYF4:Yb,Er nanoparticles are discussed in detail by employing powder X-ray diffraction, dynamic light scattering, high resolution electron microscopy, TGA-DTA, UV-DRS, FTIR and photoluminescence spectroscopy. Intense upconversion emission achieved in the microemulsion synthesized NaYF4:Yb3+,Er3+ nanocrystal can make it as useful optical phosphor for solar cell applications.

Spectroscopic investigations of OH{sup -} influence on near-infrared fluorescence quenching of Yb{sup 3+}/Tm{sup 3+} co-doped sodium-metaphosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Terra, I.A.A. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Saocarlense 400, CEP 13566-590, USP-Sao Carlos, SP (Brazil)], E-mail: idelma@ifsc.usp.br; Camargo, A.S.S. de; Terrile, M.C.; Nunes, L.A.O. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Saocarlense 400, CEP 13566-590, USP-Sao Carlos, SP (Brazil)

2008-05-15

Energy transfer processes were studied in two sets of Yb{sup 3+} and Tm{sup 3+} co-doped sodium-metaphosphate glasses, prepared in air and nitrogen atmospheres. Using Foerster, Dexter, and Miyakawa theoretical models, the energy transfer parameters were calculated. The main ion-ion energy transfer processes analyzed were energy migration among Yb{sup 3+} ions, cross-relaxations between Yb{sup 3+} and Tm{sup 3+} ions, and interactions with OH{sup -} radicals. The results indicated that Yb{yields}Tm energy transfer favors 1.8 {mu}m emissions, and there is no evidence of concentration quenching up to 2% Tm{sub 2}O{sub 3} doping. As expected, samples prepared in nitrogen atmosphere present higher fluorescence quantum efficiency than those prepared in air, and this feature is specially noted in the near-infrared region, where the interaction with the OH{sup -} radicals is more pronounced.

Nanocrystal in Er3+-doped SiO2-ZrO2 Planar Waveguide with Yb3+ Sensitizer

International Nuclear Information System (INIS)

Razaki, N. Iznie; Jais, U. Sarah; Abd-Rahman, M. Kamil; Bhaktha, S. N. B.; Chiasera, A.; Ferrari, M.

2010-01-01

Higher doping of Er 3+ in glass ceramic waveguides would cause concentration and pair-induced quenching which lead to inhomogeneous line-width of luminescence spectrum thus reduce output intensity. Concentration quenching can be overcome by introducing ZrO 2 in the glass matrix while co-doping with Yb 3+ which acts as sensitizer would improve the excitation efficiency of Er 3+ . In this study, SiO 2 -ZrO 2 planar waveguides having composition in mol percent of 70SiO 2 -30ZrO 2 doped with Er 3+ and co-doped with Yb 3+ , were prepared via sol-gel route. Narrower and shaper peaks of PL and XRD shows the formation of nanocrystals. Intensity is increase with addition amount of Yb 3+ shows sensitizing effect on Er 3+ .

A comprehensive phononics of phonon assisted energy transfer in the Yb{sup 3+} aided upconversion luminescence of Tm{sup 3+} and Ho{sup 3+} in solids

Energy Technology Data Exchange (ETDEWEB)

Debnath, Radhaballabh, E-mail: drdebnathr@gmail.com; Bose, Saptasree

2015-05-15

The theory of phonon assisted energy transfer is being widely used to explain the Yb{sup 3+} ion aided normal and upconversion emission of various rare earth ions in different Yb{sup 3+} co-doped solids. The reported phonon dynamics in many of these studies are either incomplete or erroneous. Here we report Yb{sup 3+} aided upconversion luminescence properties of Tm{sup 3+} and Ho{sup 3+} in (Yb{sup 3+}/Tm{sup 3+}) and (Yb{sup 3+}/Ho{sup 3+}) co-doped two BaO–tellurite glasses and explain their phononics in the light of Dexter's theory by proposing a comprehensive scheme. The approach is valid for other systems of different phonon structures. - Highlights: • Yb{sup 3+} aided upconversion luminescence properties of Tm{sup 3+} and Ho{sup 3+} in (Yb{sup 3+}/Tm{sup 3+}) and (Yb{sup 3+}/Ho{sup 3+}) co-doped two BaO–tellurite glasses, are reported. • Phonon assisted energy transfer in these systems are explained in the light of Dexter's theory by proposing a comprehensive scheme of phononics. • The approach is valid for other systems of different phonon structures.

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.

Fingermark detection on non-porous and semi-porous surfaces using YVO4:Er,Yb luminescent upconverting particles.

Science.gov (United States)

Ma, Rongliang; Shimmon, Ronald; McDonagh, Andrew; Maynard, Philip; Lennard, Chris; Roux, Claude

2012-04-10

This article describes the use of an anti-Stokes luminescent material (upconverter), yttrium vanadate doped with ytterbium and erbium (YVO(4):Er,Yb), for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes luminescent materials emit light at shorter wavelengths than the excitation wavelength. This property is unusual in both natural and artificial materials commonly found as exhibits in forensic science casework. As a result, fingermark detection techniques based on anti-Stokes luminescence are potentially extremely sensitive and selective. Latent fingermarks on non-luminescent and inherently luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with YVO(4):Er,Yb by dry powder and wet powder techniques. The effectiveness of YVO(4):Er,Yb for fingermark detection was compared with that of cyanoacrylate fuming and of sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF(4):Er,Yb). The results illustrate some benefit of luminescent up-converting phosphors over traditional luminescence techniques for the detection of latent fingermarks. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

NaYF4:Er,Yb/Bi2MoO6 core/shell nanocomposite: A highly efficient visible-light-driven photocatalyst utilizing upconversion

International Nuclear Information System (INIS)

Sun, Yuanyuan; Wang, Wenzhong; Sun, Songmei; Zhang, Ling

2014-01-01

Highlights: • Design and synthesis of NaYF 4 :Er,Yb/Bi 2 MoO 6 based on upconversion. • NaYF 4 :Er,Yb/Bi 2 MoO 6 nanocomposite was prepared for the first time. • Core–shell structure benefits the properties. • Upconversion contributed to the enhanced photocatalytic activity. • Helps to understand the functionality of new type photocatalysts. - Abstract: NaYF 4 :Er,Yb/Bi 2 MoO 6 core/shell nanocomposite was designed and prepared for the first time based on upconversion. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectra (DRS). The results revealed that the as-synthesized NaYF 4 :Er,Yb/Bi 2 MoO 6 consisted of spheres with a core diameter of about 26 nm and a shell diameter of around 6 nm. The core was upconversion illuminant NaYF 4 :Er,Yb and the shell was Bi 2 MoO 6 around the core, which was confirmed by EDS. The NaYF 4 :Er,Yb/Bi 2 MoO 6 exhibited higher photocatalytic activity for the photodecomposition of Rhodamine B (RhB) under the irradiation of Xe lamp and green light emitting diode (g-LED). The mechanism of the high photocatalytic activity was discussed by photoluminescence spectra (PL), which is mainly attributed to upconversion of NaYF 4 :Er,Yb in the NaYF 4 :Er,Yb/Bi 2 MoO 6 nanocomposite and the core–shell structure

Fabrication and evaluation of chitosan/NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} upconversion nanoparticles composite beads based on the gelling of Pickering emulsion droplets

Energy Technology Data Exchange (ETDEWEB)

Yan, Huiqiong; Chen, Xiuqiong; Shi, Jia; Shi, Zaifeng; Sun, Wei; Lin, Qiang, E-mail: linqianggroup@163.com; Wang, Xianghui; Dai, Zihao

2017-02-01

The rare earth ion doped upconversion nanoparticles (UCNPs) synthesized by hydrophobic organic ligands possess poor solubility and low fluorescence quantum yield in aqueous media. To conquer this issue, NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} UCNPs, synthesized by a hydrothermal method, were coated with F127 and then assembled with chitosan to fabricate the chitosan/NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} composite beads (CS/NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} CBs) by Pickering emulsion system. The characterization results revealed that the as-synthesized NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} UCNPs with an average size of 20 nm exhibited spherical morphology, high crystallinity and characteristic emission upconversion fluorescence with an overall blue color output. The NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} UCNPs were successfully conjugated on the surface of chitosan beads by the gelling of emulsion droplets. The resultant CS/NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} CBs showed good upconversion luminescent property, drug-loading capacity, release performance and excellent biocompatibility, exhibiting great potentials in targeted drug delivery and tissue engineering with potential tracking capability and lasting release performance. - Highlights: • NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} UCNPs were coated by F127 to improve aqueous dispersibility. • NaYF{sub 4}:Yb{sup 3+}/Tm{sup 3+} UCNPs were assembled with chitosan to fabricate the composite beads (CMs). • Pickering emulsions stabilized by UCNPs exhibited uniform and satisfactory emulsion droplets. • The CMs prepared by the gelling of emulsion droplet preserved upconversion luminescent property. • The resultant CMs showed good drug-loading capacity, release performance and biocompatibility.

Synthesis and characterization of Yb and Er based monosilicate powders and durability of plasma sprayed Yb2SiO5 coatings on C/C–SiC composites

International Nuclear Information System (INIS)

Khan, Zuhair S.; Zou Binglin; Huang Wenzhi; Fan Xizhi; Gu Lijian; Chen Xiaolong; Zeng Shuibing; Wang Chunjie; Cao Xueqiang

2012-01-01

Highlights: ► Ultra-pure rare-earth monosilicate powders based on Er and Yb have been fabricated by solid-state reaction. ► Spray-drying treatment results in powders with free flowing characteristics and rounded surface morphologies. ► CTEs are found to be 7.1 ppm/°C for Yb 2 SiO 5 and 7.5 ppm/°C for Er 2 SiO 5 . ► Plasma spraying has been used to deposit Yb 2 SiO 5 coatings on C/C–SiC substrate. ► Coatings remain strongly intact with the substrate on thermal cycling between ∼400 °C and 1500 °C in gas burner rig experiment. - Abstract: Rare-earth silicates such as Yb 2 SiO 5 and Er 2 SiO 5 are promising environmental barrier coating materials for ceramic matrix composites. In this work, Yb 2 SiO 5 and Er 2 SiO 5 ceramic powders have been synthesized by solid-state reaction using Yb 2 O 3 , Er 2 O 3 and SiO 2 as starting materials. The fabricated powders were subjected to spray drying treatment for subsequent synthesis of coatings by plasma spraying. The spray drying resulted in well-dispersed and spherical powder particles with good flowability. Analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry and differential scanning calorimetry (TGA/DSC) and dilatometry were applied to study the microstructural and thermal characteristics of the powders. Ultra-high purity monosilicate powders formed as a result of heating treatments at 1400 °C in a box furnace for 20 h. TG/DSC revealed the genesis temperatures of the silicate formation (low temperature polymorphs) and also showed that the solid-state reactions to form Yb and Er based monosilicates proceeded without any weight-loss in the tested temperature range. The values of coefficients of thermal expansion (CTE) of the fabricated compounds are found to be 7.1 ppm/°C for Yb 2 SiO 5 and 7.5 ppm/°C for Er 2 SiO 5 by dilatometric measurements. Besides these studies, coating formation by plasma spraying of spray-dried Yb 2 SiO 5 powders on the ceramic

Infrared to visible upconversion luminescence in Er3+/Yb3+ co-doped CeO2 inverse opal

International Nuclear Information System (INIS)

Yang, Zhengwen; Wu, Hangjun; Liao, Jiayan; Li, Wucai; Song, Zhiguo; Yang, Yong; Zhou, Dacheng; Wang, Rongfei; Qiu, Jianbei

2013-01-01

Highlights: • UC emission of Er 3+ was modified by introducing the structure of inverse opal. • Color tuning of CeO 2 :Yb, Er inverse opal was realized by inhibition of UC emission. • Two-photon excitation processes were observed in CeO 2 :Yb, Er inverse opal. -- Abstract: Infrared to visible upconversion luminescence has been investigated in Er 3+ /Yb 3+ co-doped CeO 2 inverse opal. Under the excitation of 980 nm diode lasers, visible emissions centered at 525, 547, 561, 660 and 680 nm are observed, which are assigned to the Er 3+ transitions of 2 H 11/2 → 4 I 15/2 (525 nm), 4 S 3/2 → 4 I 15/2 (547, 561 nm), 4 F 9/2 → 4 I 15/2 (660 and 680 nm), respectively. The effect of photonic band gap on the upconversion luminescence intensity was also obtained. Additionally, the upconversion luminescence mechanism was studied. The dependence of Er 3+ upconversion emission intensity on pump power reveals that it is a two-photon excitation process

Structural, Electronic and Elastic Properties of Heavy Fermion YbTM2 (TM= Ir and Pt) Laves Phase Compounds

Science.gov (United States)

Pawar, H.; Shugani, M.; Aynyas, M.; Sanyal, S. P.

2018-02-01

The structural, electronic and elastic properties of YbTM2 (TM = Ir and Pt) Laves phase intermetallic compounds which crystallize in cubic (MgCu2-type) structure, have been investigated using ab-initio full potential linearized augmented plane wave (FP-LAPW) method with LDA and LDA+U approximation. The calculated ground state properties such as lattice parameter (a0), bulk modulus (B) and its pressure derivative (B‧) are in good agreement with available experimental and theoretical data. The electronic properties are analyzed from band structures and density of states. Elastic constants are predicted first time for these compounds which obey the stability criteria for cubic system.

Down- and up-conversion emissions in Er{sup 3+}–Yb{sup 3+} codoped TeO{sub 2}–ZnO–ZnF{sub 2} glasses

Energy Technology Data Exchange (ETDEWEB)

Miguel, A. [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Arriandiaga, M.A. [Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU, Apartado 644, Bilbao (Spain); Morea, R. [Instituto de Optica, Consejo Superior de Investigaciones Científicas CSIC, Serrano 121, 28006 Madrid (Spain); Fernandez, J. [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. [Instituto de Optica, Consejo Superior de Investigaciones Científicas CSIC, Serrano 121, 28006 Madrid (Spain); Balda, R., E-mail: wupbacrr@bi.ehu.es [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)

2015-02-15

In this work, we report the near infrared and upconversion emissions of Er{sup 3+}–Yb{sup 3+} codoped fluorotellurite TeO{sub 2}–ZnO–ZnF{sub 2} glasses for different YbF{sub 3} concentrations ranging between 0.5 and 2 wt%. The study includes absorption and emission spectra and lifetime measurements for the infrared and visible fluorescence. The energy transfer between Yb{sup 3+} and Er{sup 3+} ions is confirmed by the temporal behavior of the near-infrared luminescence of Yb{sup 3+} ions as well as by the enhancement of the 1532 nm emission of Er{sup 3+} ions in the codoped samples. The Yb{sup 3+}→Er{sup 3+} energy transfer efficiency is calculated from the Yb{sup 3+} lifetimes in single and codoped samples. Back transfer from Er{sup 3+} to Yb{sup 3+} ions is present under near infrared and visible excitation of Er{sup 3+} ions at 798 and 488 nm respectively. An enhancement of the visible upconversion fluorescence is also observed in the codoped samples due to energy transfer from Yb{sup 3+} to Er{sup 3+} ions. The standardized value for the efficiency of the green upconversion emission is 1.06×10{sup −4} for the codoped sample with 2 wt% of YbF{sub 3} which is comparable to that reported in lead–zinc–tellurite glasses. The possible upconversion processes and mechanisms leading to the population of several excited levels are discussed. - Highlights: • The effect of Yb{sup 3+} concentration on the NIR and VIS emissions of Er{sup 3+}ions is studied. • TheYb{sup 3+}↔Er{sup 3+} energy transfer in fluorotellurite glasses is demonstrated. • Increase of the green upconversion emission with Yb{sup 3+} concentration due to Yb{sup 3+}→Er{sup 3+} energy transfer. • The ratio of red to green upconversion emissions depends on the concentration of Yb{sup 3+} ions.

Dual functional NaYF4:Yb3+, Er3+@NaYF4:Yb3+, Nd3+ core-shell nanoparticles for cell temperature sensing and imaging

Science.gov (United States)

Shi, Zengliang; Duan, Yue; Zhu, Xingjun; Wang, Qiwei; Li, DongDong; Hu, Ke; Feng, Wei; Li, Fuyou; Xu, Chunxiang

2018-03-01

Lanthanide-doped up-conversion nanoparticles (UCNPs) provide a remote temperature sensing approach to monitoring biological microenvironments. In this research, the UCNPs of NaYF4:Yb3+, Er3+@NaYF4:Yb3+, Nd3+ with hexagonal (β)-phase were synthesized and applied in cell temperature sensing as well as imaging after surface modification with meso-2, 3-dimercaptosuccinic acid. In the core-shell UCNPs, Yb3+ ions were introduced as energy transfer media between sensitizers of Nd3+ and activators of Er3+ to improve Er3+emission and prevent their quenching behavior due to multiple energy levels of Nd3+. Under the excitations of 808 nm and 980 nm lasers, the NaYF4:Yb3+, Er3+@NaYF4:Yb3+, Nd3+ nanoparticles exhibited an efficient green band with two emission peaks at 525 nm and 545 nm, respectively, which originated from the transitions of 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 for Er3+ ions. We demonstrate that an occurrence of good logarithmic linearity exists between the intensity ratio of these two emission peaks and the reciprocal of the inside or outside temperature of NIH-3T3 cells. A better thermal stability is proved through temperature-dependent spectra with a heating-cooling cycle. The obtained viability of NIH-3T3 cells is greater than 90% after incubations of about 12 and 24 (h), and they possess a lower cytotoxicity of UCNPs. This work provides a method for monitoring the cell temperature and its living state from multiple dimensions including temperature response, cell images and visual up-conversion fluorescent color.

Enhanced ~2.7 µm emission investigation of Er{sup 3+}:{sup 4}I{sub 11/2}→{sup 4}I{sub 13/2} transition in Yb,Er,Pr:SrLaGa{sub 3}O{sub 7} crystal

Energy Technology Data Exchange (ETDEWEB)

Wang, Yan [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Zhang, Baotong [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); College of Materials Science and Engineering, Fujian Normal University, Fuzhou, Fujian 350007 (China); Li, Jianfu; Zhu, Zhaojie; You, Zhenyu [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Tu, Chaoyang, E-mail: tcy@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2017-03-15

The bulk crystal of 5at% Yb{sup 3+}, 20 at% Er{sup 3+} and 0.2 at% Pr{sup 3+} triply doped SrLaGa{sub 3}O{sub 7} (abbr. as Yb,Er,Pr:SLGO) was grown by the Czochralski method. The effects of co-dopant Yb{sup 3+} and Pr{sup 3+} on the spectroscopic properties and the mutual energy transfer mechanism were investigated, via the measurements of its absorption, near-infrared and mid-infrared fluorescence spectra, as well as the fluorescence decay curves of Er{sup 3+}:{sup 4}I{sub 13/2} and {sup 4}I{sub 11/2} levels at room temperature. As compared with 20at% Er{sup 3+} singly doped SrLaGa{sub 3}O{sub 7} crystal, ~2.7 µm emission intensity corresponding to Er{sup 3+}:{sup 4}I{sub 11/2}→{sup 4}I{sub 13/2} transition is enhanced greatly in the Yb,Er,Pr:SLGO crystal. Spectral analyses indicate that the sensitization of Yb{sup 3+} to Er{sup 3+} improves the ~2.7 µm emission in Yb,Er,Pr:SLGO crystal, meanwhile, the depopulation of Pr{sup 3+} from Er{sup 3+} decreases the ~1.5 µm emission and inhibits the self-termination effect. The energy transfer efficiencies of Yb{sup 3+}→Er{sup 3+} (ET1), Er{sup 3+}→Pr{sup 3+} (ET2) and Er{sup 3+}→Pr{sup 3+} (ET3) were estimated and discussed. The above results conclude that Yb,Er,Pr:SLGO crystal is a good candidate for LD pumped mid-infrared laser. - Graphical abstract: As compared with Er: SrLaGa{sub 3}O{sub 7} crystal, ~2.7 µm MIR emissions corresponding to Er{sup 3+}:{sup 4}I{sub 11/2}→{sup 4}I{sub 13/2} transition were enhanced in Yb{sup 3+}, Er{sup 3+} and Pr{sup 3+} triply doped SrLaGa{sub 3}O{sub 7} crystal owing to the sensitization of co-dopant Yb{sup 3+} via ET1, at the same time, ~1.5 µm NIR emissions were weakened owing to the depopulation of co-dopant Pr{sup 3+} via ET3.

Upconversion photoluminescence of epitaxial Yb{sup 3+}/Er{sup 3+} codoped ferroelectric Pb(Zr,Ti)O{sub 3} films on silicon substrates

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yang, E-mail: zhangy_acd@hotmail.com [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Kämpfe, Thomas [Institut für Angewandte Physik, TU Dresden, 01062 Dresden (Germany); Bai, Gongxun [Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong (China); Mietschke, Michael; Yuan, Feifei; Zopf, Michael [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Abel, Stefan [IBM Research GmbH, Saümerstrasse 4, 8803 Rüschlikon (Switzerland); Eng, Lukas M. [Institut für Angewandte Physik, TU Dresden, 01062 Dresden (Germany); Hühne, Ruben [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Fompeyrine, Jean [IBM Research GmbH, Saümerstrasse 4, 8803 Rüschlikon (Switzerland); Ding, Fei, E-mail: f.ding@ifw-dresden.de [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Schmidt, Oliver G. [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, Reichenhainer strasse 70, 09107 Chemnitz (Germany)

2016-05-31

Thin films of Yb{sup 3+}/Er{sup 3+} codoped Pb(Zr,Ti)O{sub 3} (PZT:Yb/Er) have been epitaxially grown on the SrTiO{sub 3} buffered Si wafer by pulsed laser deposition. Strong upconversion photoluminescence was observed in the PZT:Yb/Er thin film. Using piezoresponse force microscopy, polar domains in the PZT:Yb/Er film can be reversibly switched with a phase change of 180°. Ferroelectric hysteresis loop shape with a well-saturated response was observed. The epitaxially grown lanthanide-doped PZT on silicon opens up a promising route to the integration of luminescent functional oxides on the silicon platform. - Highlights: • Epitaxial growth of Yb{sup 3+}/Er{sup 3+} codoped Pb(Zr,Ti)O{sub 3} films on SrTiO{sub 3} buffered silicon • Upconversion emissions were obtained from the lanthanide ion doped thin films. • Saturated ferroelectric hysteresis loops were observed. • Polar domains were switched by PFM with a phase change of 180°.

Y{sub 2}O{sub 3}:Yb/Er nanotubes: Layer-by-layer assembly on carbon-nanotube templates and their upconversion luminescence properties

Energy Technology Data Exchange (ETDEWEB)

Huang, Weishi; Shen, Jianfeng; Wan, Lei; Chang, Yu [Department of Materials Science, Fudan University, Shanghai 200433 (China); Ye, Mingxin, E-mail: mxye@fudan.edu.cn [Department of Materials Science, Fudan University, Shanghai 200433 (China); Center of Special Materials and Technology, Fudan University, Shanghai 200433 (China)

2012-11-15

Graphical abstract: Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized on a large scale via layer-by-layer assembly on carbon nanotubes templates followed by a subsequent heat treatment process. The as-prepared Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission corresponding to the {sup 4}F{sub 9/2}–{sup 4}I{sub 15/2} transition of the Er{sup 3+} ions under excitation at 980 nm. Display Omitted Highlights: ► Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized. ► CNTs were used as templates for Y{sub 2}O{sub 3}:Yb/Er nanotubes. ► LBL assembly and calcination were used for preparation of Y{sub 2}O{sub 3}:Yb/Er nanotubes. ► The as-prepared Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission. -- Abstract: Well-shaped Y{sub 2}O{sub 3}:Yb/Er nanotubes have been successfully synthesized on a large scale via layer-by-layer (LBL) assembly on carbon nanotubes (CNTs) templates followed by a subsequent heat treatment process. The crystal structure, element analysis, morphology and upconversion luminescence properties were characterized. XRD results demonstrate that the diffraction peaks of the samples calcinated at 800 °C or above can be indexed to the pure cubic phase of Y{sub 2}O{sub 3}. SEM images indicate that a large quantity of uniform and rough nanotubes with diameters of about 30–60 nm can be observed. The as-prepared Y{sub 2}O{sub 3}:Yb/Er nanotubes show a strong red emission corresponding to the {sup 4}F{sub 9/2}–{sup 4}I{sub 15/2} transition of the Er{sup 3+} ions under excitation at 980 nm, which have potential applications in such fields as nanoscale devices, molecular catalysts, nanobiotechnology, photonics and optoelectronics.

Fabrication of NaYF4:Yb,Er Nanoprobes for Cell Imaging Directly by Using the Method of Hydrion Rivalry Aided by Ultrasonic.

Science.gov (United States)

Li, Zhihua; Miao, Haixia; Fu, Ying; Liu, Yuxiang; Zhang, Ran; Tang, Bo

2016-12-01

A novel method of fabricating water-soluble bio-probes with ultra-small size such as NaYF 4 :Yb,Er (18 nm), NaGdF 4 :Yb,Er (8 nm), CaF 2 :Yb,Er (10 nm), PbS (7 nm), and ZnS (12 nm) has been developed to provide for the solubility switch of nanoparticles from oil-soluble to water-soluble in terms of hydrion rivalry aided by ultrasonic. Using NaYF 4 :Yb,Er (18 nm) as an example, we evaluate the properties of as-prepared water-soluble nanoparticles (NPs) by using thermogravimetric analyses (TGA), Fourier transform infrared spectroscopy (FTIR), zeta potential (ζ) testing, and 1H nuclear magnetic resonance ( 1 HNMR). The measured ζ value shows that the newly prepared hydrophilic NaYF 4 :Yb,Er NPs are the positively charged particles. Acting as reactive electrophilic moiety, the freshly prepared hydrophilic NaYF 4 :Yb,Er NPs have carried out the coupling with amino acids and fluorescence labeling and imaging of HeLa cells directly. Experiments indicate that the method of hydrion rivalry aided by ultrasonic provides a simple and novel opportunity to transform hydrophobic NPs into hydrophilic NPs with good reactivity, which can be imaging some specific biological targets directly.

Upconversion luminescence properties of Y2O3:Yb3+, Er3+ nanostructures

International Nuclear Information System (INIS)

De Gejihu; Qin Weiping; Zhang Jishen; Zhang Jishuang; Wang, Yan; Cao Chunyan; Cui Yang

2006-01-01

Cubic Y 2 O 3 nanostructures doped with Yb 3+ and Er 3+ ions were synthesized by a facile hydrothermal method. Three distinct shapes such as nanotubes, nanospheres and nanoflakes formed in the products by adjusting the pH value of reacting solution. Powder X-ray diffraction analyses indicate that all the three nanostructures are pure cubic phase, while electron microscopy measurements confirm the formation of different morphologies. These nanostructures exhibit strong visible upconversion luminescence under the excitation of a 978-nm diode laser. In Yb 3+ - and Er 3+ - codoped Y 2 O 3 nanocrystals, the relative intensity of green emission became stronger as the size and morphology of sample changed from tubes to flakes

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.

Quantum sized Ag nanocluster assisted fluorescence enhancement in Tm3+-Yb3+ doped optical fiber beyond plasmonics

International Nuclear Information System (INIS)

Chattopadhyay, Rik; Haldar, Arindam; Paul, Mukul C.; Das, Shyamal; Bhadra, Shyamal K.

2015-01-01

We report a process for enhancing fluorescence emission from conventional rare earth ions in optical fiber by metal nanocluster (MNC) in nonresonant indirect pumping. The process is completely different from formal metal enhanced fluorescence phenomenon as the MNCs are too small in size to support localized surface plasmon and the excitation wavelength is far from plasmon resonance frequency. We used an established theory of two coupled oscillators to explain the simultaneous enhancement of Ytterbium (Yb 3+ ) and Thulium (Tm 3+ ) emission by silver (Ag) NCs under nonresonant pumping in optical fiber. The fiber is pumped with a 980 nm fiber pigtailed laser diode with input power of 20–100 mW to excite the Yb 3+ . Four times enhancement of Yb 3+ emission of 900–1100 nm and Tm 3+ upconversion emission around 474 nm, 650 nm, and 790 nm is observed in the fiber with Ag NCs

Multifunctional hydroxyapatite/Na(Y/Gd)F4:Yb3+,Er3+ composite fibers for drug delivery and dual modal imaging.

Science.gov (United States)

Liu, Min; Liu, Hui; Sun, Shufen; Li, Xuejiao; Zhou, Yanmin; Hou, Zhiyao; Lin, Jun

2014-02-04

Porous hydroxyapatite (HAp) composite fibers functionalized with up-conversion (UC) luminescent and magnetic Na(Y/Gd)F4:Yb(3+),Er(3+) nanocrystals (NCs) have been fabricated via electrospinning. After transferring hydrophobic oleic acid-capped Na(Y/Gd)F4:Yb(3+),Er(3+) NCs into aqueous solution, these water-dispersible NCs were dispersed into precursor electrospun solution containing CTAB. Na(Y/Gd)F4:Yb(3+),Er(3+)@HAp composite fibers were fabricated by the high temperature treatment of the electrospun Na(Y/Gd)F4:Yb(3+),Er(3+) NCs decorated precursor fibers. The biocompatibility test on MC 3T3-E1 cells using MTT assay shows that the HAp composite fibers have negligible cytotoxity, which reveals the HAp composite fibers could be a drug carrier for drug delivery. Because the contrast brightening is enhanced at increased concentrations of Gd(3+), the HAp composite fibers can serve as T1 magnetic resonance imaging contrast agents. In addition, the composites uptaken by MC 3T3-E1 cells present the UC luminescent emission of Er(3+) under the excitation of a 980 nm near-infrared laser. The above findings reveal Na(Y/Gd)F4:Yb(3+),Er(3+)@HAp composite fibers have potential applications in drug storage/release and magnetic resonance/UC luminescence imaging.

Yb3+,Er3+,Eu3+-codoped YVO4 material for bioimaging with dual mode excitation

International Nuclear Information System (INIS)

Thao, Chu Thi Bich; Huy, Bui The; Sharipov, Mirkomil; Kim, Jin-Ik.; Dao, Van-Duong; Moon, Ja-Young; Lee, Yong-Ill

2017-01-01

We propose an efficient bioimaging strategy using Yb 3+ ,Er 3+ ,Eu 3+ -triplet doped YVO 4 nanoparticles which were synthesized with polymer as a template. The obtained particles possess nanoscale, uniform, and flexible excitation. The effect of Eu 3+ ions on the luminescence properties of YVO 4 :Yb 3+ ,Er 3+ ,Eu 3+ was investigated. The upconversion mechanism of the prepared material was also discussed. The structure and optical properties of the prepared material were characterized by using X-ray diffraction (XRD), Fourier-transform IR spectroscopy (FTIR), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) upconversion and photoluminescence spectra. The Commission International de I′Eclairage (CIE) chromaticity coordinates was investigated to confirm the performance of color luminescent emission. The prepared YVO 4 :Yb 3+ ,Er 3+ ,Eu 3+ nanoparticles could be easily dispersed in water by surface modification with cysteine (Cys) and glutathione (GSH). The aqueous dispersion of the modified YVO 4 :Yb 3+ ,Er 3+ ,Eu 3+ exhibits bright upconversion and downconversion luminescence and has been applied for bioimaging of HeLa cells. Our developed material with dual excitation offers a promising advance in bioimaging. - Highlights: • Prepared particles possess nanoscale size, uniform, and larger scale. • The material exhibits strong emission under dual mode excitations. • The surface material has been applied for bioimaging of HeLa cell. • Low cytotoxicity, no auto-fluorescence

Up conversion luminescence of Yb3+–Er3+ codoped CeO2 nanocrystals with imaging applications

International Nuclear Information System (INIS)

Cho, Jung-Hyun; Bass, Michael; Babu, Suresh; Dowding, Janet M.; Self, William T.; Seal, Sudipta

2012-01-01

The effects of Yb 3+ doping on up conversion in Yb 3+ –Er 3+ co-doped cerium oxide nanocrystals are reported. Green emission around 545 and 560 nm attributed to the 2 H 11/2 , 4 S 3/2 → 4 I 15/2 transitions and red emission around 660 and 680 nm due to 4 F 9/2 → 4 I 15/2 transitions under 975 nm excitation were studied at room temperature. Both green and red emission intensities increase as the Yb 3+ concentration increases from 0%. Emission strength starts to decrease after the Yb 3+ concentration exceeds a critical amount. The green emission strength peaks around 1% Yb 3+ concentration while the red emission strength peaks around 4%. An explanation of competition between different decay mechanisms is presented to account for the luminescence dependence on Yb 3+ concentration. Also, the application of up converting nanoparticles in biomedical imaging is demonstrated. - Highlights: ► Up conversion in Yb 3+ –Er 3+ co-doped cerium oxide nanocrystals. ► Different decay mechanisms determine luminescence efficiency. ► Up converting nanoparticles in biomedical imaging is demonstrated.

Modeling of Yb3+-sensitized Er3+-doped silica waveguide amplifiers

DEFF Research Database (Denmark)

Lester, Christian; Bjarklev, Anders Overgaard; Rasmussen, Thomas

1995-01-01

A model for Yb3+-sensitized Er3+-doped silica waveguide amplifiers is described and numerically investigated in the small-signal regime. The amplified spontaneous emission in the ytterbium-band and the quenching process between excited erbium ions are included in the model. For pump wavelengths...

Influence of gold nanoparticles on the 805 nm gain in Tm3+/Yb3+ codoped PbO-GeO2 pedestal waveguides

Science.gov (United States)

de Assumpção, T. A. A.; Camilo, M. E.; Alayo, M. I.; da Silva, D. M.; Kassab, L. R. P.

2017-10-01

The production and characterization of pedestal waveguides based on PbO-GeO2 amorphous thin films codoped with Tm3+/Yb3+, with and without gold nanoparticles (NPs), are reported. Pedestal structure was obtained by conventional photolithography and plasma etching. Tm3+/Yb3+ codoped PGO amorphous thin film was obtained by RF Magnetron Sputtering deposition and used as core layer in the pedestal optical waveguide. The minimum propagation losses in the waveguide were 3.6 dB/cm at 1068 nm. The internal gain at 805 nm was enhanced and increased to 8.67 dB due to the presence of gold NPs. These results demonstrate for the first time that Tm3+/Yb3+ codoped PbO-GeO2 waveguides are promising for first telecom window and integrated photonics, especially for applications on fiber network at short distances.

Preparation and up-conversion luminescence of SrAlF{sub 5}:Yb{sup 3+}/Er{sup 3+} nanorods

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jun [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China); Hua, Ruinian, E-mail: rnhua@dlnu.edu.cn [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Zhang, Wei; Feng, Zhiqing; Tang, Dongxin; Na, Liyan [College of Life Science, Dalian Nationalities University, Dalian, Liaoning 116600 (China); Chen, Baojiu, E-mail: chenmbj@sohu.com [Department of Physics, Dalian Maritime University, Dalian, Liaoning 116026 (China)

2014-03-05

Graphical abstract: The SrAlF{sub 5} nanorods co-doped with various Yb{sup 3+}/Er{sup 3+} concentrations was synthetized via a microemulsion-hydrothermal process for the first time. It was found that the optimum doping concentration of Yb{sup 3+} and Er{sup 3+} in SrAlF{sub 5} matrix was about 4 mol%. Furthermore, the temperature effect of upconversion luminescence was investigated. It was also found that the post heat-treatment could greatly improve upconversion luminescence. Highlights: • SrAlF{sub 5}:Yb{sup 3+}/Er{sup 3+} nanorods were synthesized via a microemulsion-hydrothermal process. • Crystal structure and morphology were characterized by using XRD and FESEM. • The upconversion luminescence intensity depend on LD working current was studied. • The post heat-treatment could greatly improve upconversion luminescence. -- Abstract: Yb{sup 3+} and Er{sup 3+} co-doped SrAlF{sub 5} nanorods with average diameter of 35 nm and average length of 400 nm were synthesized via a microemulsion-hydrothermal process, and their crystal structure and morphology were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The optimum doping concentration of Yb{sup 3+}/Er{sup 3+} in SrAlF{sub 5} matrix was about 4 mol%. The upconversion luminescence intensity dependence on the laser diode (LD) working current was studied and the possible upconversion mechanism was analyzed. Furthermore, the temperature effect of upconversion luminescence was investigated. It was also found that the post heat-treatment could greatly improve upconversion luminescence.

Silver nanoparticles enhanced 1.53 µm band fluorescence of Er{sup 3+}/Yb{sup 3+} codoped tellurite glasses

Energy Technology Data Exchange (ETDEWEB)

Qi, Yawei; Zhou, Yaxun, E-mail: zhouyaxun@nbu.edu.cn; Wu, Libo; Yang, Fengjing; Peng, Shengxi; Zheng, Shichao; Yin, Dandan

2014-09-15

The silver nanoparticles (NPs) was introduced into the Er{sup 3+}/Yb{sup 3+} codoped tellurite glasses with composition of TeO{sub 2}–ZnO to improve the 1.53 µm band fluorescence of Er{sup 3+} and the thermal stability of glass host. The UV–Vis–NIR absorption spectra, 1.53 µm band fluorescence spectra and fluorescence decaying curves, the differential scanning calorimeter (DSC) curves, X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images of glass samples were characterized to investigate the effect of silver NPs on the fluorescence properties of Er{sup 3+}, thermal stability and structure behavior of glass host. It is shown that the Er{sup 3+}/Yb{sup 3+} codoped tellurite glass emits intense 1.53 µm band fluorescence with peak wavelength located at about 1532 nm under the 980 nm excitation. The introduction of silver NPs further improves the fluorescence intensity of Er{sup 3+} which is attributed to the enhanced local electric field effect induced by localized surface Plasmon resonance (LSPR) of silver NPs and the possible energy transfer from silver NPs to Er{sup 3+}. An improvement by about 62% of 1.5{sup 3} µm band fluorescence intensity was found in the studied Er{sup 3+}/Yb{sup 3+} codoped tellurite glass containing 0.5 mol% amount of AgNO{sub 3}. In addition, the thermal stability of glass host increases with the introduction of silver NPs while the glass structure maintains the amorphous nature. The present results indicate that the prepared Er{sup 3+}/Yb{sup 3+} codoped tellurite glass with an appropriate amount of silver NPs has good prospect as a gain medium applied for 1.53 µm band broad and high-gain erbium-doped fiber amplifiers (EDFAs). - Highlights: • Tellurite glass with Er{sup 3+}/Yb{sup 3+} and silver NPs was prepared by melt-quenching method. • Silver NPs with average size of 12 nm and Plasmon band at 560 nm was observed. • Addition of silver NPs increased the thermal stability of tellurite glass. �

NIR to visible frequency upconversion in Er{sup 3+} and Yb{sup 3+} codoped ZrO{sub 2} phosphor

Energy Technology Data Exchange (ETDEWEB)

Singh, Vijay; Kim, Sang Hwan [Konkuk University, Department of Chemical Engineering, Seoul (Korea, Republic of); Rai, Vineet Kumar [Indian School of Mines, Department of Applied Physics, Dhanbad (India); Al-Shamery, Katharina [University of Oldenburg, Physical Chemistry, Institute for Pure and Applied Chemistry and Center of Interface Science, Oldenburg (Germany); Haase, Markus [University of Osnabrueck, Department of Inorganic Chemistry I-Materials Research, Institute of Chemistry, Osnabrueck (Germany)

2013-11-15

The ZrO{sub 2}:Er{sup 3+} codoped with Yb{sup 3+} phosphor powders have been prepared by the urea combustion route. Formation of the compounds ZrO{sub 2}:Er{sup 3+} and ZrO{sub 2}:Er{sup 3+}, Yb{sup 3+} was confirmed by XRD. The frequency upconversion emissions in the green and red regions upon excitation with a CW diode laser at {proportional_to}978 nm are reported. Codoping with Yb{sup 3+} enhances the emission intensities of the triply ionized erbium in the green and red spectral regions by about {proportional_to}130 and {proportional_to}820 times respectively. The emission properties of the ZrO{sub 2}:Er{sup 3+} phosphor powders are discussed on the basis of excited state absorption, energy transfer, and cross-relaxation energy transfer mechanisms. (orig.)

Frequency upconversion fluorescence studies of Er{sup 3+}/Yb{sup 3+}-codoped KNbO{sub 3} phosphors

Energy Technology Data Exchange (ETDEWEB)

Balakrishnaiah, R. [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Kim, Dong Woo [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Yi, Soung Soo, E-mail: ssyi@silla.ac.k [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Kim, Kwang Duk; Kim, Sung Hoon [Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Jang, Kiwan; Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

2009-05-29

Different concentrations of Er{sup 3+} and Yb{sup 3+} ions-doped potassium niobate (K{sub 0.9}NbO{sub 3}:Yb{sub (x)}Er{sub (0.1-x)} for x = 0, 0.01, 0.05, 0.09 and 0.1) polycrystalline powder phosphors were prepared by the conventional solid state reaction method and were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Energy transfer and upconversion fluorescence properties of the Yb{sup 3+} and Er{sup 3+}-codoped phosphors have been discussed. The XRD data has shown mono-phase for pure KNbO{sub 3} while the doped samples represented additional phase formation. The SEM micrographs represented the rectangular crystal growth habit for the KNbO{sub 3} phosphors when doped with 0.1 mol of Er{sup 3+} ions. An intense green emission at 557 nm along with a red emission at 674 nm was observed when the doped samples were excited with 975 nm IR radiation. The upconversion mechanism has been discussed based on the excited state absorption and energy transfer mechanisms.

Luminescence investigation of Yb3+/Er3+ codoped single LiYF4 microparticle

International Nuclear Information System (INIS)

Gao, Wei; Zheng, Hairong; He, Enjie; Lu, Ying; Gao, Fangqi

2014-01-01

Tetragonal phase LiYF 4 :Yb 3+ /Er 3+ microparticles are synthesized via facile hydrothermal method. Single LiYF 4 microparticle is excited with IR laser at 980 nm in a confocal setup, and strong green and weak red emissions are observed. It is found that single LiYF 4 :Yb 3+ /Er 3+ microparticle with sub-structure presents stronger upconversion luminescence emission and smaller intensity ratio of red to green emission than that from LiYF 4 :Yb 3+ /Er 3+ microparticle with no sub-structure. The possible mechanism, the influence of particle size and the existence of EDTA on the upconversion luminescence emission are investigated. The current study suggests that the luminescence observation with single micropaticle can effectively avoid the influence of environment and neighbor particles, which is important for investigating the luminescence properties of micro- or nano-crystals and for extending their application. - Highlights: • Single LiYF 4 microparticle is excited with IR laser at 980 nm in a confocal setup, and strong green and weak red emissions are observed. • Single LiYF 4 microparticle with different morphology exhibits different fluorescence emission intensity and intensity ratio of red to green emission. • The possible mechanism, the influence of particle size and the existence of EDTA on the upconversion emission are investigated

Upconversion and tribological properties of β-NaYF{sub 4}:Yb,Er film synthesized on silicon substrate

Energy Technology Data Exchange (ETDEWEB)

Wang, Chuanying [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Cheng, Xianhua, E-mail: xhcheng@sjtu.edu.cn [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2016-05-15

Highlights: • β-NaYF{sub 4}:Yb,Er upconversion (UC) film was synthesized on silicon substrate. • Tribological test was used to qualitatively evaluate the adhesion of the UC film. • The UC film was combined with Si substrate by covalent chemical bonds. • The method used in this work can be applicable for other UC films. - Abstract: In this work, β-NaYF{sub 4}:Yb,Er upconversion (UC) film was successfully prepared on silicon (Si) substrate via self-assemble method for the first time. The chemical composition and surface morphology of the UC film were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), water contact angle (WCA), X-ray power diffraction (XRD), and scanning electron microscopy (SEM) measurements. To investigate the effects of KH-560 primer film and chemical reactions on the UC luminescence properties of β-NaYF{sub 4}:Yb,Er UC film, decay profiles of the 540 nm and 655 nm radiations were measured. Furthermore, tribological test was applied to qualitatively evaluate the adhesion of the UC film. The results indicate that the UC film has been successfully prepared on Si substrate by covalent chemical bonds. This work provides a facile way to synthesize β-NaYF{sub 4}:Yb,Er UC film with robust adhesion to the substrate, which can be applicable for other UC films.

Sequential coating upconversion NaYF{sub 4}:Yb,Tm nanocrystals with SiO{sub 2} and ZnO layers for NIR-driven photocatalytic and antibacterial applications

Energy Technology Data Exchange (ETDEWEB)

Tou, Meijie; Luo, Zhenguo; Bai, Song; Liu, Fangying; Chai, Qunxia; Li, Sheng; Li, Zhengquan, E-mail: zqli@zjnu.edu.cn

2017-01-01

ZnO is one of the most promising materials for both photocatalytic and antibacterial applications, but its wide bandgap requires the excitation of UV light which limits their applications under visible and NIR bands. Herein, we demonstrate a facile approach to synthesize core-shell-shell hybrid nanoparticles consisting of hexagonal NaYF{sub 4}:Yb,Tm, amorphous SiO{sub 2} and wurtzite ZnO. The upconversion nanocrystals are used as the core seeds and sequentially coated with an insulting shell and a semiconductor layer. Such hybrid nanoparticles can efficiently utilize the NIR light through the upconverting process, and display notable photocatalytic performance and antibacterial activity under NIR irradiation. The developed NaYF{sub 4}:Yb,Tm@SiO{sub 2}@ZnO nanoparticles are characterized with TEM, XRD, EDS, XPS and PL spectra, and their working mechanism is also elucidated. - Highlights: • Core-shell NaYF{sub 4}:Yb,Tm@SiO{sub 2}@TiO{sub 2} NPs were synthesized via a sequential coating method. • Hybrid NaYF{sub 4}:Yb,Tm@SiO{sub 2}@TiO{sub 2} NPs show NIR-light enhanced photocatalytic activity. • NIR-driven antibacterial performance has been realized with NaYF{sub 4}:Yb,Tm@SiO{sub 2}@TiO{sub 2} NPs. • Working mechanism of the hybrid photocatalysts as antibacterial agents was proposed.

Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

International Nuclear Information System (INIS)

Lluscà, M.; López-Vidrier, J.; Lauzurica, S.; Sánchez-Aniorte, M.I.; Antony, A.; Molpeceres, C.; Hernández, S.; Garrido, B.; Bertomeu, J.

2015-01-01

Transparent and conducting ZnO:Er:Yb thin films with visible up-conversion (660-nm emission under 980-nm excitation) were fabricated by RF magnetron sputtering. The as-deposited films were found to be transparent and conducting and the activation of the Er ions in these films to produce up-conversion luminescence was achieved by different post-deposition annealing treatments in air, vacuum or by laser annealing using a Nd:YVO 4 laser. The structural, electrical and optical properties and the up-conversion efficiency of these films were found to be strongly influenced by the annealing method, and a detailed study is reported in this paper. It has been demonstrated that, although the air annealing was the most efficient in terms of up-conversion, laser annealing was the only method capable of activating Er ions while preserving the electrical conductivity of the doped films. It has been shown that a minimum energy was needed in laser annealing to optically activate the rare earth ions in the ZnO host material to produce up-conversion. Up-converting and transparent conducting ZnO:Er:Yb films with an electrical resistivity of 5×10 −2 Ω cm and transparency ~80% in the visible wavelength range has been achieved by laser annealing. - Highlights: • Transparent and conducting ZnO:Er:Yb films were grown via magnetron sputtering. • Post-annealing ZnO:Er:Yb is needed to optically activate Er ions. • Visible up-conversion emission at 660 nm is observed under 980 nm excitation. • A transparent and conducting up-converter is achieved by laser annealing

Oxygen plasma effects on zero resistance behavior of Yb,Er-doped YBCO (123) based superconductors

Energy Technology Data Exchange (ETDEWEB)

Schaefer, Helmut; Rathmann, Dirk [Department of Physics, Biophysics, and Photosynthesis, Freie Universitaet Berlin (Germany); Banko, Franziska; Steinhart, Martin [Physical Chemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany); Nordmann, Joerg; Voss, Benjamin [Inorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany); Walder, Lorenz [Organic Chemistry, Molecular Electrochemistry, Institute of Chemistry of New Materials, University of Osnabrueck (Germany)

2014-08-15

Rare-earth doped YBa{sub 2}Cu{sub 3}O{sub 7-δ} samples were synthesized starting from the corresponding oxides Y{sub 2}O{sub 3}, Yb{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, CuO as well as Ba(OH){sub 2} by heating to 950 C under air. The doping concentrations were adjusted to 15 % Yb, 7 % Er and 20 % Yb, 15 % Er, respectively, with respect to the yttrium content. The orthogonal phased (123) YBCO ceramics were exposed to an oxygen plasma for 140 and 380 min. Zero resistance temperature (T{sub c,0}) was determined by measuring the resistivity-temperature dependence using a classical four point measurement approach. Under optimal conditions with respect to the material composition and the oxygen treatment an unusual high zero resistance temperature of 97.5 K (T{sub c,onset} ∼ 101 K) was achieved. This represents an increase of T{sub c,0} by 7.5 K. The oxygen treatment could not be monitored by IR spectroscopy, X-ray fluorescence spectroscopy, and X-ray powder diffraction. The results showed good reproducibility. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Spatially selective Er/Yb-doped CaF2 crystal formation by CO2 laser exposure

International Nuclear Information System (INIS)

Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo

2014-01-01

Highlights: • Oxyfluoride glass–ceramics containing CaF 2 nanocrystals doped with Er 3+ and Yb 3+ ions were formed on the glass surface by CO 2 laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF 2 nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO 2 laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF 2 and miner Ca 2 SiO 4 nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment

Spatially selective Er/Yb-doped CaF2 crystal formation by CO2 laser exposure

International Nuclear Information System (INIS)

Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo

2015-01-01

Highlights: • Oxyfluoride glass–ceramics containing CaF 2 nanocrystals doped with Er 3+ and Yb 3+ ions were formed on the glass surface by CO 2 laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF 2 nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO 2 laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF 2 and miner Ca 2 SiO 4 nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment

Upcoversion performance improvement of NaYF4:Yb, Er by Sn codoping: Enhanced emission intensity and reduced decay time

International Nuclear Information System (INIS)

Yu, Han; Cao, Wenbing; Huang, Qingming; Ma, En; Zhang, Xinqi; Yu, Jianchang

2013-01-01

In this manuscript we report a phenomenon that upconversion emission intensity of Er 3+ was enhanced while decay time constant was decreased obviously by Sn codoping with Yb/Er into hexagonal NaYF 4 synchronously. X-ray powder diffiraction, field emission scanning electron microscope, transmission electron microscopy, X-ray photoelectron spectroscopy, electron spin-resonance spectroscopy and upconversion emission spectra were employed to explore the relation of crystal structure and properties. From these characterizations we found that symmetry of the rare earth ion local crystal field could be tuned by different Sn codoping concentration. For the variable valence property of Sn the local crystal field asymmetry and emission intensity of NaYF 4 :Yb, Er arrived to the maximum when 3 mol% Sn was codoped, while decay time was reduced. The study of this changing tends of upconversion emission intensity and decay time constant may be helpful for design and fabrication of high performance upconversion materials. - Graphical abstract: Variable-valenced Sn is introduced with Yb/Er into NaFY 4 to tune structure and local crystal field. Upconversion emission intensity of Er 3+ was enhanced while decay time constant was decreased. Display Omitted - Highlights: • NaYF 4 : Yb, Er was codoped with different concentration Sn. • Upconversion emission intensity was enhanced while decay time constant was decreased. • Introduction of variable-valenced Sn is effective to tune structure and crystal field of NaFY 4

Role of the stimulated radiation of Yb3+ ions in the formation of luminescence of the Y0.8Yb0.2F3:Tm3+ solid solution

Science.gov (United States)

Mikheev, A. V.; Kazakov, B. N.

2015-09-01

A new mechanism has been proposed for the transfer of the energy of exciting laser radiation through the donor subsystem (Yb3+) to acceptors (Tm3+), which induces multiphoton transitions in the acceptor subsystem. The coherence of the induced radiation of donors is of key importance in this mechanism. An analytical dependence of the intensity of the up-conversion luminescence of Tm3+ (1G4 → 3H6) ions in the Y0.8Yb0.2F3:Tm3+ system on the pump power at the steady-state excitation by 934-nm infrared radiation of a laser diode has been obtained using the mathematical technique of the theory of Poisson processes. In contrast to known mechanisms, this dependence approximates the experimental dependence well in a wide power range (200-1200 mW). The proposed model is applicable for any system where the energy of pump radiation is transferred to acceptors through the subsystem of donor ions.

Quantum sized Ag nanocluster assisted fluorescence enhancement in Tm{sup 3+}-Yb{sup 3+} doped optical fiber beyond plasmonics

Energy Technology Data Exchange (ETDEWEB)

Chattopadhyay, Rik; Haldar, Arindam; Paul, Mukul C.; Das, Shyamal; Bhadra, Shyamal K., E-mail: skbhadra@cgcri.res.in [Fiber Optics and Photonics Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata 700032 (India)

2015-12-07

We report a process for enhancing fluorescence emission from conventional rare earth ions in optical fiber by metal nanocluster (MNC) in nonresonant indirect pumping. The process is completely different from formal metal enhanced fluorescence phenomenon as the MNCs are too small in size to support localized surface plasmon and the excitation wavelength is far from plasmon resonance frequency. We used an established theory of two coupled oscillators to explain the simultaneous enhancement of Ytterbium (Yb{sup 3+}) and Thulium (Tm{sup 3+}) emission by silver (Ag) NCs under nonresonant pumping in optical fiber. The fiber is pumped with a 980 nm fiber pigtailed laser diode with input power of 20–100 mW to excite the Yb{sup 3+}. Four times enhancement of Yb{sup 3+} emission of 900–1100 nm and Tm{sup 3+} upconversion emission around 474 nm, 650 nm, and 790 nm is observed in the fiber with Ag NCs.

Intense blue upconversion emission and intrinsic optical bistability in Tm3+/Yb3+/Zn2+ tridoped YVO4 phosphors

Science.gov (United States)

Yadav, Manglesh; Mondal, Manisha; Mukhopadhyay, Lakshmi; Rai, Vineet Kumar

2018-04-01

Tm3+/Yb3+/Zn2+:yttrium metavanadate (YVO4) phosphors prepared through chemical coprecipitation and the solid state reaction method have been structurally characterized by an x-ray diffraction (XRD) study. Photoluminescence study of the developed phosphors under ultraviolet (UV) and near infrared (NIR) excitation has been performed. The excitation spectrum of the tetragonal zircon type YVO4 phosphors corresponding to the emission at ˜476 nm exhibits a broad excitation peak in the 250-350 nm region, which is due to charge distribution in the {{{{VO}}}4}3- group. Under 980 nm CW diode laser excitation, enhancements of about ˜3000 times and ˜40 times have been observed for the blue band in the tridoped Tm3+Yb3+Zn2+:YVO4 phosphors compared to those of the Tm3+:YVO4 singly and Tm3+/Yb3+:YVO4 codoped phosphors, respectively. A downconversion (DC) emission study shows an enhancement of about ˜50 times for the blue band in the tridoped phosphors compared to that of the singly doped phosphors. Optical bistability (OB) behavior of the developed phosphors has been also investigated upon 980 nm excitation. The calculated Commission Internationale de l’Éclairage (CIE) color coordinates lie in the blue region with 96.5% color purity under 980 nm excitation, having a color temperature of ˜3400 K. Our observations show that the developed phosphors may be suitably used in dual mode luminescence spectroscopy, display devices, and UV LED chips.

Spectral properties of Er3+/Yb3+ codoped tungsten-tellurite glasses.

Science.gov (United States)

Shen, Xiang; Nie, QiuHua; Xu, TieFeng; Gao, Yuan

2005-07-01

The spectral properties of Er3+/Yb3+ codoped tungsten-tellurite (WT) glasses have been investigated. The measured absorption spectra are analyzed by Judd-Ofelt theory. The compositional change of intensity parameter omega2 is attributed to the change in the covalency between the Er3+ and oxygen ions, the asymmetry in the local structures around the Er3+ ions can be neglected. The lifetimes of 4I(13/2) level of Er3+ in WT glasses are measured and comparable with other TeO2-based glasses. The stimulated emission cross-section is calculated based on McCumber theory. The fluorescence full width at half maximum (FWHM) and the emission cross-section (sigma(peak)) of the 4I(13/2) --> 4I(15/2) transition of Er3+ in different glass hosts have been compared. The suitability of such WT glasses as host materials for 1.5 microm broadband amplification is discussed.

ZnMoO4:Er3+,Yb3+ phosphor with controlled morphology and enhanced upconversion through alkali ions doping

Science.gov (United States)

Luitel, Hom Nath; Chand, Rumi; Watari, Takanori

2018-04-01

A facile hydrothermal method was used to synthesize ZnMoO4:Er3+,Yb3+ nanoparticles. The shapes and sizes of the nanoparticles were well tuned by simply monitoring the pH of the starting solution. Microballs consisting of agglomerated nanograins were observed at strong acidic condition. At mild pH, plates and rectangular particles were realized, while strong basic pH stabilized rods. Further increasing pH to extremely basic conditions (pH > 13), rods changed to fragile hairy structures. The nucleation and growth mechanism of nanograins to form different morphology nanoparticles were studied and illustrated. XRD patterns confirmed well crystalline, triclinic structure despite small amount of aliovalent metal ions doping. Under 980 nm excitation, the ZnMoO4:Er3+,Yb3+ nanophosphor exhibited strong green (centered at 530 and 560 nm) and weak red (centered at 660 nm) upconversion (UC) emissions. Substitution of part of the Zn2+ ions by monovalent alkali ions intensified the UC emission intensities drastically. The order of intensification was K+>Na+>Li+>Rb+>no alkali ion. When Zn2+ ions were substituted with 10 at% K+ ions, the green and red UC emissions intensities increased by more than 50 and 15 folds, respectively. Time dependent measurements confirmed efficient Yb to Er energy transfer in the ZnMoO4:Er3+,Yb3+,K+ nanophosphor. The optimized ZnMoO4:Er3+,Yb3+,K+ phosphor exhibited intense UC emissions with 0.31% quantum yield. The upconverted light is visible to naked eye while pumping by laser of less than 1 mW power and opens door for variety of novel applications.

Up-conversion routines of Er{sup 3+}–Yb{sup 3+} doped Y{sub 6}O{sub 5}F{sub 8} and YOF phosphors

Energy Technology Data Exchange (ETDEWEB)

Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Yang, Wonseok; Park, Chu-Young; Noh, Minhee; Choi, Seulki [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Park, Dahye; Jang, Ho Seong; Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

2015-11-15

Highlights: • Single-phase optical materials of Y{sub 6}O{sub 5}F{sub 8}:Er and YOF:Er were prepared. • Effective spectral converting properties were observed in Y{sub 6}O{sub 5}F{sub 8}:Er,Yb. • 980 nm diode laser was irradiated for up-converting analysis. • A multi-photon process in the phosphors was investigated. - Abstract: Optical materials composed of a Y{sub 6(1−p−q)}Er{sub 6p}Yb{sub 6q}O{sub 5}F{sub 8} (p = 0.001–0.1, q = 0.005–0.1) solid solution with Y{sub 0.99}Er{sub 0.01}OF were prepared via a solid-state reaction using excess NH{sub 4}F flux at 950 °C for 30 min. X-ray diffraction patterns of Y{sub 6(1−p−q)}Er{sub 6p}Yb{sub 6q}O{sub 5}F{sub 8} and Y{sub 0.99}Er{sub 0.01}OF were compared upon altering the synthesis temperature and the molar ratio of the NH{sub 4}F flux to the Y{sup 3+} (Er{sup 3+}, Yb{sup 3+}) ions. The effective spectral-conversion properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} ions in Y{sub 6}O{sub 5}F{sub 8} phosphors were monitored during excitation with a 980 nm wavelength diode-laser. Selection of appropriate Er{sup 3+} and/or Yb{sup 3+} concentrations in the Y{sub 6}O{sub 5}F{sub 8} structure led to achievement of the desired up-conversion emission, from the green to the red regions of the spectra. Furthermore, the mechanism of up-conversion in the phosphors was described by an energy-level schematic. Up-conversion emission spectra and the dependence of the emission intensity on pump power (between 193 and 310 mW) in the Y{sub 6(0.995−q)}Er{sub 0.03}Yb{sub 6q}O{sub 5}F{sub 8} phosphors were also investigated.

Study of broadband near-infrared emission in Tm3+-Er3+ codoped TeO2-WO3-PbO glasses.

Science.gov (United States)

Balda, R; Fernández, J; Fernández-Navarro, J M

2009-05-25

In this work, we report the near-infrared emission properties of Tm(3+)-Er(3+) codoped tellurite TeO(2)-WO(3)-PbO glasses under 794 nm excitation. A broad emission from 1350 to 1750 nm corresponding to the Tm(3+) and Er(3+) emissions is observed. The full width at half-maximum of this broadband increases with increasing [Tm]/[Er] concentration ratio up to a value of ~ 160 nm. The energy transfer between Tm(3+) and Er(3+) ions is evidenced by both the temporal behavior of the near-infrared luminescence and the effect of Tm3+ codoping on the visible upconversion of Er(3+) ions.

Modification of Ag shell on upconversion populating paths of NaYF4:Yb3+,Er3+@Ag nanocomposites

International Nuclear Information System (INIS)

Sun, Jiao; Liu, Haipeng; Wu, Di; Dong, Biao; Sun, Liankun

2013-01-01

NaYF 4 :Yb 3+ ,Er 3+ @Ag core–shell nanocomposites were prepared. Due to the outer shell of Ag, some modifications were found on the upconversion (UC) processes of NaYF 4 :Yb 3+ ,Er 3+ core nanoparticles (NPs) caused by the co-interaction of surface effect, surface plasma absorption effect and local thermal effect under infrared radiation. Upon 980 nm excitation, the relative UC intensity of the green ( 2 H 11/2 , 4 S 3/2 – 4 I 15/2 ) to red ( 4 F 9/2 – 4 I 15/2 ) and the slope of power-dependence increased intensively, and three-photon population process for the green level appeared. -- Highlights: ► NaYF 4 :Yb 3+ ,Er 3+ @Ag core/shell nanocomposites were fabricated. ► The coating of Ag outer shell leads to the increase of the green UCL. ► Three-photon population process for the green level appeared after Ag coating.

Upconversion luminescence of Er3+/Yb3+ doped Sr5(PO4)3OH phosphor powders

Science.gov (United States)

Mokoena, P. P.; Swart, H. C.; Ntwaeaborwa, O. M.

2018-04-01

Sr5(PO4)3OH co-doped with Er3+and Yb3+ powder phosphors were synthesized by urea combustion method. The crystal structure was analyzed using X-ray diffraction (XRD). Particle morphology was analyzed using a Jeol JSM 7800F thermal field emission scanning electron microscope (FE-SEM) and the chemical composition analysis was carried out using an Oxford Instruments AzTEC energy dispersive spectrometer (EDS) attached to the FE-SEM. Upconversion emission was measured by using a FLS980 Spectrometer equipped with a 980 nm NIR laser as the excitation source, and a photomultiplier (PMT) detector. The XRD data of the Sr5(PO4)3OH powder exhibited characteristic diffraction patterns of the hexagonal structure referenced in the standard JCPDS card number 00-033-1348. The sharp peaks revealed the formation of crystalline Sr5(PO4)3OH. The powders were made up of hexagonal nanospheres. The enhanced red emission due to the 4F9/2 → 4I15/2 transitions of Er3+ was observed and was attributed to up conversion (UC) energy transfer from Yb3+. The upconversion energy transfer mechanism from Yb3+ to Er3+ is discussed.

Upcoversion performance improvement of NaYF{sub 4}:Yb, Er by Sn codoping: Enhanced emission intensity and reduced decay time

Energy Technology Data Exchange (ETDEWEB)

Yu, Han, E-mail: fjfzyh@fzu.edu.cn [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China); Cao, Wenbing [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China); Huang, Qingming [Instrumentation Analysis and Research Center, Fuzhou University, Fuzhou, Fujian 350002 (China); Ma, En [Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Zhang, Xinqi [Instrumentation Analysis and Research Center, Fuzhou University, Fuzhou, Fujian 350002 (China); Yu, Jianchang [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China)

2013-11-15

In this manuscript we report a phenomenon that upconversion emission intensity of Er{sup 3+} was enhanced while decay time constant was decreased obviously by Sn codoping with Yb/Er into hexagonal NaYF{sub 4} synchronously. X-ray powder diffiraction, field emission scanning electron microscope, transmission electron microscopy, X-ray photoelectron spectroscopy, electron spin-resonance spectroscopy and upconversion emission spectra were employed to explore the relation of crystal structure and properties. From these characterizations we found that symmetry of the rare earth ion local crystal field could be tuned by different Sn codoping concentration. For the variable valence property of Sn the local crystal field asymmetry and emission intensity of NaYF{sub 4}:Yb, Er arrived to the maximum when 3 mol% Sn was codoped, while decay time was reduced. The study of this changing tends of upconversion emission intensity and decay time constant may be helpful for design and fabrication of high performance upconversion materials. - Graphical abstract: Variable-valenced Sn is introduced with Yb/Er into NaFY{sub 4} to tune structure and local crystal field. Upconversion emission intensity of Er{sup 3+} was enhanced while decay time constant was decreased. Display Omitted - Highlights: • NaYF{sub 4}: Yb, Er was codoped with different concentration Sn. • Upconversion emission intensity was enhanced while decay time constant was decreased. • Introduction of variable-valenced Sn is effective to tune structure and crystal field of NaFY{sub 4}.

The concentration effect of upconversion luminescence properties in Er3+/Yb3+-codoped Y2(MoO4)3 phosphors

International Nuclear Information System (INIS)

Lu Weili; Cheng Lihong; Sun Jiashi; Zhong Haiyang; Li Xiangping; Tian Yue; Wan Jing; Zheng Yanfeng; Huang Libo; Yu Tingting; Yu Hongquan; Chen Baojiu

2010-01-01

Y 2 (MoO 4 ) 3 :Er 3+ /Yb 3+ phosphors with fixed (varied) Er 3+ and varied (fixed) Yb 3+ concentrations were synthesized by a conventional solid-state reaction. The crystal structure of the phosphors was characterized by means of X-ray diffraction (XRD). Upon 980 nm excitation, very weak blue emission, and strong green and red upconversion emissions centered at 485, 525, 545 and 656 nm were observed. The two-photon process was confirmed to be responsible for both the green and red upconversion emissions. The effects of green upconversion emission intensity ratio ( 2 H 11/2 → 4 I 15/2 versus 4 S 3/2 → 4 I 15/2 ) and the integrated upconversion emission intensity on the Yb 3+ and Er 3+ concentrations were studied.

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.

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.

Synthesis and characterization of α-NaYF{sub 4}: Yb, Er nanoparticles by reverse microemulsion method

Energy Technology Data Exchange (ETDEWEB)

Gunaseelan, M.; Senthilselvan, J., E-mail: jsselvan@hotmail.com [Department of Nuclear Physics, University of Madras, Chennai, Tamil Nadu (India)

2016-05-06

A simple and cost effective reverse microemulsion system was newly designed to synthesis NaYF{sub 4}:20%Yb,2%Er upconverting luminescent nanoparticles. XRD results confirms the cubic structure of NaYF{sub 4} nanophosphor in the as prepared condition without any other impurity phases. The as-prepared sample itself having highly crystalline nanoparticle with well dispersed uniform morphology is the advantage of this reverse microemulsion process. HRTEM images of as prepared and calcined samples revealed spherical nanoclusters morphology with size of ~210 nm and ~245 nm respectively. The characteristic absorption wavelength that occurs at 980 nm due to transition of energy levels {sup 2}F{sub 5/2} to {sup 2}F{sub 7/2} for Yb{sup 3+} rare earth ion in as prepared and calcined upconversion nanoparticle confirms the presence of Yb{sup 3+} by UV-Visible spectroscopy which can act as a sensitizer for photonic upconversion. Therefore the absorption at NIR region and emission spectrum at visible region suggests that NaYF{sub 4}:20%Yb,2%Er is suitable for upcoversion process, due to its optical property and chemical stability this material also be useful for bio imaging applications.

Spectroscopic characterization and temporal dynamics of energy transfer process between Tm3+ -Ho3+ and Yb3+ -Tm3+ ions in LiYF4 and LiLuF4 crystals

International Nuclear Information System (INIS)

Tarelho, Luiz Vicente Gomes

2001-01-01

In this work, we perform spectroscopic studies to characterize the energy transfer processes occurring in rare-earth doped lithium fluoride systems, aiming the optimization of the population inversion of these media. Yb 3+ ion was used in order to probe the electron-phonon coupling in LiYF 4 , LiGdF 4 and LiLuF 4 matrices. In these systems it was obtained the average phononenergy, the vibronic transition probability and Huang-Rhys coupling constant. These parameters are dependent on the crystal host and the LiLuF 4 system presents excluded correlation effects, an electronic repulsion that weakens the vibronic coupling. The Tm:Ho:LiYF 4 system was studied under diode laser pumping at 796 nm, aiming the 2 μm emission optimization. The ideal conditions of concentration and laser power were determined favouring the latter emission. Upconversion processes of two photons were identified besides the energy transfer among ions. The dynamic processes of luminescence of donors and acceptors allowed one to classify the energy transfer process as an energy transfer process assisted by fast diffusion among donors. The spectroscopic study of the Yb:Tm:LiYF 4 allowed the determination of efficient non resonant transfer mechanisms between ( 2 F 5/2 ) Ytterbium level and ( 3 H 5 ) Thulium level, assisted by two phonon with hopping migration among donors ( Foerster-Burshtein model). The repopulation process of the Yb donor level is due to a cooperative sensitization between Yb-Tm pairs followed by an energy transfer process. (author)

Spectral and laser properties of Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 crystal at 1.55 µm

Science.gov (United States)

Gong, Guoliang; Chen, Yujin; Lin, Yanfu; Huang, Jianhua; Gong, Xinghong; Luo, Zundu; Huang, Yidong

2018-04-01

An Er3+/Yb3+/Ce3+ tri-doped Ca3NbGa3Si2O14 (CNGS) crystal was grown by the Czochralski method. Spectral properties of the crystal, including the polarized absorption and fluorescence spectra, the fluorescence decay, as well as the energy transfer efficiency from Yb3+ to Er3+ were investigated in detail. End-pumped by a 976 nm diode laser, a 1556 nm continuous-wave laser with a maximum output power of 202 mW and a slope efficiency of 11.4% was achieved in the Er,Yb,Ce:CNGS crystal. The results indicate the Er,Yb,Ce:CNGS crystal is a promising 1.55 µm laser gain medium.

Spectroscopy and visible frequency upconversion in Er3+-Yb3+: TeO2-ZnO glass.

Science.gov (United States)

Mohanty, Deepak Kumar; Rai, Vineet Kumar

2014-01-01

The UV-Vis-NIR absorption studies of the Er(3+)/Er(3+)-Yb(3+) doped/codoped TeO2-ZnO (TZO) glasses fabricated by the melting and quenching method has been performed. The spectroscopic radiative parameters viz. radiative transition probabilities, branching ratios and lifetimes have been determined from the absorption spectrum by using Judd-Ofelt theory. The near infrared (NIR) to visible frequency upconversion (UC) have been monitored by using an excitation of 976 nm wavelength radiation from a CW diode laser. The effect of codoping with Yb(3+) ions on the intensity of the UC emission bands from the Er(3+) ions throughout visible region has been studied. The mechanism responsible for the observed upconversion emissions in the prepared samples have been explained on the basis of excited state absorption and efficient energy transfer processes. Copyright © 2013 Elsevier B.V. All rights reserved.

Enhancement of blue upconversion luminescence in hexagonal NaYF{sub 4}:Yb,Tm by using K and Sc ions

Energy Technology Data Exchange (ETDEWEB)

Kale, Vishal, E-mail: vishal.kale@utu.fi; Soukka, Tero [University of Turku, Department of Biochemistry and Food Chemistry/Biotechnology (Finland); Hoelsae, Jorma; Lastusaari, Mika [University of Turku, Department of Chemistry (Finland)

2013-08-15

Hexagonal ({beta})-NaYF{sub 4} is recognized as one of the most efficient hosts for NIR to blue and green upconversion (UC). A new method to tune the blue UC emission in {beta}-NaYF{sub 4}:Yb,Tm nanocrystals through the possible substitution of the host material with different concentrations of K{sup +} and Sc{sup 3+} ions was investigated in detail. In this work, Na{sub 1-x}K{sub x}YF{sub 4}:Yb,Tm and NaY{sub 1-x}Sc{sub x}F{sub 4}:Yb,Tm nanocrystals were synthesized with varying Na:K and Y:Sc ratios. X-ray diffraction, transmission electron microscopy, and UC luminescence spectroscopy showed that size, morphology, and UC luminescence intensity were affected by the addition of K{sup +} and Sc{sup 3+} ions. Substituted ions disturbed the local symmetry and also resulted in changes in the crystal field. The distance between Yb{sup 3+} and Tm{sup 3+} was affected by different concentration of K{sup +} and Sc{sup 3+} ions, and those differences in the distance are responsible for tuning UC luminescence. This study revealed that when the concentration of K{sup +} and Sc{sup 3+} ions were nominally increased from 20 to 100 mol% during synthesis, hexagonal NaYF{sub 4} changed to structurally different KYF{sub 4} and Na{sub 3}ScF{sub 6} so that the solid solubility became difficult. We also demonstrate that the added K{sup +} does not enter into the NaYF{sub 4} lattice, but it still plays an important role by controlling the Na/R ratio. K{sup +} and Sc{sup 3+} ion concentration of 20 mol% during the synthesis was found to result in materials with size 30-35 nm, and shows ca. four times brighter UC emission than the previously reported lanthanide based nanocrystals. The enhancement in UC luminescence intensity makes upconversion nanophosphors versatile imaging tools for diagnosis.Graphical Abstract.

Optical properties of highly crystalline Y2O3:Er,Yb nanoparticles prepared by laser ablation in water

International Nuclear Information System (INIS)

Nunokawa, Takashi; Odawara, Osamu; Wada, Hiroyuki

2014-01-01

Y 2 O 3 :Er,Yb nanoparticles were prepared by laser ablation in water. We investigated crystallinity, distribution of dopant, and optical properties of the prepared nanoparticles. The full-width half-maximum (FWHD) of the crystalline peak of nanoparticles measured by an x-ray diffractometer (XRD) barely changed. Further, using scanning transmission electron microscopy–energy dispersive x-ray spectroscopy (STEM–EDX), we confirmed the peaks of Y, Er, Yb, and O. Moreover, on the basis of the optical properties of the nanoparticles, the emission of red ( 2 F 9/2  →  4 I 15/2 ) and green ( 2 H 11/2 , 4 S 3/2  →  4 I 15/2 ) was confirmed. We also investigated the emission intensity as a function of the excitation power of 980 nm LD in the prepared nanoparticles. The photon avalanche effect was observed at the excitation power of 100 mW. These results confirmed that uniformly Er-Yb-doped Y 2 O 3 nanoparticles were successfully prepared by laser ablation in water. (paper)

Studies on high-pressure reaction of Er/sub 2/O/sub 3/ or Yb/sub 2/O/sub 3/ with VO/sub 2/

Energy Technology Data Exchange (ETDEWEB)

Shin-ike, T [Osaka Dental Coll., Hirakata (Japan); Adachi, G; Shiokawa, J; Shimada, M; Koizumi, M

1980-12-01

The reaction of erbium sesquioxide (Er/sub 2/O/sub 3/) or ytterbium sesquioxide (Yb/sub 2/O/sub 3/) with vanadium dioxide (VO/sub 2/) at 1400/sup 0/C and 50 kbar and 30 kbar pressures was studied. Quadrivalent vanadium ions were reduced to the trivalent state, erbium vanadate (ErVO/sub 3/) or ytterbium vanadate (YbVO/sub 3/) being obtained. The crystal structure of ErVO/sub 3/ obtained at 50 kbar pressure was vaterite-type isostructural with ErBO/sub 3/ belonging to a hexagonal system, and that obtained at 30 kbar calcite-type belonging to a rhombohedral (pseudo-hexagonal) system. In the reaction of Yb/sub 2/O/sub 3/ with VO/sub 2/ at high pressure, a perovskite-type crystal was obtained. The electrical and magnetic properties of the vaterite- and the calcite-type ErVO/sub 3/ were studied.

Red, green, blue and white light upconversion emission in Yb3+/Tm3+/Ho3+ co-doped tellurite glasses

International Nuclear Information System (INIS)

Desirena, H; De la Rosa, E; Meza, O; Salas, P

2011-01-01

Several Yb 3+ /Tm 3+ /Ho 3+ co-doped transparent TeO 2 -ZnO-Na 2 O-Yb 2 O 3 -Ho 2 O 3 -Tm 2 O 3 glasses were prepared and luminescence properties were characterized. Simultaneous red, green and blue (RGB) emission were obtained after excitation at 970 nm. Colour emission was tuned from multicolour to white light with colour coordinate (0.32, 0.33) matching very well with the white reference (0.33, 0.33). Changes in colour emission were obtained by varying the intensity ratios between RGB bands that are strongly concentration dependent because of the interaction of co-dopants. The colour tunability, high quality of white light and high intensity of the emitted signal make these transparent glasses excellent candidates for applications in solid-state lighting.

Spatially selective Er/Yb-doped CaF{sub 2} crystal formation by CO{sub 2} laser exposure

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo, E-mail: kslim@chungbuk.ac.kr

2014-10-30

Highlights: • Oxyfluoride glass–ceramics containing CaF{sub 2} nanocrystals doped with Er{sup 3+} and Yb{sup 3+} ions were formed on the glass surface by CO{sub 2} laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF{sub 2} nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO{sub 2} laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF{sub 2} and miner Ca{sub 2}SiO{sub 4} nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment.

Spatially selective Er/Yb-doped CaF{sub 2} crystal formation by CO{sub 2} laser exposure

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong-Seon; Lee, Jin-Ho; Lim, Ki-Soo, E-mail: kslim@chungbuk.ac.kr

2015-04-15

Highlights: • Oxyfluoride glass–ceramics containing CaF{sub 2} nanocrystals doped with Er{sup 3+} and Yb{sup 3+} ions were formed on the glass surface by CO{sub 2} laser and a heat gun exposure. • Most of Er and Yb ions were distributed inside CaF{sub 2} nanocrystals and fluorine loss was observed in the EDS element maps. • IR-to-VIS upconversion emission efficiency of laser annealed glass ceramics was much increased and compared with that of the furnace-annealed glass ceramics. • Distributed volume of the glass ceramics were estimated by a confocal fluorescence microscope imaging. - Abstract: We report the glass–ceramic precipitation on the oxyfluoride glass surface by spatially selective annealing with a CO{sub 2} laser and a heat gun exposure. X-ray diffraction analysis showed the formation of major CaF{sub 2} and miner Ca{sub 2}SiO{sub 4} nanoparticles. We observed ∼100 nm nanoparticle aggregation by tunneling electron microscopy and element distribution in glass and crystal phases. Spatial distribution of glass ceramics near the glass surface was probed by confocal fluorescence microscope by using much enhanced emission from the Er ions in the laser-treated area. Strong emissions at 365 nm excitation and visible up-conversion emissions at 980 nm excitation also indicated well incorporation of Er and Yb ions into a crystalline environment.

∼2 μm fluorescence radiative dynamics and energy transfer between Er3+ and Tm3+ ions in silicate glass

International Nuclear Information System (INIS)

Li, Ming; Liu, Xueqiang; Guo, Yanyan; Hao, Wei; Hu, Lili; Zhang, Junjie

2014-01-01

Graphical abstract: - Highlights: • A Er 3+ /Tm 3+ co-doped silicate glass with good thermal stability (k gl = 0.402 for STE glass) is prepared. • Efficient ∼2 μm emission is observed under 808 nm and 980 nm laser excitation. • The glass structure and spectroscopic properties are confirmed by optical absorption, IR transmission, Raman and fluorescence studies. • The content of OH groups deceases efficiently after fluorine ions are introduced. • The energy transfer coefficient from Er 3+ to Tm 3+ in STFE glass is 13.39 × 10 −40 cm 6 /s. - Abstract: A Er 3+ /Tm 3+ co-doped silicate glass with good thermal stability is prepared by melt-quenching method. An efficient emission of ∼2 μm is observed under different selective laser excitations. The optical absorption and transmission spectra, Raman spectra, and emission spectra are tested to characterize ∼2 μm emission properties of Er 3+ /Tm 3+ co-doped silicate glasses and a reasonable energy transfer mechanism of ∼2 μm emission between Er 3+ and Tm 3+ ions is proposed. Based on the optical absorption spectra, the Judd–Ofelt parameters and radiative properties were calculated. Intense ∼2 μm emission is obtained from Er 3+ /Tm 3+ co-doped silicate glasses due to the efficient energy transfer from Er 3+ to Tm 3+ ions. The energy transfer coefficient from Er 3+ to Tm 3+ ions can reach as high as 13.39 × 10 −40 cm 6 /s. In addition, the population of the OH groups is decreased and the ∼2 μm emission is effectively enhanced with fluoride introduction. The emission property, together with good thermal property, indicates that Er 3+ /Tm 3+ co-doped silicate glass is a potential kind of laser glass for efficient ∼2 μm laser

Crystalline phase, profile characteristics and spectroscopic properties of Er3+/Tm3+-diffusion-codoped LiNbO3 crystal

International Nuclear Information System (INIS)

Sun, Wen-Bao; Zhang, Zi-Bo; Sun, Hong-Xue; Wong, Wing-Han; Yu, Dao-Yin; Pun, Edwin Yue-Bun

2017-01-01

Er 3+ /Tm 3+ -codoped LiNbO 3 crystal was prepared by co-diffusion of stacked Er and Tm metal films coated onto surface of off-congruent, Li-deficient LiNbO 3 substrate produced by Li-poor vapor transport equilibration technique. The crystalline phase on the diffused surface was analyzed by X-ray single-crystal diffraction. The Er 3+ and Tm 3+ profile characteristics were studied by secondary ion mass spectrometry. The emission spectra were measured under the 980 or 795 nm wavelength excitation, and the emission and absorption cross section spectra were calculated based upon McCumber theory. The lifetimes of some emissions were measured. The results show that the Er 3+ and Tm 3+ ions presence is in the form of LiNbO 3 phase. Both ions obey to Gaussian profile with a diffusion depth 21.5 μm. In the codoping case, both ions keep their respective spectroscopic features of only doping case and do not affect each other. The codoping enables to combine the wavelength emissions of both ions and the resultant emission band in the telecommunication window around 1.5 μm is as wide as 150 nm, providing the possibility of S+C+L broadband amplification by employing commercial 980 and 795 nm laser diodes as the pump sources. The Er 3+ /Tm 3+ -codoped LN is a promising host material for integrated optics. - Graphical abstract: Er 3+ /Tm 3+ -codoped LiNbO 3 crystal was prepared by co-diffusion of stacked Er and Tm metal films. The crystalline phase, diffusion profile and cross section spectra of Er 3+ and Tm 3+ ions in the diffusion layer have been investigated. The results show that the presence of Er 3+ and Tm 3+ ions is in the LiNbO 3 phase. Both ions follow Gaussian profile with a diffusion depth 21.5 μm. Both ions keep their respective spectroscopic features of only doping case. Excited state absorption is the dominant process for 795-nm-upconvered fluorescence of Tm 3+ . The codoping enables to combine the wavelength emissions of both ions and provide the possibility of S

Optical transitions of Tm3+ in oxyfluoride glasses and compositional and thermal effect on upconversion luminescence of Tm3+/Yb3+-codoped oxyfluoride glasses.

Science.gov (United States)

Feng, Li; Wu, Yinsu; Liu, Zhuo; Guo, Tao

2014-01-24

Optical properties of Tm(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 Tm(3+)/Yb(3+)-codoped SiO2-BaF2-ZnF2 glasses under 980 nm excitation. The effects of composition, concentration of the doping ions, temperature, and excitation pump power on the upconversion emissions were also systematically studied. Copyright © 2013 Elsevier B.V. All rights reserved.

Equiatomic indides REIrIn (RE=La, Pr, Nd, Er-Yb). Crystal and electronic structure

Energy Technology Data Exchange (ETDEWEB)

Zaremba, Nazar [Ivan Franko National Univ. of Lviv (Ukraine). Dept. of Inorganic Chemistry; Technische Univ. Muenchen, Garching (Germany). Fakultaet fuer Chemie; Muts, Ihor; Zaremba, Vasyl [Ivan Franko National Univ. of Lviv (Ukraine). Dept. of Inorganic Chemistry; Hlukhyy, Viktor [Technische Univ. Muenchen, Garching (Germany). Fakultaet fuer Chemie; Stein, Sebastian; Rodewald, Ute C.; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Pavlyuk, Volodymyr [Ivan Franko National Univ. of Lviv (Ukraine). Dept. of Inorganic Chemistry; Czestochowa Jan Dlugosz Univ., Czestochowa (Poland). Inst. of Chemistry, Environmental Protection and Biotechnology

2017-10-01

The equiatomic rare earth iridium indides REIrIn (RE=La, Pr, Nd, Er-Yb) were synthesized by reaction of the elements in induction or muffle furnaces and were characterized through X-ray powder patterns. The structures of LaIr{sub 0.86}In{sub 1.14}, PrIr{sub 0.89}In{sub 1.11}, NdIr{sub 0.94}In{sub 1.06}, ErIrIn (all ZrNiAl type, P anti 62m), and YbIrIn (TiNiSi type, Pnma) were refined from single crystal X-ray diffractometer data. Refinements of the occupancy parameters revealed small degrees of solid solutions with indium substitution on the iridium sites. Chemical bonding analyses and electronic structure calculations indicate the dominance of metallic bonding in addition to partial ionic interactions between the cations and polyanions, as well as covalent contributions between the indium and iridium atoms.

Enhanced photovoltaic performance of dye-sensitized solar cells based on NaYF4:Yb(3+), Er(3+)-incorporated nanocrystalline TiO2 electrodes.

Science.gov (United States)

Zhu, Guang; Wang, Hongyan; Zhang, Quanxin; Zhang, Li

2015-08-01

Near infrared to visible up-conversion of light by rare earth ion-doped phosphors (NaYF4:Yb(3+), Er(3+)) that convert multiple photons of lower energy to higher energy photons offer new possibilities for improved performance of photovoltaic devices. Here, up-conversion phosphor NaYF4:Yb(3+), Er(3+) doped nanocrystalline TiO2 films are designed and used as a electrode for dye-sensitized solar cells, and the photovoltaic performance of DSSCs based on composite electrodes are investigated. The results show the cell with NaYF4:Yb(3+), Er(3+) achieves a power conversion efficiency of 7.65% under one sun illumination (AM 1.5G, 100mWcm(-2)), which is an increase of 14% compared to the cell without NaYF4:Yb(3+), Er(3+) (6.71%). The performance improvement is attributed to the dual effects of enhanced light harvesting from extended light absorption range and increased light scattering, and lower electron transfer resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

Mesoporous silica-coated NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+} particles for drug release

Energy Technology Data Exchange (ETDEWEB)

Kong Deyan; Fan Yong; Zhang Cuimiao; Lin Jun, E-mail: jlin@ciac.jl.c [Chinese Academy of Sciences, State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry (China)

2010-02-15

NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+} nanoparticles were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. These NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+} nanoparticles can be coated with mesoporous silica using nonionic triblock copolymer EO{sub 20}PO{sub 70}EO{sub 20} (P 123) as structure-directing agent and other materials. The composites can load ibuprofen and release the drug in the phosphate buffer solution (PBS). The composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen absorption/desorption isotherms, fluorescence spectra, and UV/Vis absorption spectra, respectively. The composites have the mesoporous structure. In addition, the composites emit red fluorescence (from Er{sup 3+}) under 980 nm near infrared laser excitation, which can be used as fluorescent probes in the drug-delivery system.

The risk assessment of Gd_2O_3:Yb"3"+/Er"3"+ nanocomposites as dual-modal nanoprobes for magnetic and fluorescence imaging

International Nuclear Information System (INIS)

Huang, Long; Tian, Xiumei; Liu, Jun; Zheng, Cunjing; Xie, Fukang; Li, Li

2017-01-01

Our group has synthesized Gd_2O_3:Yb"3"+/Er"3"+ nanocomposites as magnetic/fluorescence imaging successfully in the previous study, which exhibit good uniformity and monodispersibility with a mean size of 7.4 nm. However, their systematic risk assessment remains unknown. In this article, the in vitro biocompatibility of the Gd_2O_3:Yb"3"+/Er"3"+ was assessed on the basis of cell viability and apoptosis. In vivo immunotoxicity was evaluated by monitoring the product of reactive oxygen species (ROS), clusters of differentiation (CD) markers, and superoxide dismutase (SOD) in Balb/c mice. No significant differences were found in cell viability, apoptosis, and immunotoxicity between our Gd_2O_3:Yb"3"+/Er"3"+ and gadodiamide which are used commonly in clinical. Few nanoprobes were localized in the phagosomes of the liver, heart, lung, spleen, kidney, brain, and tumor under the transmission electron microscopy (TEM) images. In addition, our products reveal good T_1-weighted contrast enhancement of xenografted murine tumor. Therefore, the above results may contribute to the effective application of Gd_2O_3:Yb"3"+/Er"3"+ as molecular imaging contrast agents and dual-modal nanoprobes for cancer detection.

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.

Spectroscopic properties and diode-pumped 1594 nm laser performance of Er:Yb:Li6Y(BO3)3 crystal

Science.gov (United States)

Zhao, Y. W.; Lin, Y. F.; Chen, Y. J.; Gong, X. H.; Luo, Z. D.; Huang, Y. D.

2008-03-01

An Er3+/Yb3+-codoped Li6Y(BO3)3 crystal was grown by the Czochralski method. The polarized absorption spectra and the fluorescence decay curve were recorded. The efficiency of energy transfer from Yb3+ to Er3+ ions was estimated. Quasi-continuous-wave output power of 325 mW at 1594 nm was realized under the absorbed pump power of 10.4 W in a hemispherical cavity. The absorbed pump threshold and slope efficiency of the laser are 6.0 W and 7.2%, respectively.

Effect of silver nanoparticles on the 1.53 μm fluorescence in Er3+/Yb3+ codoped tellurite glasses

Science.gov (United States)

Wu, Libo; Zhou, Yaxun; Zhou, Zizhong; Cheng, Pan; Huang, Bo; Yang, Fengjing; Li, Jun

2016-07-01

Improving the spectroscopic properties of rare earth (RE) doped glass materials is a challenging task. In the present work the metallic silver nanoparticles (Ag NPs) were embedded into Er3+/Yb3+ codoped tellurite glasses with composition TeO2-Bi2O3-TiO2, prepared using melt-quenching and subsequent heat-treated techniques, and the improved effect of Ag NPs on the 1.53 μm band fluorescence of Er3+ ions was investigated. About 24 h heat-treatment of Er3+/Yb3+ codoped tellurite glass containing 1 mol % amount of AgNO3 at the temperature 370 °C yielded the well-dispersed and near-spherical Ag NPs with ∼11.4 nm average diameter as evidenced by transmission electron microscopy (TEM) image. The intense 1.53 μm band fluorescence was observed in the prepared Er3+/Yb3+ codoped tellurite glasses under the excitation of 980 nm and was further improved with the presence of Ag NPs in the glass matrix, which is attributed to the enhanced local electric field around doped RE ions induced by Ag NPs and the possible energy transfer from Ag NPs to Er3+ ions. The enhanced local electric field was well demonstrated by comparing the variation of emission spectra of hypersensitive probe Eu3+ ions in tellurite glasses with and without Ag NPs. From the Judd-Ofelt analysis, it was also found that the value of Ω6 intensity parameter increased slightly with the increase of Ag NPs concentration in a certain range, also confirming the possibility of realizing strong fluorescence emission. In addition, the amorphous structural nature was demonstrated by the measured X-ray diffraction (XRD) patterns with no sharp diffraction peak. The enhanced 1.53 μm band fluorescence indicates that the Er3+/Yb3+ codoped tellurite glass with an appropriate amount of Ag NPs is a promising candidate for the development of Er3+-doped fiber amplifiers (EDFAs) applied in the WDM systems.

Energy transfer and infrared-to-visible upconversion luminescence of Er3+/Yb3+-codoped halide modified tellurite glasses

International Nuclear Information System (INIS)

Zhang, Q.Y.; Feng, Z.M.; Yang, Z.M.; Jiang, Z.H.

2006-01-01

We report on the energy transfer and frequency upconversion spectroscopic properties of Er 3+ -doped and Er 3+ /Yb 3+ -codoped TeO 2 -ZnO-Na 2 O-PbCl 2 halide modified tellurite glasses upon excitation with 808 and 978 nm laser diode. Three intense emissions centered at around 529, 546 and 657 nm, alongwith a very weak blue emission at 410 nm have clearly been observed for the Er 3+ /Yb 3+ -codoped halide modified tellurite glasses upon excitation at 978 nm and the involved mechanisms are explained. The quadratic dependence of fluorescence on excitation laser power confirms the fact that the two-photon contribute to the infrared to green-red upconversion emissions. And the blue upconversion at 410 nm involved a sequential three-photon absorption process

Luminescence investigation of Yb{sup 3+}/Er{sup 3+} codoped single LiYF{sub 4} microparticle

Energy Technology Data Exchange (ETDEWEB)

Gao, Wei; Zheng, Hairong, E-mail: hrzheng@snnu.edu.cn; He, Enjie; Lu, Ying; Gao, Fangqi

2014-08-01

Tetragonal phase LiYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microparticles are synthesized via facile hydrothermal method. Single LiYF{sub 4} microparticle is excited with IR laser at 980 nm in a confocal setup, and strong green and weak red emissions are observed. It is found that single LiYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microparticle with sub-structure presents stronger upconversion luminescence emission and smaller intensity ratio of red to green emission than that from LiYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microparticle with no sub-structure. The possible mechanism, the influence of particle size and the existence of EDTA on the upconversion luminescence emission are investigated. The current study suggests that the luminescence observation with single micropaticle can effectively avoid the influence of environment and neighbor particles, which is important for investigating the luminescence properties of micro- or nano-crystals and for extending their application. - Highlights: • Single LiYF{sub 4} microparticle is excited with IR laser at 980 nm in a confocal setup, and strong green and weak red emissions are observed. • Single LiYF{sub 4} microparticle with different morphology exhibits different fluorescence emission intensity and intensity ratio of red to green emission. • The possible mechanism, the influence of particle size and the existence of EDTA on the upconversion emission are investigated.

Synthesis of Er(III)/Yb(III)-doped BiF3 upconversion nanoparticles for use in optical thermometry.

Science.gov (United States)

Du, Peng; Yu, Jae Su

2018-03-23

The authors describe an ethylene glycol assisted precipitation method for synthesis of Er(III)/Yb(III)-doped BiF 3 nanoparticles (NPs) at room temperature. Under 980-nm light irradiation, the NPs emit upconversion (UC) emission of Er(III) ions as a result of a two-photon absorption process. The temperature-dependent green emissions (peaking at 525 and 545 nm) are used to establish an unambiguous relationship between the ratio of fluorescence intensities and temperature. The NPs have a maximum sensitivity of 6.5 × 10 -3  K -1 at 619 K and can be applied over the 291-691 K temperature range. The results indicate that these NPs are a promising candidate for optical thermometry. Graphical abstract Schematic of the room-temperature preparation of Er(III)/Yb(III)-doped BiF 3 nanoparticles with strongly temperature-dependent upconversion emission.

Structural and photoluminescence study of Er-Yb codoped nanocrystalline ZrO{sub 2}-B{sub 2}O{sub 3} solid solution

Energy Technology Data Exchange (ETDEWEB)

Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y nanoestructurados (EMANA), Centro de Investigaciones en Optica, A. C., Loma del Bosque 115, Col. Lomas del Campestre, C.P. 37150 Leon, Gto. (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y nanoestructurados (EMANA), Centro de Investigaciones en Optica, A. C., Loma del Bosque 115, Col. Lomas del Campestre, C.P. 37150 Leon, Gto. (Mexico); Rodriguez, G. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Vega, M. [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, A.P. 14-805, 07730 Mexico, DF (Mexico)

2012-09-20

Codoped Er{sup 3+} and Yb{sup 3+} nanocrystalline ZrO{sub 2}-B{sub 2}O{sub 3} phosphor obtained by a modified sol-gel method is demonstrated. The addition of up to 2.5 mol% B{sub 2}O{sub 3} to nanocrystalline ZrO{sub 2}:Yb(2%), Er(1%) keep the tetragonal rare-earth stabilized ZrO{sub 2} phase; whereas higher B{sub 2}O{sub 3} content destabilize the tetragonal phase, leading to the tetragonal to monoclinic transition with no tetragonal ZrO{sub 2} phase segregation. Visible upconversion of the luminescent active ions, Er{sup 3+} and Yb{sup 3+}, depend strongly on B{sub 2}O{sub 3} content. The PL intensity is strongly quenched for high B{sub 2}O{sub 3} content due to increasing multiphonon relaxation processes related to B-O and B-O-B vibronic modes.

The investigation of the decay of the deformed 167Yb, 164Tm, 225Ac, 221Fr nuclei. Beta-spectrograph with positional-sensitive detector

International Nuclear Information System (INIS)

Butabaev, Yu.S.

1994-01-01

The decay of the deformed 167 Yb, 164 Tm, 225 Ac, 221 Fr nuclei is investigated in this work. For 167 Yb and 164 Tm decays the specters of the conversion electrons were measured. 32 γ-transitions were found for 167 Yb decay, 6 of which were found for the first time. The multipolarities for 9 γ-transitions were found. For 164 Tm decay 23 new γ-transitions were found. The theoretical investigations of the collective states in the nucleus were carried out. Octupole-rotatory line with k=1 - was found in the measurement of conversion electrons specters of the short-life nuclei. Device' nonlinearity was 0,04%. Resolution was Δβρ/βρ 0,11%. Effective light yield was 1-2 %. The decay of 225 Ac and 221 Fr nuclei were investigated. The investigations of α-γ -coincidence, α-γ - rays were carried out. 24 new γ -transitions for 225 Ac and 13 ones for 221 Fr were found. The new levels and their intensities were defined more precisely. Intensity balance calculations were carried out and the full populations of the nuclear levels were calculated. (author). 3 tabs.; 10 figs

Yb{sup 3+},Er{sup 3+},Eu{sup 3+}-codoped YVO{sub 4} material for bioimaging with dual mode excitation

Energy Technology Data Exchange (ETDEWEB)

Thao, Chu Thi Bich [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of); Huy, Bui The [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of); Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Da Nang (Viet Nam); Sharipov, Mirkomil [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of); Kim, Jin-Ik. [Department of Biochemistry and Health Science, Changwon National University, Changwon 641-773 (Korea, Republic of); Dao, Van-Duong [Department of Chemical Engineering & Applied Chemistry, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Moon, Ja-Young [Department of Biochemistry and Health Science, Changwon National University, Changwon 641-773 (Korea, Republic of); Lee, Yong-Ill, E-mail: yilee@changwon.ac.kr [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of)

2017-06-01

We propose an efficient bioimaging strategy using Yb{sup 3+},Er{sup 3+},Eu{sup 3+}-triplet doped YVO{sub 4} nanoparticles which were synthesized with polymer as a template. The obtained particles possess nanoscale, uniform, and flexible excitation. The effect of Eu{sup 3+} ions on the luminescence properties of YVO{sub 4}:Yb{sup 3+},Er{sup 3+},Eu{sup 3+} was investigated. The upconversion mechanism of the prepared material was also discussed. The structure and optical properties of the prepared material were characterized by using X-ray diffraction (XRD), Fourier-transform IR spectroscopy (FTIR), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) upconversion and photoluminescence spectra. The Commission International de I′Eclairage (CIE) chromaticity coordinates was investigated to confirm the performance of color luminescent emission. The prepared YVO{sub 4}:Yb{sup 3+},Er{sup 3+},Eu{sup 3+} nanoparticles could be easily dispersed in water by surface modification with cysteine (Cys) and glutathione (GSH). The aqueous dispersion of the modified YVO{sub 4}:Yb{sup 3+},Er{sup 3+},Eu{sup 3+} exhibits bright upconversion and downconversion luminescence and has been applied for bioimaging of HeLa cells. Our developed material with dual excitation offers a promising advance in bioimaging. - Highlights: • Prepared particles possess nanoscale size, uniform, and larger scale. • The material exhibits strong emission under dual mode excitations. • The surface material has been applied for bioimaging of HeLa cell. • Low cytotoxicity, no auto-fluorescence.

Synthesis of g-C{sub 3}N{sub 4}-based NaYF{sub 4}:Yb,Tm@TiO{sub 2} ternary composite with enhanced Vis/NIR-driven photocatalytic activities

Energy Technology Data Exchange (ETDEWEB)

Cheng, Erjian, E-mail: ejcheng6@gmail.com [Department of Materials Physics, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China); Zhou, Shiqi; Li, Mohua [Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China); Li, Zhengquan, E-mail: zqli@zjnu.edu.cn [Department of Materials Physics, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China); Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China)

2017-07-15

Highlights: • The g-C{sub 3}N{sub 4}-based NaYF{sub 4}:Yb,Tm@TiO{sub 2} nanocomposite was fabricated by a facile approach. • The as-prepared composites exhibit enhanced activities under Vis and/or NIR lights. • Upconversion and semiconductor heterojunction lie behind the improved photocatalysis. • Photocatalytic working mechanism of this ternary nanocomposite was proposed. - Abstract: Upconversion (UC) NaYF{sub 4}:Yb,Tm nanocrystals (NCs) are capable of converting low-energy near-infrared (NIR) photons to high-energy ultraviolet (UV) and visible (Vis) photons. Integration of NaYF{sub 4}:Yb,Tm with graphitic carbon nitride (g-C{sub 3}N{sub 4}) can extend the spectral response of g-C{sub 3}N{sub 4} to the NIR range. However, photocatalytic activity of NaYF{sub 4}:Yb,Tm/g-C{sub 3}N{sub 4} is still severely limited by the high recombination rate of photo-generated (PG) electrons and holes (e{sup –}/h{sup +}) in the g-C{sub 3}N{sub 4}. Herein, we report a facile approach to fabricate a ternary nanocomposite consisting of NaYF{sub 4}:Yb,Tm, TiO{sub 2} and g-C{sub 3}N{sub 4}. When NaYF{sub 4}:Yb,Tm NCs were coated with a TiO{sub 2} shell and sequentially assembled with g-C{sub 3}N{sub 4} nanosheets (NSs), a semiconductor heterojunction can be fabricated on the UC particles. The as-prepared nanocomposites possess an enhanced photocatalytic activity under Vis and/or NIR lights due to the formation of heterojunction and UC effect. The ternary nanocomposites have been characterized in detail and their photocatalytic mechanism is proposed. Such kind of ternary nanocomposites may provide a new scenario for the design and synthesis of composite photocatalysts for efficiently utilizing the Vis/NIR lights in environmental remedy.

Utilization of visible to NIR light energy by Yb"+"3, Er"+"3 and Tm"+"3 doped BiVO_4 for the photocatalytic degradation of methylene blue

International Nuclear Information System (INIS)

Regmi, Chhabilal; Kshetri, Yuwaraj K.; Ray, Schindra Kumar; Pandey, Ramesh Prasad; Lee, Soo Wohn

2017-01-01

Highlights: • Lanthanide doped BiVO_4 as highly efficient upconversion and photocatalytic material. • Well defined beads like morphology for better photocatalytic activity. • Effective utilization of NIR and visible light for efficient photocatalytic degradation of methylene blue. • Nontoxic to human cells, potential for application in biological fields. - Abstract: Lanthanide-doped BiVO_4 semiconductors with efficient photocatalytic activities over a broad range of the solar light spectrum have been synthesized by the microwave hydrothermal method using ethylenediaminetetraacetic acid (EDTA). The structural, morphological, and optical properties of the as-synthesized samples were evaluated by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray powder diffraction (XRD), Raman spectroscopy, FT-IR spectroscopy, UV–vis diffuse reflectance spectroscopy (DRS), and photoluminescence spectroscopy (PL). The chemical compositions were analyzed by X-ray photoelectron spectroscopy (XPS). The toxicity of the samples was measured using Mus musculus skin melanoma cells (B16-F10 (ATCC"® CRL-6475™)) and were found to be nontoxic for human cells. The photocatalytic efficiency of the prepared samples was evaluated by methylene blue (MB) degradation. The best photocatalytic activity was shown by BiVO_4 with 6:3:3 mol percentage of Yb"+"3:Er"+"3:Tm"+"3 in all solar light spectrum. The synthesized samples possess low band gap energy and a hollow structure suitable for the better photocatalytic activity. The observed NIR photoactivity supports that the upconversion mechanism is involved in the overall photocatalytic process. Therefore, this approach provides a better alternative upconversion material for integral solar light absorption.

Yb and Er co-doped Y2Ce2O7 nanoparticles: synthesis and ...

Indian Academy of Sciences (India)

much attention due to their potential applications in display .... Figure 1. XRD patterns of Yb3+ and Er3+ co-doped Y2Ce2O7 nanoparticles prepared for 4 h at different sintering .... vels relax to the ground 4I15/2 level (You et al 2012). For.

Measurement of formation cross sections of short-lived nuclei by 14 MeV neutron. Nd, Sm, Dy, Er, Yb

Energy Technology Data Exchange (ETDEWEB)

Sakane, H.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan). School of Engineering; Iida, T.; Takahashi, A.

1997-03-01

Eight neutron activation cross sections producing the nuclei with half-lives between 3 min and 24 min were obtained at the energy range between 13.4 and 14.9 MeV by activation method. The cross sections were {sup 146}Nd(n,p){sup 146}Pr, {sup 154}Sm(n,{alpha}){sup 151}Nd, {sup 162}Dy(n,p){sup 162}Tb, {sup 163}Dy(n,np){sup 162}Tb, {sup 163}Dy(n,p){sup 163}Tb, {sup 164}Dy(n,p){sup 164}Tb, {sup 170}Er(n,{alpha}){sup 167}Dy, {sup 174}Yb(n,p){sup 170}Tm. {sup 163}Dy(n,np){sup 162}Tb (T{sub 1/2}=7.7 min) was obtained for the first time. Present results are compared with previous results and the evaluated data of JENDL-3 and ENDF/B-VI. There are some discrepancies between present results and the JENDL-3 and ENDF/B-VI. (author)

Up-conversion luminescent properties of La{sub (0.80−x)}VO{sub 4}:Yb{sub x}, Er{sub 0.20} phosphors

Energy Technology Data Exchange (ETDEWEB)

Choi, Dong Hwa; Kang, Deok Hwa [Department of Materials Science and Engineering, Silla University, Busan 617-736 (Korea, Republic of); Yi, Soung Soo, E-mail: ssyi@silla.ac.kr [Department of Materials Science and Engineering, Silla University, Busan 617-736 (Korea, Republic of); Jang, Kiwan [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

2015-11-15

Highlights: • A novel green and red emitting LaVO{sub 4}:Yb{sub x}{sup 3+}, Er{sub 0.20}{sup 3+} phosphors were synthesized. • Their structures, luminescent properties have also been investigated. • Major laser transition for Er{sup 3+} ion is {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2} (525 nm). • These results suggest the possibility as photonic devices. - Abstract: Yb{sup 3+}, Er{sup 3+} co-doped LaVO{sub 4} phosphors were synthesized by solid state reaction method. Yb{sup 3+} concentrations were changed from 0.01 to 0.20 mol for the fixed Er{sup 3+} concentration at 0.2 mol. The crystalline structure of samples was investigated by X-ray diffraction (XRD). The composition was investigated by X-ray photoelectron spectroscopy (XPS) analysis. The surface morphology was observed by scanning electron microscope (SEM). The red and green up-conversion emissions were observed in Yb{sup 3+}, Er{sup 3+} co-doped LaVO{sub 4} phosphors under the excitation of 980 nm laser diode. Several emissions in green and red regions of the spectrum were observed near 525 nm, 553 nm and 659 nm radiated by {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2}, and {sup 4}F{sub 3/2} → {sup 4}I{sub 15/2} transitions, respectively.

Aptamer biosensor for Salmonella typhimurium detection based on luminescence energy transfer from Mn2 +-doped NaYF4:Yb, Tm upconverting nanoparticles to gold nanorods

Science.gov (United States)

Cheng, Keyi; Zhang, Jianguo; Zhang, Liping; Wang, Lun; Chen, Hongqi

2017-01-01

A highly sensitive luminescent bioassay for the detection of Salmonella typhimurium was fabricated using Mn2 +-doped NaYF4:Yb,Tm upconversion nanoparticles (UCNPs) as the donor and gold nanorods (Au NRs) as the acceptor and utilizing an energy transfer (LET) system. Mn2 +-doped NaYF4:Yb,Tm UCNPs with a strong emission peak at 807 nm were obtained by changing the doped ion ratio. Carboxyl-terminated Mn2 +-doped NaYF4:Yb,Tm UCNPs were coupled with S. typhimurium aptamers, which were employed to capture and concentrate S. typhimurium. The electrostatic interactions shorten the distance between the negatively charged donor and the positively charged acceptor, which results in luminescence quenching. The added S. typhimurium leads to the restoration of luminescence due to the formation of UCNPs-aptamers-S. typhimurium, which repels the UCNPs-aptamers from the Au NRs. The LET system does not occur because of the nonexistence of the luminescence emission band of Mn2 +-doped NaYF4:Yb,Tm UCNPs, which had large spectral overlap with the absorption band of Au NRs. Under optimal conditions, the linear range of detecting S. typhimurium was 12 to 5 × 105 cfu/mL (R = 0.99). The limit of detection for S. typhimurium was as low as 11 cfu/mL in an aqueous buffer. The measurement of S. typhimurium in milk samples was satisfied in accordance with the plate-counting method, suggesting that the proposed method was of practical value in the application of food security.

Multifunctional BaYbF5: Gd/Er upconversion nanoparticles for in vivo tri-modal upconversion optical, X-ray computed tomography and magnetic resonance imaging.

Science.gov (United States)

Li, Xiaolong; Yi, Zhigao; Xue, Zhenluan; Zeng, Songjun; Liu, Hongrong

2017-06-01

Development of high-quality upconversion nanoparticles (UCNPs) with combination of the merits of multiple molecular imaging techniques, such as, upconversion luminescence (UCL) imaging, X-ray computed tomography (CT), and magnetic resonance (MR) imaging, could significantly improve the accuracy of biological diagnosis. In this work, multifunctional BaYbF 5 : Gd/Er (50:2mol%) UCNPs were synthesized via a solvothermal method using oleic acid (OA) as surface ligands (denoted as OA-UCNPs). The OA-UCNPs were further treated by diluted HCl to form ligand-free UCNPs (LF-UCNPs) for later bioimaging applications. The cytotoxicity assay in HeLa cells shows low cell toxicity of these LF-UCNPs. Owing to the efficient UCL of BaYbF 5 : Gd/Er, the LF-UCNPs were successfully used as luminescent bioprobe in UCL bioimaging. And, X-ray CT imaging reveals that BaYbF 5 : Gd/Er UCNPs can act as potential contrast agents for detection of the liver and spleen in the live mice owing to the high-Z elements (e.g., Ba, Yb, and Gd) in host matrix. Moreover, with the addition of Gd, the as-designed UCNPs exhibit additional positive contrast enhancement in T 1 -weighted MR imaging. These findings demonstrate that BaYbF 5 : Gd/Er UCNPs are potential candidates for tri-modal imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Spectral-converting study of La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) phosphors

Energy Technology Data Exchange (ETDEWEB)

Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

2014-09-15

Optical materials composed of La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) solid solution were prepared via a solid-state reaction using excess NH{sub 4}Cl flux at 950 °C for 30 min. X-ray diffraction patterns of La{sub 1−m}Er{sub m}OCl were compared upon altering the molar ratios of the flux to the La{sup 3+} (Er{sup 3+}, Yb{sup 3+}) ions. By means of photoluminescence spectra, the dependence of the luminescence intensity as a function of the Er{sup 3+} content and the color CIE coordinates of the Er{sup 3+}-doped layered LaOCl compounds were also investigated under excitation by near-ultraviolet (NUV) and visible light. The spectral conversion properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} ions doped into LaOCl phosphors were elucidated under diode-laser irradiation of 980 nm in wavelength. The desired up-conversion of the emitting light, passing throughout the green, orange, and red regions of the spectrum, was achieved by appropriate Er{sup 3+} and/or Yb{sup 3+} concentrations in the LaOCl host structure under 980-nm-excitation light, while its mechanism in the phosphors was described by an energy-level schematic. Up-conversion emission spectra and the dependence of the emission intensity on pump power in the La{sub 0.89}Er{sub 0.1}Yb{sub 0.01}OCl phosphor were investigated under diode-laser irradiation of both wavelengths, 980 and 1550 nm. - Highlights: • Flux-assisted La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) phosphors were prepared. • Distinctive photoluminescence properties of Er{sup 3+}-doped LaOCl were investigated. • Spectral converting properties of Er{sup 3+} and Yb{sup 3+} in LaOCl phosphors were elucidated. • Up-conversion mechanisms are proposed on the basis of an energy-level diagram. • Dependence of the emission intensity on pump power in the phosphor was investigated.

Upconversion improvement in KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} nanoparticles by doping Al{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Zhou, Haifang [Fuzhou University, School of Physics and Information Engineering, and Institute of Micro-Nano Devices and Solar Cells, Fuzhou (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou, Jiangsu (China); Wang, Xiechun; Lai, Yunfeng; Cheng, Shuying; Zheng, Qiao; Yu, Jinlin [Fuzhou University, School of Physics and Information Engineering, and Institute of Micro-Nano Devices and Solar Cells, Fuzhou (China)

2017-10-15

Rare-earth ion-doped upconversion (UC) materials show great potential applications in optical and optoelectronic devices due to their novel optical properties. In this work, hexagonal KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} nanoparticles (NPs) were successfully synthesized by a hydrothermal method, and remarkably enhanced upconversion luminescence in green and red emission bands in KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} NPs has been achieved by doping Al{sup 3+} ions under 980 nm excitation. Compared to the aluminum-free KLaF{sub 4}:Yb{sup 3+}/Er{sup 3+} NPs sample, the UC fluorescence intensities of the green and red emissions of NPs doped with 10 at.% Al{sup 3+} ions were significantly enhanced by 5.9 and 7.3 times, respectively. Longer lifetimes of the doped samples were observed for the {sup 4}S{sub 3/2} state and {sup 4}F{sub 9/2} state. The underlying reason for the UC enhancement by doping Al{sup 3+} ions was mainly ascribed to distortion of the local symmetry around Er{sup 3+} ions and adsorption reduction of organic ligands on the surface of NPs. In addition, the influence of doping Al{sup 3+} ions on the structure and morphology of the NPs samples was also discussed. (orig.)

Upconversion and pump saturation mechanisms in Er3+/Yb3+ co-doped Y2Ti2O7 nanocrystals

International Nuclear Information System (INIS)

Wang, Fengxiao; Song, Feng; Zhang, Gong; Han, Yingdong; Li, Qiong; Tian, Jianguo; Ming, Chengguo

2014-01-01

The Er 3+ /Yb 3+ co-doped Y 2 Ti 2 O 7 nanocrystals were synthesized by the sol–gel method. X-ray diffraction, transmission electronic microscopy, and photoluminescence spectra were measured to verify the Y 2 Ti 2 O 7 nanocrystalline produced in the sample annealed at 800 °C. The anomalous slopes of the fitted line in the log-log plots for upconversion emissions and the pump-saturation effect of near-infrared emission were observed in the nanocrystalline samples. A theoretical model of practical Er 3+ /Yb 3+ co-doped system based on the rate equations were put forward and explained the experimental phenomena well

Yb3+ can be much better than Dy3+: SMM properties and controllable self-assembly of novel lanthanide 3,5-dinitrobenzoate-acetylacetonate complexes.

Science.gov (United States)

Gavrikov, Andrey V; Efimov, Nikolay N; Ilyukhin, Andrey B; Dobrokhotova, Zhanna V; Novotortsev, Vladimir M

2018-05-01

The first representatives of the binuclear lanthanide 3,5-dinitrobenzoate-acetylacetonate complexes, namely isostructural compounds [Ln(dnbz)(acac)2(H2O)(EtOH)]2 (Ln = Eu (1), Gd (2), Tb (3), Dy (4), Ho (5), Er (6), Tm (7), and Yb (8); dnbz - 3,5-dinitrobenzoate anion; acac - acetylacetonate (pentane-2,4-dionate) anion) were prepared and characterized. The SMM behavior of the Yb compound 8 was shown to be surprisingly less sensitive to the composition of the Yb3+ coordination environment in comparison with that of the Dy derivative. For Yb compound 8, the anisotropy barrier is Δeff/kB = 26 K under the dc field of 2000 Oe. This value is the highest one currently known for binuclear Yb complexes.

Ultrasmall, water dispersible, TWEEN80 modified Yb:Er:NaGd(WO4)2 nanoparticles with record upconversion ratiometric thermal sensitivity and their internalization by mesenchymal stem cells

Science.gov (United States)

Cascales, Concepción; Paíno, Carlos L.; Bazán, Eulalia; Zaldo, Carlos

2017-05-01

This work presents the synthesis by coprecipitation of diamond shaped Yb:Er:NaGd(WO4)2 crystalline nanoparticles (NPs) with diagonal dimensions in the 5-7 nm × 10-12 nm range which have been modified with TWEEN80 for their dispersion in water, and their interaction with mesenchymal stem cells (MSCs) proposed as cellular NP vehicles. These NPs belong to a large family of tetragonal Yb:Er:NaT(XO4)2 (T = Y, La, Gd, Lu; X = Mo, W) compounds with green (2H11/2 + 4S3/2 → 4I15/2) Er-related upconversion (UC) efficiency comparable to that of Yb:Er:β-NaYF4 reference compound, but with a ratiometric thermal sensitivity (S) 2.5-3.5 times larger than that of the fluoride. At the temperature range of interest for biomedical applications (˜293-317 K/20-44 °C) S = 108-118 × 10-4 K-1 for 20 at%Yb:5 at%Er:NaGd(WO4)2 NPs, being the largest values so far reported using the 2H11/2/4S3/2 Er intensity ratiometric method. Cultured MSCs, incubated with these water NP emulsions, internalize and accumulate the NPs enclosed in endosomes/lysosomes. Incubations with up to 10 μg of NPs per ml of culture medium maintain cellular metabolism at 72 h. A thermal assisted excitation path is discussed as responsible for the UC behavior of Yb:Er:NaT(XO4)2 compounds.

Thermomchromic Reaction-Induced Reversible Upconversion Emission Modulation for Switching Devices and Tunable Upconversion Emission Based on Defect Engineering of WO3:Yb3+,Er3+ Phosphor.

Science.gov (United States)

Ruan, Jiufeng; Yang, Zhengwen; Huang, Anjun; Zhang, Hailu; Qiu, Jianbei; Song, Zhiguo

2018-05-02

Reversible luminescence modulation of upconversion phosphors has the potential applications as photoswitches and optical memory and data storage devices. Previously, the photochromic reaction was extensively used for the realization of reversible luminescence modulation. It is very necessary to develop other approaches such as thermomchromic reaction to obtain the reversible upconversion luminescence modulation. In this work, the WO 3 :Yb 3+ ,Er 3+ phosphors with various colors were prepared at various temperatures, exhibiting tunable upconversion luminescence attributed to the formation of oxygen vacancies in the host. Upon heat treatment in the reducing atmosphere or air, the WO 3 :Yb 3+ ,Er 3+ phosphors show a reversible thermomchromic property. The reversible upconversion luminescence modulation of WO 3 :Yb 3+ ,Er 3+ phosphors was observed based on thermomchromic reaction. Additionally, the upconversion luminescence modulation is maintained after several cycles, indicating its excellent stability. The WO 3 :Yb 3+ ,Er 3+ phosphors with reversible upconversion luminescence and excellent reproducibility have potential applications as the photoswitches and optical memory and data storage devices.

Near infra red light emitting Y2Sn2O7: Yb-Er nanoparticles

International Nuclear Information System (INIS)

Nigam, Sandeep; Sudarsan, V.; Vatsa, R.K.

2011-01-01

There is an increasing interest in erbium doped nanomaterials host, since they emit in the near-infrared region and are potential candidates for optical telecommunication, high-power and infrared lasers. Further, erbium-ytterbium-co-doped matrices have been particularly investigated as Yb 3+ ions play the role of sensitizers. In the present work, Y 2 Sn 2 O 7 nanoparticles co-doped with lanthanide ions Yb 3+ and Er 3+ were prepared based on the urea hydrolysis of Y 3+ , Sn 4+ , and Ln 3+ in ethylene glycol medium at 150 deg C followed by heating at 700 deg C. As prepared samples are amorphous in nature, and the sample heated at 700 deg C showed well crystalline pyrochlore structure. Based on TEM studies, it has been established that nano-particles are highly crystalline, with size range in the range of 2-5 nm. Luminescence measurements were carried out for the as prepared samples and those heated at 700 deg C. As prepared sampled showed very poor luminescence. However on heating to 700 deg C, strong emission in the NIR region was observed upon UV-excitation as can be seen. The peak observed around 1530 nm has been attributed to 4 I 13/2 → 4 I 15/2 transition of Er 3+ and the peak around 980 nm is due to 2 F 5/2 → 2 F 7/2 transition of Yb 3+ . (author)

Cooperative emission in ion implanted Yb:YAG waveguides

Energy Technology Data Exchange (ETDEWEB)

Vazquez, G V; Desirena, H; De la Rosa, E [Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Flores-Romero, E; Rickards, J; Trejo-Luna, R [Instituto de Fisica, UNAM, Apartado Postal 20364, 01000 Mexico, D. F. (Mexico); Marquez, H, E-mail: gvvazquez@cio.mx [Departamento de Optica, CICESE, Km 107 Carr. Tijuana-Ensenada, 22860 Ensenada, B. C. (Mexico)

2011-01-01

In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb{sup 3+} ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm{sup 3+} and Er{sup 3+} traces. The results include absorption and emission curves as well as decay time rates.

Cooperative emission in ion implanted Yb:YAG waveguides

International Nuclear Information System (INIS)

Vazquez, G V; Desirena, H; De la Rosa, E; Flores-Romero, E; Rickards, J; Trejo-Luna, R; Marquez, H

2011-01-01

In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb 3+ ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm 3+ and Er 3+ traces. The results include absorption and emission curves as well as decay time rates.

Crystalline phase, profile characteristics and spectroscopic properties of Er{sup 3+}/Tm{sup 3+}-diffusion-codoped LiNbO{sub 3} crystal

Energy Technology Data Exchange (ETDEWEB)

Sun, Wen-Bao [Department of Opto-electronics and Information Engineering, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Optoelectronic Information Technology, Ministry of Education (Tianjin University), Tianjin 300072 (China); Zhang, Zi-Bo [Department of Engineering, Pierre and Marie Curie University (University of Paris VI), 4 place Jussieu, 75005 Paris (France); Sun, Hong-Xue [Department of Opto-electronics and Information Engineering, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Optoelectronic Information Technology, Ministry of Education (Tianjin University), Tianjin 300072 (China); Wong, Wing-Han, E-mail: eewhwong@cityu.edu.hk [Department of Opto-electronics and Information Engineering, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Optoelectronic Information Technology, Ministry of Education (Tianjin University), Tianjin 300072 (China); Department of Electronic Engineering and State Key Laboratory of Millimeter Waves, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Yu, Dao-Yin [Department of Opto-electronics and Information Engineering, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Optoelectronic Information Technology, Ministry of Education (Tianjin University), Tianjin 300072 (China); Pun, Edwin Yue-Bun [Department of Electronic Engineering and State Key Laboratory of Millimeter Waves, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); and others

2017-04-15

Er{sup 3+}/Tm{sup 3+}-codoped LiNbO{sub 3} crystal was prepared by co-diffusion of stacked Er and Tm metal films coated onto surface of off-congruent, Li-deficient LiNbO{sub 3} substrate produced by Li-poor vapor transport equilibration technique. The crystalline phase on the diffused surface was analyzed by X-ray single-crystal diffraction. The Er{sup 3+} and Tm{sup 3+} profile characteristics were studied by secondary ion mass spectrometry. The emission spectra were measured under the 980 or 795 nm wavelength excitation, and the emission and absorption cross section spectra were calculated based upon McCumber theory. The lifetimes of some emissions were measured. The results show that the Er{sup 3+} and Tm{sup 3+} ions presence is in the form of LiNbO{sub 3} phase. Both ions obey to Gaussian profile with a diffusion depth 21.5 μm. In the codoping case, both ions keep their respective spectroscopic features of only doping case and do not affect each other. The codoping enables to combine the wavelength emissions of both ions and the resultant emission band in the telecommunication window around 1.5 μm is as wide as 150 nm, providing the possibility of S+C+L broadband amplification by employing commercial 980 and 795 nm laser diodes as the pump sources. The Er{sup 3+}/Tm{sup 3+}-codoped LN is a promising host material for integrated optics. - Graphical abstract: Er{sup 3+}/Tm{sup 3+}-codoped LiNbO{sub 3} crystal was prepared by co-diffusion of stacked Er and Tm metal films. The crystalline phase, diffusion profile and cross section spectra of Er{sup 3+} and Tm{sup 3+} ions in the diffusion layer have been investigated. The results show that the presence of Er{sup 3+} and Tm{sup 3+} ions is in the LiNbO{sub 3} phase. Both ions follow Gaussian profile with a diffusion depth 21.5 μm. Both ions keep their respective spectroscopic features of only doping case. Excited state absorption is the dominant process for 795-nm-upconvered fluorescence of Tm{sup 3+}. The

Modification of Ag shell on upconversion populating paths of NaYF{sub 4}:Yb{sup 3+},Er{sup 3+}@Ag nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Sun, Jiao [Norman Bethune College of Medicine, Jilin University, Changchun, Jilin Province 130021 (China); Liu, Haipeng [Department of Plastic and Reconstructive Surgery, The First Hospital of JiLin University, Jilin Province 130021 (China); Wu, Di [Norman Bethune College of Medicine, Jilin University, Changchun, Jilin Province 130021 (China); Dong, Biao, E-mail: dongb@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China); Sun, Liankun [Norman Bethune College of Medicine, Jilin University, Changchun, Jilin Province 130021 (China)

2013-01-15

NaYF{sub 4}:Yb{sup 3+},Er{sup 3+}@Ag core-shell nanocomposites were prepared. Due to the outer shell of Ag, some modifications were found on the upconversion (UC) processes of NaYF{sub 4}:Yb{sup 3+},Er{sup 3+} core nanoparticles (NPs) caused by the co-interaction of surface effect, surface plasma absorption effect and local thermal effect under infrared radiation. Upon 980 nm excitation, the relative UC intensity of the green ({sup 2}H{sub 11/2}, {sup 4}S{sub 3/2}-{sup 4}I{sub 15/2}) to red ({sup 4}F{sub 9/2}-{sup 4}I{sub 15/2}) and the slope of power-dependence increased intensively, and three-photon population process for the green level appeared. -- Highlights: Black-Right-Pointing-Pointer NaYF{sub 4}:Yb{sup 3+},Er{sup 3+}@Ag core/shell nanocomposites were fabricated. Black-Right-Pointing-Pointer The coating of Ag outer shell leads to the increase of the green UCL. Black-Right-Pointing-Pointer Three-photon population process for the green level appeared after Ag coating.

Enhancing upconversion emission of Er, Yb co-doped highly transparent YF3 films by synergistic tuning nano-textured morphology and crystallinity

International Nuclear Information System (INIS)

Qu, Ming-Hao; Wang, Ru-Zhi; Chen, Yan; Zhang, Ying; Li, Kai-Yu; Zhou, Hua; Yan, Hui

2014-01-01

Highly transparent Er, Yb codoped YF 3 upconversion films were successfully prepared by electron beam deposition method. The effects of the substrate temperature on the morphology, crystallinity and emission characteristics of Er, Yb codoped YF 3 films were studied carefully. It was found that the morphology and crystallinity varied from smooth amorphous to root-intertwined polycrystalline structure with the substrate temperature increase. Besides, the emission characteristics of the films can be modulated by the synergy of their surface morphologies and crystallinities. Remarkably, a large enhancement of the upconversion emission, up to five decades while only an insignificant decrease of the optical transmittance (10% at most), was achieved by forming root-intertwined polycrystalline structures. These highly transparent upconversion films may have good potential for enhancing the conversion efficiency of wide band-gap solar cells. -- Highlights: • Er, Yb co-dopedYF 3 upconversion films have been successfully prepared. • The upconversion property can be modulated by morphology and crystallinity. • The upconversion transparent YF 3 films are promising for solar cells applications

Multifunctional BaYbF{sub 5}: Gd/Er upconversion nanoparticles for in vivo tri-modal upconversion optical, X-ray computed tomography and magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Li, Xiaolong; Yi, Zhigao; Xue, Zhenluan; Zeng, Songjun, E-mail: songjunz@hunnu.edu.cn; Liu, Hongrong, E-mail: hrliu@hunnu.edu.cn

2017-06-01

Development of high-quality upconversion nanoparticles (UCNPs) with combination of the merits of multiple molecular imaging techniques, such as, upconversion luminescence (UCL) imaging, X-ray computed tomography (CT), and magnetic resonance (MR) imaging, could significantly improve the accuracy of biological diagnosis. In this work, multifunctional BaYbF{sub 5}: Gd/Er (50:2 mol%) UCNPs were synthesized via a solvothermal method using oleic acid (OA) as surface ligands (denoted as OA-UCNPs). The OA-UCNPs were further treated by diluted HCl to form ligand-free UCNPs (LF-UCNPs) for later bioimaging applications. The cytotoxicity assay in HeLa cells shows low cell toxicity of these LF-UCNPs. Owing to the efficient UCL of BaYbF{sub 5}: Gd/Er, the LF-UCNPs were successfully used as luminescent bioprobe in UCL bioimaging. And, X-ray CT imaging reveals that BaYbF{sub 5}: Gd/Er UCNPs can act as potential contrast agents for detection of the liver and spleen in the live mice owing to the high-Z elements (e.g., Ba, Yb, and Gd) in host matrix. Moreover, with the addition of Gd, the as-designed UCNPs exhibit additional positive contrast enhancement in T{sub 1}-weighted MR imaging. These findings demonstrate that BaYbF{sub 5}: Gd/Er UCNPs are potential candidates for tri-modal imaging. - Graphical abstract: Multifunctional BaYbF{sub 5}: Gd/Er upconversion nanoparticles with efficient upconversion emission, high absorption coefficient, predominant paramagnetic behavior, and low biological toxicity were demonstrated for tri-modality in vivo UCL, CT and MR imaging. Display Omitted - Highlights: • The multifunctional UCNPs with high monodispersity were synthesized. • The UCNPs present large r{sub 1} value and binary CT contrast agents. • These UCNPs were demonstrated as optimal probes for tri-modal bioimaging.

A multifunctional β-CD-modified Fe3O4@ZnO:Er3+,Yb3+ nanocarrier for antitumor drug delivery and microwave-triggered drug release

International Nuclear Information System (INIS)

Peng, Hongxia; Cui, Bin; Li, Guangming; Wang, Yingsai; Li, Nini; Chang, Zhuguo; Wang, Yaoyu

2015-01-01

We constructed a novel core–shell structured Fe 3 O 4 @ZnO:Er 3+ ,Yb 3+ @(β-CD) nanoparticles used as drug carrier to investigate the loading and controllable release properties of the chemotherapeutic drug etoposide (VP-16). The cavity of β-cyclodextrin is chemically inert, it can store etoposide molecules by means of hydrophobic interactions. The Fe 3 O 4 core and ZnO:Er 3+ ,Yb 3+ shell functioned successfully for magnetic targeting and up-conversion fluorescence imaging, respectively. In addition, the ZnO:Er 3+ ,Yb 3+ shell acts as a good microwave absorber with excellent microwave thermal response property for microwave triggered drug release (the VP-16 release of 18% under microwave irradiation for 15 min outclass the 2% within 6 h without microwave irradiation release). The release profile could be controlled by the duration and number of cycles of microwave application. This material therefore promises to be a useful noninvasive, externally controlled drug-delivery system in cancer therapy. - Graphical abstract: We functionalized a multifunctional core–shell Fe 3 O 4 @ZnO:Er 3+ ,Yb 3+ nanocarriers by adding β-cyclodextrin, which is capable of carrying drug molecules and triggered release of the drug by microwave treatment. - Highlights: • We constructed Fe 3 O 4 @ZnO:Er 3+ ,Yb 3+ @(β-CD) nanoparticles used as a drug carrier. • The nanoparticles have magnetic and up-conversion fluorescence properties. • The nanoparticles have excellent microwave thermal response property. • The nanocomposite could be a controllable drug release triggered by microwave

One-pot synthesis of hollow structured upconversion luminescent β-NaYF4:Yb0.2Er0.02 nanoparticles

International Nuclear Information System (INIS)

Wu, Qinglong; Pei, Jianfeng; De, Gejihu

2014-01-01

Monodisperse, uniform, and hollow structured hexagonal sodium yttrium fluoride nanoparticles co-doped with Yb 3+ and Er 3+ (NaYF 4 :Yb 3+ , Er 3+ ) were successfully prepared by a facile one-pot thermal decomposition route. The crystal structure, morphology and upconversion spectra of the sample were investigated using X-ray powder diffractometer, transmission electron microscope, and fluorescence spectrophotometer with an external 980 nm single-wavelength diode laser. The synthesized nanoparticles were easily dispersed in nonpolar solvents, showed an extremely narrow particle distribution, and were determined to have a diameter about (14.3)±(1.1) nm. Moreover, the nanoparticles were dispersed in water via modification of the capping oleic acid ligand by HCl. To the synthesis of such monidisperse, water-soluble, hollow structured lanthanide-doped upconversion nanoparticles may lead to potential applications in drug delivery and bioimaging. - Highlights: • Hollow structured hexagonal NaYF 4 :Yb 0.2 Er 0.02 luminescent nanoparticles were prepared by a facile one-pot thermal decomposition route. • HCl was used to render the nanoparticles to water solubility. • The bright green light and transparent solution indicate that as-treated water-soluble nanoparticles may lead to potential applications in drug delivery and bioimaging

Spectroscopic characterization and temporal dynamics of energy transfer process between Tm{sup 3+} -Ho{sup 3+} and Yb{sup 3+} -Tm{sup 3+} ions in LiYF{sub 4} and LiLuF{sub 4} crystals; Caracterizacao espectroscopica e dinamica temporal dos processos de transferencia de energia entre os ions Tm{sup 3+} -Ho{sup 3+} e Yb{sup 3+} -Tm{sup 3+} em cristais de LiYF{sub 4} and LiLuF{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Tarelho, Luiz Vicente Gomes

2001-07-01

In this work, we perform spectroscopic studies to characterize the energy transfer processes occurring in rare-earth doped lithium fluoride systems, aiming the optimization of the population inversion of these media. Yb{sup 3+} ion was used in order to probe the electron-phonon coupling in LiYF{sub 4}, LiGdF{sub 4} and LiLuF{sub 4} matrices. In these systems it was obtained the average phononenergy, the vibronic transition probability and Huang-Rhys coupling constant. These parameters are dependent on the crystal host and the LiLuF{sub 4} system presents excluded correlation effects, an electronic repulsion that weakens the vibronic coupling. The Tm:Ho:LiYF{sub 4} system was studied under diode laser pumping at 796 nm, aiming the 2 {mu}m emission optimization. The ideal conditions of concentration and laser power were determined favouring the latter emission. Upconversion processes of two photons were identified besides the energy transfer among ions. The dynamic processes of luminescence of donors and acceptors allowed one to classify the energy transfer process as an energy transfer process assisted by fast diffusion among donors. The spectroscopic study of the Yb:Tm:LiYF{sub 4} allowed the determination of efficient non resonant transfer mechanisms between ({sup 2}F{sub 5/2}) Ytterbium level and ({sup 3}H{sub 5}) Thulium level, assisted by two phonon with hopping migration among donors ( Foerster-Burshtein model). The repopulation process of the Yb donor level is due to a cooperative sensitization between Yb-Tm pairs followed by an energy transfer process. (author)

Laser-induced, Er3+ trace-sensitized red-to-blue photon avalanche up-conversion in Tm3+-doped LiKYF5 crystals

International Nuclear Information System (INIS)

Jouart, J P; Bouffard, M; Boulma, E; Diaf, M; Vojtenko, E N; Khaidukov, N M

2005-01-01

The results for a spectroscopic study demonstrating that the excited-state absorption(ESA) of Tm 3+ :LiKYF 5 at 648nm is dependent on the purity of starting materials used for synthesizing the crystal are presented. The Er 3+ -free LiKYF 5 crystal doped with Tm 3+ is transparent at 648 nm because the majority of the Tm 3+ ions are in the ground 3 H 6 state whatever the selective excitation intensity, whereas the Er 3+ -contaminated crystal is semi-transparent. In the second case a small increase of the excitation intensity above a certain threshold produces an abrupt enhancement of the ESA process at 648 nm as well as the blue and the green emissions that are detected. All three processes, namely ESA corresponding to the 3 F 4 (2) → 1 G 4 (2) Tm 3+ transition, the blue emission due to the 1 G 4 → 3 H 6 Tm 3+ transition and the green emission from the 4 S 3/2 Er 3+ level, are sensitized with the Tm 3+ → Er 3+ → Tm 3+ energy transfers which promote the conversion of Tm 3+ ions from the 1 G 4 and the 3 H 4 states to the metastable 3 F 4 state

NIR to visible upconversion in Er3+/Yb3+ co-doped CaYAl3O7 phosphor obtained by solution combustion process

International Nuclear Information System (INIS)

Singh, Vijay; Rai, Vineet Kumar; Al-Shamery, Katharina; Nordmann, Joerg; Haase, Markus

2011-01-01

Using the combustion synthesis, CaYAl 3 O 7 :Er 3+ phosphor powders co-doped with Yb 3+ have been prepared at low temperatures (550 o C) in a few minutes. Formation of the compound was confirmed by X-ray powder diffraction. Near-infrared to visible upconversion fluorescence emission in the Er 3+ doped CaYAl 3 O 7 phosphor powder has been observed. The effect of co-doping with triply ionized ytterbium in the CaYAl 3 O 7 :Er 3+ phosphor has been studied and the process involved is discussed. - Highlights: → The green emitting up-conversion CaYAl 3 O 7 :Er 3+ phosphor powders co-doped with Yb 3+ have been prepared by easy combustion method. → The combustion method is a simple, energy saving, fast and economical viable process. → The luminescence intensity in the co-doped phosphor is enhanced by several times compared to that of the singly (Er 3+ ) doped phosphor.

Enhanced Power Conversion Efficiency of Perovskite Solar Cells with an Up-Conversion Material of Er3+-Yb3+-Li+ Tri-doped TiO2.

Science.gov (United States)

Zhang, Zhenlong; Qin, Jianqiang; Shi, Wenjia; Liu, Yanyan; Zhang, Yan; Liu, Yuefeng; Gao, Huiping; Mao, Yanli

2018-05-11

In this paper, Er 3+ -Yb 3+ -Li + tri-doped TiO 2 (UC-TiO 2 ) was prepared by an addition of Li + to Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 presented an enhanced up-conversion emission compared with Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 was applied to the perovskite solar cells. The power conversion efficiency (PCE) of the solar cells without UC-TiO 2 was 14.0%, while the PCE of the solar cells with UC-TiO 2 was increased to 16.5%, which presented an increase of 19%. The results suggested that UC-TiO 2 is an effective up-conversion material. And this study provided a route to expand the spectral absorption of perovskite solar cells from visible light to near-infrared using up-conversion materials.

Enhanced infrared-to-visible up-conversion emission and temperature sensitivity in (Er3+,Yb3+, and W6+) tri-doped Bi4Ti3O12 ferroelectric oxide

Science.gov (United States)

Bokolia, Renuka; Mondal, Manisha; Rai, V. K.; Sreenivas, K.

2017-02-01

Strong up conversion (UC) luminescence at 527, 550, and 662 nm is compared under an excitation of 980 nm in single doped (Er3+), co-doped (Er3+/Yb3+), and (Er3+/Yb3+/W6+) tri-doped bismuth titanate (Bi4Ti3O12). For the co-doped system, the frequency (UC) emission intensity due to Er3+ ions is enhanced significantly in the green bands due to the efficient energy transfer from Yb3+ to Er3+ ions. Further increase in the emission intensity is seen with non-luminescent W6+ ions in the tri-doped system due to the modification in the local crystal field around the Er3+ ions, and is evidenced through a gradual change in the crystal structure of the host lattice with increasing W6+ content. The observed changes in the fluorescence lifetime and the associated energy transfer mechanisms are discussed. A progressive reduction of the lifetime of the 4S3/2 levels of Er3+ ions from 72 to 58.7 μs with the introduction of Yb3+ and W6+ dopant increases the transition probability and enhances the UC emission intensity. The efficiency of the energy transfer process ( η ) in the co-doped and tri-doped systems is found to be 9.4% and 18.6%, respectively, in comparison to the single doped system. Temperature sensing based on the fluorescence intensity ratio (FR) technique shows high sensitivity (0.0123 K-1) in the high temperature range (293 to 523 K) for an optimum content of Er3+, Yb3+, and W6+ with x = 0.03, y = 0.18, and z = 0.06 at. % in the tri-doped Bi4-x-yErxYbyTi3-zWzO12 ferroelectric composition, and is found useful for potential applications in optical thermometry.

Zearalenone altered the cytoskeletal structure via ER stress- autophagy- oxidative stress pathway in mouse TM4 Sertoli cells.

Science.gov (United States)

Zheng, Wanglong; Wang, Bingjie; Si, Mengxue; Zou, Hui; Song, Ruilong; Gu, Jianhong; Yuan, Yan; Liu, Xuezhong; Zhu, Guoqiang; Bai, Jianfa; Bian, Jianchun; Liu, ZongPing

2018-02-20

The aim of this study was to investigate the molecular mechanisms of the destruction of cytoskeletal structure by Zearalenone (ZEA) in mouse-derived TM4 cells. In order to investigate the role of autophagy, oxidative stress and endoplasmic reticulum(ER) stress in the process of destruction of cytoskeletal structure, the effects of ZEA on the cell viability, cytoskeletal structure, autophagy, oxidative stress, ER stress, MAPK and PI3K- AKT- mTOR signaling pathways were studied. The data demonstrated that ZEA damaged the cytoskeletal structure through the induction of autophagy that leads to the alteration of cytoskeletal structure via elevated oxidative stress. Our results further showed that the autophagy was stimulated by ZEA through PI3K-AKT-mTOR and MAPK signaling pathways in TM4 cells. In addition, ZEA also induced the ER stress which was involved in the induction of the autophagy through inhibiting the ERK signal pathway to suppress the phosphorylation of mTOR. ER stress was involved in the damage of cytoskeletal structure through induction of autophagy by producing ROS. Taken together, this study revealed that ZEA altered the cytoskeletal structure via oxidative stress - autophagy- ER stress pathway in mouse TM4 Sertoli cells.

The risk assessment of Gd{sub 2}O{sub 3}:Yb{sup 3+}/Er{sup 3+} nanocomposites as dual-modal nanoprobes for magnetic and fluorescence imaging

Energy Technology Data Exchange (ETDEWEB)

Huang, Long [Sun Yat-sen University, Department of Histology and Embryology, Zhongshan School of Medicine (China); Tian, Xiumei [Guangzhou Medical University, Department of Biomedical Engineering (China); Liu, Jun [Guangdong Ocean University, School of Electronics and Information Technology (China); Zheng, Cunjing; Xie, Fukang, E-mail: frankxie2000@yahoo.com [Sun Yat-sen University, Department of Histology and Embryology, Zhongshan School of Medicine (China); Li, Li, E-mail: li2@mail.sysu.edu.cn [Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Imaging Diagnosis and Interventional Center (China)

2017-02-15

Our group has synthesized Gd{sub 2}O{sub 3}:Yb{sup 3+}/Er{sup 3+} nanocomposites as magnetic/fluorescence imaging successfully in the previous study, which exhibit good uniformity and monodispersibility with a mean size of 7.4 nm. However, their systematic risk assessment remains unknown. In this article, the in vitro biocompatibility of the Gd{sub 2}O{sub 3}:Yb{sup 3+}/Er{sup 3+} was assessed on the basis of cell viability and apoptosis. In vivo immunotoxicity was evaluated by monitoring the product of reactive oxygen species (ROS), clusters of differentiation (CD) markers, and superoxide dismutase (SOD) in Balb/c mice. No significant differences were found in cell viability, apoptosis, and immunotoxicity between our Gd{sub 2}O{sub 3}:Yb{sup 3+}/Er{sup 3+} and gadodiamide which are used commonly in clinical. Few nanoprobes were localized in the phagosomes of the liver, heart, lung, spleen, kidney, brain, and tumor under the transmission electron microscopy (TEM) images. In addition, our products reveal good T{sub 1}-weighted contrast enhancement of xenografted murine tumor. Therefore, the above results may contribute to the effective application of Gd{sub 2}O{sub 3}:Yb{sup 3+}/Er{sup 3+} as molecular imaging contrast agents and dual-modal nanoprobes for cancer detection.

Utilization of IR laser pumped anti-Stokes emission of Er-Yb doped systems for identification of securities

International Nuclear Information System (INIS)

Kuzmin, A.N.; Ryabtsev, G.I.; Ketko, G.A.; Gorelenko, A.Yu.; Demidovich, A.A.; Strek, W.; Maruszewicz, K.; Deren, P.

1996-01-01

In this paper we present a utilization of anti-Stokes luminescence of Er-Yb systems for identification of securities. A simple method of detection of an up-conversion phenomenon in such system by means of IR laser operating in the region 960-1010 nm is proposed. (author)

Recoil-distance lifetime measurements of the ground-state band in 164Dy, 170Er, and 174Yb

International Nuclear Information System (INIS)

Sie, S.H.; Gebbie, D.W.

1977-06-01

Mean-lives of the 4 + , 6 + and 8 + levels of the ground-state band in 164 Dy, 170 Er and 174 Yb have been measured by the recoil-distance technique following multiple Coulomb excitation with 32 S projectiles of energy 120-140 MeV. The gamma-rays were detected in coincidence with backscattered particles. The results are compared with theoretical predictions of the adiabatic rotor model. The 6 + and 8 + lifetimes in 164 Dy are found to correspond to a slight reduction in B(E2) values over the rotational model prediction, while for for the 4 + state a 12% reduction was observed. In 170 Er and 174 Yb the lifetimes are consistent with rotational model predictions with a slight enhancement of B(E2) values at higher spins. Comparison with other results from Doppler broadened lineshape analysis confirms the need to adjust the electronic stopping powers of Northcliffe and Schilling in the lineshape calculations. (Author)

Fluorescence resonance energy transfer between NaYF4:Yb,Tm upconversion nanoparticles and gold nanorods: Near-infrared responsive biosensor for streptavidin

International Nuclear Information System (INIS)

Zhang, Shuang; Wang, Jing; Xu, Wen; Chen, Boting; Yu, Wei; Xu, Lin; Song, Hongwei

2014-01-01

We represent a fluorescence resonance energy transfer (FRET) system using upconversion nanoparticles (UCNPs) and the gold nanorods (GNRs) as the energy donor–acceptor pair for directly determining streptavidin in near-infrared (NIR) region. NaYF 4 :Yb,Tm UCNPs, which had a strong emission at 800 nm under 980-nm excitation, were adopted as the energy donor. The GNRs, which demonstrated strong surface plasmon absorption around 800 nm, were chosen as acceptor to quench the 800 nm emissions of the UCNPs. There had the spectral overlap between the emission of the donor nanoparticles (UCNPs) and the absorption of the acceptor nanoparticles (GNRs). This UCNP-based FRET system was then used to determine the amount of streptavidin. In this system, NaYF 4 :Yb,Tm UCNPs conjugated with biotin, while GNRs conjugated with streptavidin. When added GNRs into UCNPs, the streptavidin were preferred to bind with biotin and decreased spacing between the donor and acceptor NPs. Consequently, FRET occurred and a linear relationship between the luminescence quenching efficiency and the concentration of streptavidin was obtained. Owing to the aforementioned merits of UCNPs as an energy donor and the strong quenching ability of GNRs, satisfactory analytical performances have been acquired. -- Highlights: • NaYF4:Yb,Tm and GNRs are as NIR energy donor and quenching acceptor for FRET. • Linkage between biotin and streptavidin make the distance between the donors and the acceptors short enough for FRET. • The FRET system in this work was applicable for the detection of streptavidin. • The donor and acceptor NPs can be modified by proper molecules for other biological molecules detection

Dependence of upconversion emission intensity on Yb3+ concentration in Er3+/Yb3+ co-doped flake shaped Y2(MoO4)3 phosphors

International Nuclear Information System (INIS)

Lu Weili; Cheng Lihong; Zhong Haiyang; Sun Jiashi; Wan Jing; Tian Yue; Chen Baojiu

2010-01-01

Yttrium molybdate phosphors with fixed Er 3+ and various Yb 3+ concentrations were synthesized via a co-precipitation method. The crystal structure and the morphology of the phosphor were characterized by means of x-ray diffraction and field-emission scanning electron microscopy. Under 980 nm excitation, red and green upconversion emissions centred at 660, 553 and 530 nm were observed. Quantitative analyses on the dependence of upconversion emission intensity on the working current of a laser diode (LD) indicated that two-photon processes are responsible for both red and green upconversion emissions in both cases of low and high Yb 3+ concentrations. The relationship between the emission intensity ratio of 2 H 11/2 → 4 I 15/2 to 4 S 3/2 → 4 I 15/2 and the working current of the LD was studied for the samples doped with low and high Yb 3+ concentrations. Finally, a set of rate equations was established based on the possible upconversion mechanism, and an empirical formula was proposed to describe the Yb 3+ concentration dependence of upconversion emission intensity; the empirical formula fits well with the experimental data.

Strong enhancement of the upconversion emission in ZrO{sub 2}: Yb{sup 3+}, Er{sup 3+}, Gd{sup 3+} nanocubes synthesized with Na{sub 2}S

Energy Technology Data Exchange (ETDEWEB)

Urbina-Frías, Alejandra; López-Luke, Tzarara; Oliva, Jorge [Centro de Investigaciones en Óptica, A.P. 1-948, León, Guanajuato 37150 (Mexico); Salas, Pedro [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, A.P. 1-1010, Querétaro 76000 (Mexico); Torres-Castro, Alejandro [Universidad Autónoma de Nuevo León, A.P. 126-F, Monterrey, NeNuevo Leon 66450 (Mexico); De la Rosa, Elder, E-mail: elder@cio.mx [Centro de Investigaciones en Óptica, A.P. 1-948, León, Guanajuato 37150 (Mexico)

2016-04-15

In this work, the structural, morphological and luminescent characterization of ZrO{sub 2}:Yb{sup 3+},Er{sup 3+}, Gd{sup 3+} nanocrystals prepared with Na{sub 2}S by precipitation method is reported. The XRD spectra showed a mixture of tetragonal (88%) and monoclinic phases (12%) in samples fabricated with and without Na{sub 2}S. The tetragonal phase (100%) was stabilized by the introduction of the Gd{sup 3+}. According to TEM images, samples showed a cubic morphology with an average size of 150 nm, when both, Na{sub 2}S and Gd{sup 3+} were added. Red (678 nm), green (545 nm) and ultraviolet (275, 285 nm) emissions were obtained as a result of the upconversion process due to the energy transfer between Yb{sup 3+}–Er{sup 3+}–Gd{sup 3+} ions, under 970 nm of excitation. The integrated red band showed an increment of 40% and 125%, for samples prepared with Na{sub 2}S and combined with Gd{sup 3+}, respectively, compared to the ZrO{sub 2}:Yb{sup 3+}–Er{sup 3+} sample. Such increments are explained in terms of the surface pasivation by using Na{sub 2}S during the synthesis process and the role of Gd{sup 3+} as a reservoir of energy from Er{sup 3+}. - Highlights: • ZrO{sub 2}:Yb,Er nanoparticles were synthesized by a precipitation method. • ZrO{sub 2}:Yb,Er nanoparticles were prepared with Na{sub 2}S and sensitized with Gd{sup 3+}. • An increment of 40% in luminescence occurred in samples prepared with Na{sub 2}S. • An increment of 125% were obtained by the synergistic effect between Na{sub 2}S and Gd3{sup +}.

Efficient NIR (near-infrared) luminescent ZnLn-grafted (Ln=Nd, Yb or Er) PNBE (Poly(norbornene))

Energy Technology Data Exchange (ETDEWEB)

Liu, Lin; Feng, Hei-Ni; Fu, Guo-Rui; Li, Bao-Ning [School of Chemical Engineering, Shaanxi Key Laboratory of Degradable Medical Material, Northwest University, Xi’an 710069, Shaanxi (China); Lü, Xing-Qiang, E-mail: lvxq@nwu.edu.cn [School of Chemical Engineering, Shaanxi Key Laboratory of Degradable Medical Material, Northwest University, Xi’an 710069, Shaanxi (China); Wong, Wai-Kwok [Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong (China); Jones, Richard A. [Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712-0165 (United States)

2017-06-15

Through the ring-opening metathesis polymerization (ROMP) of norbornene (NBE) with each of allyl-containing complex monomers [Zn(L){sub 2}(µ{sub 1}-OAc)Ln(µ{sub 2}-OAc){sub 2}] (Ln=La, 1; Nd, 2; Yb, 3; Er, 4 or Gd, 5; HL=4-allyl-2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol), a series of ZnLn-grafted polymers Poly([Zn(L){sub 2}(µ{sub 1}-OAc)Ln(µ{sub 2}-OAc){sub 2}]-co-NBE) with desired physical properties were obtained, respectively. Within near-infrared (NIR) luminescent polymers, Poly(3-co-NBE) endows an attractive quantum yield of 1.47% in solid state, and exhibits an effective prevention of high-concentration self-quenching. - Graphical abstract: Through grafting of [Zn(L){sub 2}(µ{sub 1}-OAc)Ln(µ{sub 2}-OAc){sub 2}] (Ln=Nd, 2; Yb, 3 or Er, 4) into PNBE with desired physical properties including NIR luminescence, Poly(3-co-NBE) exhibits an attractive quantum yield of 1.47% and an effective emitters' clustering prevention.

Phosphate-core silica-clad Er/Yb-doped optical fiber and cladding pumped laser.

Science.gov (United States)

Egorova, O N; Semjonov, S L; Velmiskin, V V; Yatsenko, Yu P; Sverchkov, S E; Galagan, B I; Denker, B I; Dianov, E M

2014-04-07

We present a composite optical fiber with a Er/Yb co-doped phosphate-glass core in a silica glass cladding as well as cladding pumped laser. The fabrication process, optical properties, and lasing parameters are described. The slope efficiency under 980 nm cladding pumping reached 39% with respect to the absorbed pump power and 28% with respect to the coupled pump power. Due to high doping level of the phosphate core optimal length was several times shorter than that of silica core fibers.

Over 19 W Single-Mode 1545 nm Er,Yb Codoped All-Fiber Laser

Directory of Open Access Journals (Sweden)

Jiadong Wu

2017-01-01

Full Text Available We report a high-power cladding-pumped Er,Yb codoped all-fiber laser with truly single transverse mode output. The fiber laser is designed to operate at 1545 nm by the use of a pair of fiber Bragg gratings (FBGs to lock and narrow the output spectrum, which can be very useful in generating the eye-safe ~1650 nm laser emission through the Stimulated Raman Scattering (SRS in silica fibers that is of interest in many applications. Two pieces of standard single-mode fibers are inserted into the laser cavity and output port to guarantee the truly single-mode output as well as good compatibility with other standard fiber components. We have obtained a maximum output power of 19.2 W at 1544.68 nm with a FWHM spectral width of 0.08 nm, corresponding to an average overall slope efficiency of 31.9% with respect to the launched pump power. This is, to the best of our knowledge, the highest output power reported from simple all-fiber single-mode Er,Yb codoped laser oscillator architecture.

On observation of the downconversion mechanism in Er{sup 3+}/Yb{sup 3+} co-doped tellurite glass using thermal and optical parameters

Energy Technology Data Exchange (ETDEWEB)

Figueiredo, M.S.; Santos, F.A. [Universidade Federal da Grande Dourados, Faculdade de Ciências Exatas e Tecnologias, Dourados, MS (Brazil); Yukimitu, K.; Moraes, J.C.S. [Universidade Estadual Paulista, UNESP, Departamento de Física e Química, Av. Brasil, 56, 15385-000 Ilha Solteira, SP (Brazil); Nunes, L.A.O. [Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, SP (Brazil); Andrade, L.H.C. [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, Cidade Universitária de Dourados, CP 351, Dourados, MS (Brazil); Lima, S.M., E-mail: smlima@uems.br [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, Cidade Universitária de Dourados, CP 351, Dourados, MS (Brazil)

2015-01-15

In this work we report the observed downconversion (DC) mechanism in Er{sup 3+}/Yb{sup 3+}-codoped tellurite glasses (in mol%, 80TeO{sub 2}–10Li{sub 2}O–10TiO{sub 2}). The samples were synthesized by the conventional melt-quenching method and then studied using optical spectroscopy and thermal lens spectroscopy (TLS). These characterizations enabled investigation of the radiative and nonradiative processes involved in energy transfer from erbium to ytterbium. The visible Er{sup 3+} fluorescence intensities decreased as a function of the Yb{sup 3+} concentration, and there was a corresponding increase in the ytterbium emission at around 980 nm. Simultaneously, there was a reduction in the heat-generated due nonradiative decays (∼21%) when ytterbium was added. This temperature change was measured by TLS measurements and the results corroborate with the indicated by spectroscopic interpretation. - Highlights: • Energy transfer from erbium to ytterbium in tellurite glass. • ∼56% of cross-relaxation efficiency from Er{sup 3+} to Yb{sup 3+}. • Downconversion effect in tellurite glasses. • Downconversion effect observation by thermal lens spectroscopy.

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.

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

Mixing up-conversion excitation behaviors in Er3+/Yb3+-codoped aluminum germanate glasses for visible waveguide devices

International Nuclear Information System (INIS)

Gong, H.; Lin, L.; Zhao, X.; Pun, E.Y.B.; Yang, D.L.; Lin, H.

2010-01-01

A mixing up-conversion excitation phenomenon in Er 3+ /Yb 3+ -codoped aluminum germanate (Na 2 O-MgO-Al 2 O 3 -GeO 2 , NMAG for short) glasses for K + -Na + ion-exchanged waveguides was observed and characterized. The green and red up-conversion luminescence of Er 3+ is due to a two-photon excitation process under low-power excitation of a 974 nm diode laser, however, with increasing the pumping power, the green emission turns to follow a combination of two- and three-photon excitation effects while the red one still agrees with a two-photon excitation law. Under high-power pumping, owing to potential thermal effect, the population ratio between the 2 H 11/2 and 4 S 3/2 levels adjusts acutely, which results in a distinct exhibition in 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 emission transitions. Green transmission trace has been observed in K + -Na + ion-exchanged Er 3+ /Yb 3+ -codoped NMAG glass waveguide and it provides an original reference in developing visible waveguide amplifiers and lasers.

Thermoluminescence and optically stimulated luminescence properties of nanocrystalline Er3+ and Yb3+ doped Y3Al5O12 exposed to β-rays

International Nuclear Information System (INIS)

RodrIguez, R A; Rosa, E de la; Salas, P; Melendrez, R; Barboza-Flores, M

2005-01-01

The thermoluminescence (TL) and optically stimulated luminescence (OSL) characterization of Er 3+ and Yb 3+ doped Y 3 Al 5 O 12 nanocrystalline samples prepared by the precipitation process and exposed to β-rays are discussed. The TL as well as the OSL were two orders of magnitude higher in Er 3+ doped than in Yb 3+ specimens. The charge trapping and the radiative thermally stimulated recombination processes in Y 3 Al 5 O 12 : Er 3+ involve four trapping states at 166, 243, 342 and 424 deg. C, but just two trapping levels at 219 and 413 deg. C for Y 3 Al 5 O 12 : Yb 3+ at a heating rate of 10 deg. C s -1 . The photostimulation with 470 nm light causes in both phosphors a radiative recombination of the optically free charge carriers belonging to the same trapping states. The TL and the OSL as a function of radiation dose behaviour were linear in the 10-100 Gy dose range. The results provide evidence of the potential uses of these materials in radiation storage and dosimeter devices

Y2O3:Yb,Er@mSiO2-CuxS double-shelled hollow spheres for enhanced chemo-/photothermal anti-cancer therapy and dual-modal imaging

Science.gov (United States)

Yang, Dan; Yang, Guixin; Wang, Xingmei; Lv, Ruichan; Gai, Shili; He, Fei; Gulzar, Arif; Yang, Piaoping

2015-07-01

Multifunctional composites have gained significant interest due to their unique properties which show potential in biological imaging and therapeutics. However, the design of an efficient combination of multiple diagnostic and therapeutic modes is still a challenge. In this contribution, Y2O3:Yb,Er@mSiO2 double-shelled hollow spheres (DSHSs) with up-conversion fluorescence have been successfully prepared through a facile integrated sacrifice template method, followed by a calcination process. It is found that the double-shelled structure with large specific surface area and uniform shape is composed of an inner shell of luminescent Y2O3:Yb,Er and an outer mesoporous silica shell. Ultra small CuxS nanoparticles (about 2.5 nm) served as photothermal agents, and a chemotherapeutic agent (doxorubicin, DOX) was then attached onto the surface of mesoporous silica, forming a DOX-DSHS-CuxS composite. The composite exhibits high anti-cancer efficacy due to the synergistic photothermal therapy (PTT) induced by the attached CuxS nanoparticles and the enhanced chemotherapy promoted by the heat from the CuxS-based PTT when irradiated by 980 nm near-infrared (NIR) light. Moreover, the composite shows excellent in vitro and in vivo X-ray computed tomography (CT) and up-conversion fluorescence (UCL) imaging properties owing to the doped rare earth ions, thus making it possible to achieve the target of imaging-guided synergistic therapy.Multifunctional composites have gained significant interest due to their unique properties which show potential in biological imaging and therapeutics. However, the design of an efficient combination of multiple diagnostic and therapeutic modes is still a challenge. In this contribution, Y2O3:Yb,Er@mSiO2 double-shelled hollow spheres (DSHSs) with up-conversion fluorescence have been successfully prepared through a facile integrated sacrifice template method, followed by a calcination process. It is found that the double-shelled structure with large

Utilization of visible to NIR light energy by Yb{sup +3}, Er{sup +3} and Tm{sup +3} doped BiVO{sub 4} for the photocatalytic degradation of methylene blue

Energy Technology Data Exchange (ETDEWEB)

Regmi, Chhabilal [Research Center for Eco-Multifunctional Nanomaterials, Sun Moon University, Chungnam 31460 (Korea, Republic of); Kshetri, Yuwaraj K. [Department of Advanced Materials Engineering, Sun Moon University, Chungnam 31460 (Korea, Republic of); Ray, Schindra Kumar [Research Center for Eco-Multifunctional Nanomaterials, Sun Moon University, Chungnam 31460 (Korea, Republic of); Pandey, Ramesh Prasad [Institute of Biomolecule Reconstruction, Department of BT-Convergent Pharmaceutical Engineering, Sun Moon University, Chungnam 31460 (Korea, Republic of); Lee, Soo Wohn, E-mail: swlee@sunmoon.ac.kr [Research Center for Eco-Multifunctional Nanomaterials, Sun Moon University, Chungnam 31460 (Korea, Republic of)

2017-01-15

Highlights: • Lanthanide doped BiVO{sub 4} as highly efficient upconversion and photocatalytic material. • Well defined beads like morphology for better photocatalytic activity. • Effective utilization of NIR and visible light for efficient photocatalytic degradation of methylene blue. • Nontoxic to human cells, potential for application in biological fields. - Abstract: Lanthanide-doped BiVO{sub 4} semiconductors with efficient photocatalytic activities over a broad range of the solar light spectrum have been synthesized by the microwave hydrothermal method using ethylenediaminetetraacetic acid (EDTA). The structural, morphological, and optical properties of the as-synthesized samples were evaluated by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray powder diffraction (XRD), Raman spectroscopy, FT-IR spectroscopy, UV–vis diffuse reflectance spectroscopy (DRS), and photoluminescence spectroscopy (PL). The chemical compositions were analyzed by X-ray photoelectron spectroscopy (XPS). The toxicity of the samples was measured using Mus musculus skin melanoma cells (B16-F10 (ATCC{sup ®} CRL-6475™)) and were found to be nontoxic for human cells. The photocatalytic efficiency of the prepared samples was evaluated by methylene blue (MB) degradation. The best photocatalytic activity was shown by BiVO{sub 4} with 6:3:3 mol percentage of Yb{sup +3}:Er{sup +3}:Tm{sup +3} in all solar light spectrum. The synthesized samples possess low band gap energy and a hollow structure suitable for the better photocatalytic activity. The observed NIR photoactivity supports that the upconversion mechanism is involved in the overall photocatalytic process. Therefore, this approach provides a better alternative upconversion material for integral solar light absorption.

Fluorescence resonance energy transfer between NaYF{sub 4}:Yb,Tm upconversion nanoparticles and gold nanorods: Near-infrared responsive biosensor for streptavidin

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shuang; Wang, Jing; Xu, Wen; Chen, Boting; Yu, Wei; Xu, Lin; Song, Hongwei, E-mail: songhw@jlu.edu.cn

2014-03-15

We represent a fluorescence resonance energy transfer (FRET) system using upconversion nanoparticles (UCNPs) and the gold nanorods (GNRs) as the energy donor–acceptor pair for directly determining streptavidin in near-infrared (NIR) region. NaYF{sub 4}:Yb,Tm UCNPs, which had a strong emission at 800 nm under 980-nm excitation, were adopted as the energy donor. The GNRs, which demonstrated strong surface plasmon absorption around 800 nm, were chosen as acceptor to quench the 800 nm emissions of the UCNPs. There had the spectral overlap between the emission of the donor nanoparticles (UCNPs) and the absorption of the acceptor nanoparticles (GNRs). This UCNP-based FRET system was then used to determine the amount of streptavidin. In this system, NaYF{sub 4}:Yb,Tm UCNPs conjugated with biotin, while GNRs conjugated with streptavidin. When added GNRs into UCNPs, the streptavidin were preferred to bind with biotin and decreased spacing between the donor and acceptor NPs. Consequently, FRET occurred and a linear relationship between the luminescence quenching efficiency and the concentration of streptavidin was obtained. Owing to the aforementioned merits of UCNPs as an energy donor and the strong quenching ability of GNRs, satisfactory analytical performances have been acquired. -- Highlights: • NaYF4:Yb,Tm and GNRs are as NIR energy donor and quenching acceptor for FRET. • Linkage between biotin and streptavidin make the distance between the donors and the acceptors short enough for FRET. • The FRET system in this work was applicable for the detection of streptavidin. • The donor and acceptor NPs can be modified by proper molecules for other biological molecules detection.

Synthesis of green emission upconversion phosphor nanosheets (LaNb{sub 2}O{sub 7}) doped with Er{sup 3+} and Yb{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Takasugi, Soichi [Course of Science and Technology, Graduate School of Science and Technology, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Iida, Riku [Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Tomita, Koji, E-mail: tomita@keyaki.cc.u-tokai.ac.jp [Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Iwaoka, Michio [Course of Science and Technology, Graduate School of Science and Technology, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Katagiri, Kiyofumi [Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Osada, Minoru [International Center for Materials Nano architectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Kakihana, Masato [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

2016-05-15

LaNb{sub 2}O{sub 7}:Er{sup 3+},Yb{sup 3+} upconversion (UPC) phosphor nanosheets were prepared by exfoliating a KLaNb{sub 2}O{sub 7}:Er{sup 3+},Yb{sup 3+} layered compound. Highly crystalline nanosheets with a thickness and lateral size of 3.91 nm and approximately 300 nm, respectively, were obtained. The UPC emission intensity of the nanosheets was 7.6 times greater than that of mechanically milled particles (100–500 nm) of bulk KLaNb{sub 2}O{sub 7}:Er{sup 3+},Yb{sup 3+}. The UPC emission intensities of the nanosheets dispersed in different solvents (H{sub 2}O, D{sub 2}O, CH{sub 3}OH, CH{sub 2}Cl{sub 2}, and CCl{sub 4}) were measured, and the intensities were observed to decrease in the order CCl{sub 4}>CH{sub 2}Cl{sub 2}>D{sub 2}O>CH{sub 3}OH>H{sub 2}O. Because of the large surface area of the nanosheets, their emission intensity was decreased depending on the solvent's vibrational energy. - Highlights: • La{sub 0.45}Er{sub 0.05}Yb{sub 0.5}Nb{sub 2}O{sub 7} nanosheets were synthesized by a soft breakdown method (exfoliation). • The lateral size and thickness of the nanosheets were approximately 300 nm and approximately 3.91 nm, respectively. • The exfoliated nanosheets exhibited bright upconversion emission 7.6 times more intense than that of the milled sample (100–500 nm). • The nanosheets dispersed in solvents exhibited greatly different upconversion emission intensities depending on the solvent's vibrational energy.

Rare earth elements in the Pacific and Atlantic Oceans. [Pr, Tb, Ho, Tm, Lu, La, Nd, Sm, Eu, Gd, Yb, Ce

Energy Technology Data Exchange (ETDEWEB)

Baar, H J.W. de; Bacon, M P; Brewer, P G; Bruland, K W

1985-09-01

The first profiles of Pr, Tb, Ho, Tm and Lu in the Pacific Ocean, as well as profiles of La, Ce, Nd, Sm, Eu, Gd and Yb are reported. Concentrations of REE (except Ce) in the deep water are two to three times higher than those observed in the deep Atlantic Ocean. Surface water concentrations are typically lower than in the Atlantic Ocean, especially for the heavier elements Ho,Tm,Yb and Lu. Cerium is strongly depleted in the Pacific water column, but less so in the oxygen minimum zone. The distribution of the REE group is consistent with two simultaneous processes: (1) cycling similar to that of opal and calcium carbonate, and (2) adsorptive scavenging by settling particles and possibly by uptake at ocean boundaries. However, the first process can probably not be sustained by the low REE contents of shells, unless additional adsorption on surfaces is invoked. The second process, adsorptive scavenging, largely controls the oceanic distribution and typical seawater pattern of the rare earths. (author).

Infrared emissions in MgSrAl10O17:Er3+ phosphor co-doped with Yb3+/Ba2+/Ca2+ obtained by solution combustion route

International Nuclear Information System (INIS)

Singh, Vijay; Kumar Rai, Vineet; Venkatramu, V.; Chakradhar, R.P.S.; Hwan Kim, Sang

2013-01-01

An intense infrared emitting MgSrAl 10 O 17 :Er 3+ phosphor co-doped with Yb 3+ , Ba 2+ and Ca 2+ ions have been prepared by a solution combustion method. Phase purity of the derived compounds was confirmed by X-ray diffraction technique. The vibrational properties of MgSrAl 10 O 17 phosphor was studied by Fourier transform infrared spectroscopy. The broad and strong infrared emission of Er 3+ ions at around 1.53 μm was observed upon excitation at 980 nm. Effect of co-doping with the Yb 3+ , Ba 2+ and Ca 2+ ions on the infrared luminescence intensity of Er 3+ ions and the mechanism responsible for the variation in the infrared intensity have been discussed. The results indicate that these materials may be suitable for the optical telecommunication window and wavelength division multiplexing applications. - Highlights: ► The hexagonal phase of MgSrAl 10 O 17 could be obtained by the low temperature combustion method. ► The broad and strong infrared emission of Er 3+ ions at around 1.53 μm was observed. ► Effect of co-doping with the Yb 3+ , Ba 2+ and Ca 2+ ions on the infrared luminescence intensity of Er 3+ were reported.

Effect of Tm{sup 3+} codoping on the near-infrared and upconversion emissions of Er{sup 3+} in TeO{sub 2}–ZnO–ZnF{sub 2} glasses

Energy Technology Data Exchange (ETDEWEB)

Miguel, A. [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU,Alda. Urquijo s/n, 48013 Bilbao (Spain); Arriandiaga, M.A. [Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU, Apartado 644, Bilbao (Spain); Morea, R. [Instituto de Optica, Consejo Superior de Investigaciones Científicas CSIC, Serrano 121, 28006 Madrid (Spain); Fernandez, J. [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. [Instituto de Optica, Consejo Superior de Investigaciones Científicas CSIC, Serrano 121, 28006 Madrid (Spain); Balda, R., E-mail: wupbacrr@bi.ehu.es [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)

2014-10-15

In this work, we report the near-infrared emission and upconversion of Er{sup 3+}–Tm{sup 3+} codoped fluorotellurite TeO{sub 2}–ZnO–ZnF{sub 2} glasses for different Tm{sup 3+} concentrations by using steady-state and time-resolved spectroscopy. A broad emission from 1350 to 1700 nm corresponding to the {sup 3}H{sub 4}→{sup 3}F{sub 4} (Tm{sup 3+}) and {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} (Er{sup 3+}) emissions which cover the complete telecommunication window of the wavelength-division-multiplexing transmission systems is observed. The full width at half-maximum of this broadband increases with increasing Tm{sup 3+}/Er{sup 3+} concentration ratio up to a value of∼150 nm. Energy transfer between Er{sup 3+} and Tm{sup 3+} ions is also observed and analyzed by both the temporal behavior of the near-infrared luminescence and the effect of Tm{sup 3+} codoping on the visible upconversion of Er{sup 3+} ions. The addition of Tm{sup 3+} reduces the upconverted green emission due to Er{sup 3+}→Tm{sup 3+} energy transfer whereas the red emission is enhanced due to the cross-relaxation {sup 3}F{sub 4}→{sup 3}H{sub 6}(Tm{sup 3+}):{sup 4}I{sub 11/2}→{sup 4}F{sub 9/2}(Er{sup 3+}) process. - Highlights: • Broadband emission covering the bands S, C+L and U of the optical telecommunications. • The effect of Tm{sup 3+} concentration were investigated in Er{sup 3+}–Tm{sup 3+} codoped fluorotellurite glasses. • Efficient Er{sup 3+}↔Tm{sup 3+} energy transfer in fluorotellurite glasses. • Increase of the red upconversion emission with Tm{sup 3+} concentration due to cross-relaxation processes.

Up-conversion emission of Er{sup 3+}/Yb{sup 3+}co-doped BaBi{sub 2}Nb{sub 2}O{sub 9} (BBN) phosphors

Energy Technology Data Exchange (ETDEWEB)

Façanha, M.X., E-mail: marcello.facanha@uece.br [Departamento de Química, Centro de Ciências, Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Faculdade de Educação de Crateús (FAEC), Universidade Estadual do Ceará (UECE), Fortaleza, Ceará (Brazil); Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Nascimento, J.P.C. do [Departamento de Química, Centro de Ciências, Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Silva, M.A.S., E-mail: marceloassilva@yahoo.com.br [Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); and others

2017-03-15

On this paper, polycrystalline samples of the tetragonal systems BaBi{sub 2}Nb{sub 2}O{sub 9} (BBN) and BBN co-doped with Er{sup 3+}/Yb{sup 3+} (BBN: 0.04Er{sup 3+}yYb{sup 3+}, where y=0.02, 0.04, 0.06 and 0.08 mol%) were synthesized by the solid state method. The crystalline structure and photoluminescent properties of the ceramic phosphors were investigated by powder X-ray diffraction (PXRD), Raman spectroscopy and spectral analysis of up-conversion (UC) emission. The results reveal that all compositions crystallize in the I4/mmm space group at room temperature, and show UC green emissions (centered at 525 nm and 550 nm) and red (around 660 nm) coming from ({sup 2}H{sub 11/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2}) and ({sup 4}F{sub 9/2}→{sup 4}I{sub 15/2}) transitions, respectively, under excitation at 980 nm. Increasing variations of the Yb{sup 3+} sensitizer concentration in the host BBN, lead to a significant intensity increase in both UC emissions due to the efficiency of the energy-transfer process. The BBN: 0.04 mol%Er{sup 3+}0.08 mol%Yb{sup 3+} composition showed the higher intensity bands, thus establishing the BBN as an alternative host material for luminescent centers.

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.

The effect of intentional potassium co-doping on the luminescent properties of Yb3+ and Tm3+ doped α-NaYF4 core and core–shell nanoparticles

International Nuclear Information System (INIS)

Misiak, Małgorzata; Stręk, Wiesław; Arabasz, Sebastian; Bednarkiewicz, Artur

2016-01-01

Simple and effective ways to circumvent limited luminescence efficiency of up-converting nanoparticles (UCNPs) are sought. One of the methods relays on distorting the crystallographic structure of host material by co-doping the nanocrystals with optically inactive co-dopants. Here we study the influence of K + doping and surface passivation on the up-converting properties of the α-NaYF 4 nanocrystals co-doped with 20% Yb 3+ and 0.1 or 2% Tm 3+ . The intentionally chosen concentrations of K + ions, which were meant to replaced sodium ions were fixed to 0, 5, 10, 20 to 30%. Potassium ions modified the spectroscopic properties of both core and core–shell NPs, but the differences were noticed between samples doped with 0.1% Tm 3+ and 2% Tm 3+ ions. Replacement of sodium by potassium ions decreased up-conversion luminescence intensity as well as shortened thulium excited states lifetimes in the samples doped with 0.1% Tm 3+ , while the opposite behavior was found in the samples co-doped with higher 2% thulium concentration. - Highlights: • We studied the influence of K + doping on luminescent properties of α-NaYF 4 :YbTm. • The 0.1 and 2% Tm doped core and core–shell samples were investigated. • K + -doping influence on UC properties was different in low and highly Tm doped NPs. • The explanations of the observed variations were proposed.

LANDSAT TM and SAR - ERS1 data for analysis of Vrancea seismic region

International Nuclear Information System (INIS)

Zoran, M.

2002-01-01

This paper is aimed to present the results of the application of LANDSAT TM and SAR- ERS1 satellite data for Vrancea seismic area investigation, in order to emphasize geomorphological features as well as to identify faulting zones responsible of seismic events generation. Remote sensing analysis and field studies of active faults can provide a geologic history that overcomes many of the shortcomings of instrumental and historic records. Vrancea - Focsani is structurally and seismically complex area, bounded by latitudes 45.6 angle N and 46.0 angle N and longitudes 26.5 angle E and 27.5 angle E. The Peceneaga -Camena Fault, a deep crustal fracture with dextral slip, is considered to be North-Eastern boundary of the Moesian Platform. The Eastern unit of the Moesian Sub-Plate is characterized by a series of principal faults with a North-Western orientation and by a secondary system of faults orientated NE-SW. NW trending crustal fractures are also evidenced East of the Peceneaga-Camena Fault, within our test area. A SAR- ERS1 image and a multispectral Landsat TM data set were used and processed with EASI/PACE image processing software package as well as with developed algorithms. In order to a better management all the information available on the study area, data acquired have been integrated in a unique database. This information consists of thematic maps from cartography, land use map from classification of remotely sensed data. This study revealed that satellite data used are excellent for recognizing the continuity and regional relationships of faults. Linear features in TM images appear shorter and denser distributed, whereas ERS1 images are dominated by the principal structures. In certain cases they complete the lineaments and lineament patterns derived from TM data. Higher spatial resolution satellite data and SAR interferometric data are needed for mapping of these features. Remote sensing techniques provide a means for locating, identifying and mapping

Upconversion emission and cathodoluminescence of Er"3"+-doped NaYbF_4 nanoparticles for low-temperature thermometry and field emission displays

International Nuclear Information System (INIS)

Du, Peng; Yu, Jae Su; Luo, Laihui

2017-01-01

The Er"3"+-doped NaYbF_4 nanoparticles were fabricated by a hydrothermal method. The green and red emissions located at around 525, 542 and 657 nm corresponding to the "2H_1_1_/_2 → "4I_1_5_/_2, "4S_3_/_2 → "4I_1_5_/_2 and "4F_9_/_2 → "4I_1_5_/_2 transitions of Er"3"+ ions, respectively, were observed when pumped at 980 nm light. Furthermore, with the help of the fluorescence intensity ratio technique, the thermometric properties of as-prepared products from the thermally coupled "2H_1_1_/_2 and "4S_3_/_2 levels of Er"3"+ ions were studied by analyzing temperature-dependent upconversion (UC) emission spectra. The maximum sensitivity for the Er"3"+-doped NaYbF_4 nanoparticles was found to be around 0.0043 K"- "1 with a temperature range of 93-293 K. In addition, the cathodoluminescence (CL) spectrum of the synthesized nanoparticles was nearly the same as the UC emission spectrum and the CL emission intensity did not exhibit saturation with the increase of accelerating voltage and filament current. (orig.)

High-gain polymer optical waveguide amplifiers based on core-shell NaYF4/NaLuF4: Yb3+, Er3+ NPs-PMMA covalent-linking nanocomposites

Science.gov (United States)

Zhang, Meiling; Zhang, Weiwei; Wang, Fei; Zhao, Dan; Qu, Chunyang; Wang, Xibin; Yi, Yunji; Cassan, Eric; Zhang, Daming

2016-11-01

Waveguide amplifiers have always been significant key components for optical communication. Unfortunately, the low concentration of rare earth ions doped in the host material and the inadequate optimization of the waveguide structure have been the common bottleneck limitations. Here, a novel material, NaYF4/NaLuF4: 20% Yb3+, 2% Er3+ nanoparticle-Polymeric Methyl Methacrylate covalent-linking nanocomposite, was synthesized. The concentrations of Er3+ and Yb3+ doping increased an order of magnitude. Under a 980 nm laser excitation, highly efficient emission at 1.53 μm was obtained. The characteristic parameters of the single mode waveguide were carefully designed and optimized by using a finite difference method. A formulized iteration method is presented for solving the rate equations and the propagation equations of the EYCDWA, and both the steady state behavior and the gain were numerically simulated. The optimal Er3+ and Yb3+ concentrations are 2.8 × 1026 m-3 and 2.8 × 1027 m-3, and the optimal waveguide length is 1.3 cm. Both theoretical and experimental results indicated that, for an input signal power of 0.1 mW and a pump power of 400 mW, a net gain of 15.1 dB at 1530 nm is demonstrated. This result is the highest gain ever reported in polymer-based waveguide amplifiers doped with inorganic Er3+-Yb3+ codoped nanocrystals.

Modifying the size and uniformity of upconversion Yb/Er:NaGdF4 nanocrystals through alkaline-earth doping.

Science.gov (United States)

Lei, Lei; Chen, Daqin; Huang, Ping; Xu, Ju; Zhang, Rui; Wang, Yuansheng

2013-11-21

NaGdF4 is regarded as an ideal upconversion (UC) host material for lanthanide (Ln(3+)) activators because of its unique crystal structure, high Ln(3+) solubility, low phonon energy and high photochemical stability, and Ln(3+)-doped NaGdF4 UC nanocrystals (NCs) have been widely investigated as bio-imaging and magnetic resonance imaging agents recently. To realize their practical applications, controlling the size and uniformity of the monodisperse Ln(3+)-doped NaGdF4 UC NCs is highly desired. Unlike the routine routes by finely adjusting the multiple experimental parameters, herein we provide a facile and straightforward strategy to modify the size and uniformity of NaGdF4 NCs via alkaline-earth doping for the first time. With the increase of alkaline-earth doping content, the size of NaGdF4 NCs increases gradually, while the size-uniformity is still retained. We attribute this "focusing" of size distribution to the diffusion controlled growth of NaGdF4 NCs induced by alkaline-earth doping. Importantly, adopting the Ca(2+)-doped Yb/Er:NaGdF4 NCs as cores, the complete Ca/Yb/Er:NaGdF4@NaYF4 core-shell particles with excellent size-uniformity can be easily achieved. However, when taking the Yb/Er:NaGdF4 NCs without Ca(2+) doping as cores, they could not be perfectly covered by NaYF4 shells, and the obtained products are non-uniform in size. As a result, the UC emission intensity of the complete core-shell NCs increases by about 30 times in comparison with that of the cores, owing to the effective surface passivation of the Ca(2+)-doped cores and therefore protection of Er(3+) in the cores from the non-radiative decay caused by surface defects, whereas the UC intensity of the incomplete core-shell NCs is enhanced by only 3 times.

Investigation on the structural changes of ZnO:Er:Yb thin film during laser annealing to fabricate a transparent conducting upconverter

Energy Technology Data Exchange (ETDEWEB)

Lluscà, Marta, E-mail: marta.llusca@gmail.com [Department of Applied Physics, Universitat de Barcelona, 08028 Barcelona (Spain); Future Industries Institute, University of South Australia, Mawson Lakes, 5095 South Australia (Australia); López-Vidrier, Julian [Department of Electronics, Universitat de Barcelona, 08028 Barcelona (Spain); IMTEK, Faculty of Engineering, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany); Lauzurica, Sara; Canteli, David; Sánchez-Aniorte, Maria I.; Molpeceres, Carlos [Centro Láser, Universidad Politécnica de Madrid, 28031 Madrid (Spain); Antony, Aldrin [Department of Applied Physics, Universitat de Barcelona, 08028 Barcelona (Spain); Indian Institute of Technology Bombay, 400076 Mumbai (India); Hernández, Sergi [Department of Electronics, Universitat de Barcelona, 08028 Barcelona (Spain); Alcobé, Xavier [Unitat de Difracció de Raigs X, Centres Científics i Tecnològics, Universitat de Barcelona, 08028 Barcelona (Spain); Garrido, Blas [Department of Electronics, Universitat de Barcelona, 08028 Barcelona (Spain); Bertomeu, Joan [Department of Applied Physics, Universitat de Barcelona, 08028 Barcelona (Spain)

2017-05-15

A transparent and conducting ZnO:Er:Yb thin film with upconversion properties has been achieved after being annealed with continuous laser radiation just before the ablation point of the material. This work demonstrates that the laser energy preserves the conductivity of the film and at the same time creates an adequate surrounding for Er and Yb to produce visible upconversion at 660, 560, 520, and 480 nm under 980 nm laser excitation. The relation between the structural, electrical and upconversion properties is discussed. It is observed that the laser energy melts part of the material, which recrystallizes creating rare earth oxides and two different wurtzite structures, one with substitutional rare earths and oxygen vacancies (responsible for the conductivity) and the other without substitutional rare earth ions (responsible for the upconversion emission).

Raman and optical absorption spectroscopic investigation of Yb-Er codoped phosphate glasses containing SiO2

Institute of Scientific and Technical Information of China (English)

Youkuo Chen; Lei Wen; Lili Hu; Wei Chen; Y. Guyot; G. Boulon

2009-01-01

Yb-Er codoped Na2O-Al2O3-P2Os-xSiO2 glasses containing 0 鈥? 20 mol% SiO2 were prepared successfully. The addition of SiO2 to the phosphate glass not only lengthens the bond between P5+ and non-bridging oxygen but also reduces the number of P=O bond. In contrast with silicate glass in which there is only four-fold coordinated Si4+, most probably there coexist [SiO4] tetrahedron and [SiO6] octahedron in our glasses. Within the range of 0 鈥? 20 mol% SiO2 addition, the stimulated emission cross-section of Er3+ ion only decreases no more than 10%. The Judd-Ofelt intensity parameters of Er3+, 惟.2 does not change greatly, but 惟74 and 惟6 decrease obviously with increasing SiO2 addition, because the bond between Er + and O2- is more strongly covalently bonded.

Analyses of TmAl{sub 2} and ErAl{sub 2} composite for use as an active magnetic regenerator close to liquid helium temperature

Energy Technology Data Exchange (ETDEWEB)

Souza, M.V. de, E-mail: marcos_vinicios@hotmail.com [Núcleo de Pós-Graduação em Física, Campus prof. José Aluísio de Campos, UFS, 49100-000, São Cristóvão, SE (Brazil); Silva, J.A. da [Núcleo de Pós-Graduação em Física, Campus prof. José Aluísio de Campos, UFS, 49100-000, São Cristóvão, SE (Brazil); Silva, L.S. [Núcleo de Pós-Graduação em Física, Campus prof. José Aluísio de Campos, UFS, 49100-000, São Cristóvão, SE (Brazil); Instituto Federal de Tocantins, IFTO – Campus Colinas do Tocantins, AV. Bernardo Sayao S/N, Chácara Raio de Sol, Setor Santa Maria, CEP 77760-000, Colinas do Tocantins, TO (Brazil)

2017-07-01

Highlights: • Modeling of the thermodynamics quantities in RAl{sub 2} (R = Er, Tm) single crystal and polycrystal. • An optimal hybrid magnetocaloric material using TmAl{sub 2} and ErAl{sub 2} compounds. • Suppression of the ferromagnetic canted order in the compound TmAl{sub 2} in single crystal form. - Abstract: We report the thermodynamic properties of selected intermetallic RAl{sub 2} (R = Er, Tm) compounds calculated by using a model Hamiltonian, including the Zeeman-exchange interactions and the crystalline electrical field, which are responsible for the magnetic anisotropy. The relationship between the behavior of the temperature-dependent magnetization, calculated in different crystallographic directions for several magnetic fields, and the influence of spin reorientation on the magnetocaloric effect, is discussed. In order to validate the obtained theoretical results, experimental data are compared to calculated data. Also, an optimum molar fraction of the ErAl{sub 2} and TmAl{sub 2} composite was determined theoretically, showing a high potential for use in a regenerative thermal cycle, especially close to the liquid helium temperature range.

Synthesis and characterization of the novel rare earth orthophosphates Y0.5Er0.5PO4 and Y0.5Yb0.5PO4

International Nuclear Information System (INIS)

Schildhammer, Daniel; Petschnig, Lucas L.; Fuhrmann, Gerda; Heymann, Gunter; Schottenberger, Herwig; Huppertz, Hubert; Tribus, Martina

2016-01-01

The new mixed rare earth (RE) orthophosphates Y 0.5 Er 0.5 PO 4 and Y 0.5 Yb 0.5 PO 4 were synthesized by a classical solid state reaction in an electrical furnace at 1200 C. As starting materials, the corresponding rare earth oxides and diammonium hydrogen phosphate were used. The powder diffraction analyses revealed that the new compounds Y 0.5 Er 0.5 PO 4 and Y 0.5 Yb 0.5 PO 4 crystallize in a zircon-type structure being isostructural with the rare earth orthophosphate YPO 4 . Y 0.5 Er 0.5 PO 4 and Y 0.5 Yb 0.5 PO 4 crystallize in the tetragonal space group I4 1 /amd (no. 141) with four formula units in the unit cell. The structural parameters based on Rietveld refinements are a = 687.27(2), c = 601.50(2) pm, V = 0.28412(1) nm 3 , R p = 0.0143, and R wp = 0.0186 (all data) for Y 0.5 Er 0.5 PO 4 and a = 684.61(2), c = 599.31(2) pm, V = 0.28089(2) nm 3 , R p = 0.0242, and R wp = 0.0313 (all data) for Y 0.5 Yb 0.5 PO 4 . Furthermore, the structure of Y 0.5 Er 0.5 PO 4 was refined from single-crystal X-ray diffraction data: a = 687.78(5), c = 601.85(4) pm, V = 0.28470(5) nm 3 , R 1 = 0.0165, and wR 2 = 0.0385 (all data). In both compounds, the rare earth metal ions are eightfold coordinated by oxygen atoms, forming two unique interlocking tetrahedra with two individual RE-O distances. The tetrahedral phosphate groups [PO 4 ] 3- are slightly distorted in both compounds. The individual rare earth ions share a common position (Wyckoff site 4a). The presence of two rare earth ions in the structures of the new orthophosphates Y 0.5 Er 0.5 PO 4 and Y 0.5 Yb 0.5 PO 4 was additionally confirmed by single-crystal EDX spectroscopy revealing a ratio of 1:1.

HIGH REPETITION RATE MICROCHIP ER3+,YB3+:YAL3(BO34 DIODE-PUMPED LASER

Directory of Open Access Journals (Sweden)

K. N. Gorbachenya

2012-01-01

Full Text Available Diode-pumped passively Q-switched microchip Er,Yb:YAl3(BO34 laser for range-finding has been demonstrated. By using a Co2+:MgAl2O4 as a saturable absorber TEM00–mode Q-switched average output power of 315 mW was demonstrated at 1522 nm with pulse duration of 5 ns and pulse energy of 5,25 μJ at a repetition rate of 60 kHz.

Selective separation of yttrium by CA-100 in the presence of a complexing agent

International Nuclear Information System (INIS)

Sun Xiaobo; Wang Yige; Li Deqian

2006-01-01

The selective separation of Y from yttrium solution containing small heavy rare earth (HRE) impurities (Ho, Er, Tm, Yb, Lu) by liquid-liquid extraction using CA-100 in the presence of a water-soluble complexing agent of ethylenediaminetetraacetic acid (EDTA) was experimentally studied at 298 K. Experiments were carried out in two feeds, Feed-I: [RE] f = 4.94 x 10 -3 M, Y = 98.5%, HRE (Ho, Er, Tm, Yb, Lu) = 1.5%; Feed-II: [RE] f = 4.94 x 10 -3 M, Y = 99.9%, HRE (Ho, Er, Tm, Yb, Lu) = 0.1%, as a function of equilibrium pH (pH eq ), the concentration ratio of [EDTA]:[HRE impurities]. It was shown that the extraction of HRE in the presence of EDTA was suppressed when compared to that of Y because of the masking effect, while the selective extraction of Y was enhanced and the separation factors increased to maximum at appropriate condition for Feed-I: Y/Ho = 1.53, Y/Er 3.09, Y/Tm = 5.61, Y/Yb = 12.04, Y/Lu = 27.51 at pH 4.37 and [EDTA]:[HRE impurities] = 4:1, for Feed-II: Y/Ho = 1.32, Y/Er = 1.91, Y/Tm = 2.00, Y/Yb 3.05, Y/Lu = 3.33 at pH 4.42 and [EDTA]:[HRE impurities] = 8:1. The separation and purification of Y by this method was discussed

Efficient continuous-wave and passively Q-switched pulse laser operations in a diffusion-bonded sapphire/Er:Yb:YAl3(BO3)4/sapphire composite crystal around 1.55 μm.

Science.gov (United States)

Chen, Yujin; Lin, Yanfu; Huang, Jianhua; Gong, Xinghong; Luo, Zundu; Huang, Yidong

2018-01-08

A composite crystal consisting of a 1.5-mm-thick Er:Yb:YAl 3 (BO 3 ) 4 crystal between two 1.2-mm-thick sapphire crystals was fabricated by the thermal diffusion bonding technique. Compared with a lone Er:Yb:YAl 3 (BO 3 ) 4 crystal measured under the identical experimental conditions, higher laser performances were demonstrated in the sapphire/Er:Yb:YAl 3 (BO 3 ) 4 /sapphire composite crystal due to the reduction of the thermal effects. End-pumped by a 976 nm laser diode in a hemispherical cavity, a 1.55 μm continuous-wave laser with a maximum output power of 1.75 W and a slope efficiency of 36% was obtained in the composite crystal when the incident pump power was 6.54 W. Passively Q-switched by a Co 2+ :MgAl 2 O 4 crystal, a 1.52 μm pulse laser with energy of 10 μJ and repetition frequency of 105 kHz was also realized in the composite crystal. Pulse width was 315 ns. The results show that the sapphire/Er:Yb:YAl 3 (BO 3 ) 4 /sapphire composite crystal is an excellent active element for 1.55 μm laser.

Magnetism in RRhGe (R = Tb, Dy, Er, Tm): An experimental and theoretical study

Energy Technology Data Exchange (ETDEWEB)

Gupta, Sachin [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Suresh, K.G., E-mail: suresh@phy.iitb.ac.in [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Nigam, A.K. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Lukoyanov, A.V. [Institute of Metal Physics, Russian Academy of Sciences, Ural Branch, Yekaterinburg 620137 (Russian Federation); Ural Federal University, Yekaterinburg 620002 (Russian Federation)

2015-08-15

Highlights: • RRhGe (R = Tb, Dy, Er, Tm) compounds show low temperature antiferromagnetic ordering. • All compounds show field induced metamagnetic transitions. • Some of these compounds show large magnetocaloric effect and magnetoresistance. • Change of sign in MR take place on temperature variation. - Abstract: RRhGe (R = Tb, Dy, Er, Tm) compounds have been studied by different experimental probes and theoretical ab initio calculations. These compounds show very interesting magnetic and transport properties. All the compounds are antiferromagnetic with some of them showing spin-reorientation transition at low temperatures. The magnetocaloric effect estimated from magnetization data shows high values in all these compounds. Magnetoresistance is negative near the ordering temperatures and positive at low temperatures. The electronic structure calculations accounting for electronic correlations in the 4f rare-earth shell reveal the closeness of the antiferromagnetic ground state and other types of magnetic orderings in the rare-earth sublattice. These calculations are also in agreement with the experimental results.

Near infrared and upconversion luminescence behaviour of Er3+/Yb3+ codoped boro-tellurite glasses

Science.gov (United States)

Maheshvaran, K.; Arunkumar, S.; Vijayakumar, R.; Marimuthu, K.

2014-04-01

The broadband NIR and upconversion luminescence behavior in a new series of Er3+/Yb3+ codoped TeO2-B2O3-SrO-BaO-Li2O-LiF glasses have been studied exciting at a wavelength of 980 nm using semiconductor laser. A broadband emission is observed from 1450 to 1650 nm with a full width at half maximum (FWHM) around 165 nm in 0.5wt% Yb3+ ion content E0.5YLTB glass. The radiative parameters such as transition probability (A), stimulated emission cross-section (σE), experimental and calculated branching ratios (βR), optical gain width (σp×FWHM) and radiative lifetime (τcal) have been calculated for the 4I13/2→4I15/2 NIR emission. Upconversion luminescence spectra of the prepared glasses have been studied and the ESA & ET processes have also been discussed and reported.

Hydrothermal synthesis of superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er core@shell monodisperse nanoparticles and their subsequent ligand exchange in water

Energy Technology Data Exchange (ETDEWEB)

Qin, Zhenli; Du, Sinan; Luo, Yang; Liao, Zhijian; Zuo, Fang, E-mail: polymerzf@swun.cn; Luo, Jianbin; Liu, Dong

2016-08-15

Graphical abstract: An efficient hydrothermal method was used to fabricate the superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2(*)+}-doped NaYF{sub 4}:Yb/Er nanoparticles (NPs) with core@shell structures through a seed-growth procedure. Then using PEG phosphate ligand to displace oleate from the as-synthesized NPs, hydrophilic Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er NPs with good water solubility are obtained. - Highlights: • Homogeneous size distribution of magnetic-upconversion core@shell structured nanoparticles (NPs) were synthesized. • The core@shell nanostructures were obtained by seed-growth method. • The oleic acid coated Fe{sub 3}O{sub 4} NPs were used as seeds and cores. • The magnetic-upconversion NPs emitted red luminescence under a 980 nm laser. • Synthesized magnetic-upconversion NPs were phase transferred using ligand exchange process. - Abstract: We report the use of an efficient hydrothermal method to synthesize superparamagnetic and red luminescent bifunctional Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er nanoparticles (NPs) with core@shell structures via a seed-growth procedure. Oleic acid coated Fe{sub 3}O{sub 4} (OA-Fe{sub 3}O{sub 4}) NPs were initially synthesized using a coprecipitation method. The as-synthesized OA-Fe{sub 3}O{sub 4} NPs were then used as seeds, on which the red upconversion luminescent shell (Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er) was formed. Furthermore, hydrophobic to hydrophilic surface modification of the Fe{sub 3}O{sub 4}@Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er NPs was achieved via a ligand exchange method where oleic acid was displaced by a PEG phosphate ligand [PEG = poly(ethylene glycol)]. These materials were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, and vibrating sample magnetometry (VSM). The Fe{sub 3}O{sub 4} cores were uniformly coated with a Mn{sup 2+}-doped NaYF{sub 4}:Yb/Er

New Sr{sub 1−x−z}R{sub x}(NH{sub 4}){sub z}F{sub 2+x−z} (R = Yb, Er) solid solution as precursor for high efficiency up-conversion luminophor and optical ceramics on the base of strontium fluoride

Energy Technology Data Exchange (ETDEWEB)

Rozhnova, Yu. A. [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation); A.M. Prokhorov General Physics Institute, RAS, Moscow (Russian Federation); Kuznetsov, S.V. [A.M. Prokhorov General Physics Institute, RAS, Moscow (Russian Federation); Luginina, A.A. [All-Russian Institute for Scientific and Technical Information (VINITI), Moscow (Russian Federation); Voronov, V.V.; Ryabova, A.V.; Pominova, D.V.; Ermakov, R.P. [A.M. Prokhorov General Physics Institute, RAS, Moscow (Russian Federation); Usachev, V.A.; Kononenko, N.E. [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation); Baranchikov, A.E.; Ivanov, V.K. [N.S. Kurnakov Institute of General and Inorganic Chemistry, RAS, Moscow (Russian Federation); Fedorov, P.P., E-mail: ppfedorov@yandex.ru [A.M. Prokhorov General Physics Institute, RAS, Moscow (Russian Federation)

2016-04-01

In this paper, we describe the use of self-fluorinating conditions for the thermal treatment of Sr{sub 1−x−y−z}Yb{sub x}Er{sub y}(NH{sub 4}){sub z}F{sub 2+x+y−z} precursor for the preparation of high-efficiency SrF{sub 2}:Yb:Er up-converter powders. We report actual SrF{sub 2}:Yb:Er compositions with up-conversion efficiencies exceeding 4% (pumping power 1 W/cm{sup 2} at 974 nm wavelength) and describe the synthesis of ceramics with higher than 80% transmittance at 0.42–7.0 μm. The latter ceramics can be used as a potential IR radiation visualizer. For the first time, we present an analysis of correlation between up-conversion luminescence energy yield and specimen composition for SrF{sub 2}:Yb:Er nanopowders. Taking into account the observed erbium ion up-conversion luminescence in the red part of the visible spectrum, we recommend certain SrF{sub 2}:Yb:Er compositions for practical application in photodynamic cancer therapy. - Highlights: • SrF{sub 2}:Yb/Er luminophor nanopowders were precipitated from aqueous solutions. • Precipitation of Sr{sub 1−x−y−z}Yb{sub x}Er{sub y}(NH{sub 4}){sub z}F{sub 2+x+y−z} solid solution has been proved. • Up-conversion luminescence energy yield luminophors of more than 4% were obtained. • Optical ceramics with 80% transmittance in 0.42–7.0 μm range was synthesized.

Photoluminescence of rare-earth ion (Eu3+, Tm3+, and Er3+)-doped and co-doped ZnNb2O6 for solar cells

Science.gov (United States)

Gao, Sen-Pei; Qian, Yan-Nan; Wang, Biao

2015-08-01

Visible converted emissions produced at an excitation of 286 nm in ZnNb2O6 ceramics doped with rare-earth ions (RE = Eu3+, Tm3+, Er3+ or a combination of these ions) were investigated with the aim of increasing the photovoltaic efficiency of solar cells. The structure of RE:ZnNb2O6 ceramics was confirmed by x-ray diffraction patterns. The undoped ZnNb2O6 could emit a blue emission under 286-nm excitation, which is attributed to the self-trapped excitons’ recombination of the efficient luminescence centers of edge-shared NbO6 groups. Upon 286-nm excitation, Eu:ZnNb2O6, Tm:ZnNb2O6, and Er:ZnNb2O6 ceramics showed blue, green, and red emissions, which correspond to the transitions of 5D0 → 7FJ (J = 1-4) (Eu3+), 1G4 → 3H6 (Tm3+), and 2H11/2/4S3/2 → 4I15/2 (Er3+), respectively. The calculated CIE chromaticity coordinates of Eu:ZnNb2O6, Tm:ZnNb2O6, and Er:ZnNb2O6 are (0.50, 0.31), (0.14, 0.19), and (0.29, 0.56), respectively. RE ion-co-doped ZnNb2O6 showed a combination of characteristic emissions. The chromaticity coordinates of Eu/Tm:ZnNb2O6, Eu/Er:ZnNb2O6, and Tm/Er:ZnNb2O6 were calculated to be (0.29, 0.24), (0.45, 0.37), and (0.17, 0.25). Project supported by the National Natural Science Foundation of China (Grant Nos. 10572155 and 10732100) and the Research Fund for the Doctoral Program of Ministry of Education, China (Grant No. 20130171130003).

Coupling of Ag Nanoparticle with Inverse Opal Photonic Crystals as a Novel Strategy for Upconversion Emission Enhancement of NaYF4: Yb(3+), Er(3+) Nanoparticles.

Science.gov (United States)

Shao, Bo; Yang, Zhengwen; Wang, Yida; Li, Jun; Yang, Jianzhi; Qiu, Jianbei; Song, Zhiguo

2015-11-18

Rare-earth-ion-doped upconversion (UC) nanoparticles have generated considerable interest because of their potential application in solar cells, biological labeling, therapeutics, and imaging. However, the applications of UC nanoparticles were still limited because of their low emission efficiency. Photonic crystals and noble metal nanoparticles are applied extensively to enhance the UC emission of rare earth ions. In the present work, a novel substrate consisting of inverse opal photonic crystals and Ag nanoparticles was prepared by the template-assisted method, which was used to enhance the UC emission of NaYF4: Yb(3+), Er(3+) nanoparticles. The red or green UC emissions of NaYF4: Yb(3+), Er(3+) nanoparticles were selectively enhanced on the inverse opal substrates because of the Bragg reflection of the photonic band gap. Additionally, the UC emission enhancement of NaYF4: Yb(3+), Er(3+) nanoparticles induced by the coupling of metal nanoparticle plasmons and photonic crystal effects was realized on the Ag nanoparticles included in the inverse opal substrate. The present results demonstrated that coupling of Ag nanoparticle with inverse opal photonic crystals provides a useful strategy to enhance UC emission of rare-earth-ion-doped nanoparticles.

Optical gain at 1.53 {mu}m in Er{sup 3+}-Yb{sup 3+} co-doped porous silicon waveguides

Energy Technology Data Exchange (ETDEWEB)

Najar, A. [Laboratoire d' Optronique UMR 6082-FOTON, Universite de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Laboratoire de Spectroscopie Raman, Faculte des Sciences de Tunis, 2092 El Manar, Tunis (Tunisia)], E-mail: najar.adel@laposte.net; Charrier, J. [Laboratoire d' Optronique UMR 6082-FOTON, Universite de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Ajlani, H. [Laboratoire de Spectroscopie Raman, Faculte des Sciences de Tunis, 2092 El Manar, Tunis (Tunisia); Lorrain, N.; Haesaert, S. [Laboratoire d' Optronique UMR 6082-FOTON, Universite de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Oueslati, M. [Laboratoire de Spectroscopie Raman, Faculte des Sciences de Tunis, 2092 El Manar, Tunis (Tunisia); Haji, L. [Laboratoire d' Optronique UMR 6082-FOTON, Universite de Rennes 1, 6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France)

2008-01-15

Erbium-ytterbium (Er-Yb)-co-doped porous silicon planar waveguides were prepared from P{sup +}-type (1 0 0) oriented silicon wafer. Erbium and ytterbium ions were electrochemically introduced into the porous structure of the waveguide core. The doping profiles of erbium and ytterbium ions were determined by EDX analysis performed on sample cross-section. The mean concentration in the guiding layer is of about 1 x 10{sup 20} cm{sup -3}. The refractive indices were measured from co-doped porous silicon and undoped waveguides after the thermal treatments. The photoluminescence (PL) peak of optically activated erbium ions at 1.53 {mu}m was recorded. The PL enhancement is the result of the energy transfer from the excited state of Yb to the state of Er. Optical losses at 1.55 {mu}m were measured on these waveguides and were of about 2 dB/cm. An internal gain at 1.53 {mu}m of 5.8 dB/cm has been measured with a pump power of 65 mW at 980 nm.

Synthesis of NaLuF4:Er3+, Yb3+, Ce3+ nanoparticles and study of photoluminescent properties in C - band

Directory of Open Access Journals (Sweden)

Khaydukov K.V.

2017-01-01

Full Text Available The novel core@shell nanocrystals β-NaLuF4@NaLuF4 co-doped with rare-earth ions Er3+, Yb3+, Ce3+ have been synthesized. The nano-particles indicate the intensive lines of anti-Stokes luminescence in the telecommunication С - band of spectrum when pumped at 970-980 nm. The nanoparticles have been characterized by transmission electron microscopy and spectrofluorimetry. The nanoparticles have a size 40-80 nm and possess the intensive photo-luminescence 73 nm bandwidth centered around 1530 nm. The photo-luminescence kinetics of β-NaLuF4: Er3+/ Yb3+/ Ce3+ has been studied in IR range of spectrum. We have demonstrated that doping with cerium ions prevents serial stepwise excitation of erbium ions. Consequently, the lifetime of transition in erbium 4I13/2→4I15/2 has risen up to 6.9 ms. Intensity of 1530 nm line in Er3+ ions excited at 980 nm has been increased up to 6 times. Therefore, the nanoparticles are applicable to fabrication of compact waveguide amplifiers for C - band.

Blue and green emissions with high color purity from nanocrystalline Ca2Gd8Si6O26:Ln (Ln = Tm or Er) phosphors

International Nuclear Information System (INIS)

Seeta Rama Raju, G.; Park, Jin Young; Jung, Hong Chae; Pavitra, E.; Moon, Byung Kee; Jeong, Jung Hyun; Yu, Jae Su; Kim, Jung Hwan; Choi, Haeyoung

2011-01-01

Graphical abstract: Highlights: → Nanocrystalline Ca 2 Gd 8 Si 6 O 26 (CGS):Tm 3+ and CGS:Er 3+ phosphors were prepared by solvothermal reaction method. → The visible luminescence properties of phosphors were investigated by exciting with ultraviolet (UV) or near-UV light and low voltage electron beam (0.5-5 kV). → The photoluminescence spectra of CGS:Tm 3+ under 359 nm excitation and CGS:Er 3+ under 380 nm excitation showed the strong blue ( 1 D 2 → 3 F 4 at 456 nm) and green ( 4 S 3/2 → 4 I 15/2 at 550 nm) colors with the color purity 87% and 96%, respectively → The low accelerating voltage cathodoluminescence spectra of CGS:Tm 3+ and CGS:Er 3+ showed the strong blue and green emissions with the high color purity 95% and 96%, respectively. → The obtained results are hint at the promising applications to produce high quality LEDs and FED devices. - Abstract: Blue and green light emissive nanocrystalline Ca 2 Gd 8 Si 6 O 26 (CGS):Tm 3+ and CGS:Er 3+ phosphors with high color purity were prepared by solvothermal reaction method. The structural and morphological properties of these phosphors were evaluated by the powder X-ray diffraction (XRD) and scanning electron microscopy, respectively. From the XRD results, Tm 3+ :CGS and Er 3+ :CGS phosphors had the characteristic peaks of oxyapatite in the hexagonal lattice structure. The visible luminescence properties of phosphors were obtained by ultraviolet (UV) or near-UV light and low voltage electron beam (0.5-5 kV) excitation. The photoluminescence and cathodoluminescence properties were investigated by changing the variation of Tm 3+ or Er 3+ concentrations and the acceleration voltage, respectively. The CGS:Tm 3+ phosphors exhibited the blue emission due to 1 D 2 → 3 F 4 transition, while the CGS:Er 3+ phosphors showed the green emission due to 4 S 3/2 → 4 I 15/2 transition. The color purity and chromaticity coordinates of the fabricated phosphors are comparable to or better than those of standard

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method.

Science.gov (United States)

Gavrilović, Tamara V; Jovanović, Dragana J; Lojpur, Vesna; Dramićanin, Miroslav D

2014-02-27

Synthesis of Eu(3+)- and Er(3+)/Yb(3+)-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each particle comprises a single crystallite. Eu(3+)-doped GdVO4 nanoparticles emit red light through downconversion upon UV excitation. Er(3+)/Yb(3+)-doped GdVO4 nanoparticles exhibit several functions; apart from the downconversion of UV radiation into visible green light, they act as upconvertors, transforming near-infrared excitation (980 nm) into visible green light. The ratio of green emissions from (2)H11/2 → (2)I15/2 and (4)S3/2 → (4)I15/2 transitions is temperature dependent and can be used for nanoscale temperature sensing with near-infrared excitation. The relative sensor sensitivity is 1.11%K(-1), which is among the highest sensitivities recorded for upconversion-luminescence-based thermometers.

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method

Science.gov (United States)

Gavrilović, Tamara V.; Jovanović, Dragana J.; Lojpur, Vesna; Dramićanin, Miroslav D.

2014-02-01

Synthesis of Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each particle comprises a single crystallite. Eu3+-doped GdVO4 nanoparticles emit red light through downconversion upon UV excitation. Er3+/Yb3+-doped GdVO4 nanoparticles exhibit several functions; apart from the downconversion of UV radiation into visible green light, they act as upconvertors, transforming near-infrared excitation (980 nm) into visible green light. The ratio of green emissions from 2H11/2 --> 2I15/2 and 4S3/2 --> 4I15/2 transitions is temperature dependent and can be used for nanoscale temperature sensing with near-infrared excitation. The relative sensor sensitivity is 1.11%K-1, which is among the highest sensitivities recorded for upconversion-luminescence-based thermometers.

Investigation of thermal stability and spectroscopic properties in Er3+/Yb3+-codoped TeO2-Li2O-B2O3-GeO2 glasses.

Science.gov (United States)

Nie, Qiu-Hua; Gao, Yuan; Xu, Tie-Feng; Shen, Xiang

2005-06-01

The new Er3+/Yb3+ co-doped 70TeO2-5Li2O-(25-x)B2O3-xGeO2 (x = 0, 5, 10, 15 fand 20 mol.%) glasses were prepared. The thermal stability, absorption spectra, emission spectra and lifetime of the 4I(13/2) level of Er3+ ions were measured and studied. The FT-IR spectra were carried out in order to investigate the structure of local arrangements in glasses. It is found that the thermal stability, absorption cross-section of Yb3+, emission intensity and lifetime of the 4I(13/2) level of Er3+ increase with increasing GeO2 content in the glass composition, while the fluorescence width at half maximum (FWHM) at 1.5 um of Er3+ is about 70 nm. The obtained data suggest that this system glass can be used as a candidate host material for potential broadband optical amplifiers.

Spectroscopic properties of Er3+/Yb3+ Co-doped zinc boro-tellurite glasses for 1.5 xB5m broadband optical amplifiers

Science.gov (United States)

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

2015-06-01

A new series of Er3+/Yb3+ co-doped Zinc boro-tellurite glasses with the chemical composition (40-x-y)B2O3+ 25TeO2+20ZnO+15BaO+xYb2O3+yEr2O3 (where x = 0.1, 0.5, 1 and 3; y =1 in wt %) were prepared by melt quenching technique and their spectroscopic behavior were studied through UV-Vis-NIR absorption and NIR luminescence measurements. The bonding parameters (β ¯ and δ) and Judd-Ofelt (JO) intensity parameters Ωλ (λ=2, 4 and 6) have been calculated from the band positions of the absorption spectra. A broad near-infrared emission band at 1540 nm with a full width at half maximum around 80 nm was observed from the NIR luminescence spectra by monitoring an excitation at 980 nm. The absorption cross-section and emission cross-section for the4I13/2→4I15/2 transition of the Er3+ ions were also determined using McCumber theory and the results were discussed and reported.

NIR luminescent Er{sup 3+}/Yb{sup 3+} co-doped SiO{sub 2}-ZrO{sub 2} nanostructured planar and channel waveguides: Optical and structural properties

Energy Technology Data Exchange (ETDEWEB)

Cunha, Cesar dos Santos [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto/SP (Brazil); Ferrari, Jefferson Luis [Grupo de Pesquisa em Quimica de Materiais - (GPQM), Departamento de Ciencias Naturais, Universidade Federal de Sao Joao Del Rei, Campus Dom Bosco, Praca Dom Helvecio, 74, 36301-160, Sao Joao Del Rei, MG (Brazil); Oliveira, Drielly Cristina de [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto/SP (Brazil); Maia, Lauro June Queiroz [Grupo Fisica de Materiais, Instituto de Fisica, UFG, Campus Samambaia, Caixa Postal 131, 74001-970, Goiania/GO (Brazil); Gomes, Anderson Stevens Leonidas [Departamento de Fisica, Universidade Federal de Pernambuco, Cidade Universitaria, Recife/PE, 50670-901 (Brazil); Ribeiro, Sidney Jose Lima [Laboratorio de Materiais Fotonicos, Instituto de Quimica, UNESP, Caixa Postal 355, 14801-970, Araraquara/SP (Brazil); and others

2012-09-14

Optical and structural properties of planar and channel waveguides based on sol-gel Er{sup 3+} and Yb{sup 3+} co-doped SiO{sub 2}-ZrO{sub 2} are reported. Microstructured channels with high homogeneous surface profile were written onto the surface of multilayered densified films deposited on SiO{sub 2}/Si substrates by a femtosecond laser etching technique. The densification of the planar waveguides was evaluated from changes in the refractive index and thickness, with full densification being achieved at 900 Degree-Sign C after annealing from 23 up to 500 min, depending on the ZrO{sub 2} content. Crystal nucleation and growth took place together with densification, thereby producing transparent glass ceramic planar waveguides containing rare earth-doped ZrO{sub 2} nanocrystals dispersed in a silica-based glassy host. Low roughness and crack-free surface as well as high confinement coefficient were achieved for all the compositions. Enhanced NIR luminescence of the Er{sup 3+} ions was observed for the Yb{sup 3+}-codoped planar waveguides, denoting an efficient energy transfer from the Yb{sup 3+} to the Er{sup 3+} ion. Highlights: Black-Right-Pointing-Pointer Sol-gel high NIR luminescent nanostructured planar and channel waveguides. Black-Right-Pointing-Pointer Microstructured channels written by a femtosecond laser etching technique. Black-Right-Pointing-Pointer Transparent glass ceramic with rare earth-doped ZrO{sub 2} nanocrystals in a silica host. Black-Right-Pointing-Pointer Enhanced NIR luminescence, efficient energy transfer from the Yb{sup 3+} to the Er{sup 3+} ion. Black-Right-Pointing-Pointer New planar channel waveguides to be applied as EDWA in the C telecommunication band.

Radiative transition, local field enhancement and energy transfer microcosmic mechanism of tellurite glasses containing Er3+, Yb3+ ions and Ag nanoparticles

International Nuclear Information System (INIS)

Zhang, Wenjun; Lin, Jian; Cheng, Mingzhao; Zhang, Shuo; Jia, Yujie; Zhao, Junhong

2015-01-01

Er 3+ -doped, Er 3+ /Yb 3+ co-doped tellurite glass with and without Ag NPs were synthesized by melt-quenching method. The high resolution transmission electron microscopy (HR-TEM) and selected area electron diffractions (SAED) manifest growth of Ag NPs. The UV–vis–NIR absorption spectroscopy and fluorescence spectroscopy were measured. The optical band gap and multiphonon relaxation rate constants were calculated. The electronic band structure and local density of state (DOS) of Ag NPs are calculated. The fluorescence emission and enhancement mechanism including localized surface plasmon resonance (LSPR) and energy transfer (ET) microcosmic mechanism were discussed. The electric field distributions of Ag NPs are emulated by FDTD solutions software. Local field enhancement (LFE) induced by LSPR and lightning rod effect was found to be responsible for the fluorescence enhancement while energy transfer from Ag NPs to rare-earth was considered ignorable in the samples without photoluminescent emission. - Highlights: • Tellurite glasses containing Er 3+ , Yb 3+ and Ag NPs are prepared. • Judd–Ofelt and multiphonon relaxation are calculated. • The electronic band structures of Ag NPs are calculated. • The energy transfer mechanism is discussed. • The plasmon resonance effect of Ag NPs is discussed

Upconversion emission and cathodoluminescence of Er{sup 3+}-doped NaYbF{sub 4} nanoparticles for low-temperature thermometry and field emission displays

Energy Technology Data Exchange (ETDEWEB)

Du, Peng; Yu, Jae Su [Kyung Hee University, Department of Electronics and Radio Engineering, Yongin (Korea, Republic of); Luo, Laihui [Ningbo University, Department of Microelectronic Science and Engineering, Ningbo (China)

2017-03-15

The Er{sup 3+}-doped NaYbF{sub 4} nanoparticles were fabricated by a hydrothermal method. The green and red emissions located at around 525, 542 and 657 nm corresponding to the {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} transitions of Er{sup 3+} ions, respectively, were observed when pumped at 980 nm light. Furthermore, with the help of the fluorescence intensity ratio technique, the thermometric properties of as-prepared products from the thermally coupled {sup 2}H{sub 11/2} and {sup 4}S{sub 3/2} levels of Er{sup 3+} ions were studied by analyzing temperature-dependent upconversion (UC) emission spectra. The maximum sensitivity for the Er{sup 3+}-doped NaYbF{sub 4} nanoparticles was found to be around 0.0043 K{sup -} {sup 1} with a temperature range of 93-293 K. In addition, the cathodoluminescence (CL) spectrum of the synthesized nanoparticles was nearly the same as the UC emission spectrum and the CL emission intensity did not exhibit saturation with the increase of accelerating voltage and filament current. (orig.)

Optical transitions of Er3+/Yb3+ codoped TeO2-WO3-Bi2O3 glass.

Science.gov (United States)

Shen, Xiang; Nie, Qiuhua; Xu, Tiefeng; Gao, Yuan

2005-10-01

Optical absorption and emission properties of the Er3+/Yb3+ codoped TeO2-WO3-Bi2O3 (TWB) glass has been investigated. The transition probabilities, excited state lifetimes, and the branching ratios have been predicted for Er3+ based on the Judd-Ofelt theory. The broad 1.5 microm fluorescence was observed under 970 nm excitation, and its full width at half maximum (FWHM) is 77 nm. The emission cross-section is calculated using the McCumber theory, and the peak emission cross-section is 1.03 x 10(-21) cm2 at 1.531 microm. This value is much larger than those of the silicate and phosphate glasses. Efficient green and weak red upconversion luminescence from Er3+ centers in the glass sample was observed at room temperature, and the upconversion excitation processes have been analyzed.

Fiber-optic thermometer application of thermal radiation from rare-earth end-doped SiO2 fiber

International Nuclear Information System (INIS)

Katsumata, Toru; Morita, Kentaro; Komuro, Shuji; Aizawa, Hiroaki

2014-01-01

Visible light thermal radiation from SiO 2 glass doped with Y, La, Ce, Pr, Nd, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu were studied for the fiber-optic thermometer application based on the temperature dependence of thermal radiation. Thermal radiations according to Planck's law of radiation are observed from the SiO 2 fibers doped with Y, La, Ce, Pr, Eu, Tb, and Lu at the temperature above 1100 K. Thermal radiations due to f-f transitions of rare-earth ions are observed from the SiO 2 fibers doped with Nd, Dy, Ho, Er, Tm, and Yb at the temperature above 900 K. Peak intensities of thermal radiations from rare-earth doped SiO 2 fibers increase sensitively with temperature. Thermal activation energies of thermal radiations by f-f transitions seen in Nd, Dy, Ho, Er, Tm, and Yb doped SiO 2 fibers are smaller than those from SiO 2 fibers doped with Y, La, Ce, Pr, Eu, Tb, and Lu. Thermal radiation due to highly efficient f-f transitions in Nd, Dy, Ho, Er, Tm, and Yb ions emits more easily than usual thermal radiation process. Thermal radiations from rare-earth doped SiO 2 are potentially applicable for the fiber-optic thermometry above 900 K

Comparative evaluation of two methods for 172Tm production in nuclear reactors

International Nuclear Information System (INIS)

Cohen, I.M.; Hayes, Alejandro; Melcer, Elsa

2016-01-01

A comparative evaluation of two methods for the production of 172 Tm in nuclear reactors is carried out. They are respectively based on two chains of double neutron capture reactions, 170 Er(n,γ) 171 Er(n,γ) 172 Er(β - ) 172 Tm and 170 Er(n,γ) 171 Er(β - ) 171 Tm(n,γ) 172 Tm, and a chain of triple neutron capture: 169 Tm(n,γ) 170 Tm(n,γ) 71 Tm(n,γ) 172 Tm. Theoretical considerations with respect to both ways of production are formulated and the mathematical equation are solved. Experiments of irradiation of Er 2 O 3 and Tm 2 O 3 were performed. Advantages and drawbacks of both methods are discussed. (author)

Structural and light up-conversion luminescence properties of Er3+-Yb3+-W6+ substituted Bi4Ti3O12

Science.gov (United States)

Bokolia, Renuka; Rai, Vineet K.; Chauhan, Lalita; Sreenivas, K.

2016-05-01

The structural and light up-conversion (UC) luminescence properties of W6+ substituted Bi3.79Er0.03Yb0.18Ti3-xWxO12 (0 ≤ x ≤ 0.10) ceramics prepared by solid state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of single phase material with orthorhombic structure. A decrease in the lattice parameters and unit cell volume is observed with increasing W content. Strong UC luminescence at 527, 548 and 662 nm is seen under an excitation of 980 nm for an optimum W content (x = 0.06) and is attributed to the transitions 2H11/2 →4I15/2, 4S3/2 →4I15/2 and 4F9/2 →4I15/2 respectively. The improved UC luminescence is ascribed to the reduced defects such as oxygen vacancies and change in the crystal field around Er3+ ions due to B-site (Ti4+) substitution with W6+ ions. Enhanced UC emission is observed for an optimum content of w6+ in the prepared composition Bi3.79Er0.03Yb0.18Ti3-xWxO12 for x = 0.06.

Passively Q-switched microchip Er, Yb:YAl3(BO3)4 diode-pumped laser.

Science.gov (United States)

Kisel, V E; Gorbachenya, K N; Yasukevich, A S; Ivashko, A M; Kuleshov, N V; Maltsev, V V; Leonyuk, N I

2012-07-01

We report, for the first time to our knowledge, a diode-pumped cw and passively Q-switched microchip Er, Yb:YAl(3)(BO(3))(4) laser. A maximal output power of 800 mW at 1602 nm in the cw regime was obtained at an absorbed pump power of 7.7 W. By using Co(2+):MgAl(2)O(4) as a saturable absorber, a TEM(00)-mode Q-switched average output power of 315 mW was demonstrated at 1522 nm, with pulse duration of 5 ns and pulse energy of 5.25 μJ at a repetition rate of 60 kHz.

Synthesis and green up-conversion fluorescence of colloidal La0.78Yb0.20Er0.02F3/SiO2 core/shell nanocrystals

International Nuclear Information System (INIS)

Wang Yan; Qin Weiping; Zhang Jisen; Cao Chunyan; Zhang Jishuang; Jin Ye; Zhu Peifen; Wei Guodong; Wang Guofeng; Wang Lili

2007-01-01

Water-soluble PVP-stabilized hexagonal-phase La 0.78 Yb 0.20 Er 0.02 F 3 nanocrystals (NCs) were synthesized by hydrothermal method. The NCs were coated with a very thin silica shell, and amino groups were introduced to the surface of silica shells by copolymerization of 3-aminopropyl(triethoxy)silane. The core/shell NCs can be dispersed in ethanol and water to form stable colloidal solution. The transmission electron microscopy (TEM), selected area electron diffraction (SAED), powder X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the core/shell materials. In addition, the green up-conversion fluorescence mechanism of La 0.78 Yb 0.20 Er 0.02 F 3 /SiO 2 NCs was studied with a 980-nm diode laser as excitation source. The water solubility, small core/shell particles size, and well colloidal stability mean the green up-conversion fluorescence NCs have potential applications in bioassay. - Graphical abstract: Colloidal La 0.78 Yb 0.20 Er 0.02 F 3 /SiO 2 Core/Shell nanocrystals (NCs) were synthesized and the free amino groups were introduced to the surface of silica shells by copolymerization 3-aminopropyl(triethoxy)silane. The NCs can be dispersed in ethanol and water to form stable colloidal solution. In addition, the NCs exhibit green up-conversion fluorescence under 980-nm excitation

Template-free synthesis and luminescent properties of hollow Ln:YOF (Ln = Eu or Er + Yb) microspheres

Energy Technology Data Exchange (ETDEWEB)

Martinez-Castro, E. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain); García-Sevillano, J.; Cussó, F. [Dpto. Física de Materiales, C-04, Universidad Autónoma de Madrid, Avda. Francisco Tomás y Valiente, 7, 28049 Madrid (Spain); Ocaña, M., E-mail: mjurado@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain)

2015-01-15

Highlights: • Hollow lanthanide doped YOF spheres have been synthesised through a template-free procedure. • Strong red emissions are observed for Eu-doped spheres under UV illumination. • Concentration quenching of luminescence takes place in the spheres at very high Eu doping levels. • Bright red emission is observed for Er, Yb codoped spheres, making this matrix advantageous for biomedical imaging. - Abstract: A method for the synthesis of hollow lanthanide doped yttrium oxyfluoride (YOF) spheres in the micrometer size range with cubic structure based on the pyrolysis at 600 °C of liquid aerosols generated from aqueous solutions containing the corresponding rare earth chlorides and trifluoroacetic acid has been developed. This procedure, which has been used for the first time for the synthesis of YFO based materials, is simpler and advantageous when compared with other methods usually employed for the production of hollow spheres since it does not require the use of sacrificial templates. In addition, it is continuous, which is desirable because of practical reasons. The procedure is also suitable for doping the YOF spheres with europium cations resulting in down converting red phosphors when activated with UV light, or for co-doping with both Er{sup 3+} and Yb{sup 3+} giving rise to up-converting phosphors, which emit intense red light under near infrared (NIR) irradiation. Because of their optical properties and hollow architecture, the developed materials may find applications in optoelectronic devices and biotechnology.

Improving pure red upconversion emission of Co-doped Y{sub 2}O{sub 3}:Yb{sup 3+}–Er{sup 3+} nanocrystals with a combination of sodium sulfide and surfactant Pluronic-F127

Energy Technology Data Exchange (ETDEWEB)

López-Luke, T., E-mail: tzarara@cio.mx [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37160, México (Mexico); De la Rosa, E., E-mail: elder@cio.mx [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37160, México (Mexico); Campos Villalobos, I. [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37160, México (Mexico); Rodriguez, R.A. [Universidad de Guadalajara, Unidad Lagos, Lagos de Moreno, Jal. 47460, México (Mexico); Ángles-Chávez, C. [Instituto Mexicano del Petróleo, Cd. México, D.F. 07730, México (Mexico); Salas, P. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, A.P. 1-1010, Querétaro, Qro. 76000, México (Mexico); Wheeler, Damon A.; Zhang, J.Z. [Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064 (United States)

2014-01-15

Nanocrystals of Y{sub 2}O{sub 3}:Yb{sup 3+}–Er{sup 3+} (2:1 mol% Yb{sup 3+}:Er{sup 3+}) were prepared by a novel precipitation technique using Na{sub 2}S and Pluronic-F127 (PF127) surfactant. Crystal structure, particle size, red emission intensity and fluorescence decay lifetimes were determined using microscopy and spectroscopy techniques. TEM analysis indicates that the average particle size ranged from 40 to 70 nm. The nanocrystals showed a strong red emission band centered at 663 nm after excitation at 970 nm. The upconverted signal intensity was improved 250% with an optimum concentration of Na{sub 2}S (0.48 M) and PF127 (0.1 mM). The improvement was explained in terms of the reduction of surface contaminants as well as the cubic crystalline phase of the parent Y{sub 2}O{sub 3} material. Interestingly, the formation of sulfates (SO{sub 4}{sup 2−}) is faster than that of O–H, which is responsible for quenching the red and green emissions. The results suggest that Na{sub 2}S and PF127 are good candidates for surface passivation, especially when used in conjunction. The preparation of Y{sub 2}O{sub 3}:Yb{sup 3+}–Er{sup 3+} using Na{sub 2}S with strong red emission band was produced at a lower cost than that of other sulfuration processes. -- Highlights: • . • Strong red emission band centered at 663 nm was obtained after excitation at 970 nm. • Yb-Er codoped Y2O3 nanocrystals with average size ranging from 40 to 70 nm. • Improvement of the red emission in Y2O3:Yb-Er nanocrystals by the introduction of sodium sulfide and pluronic. • Passivation of nanocrystal surface with sodium sulfide and pluoronic.

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method

OpenAIRE

Gavrilović, Tamara V.; Jovanović, Dragana J.; Lojpur, Vesna; Dramićanin, Miroslav D.

2014-01-01

Synthesis of Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each ...

2.05 xB5m emission properties and energy transfer mechanism of germanate glass doped with Ho3+, Tm3+, and Er3+

Science.gov (United States)

Xu, Rongrong; Wang, Meng; Tian, Ying; Hu, Lili; Zhang, Junjie

2011-03-01

A new GeO2-Ga2O3-Na2O-BaO-La2O3 germanate glass doped with Ho2O3, Tm2O3, and Er2O3 has been investigated for application as a laser material at the 2 μm region. The spectroscopic properties and energy transfer mechanisms of Ho3+ sensitized by Tm3+ and Er3+ are analyzed. Based on the measurement of absorption spectra, the Judd-Ofelt intensity parameters, radiation emission probability, branching ratio, and lifetime of Ho3+ are calculated to evaluate the spectroscopic properties. The maximum value of emission cross section of Ho3+ around 2.05 μm is 8.003×10-21 cm2, which indicates that the germanate glass may provide high gain as a good medium in high-power level laser system. It is also found that the 2.05 μm emission of Ho3+:5I7→5I8 can be greatly enhanced by adding the proper amount of Er2O3 and Tm2O3 under excitation at 808 nm. With the large energy transfer coefficient, the high efficient energy transfer process among Ho3+, Tm3+, and Er3+ ions is proven.

Up-conversion and near infrared luminescence in Er3+/Yb3+ co-doped glass-ceramic containing MgGa2O4 nano-crystals

International Nuclear Information System (INIS)

Sun, Jiaju; Yu, Lixin; Li, Fuhai; Wei, Shuilin; Li, Songchu

2016-01-01

The MgO–Ga 2 O 3 –SiO 2 (MG-S) glasses and nanocrystalline glass-ceramics (GCs) containing MgGa 2 O 4 nanocrystals codoped with Er 3+ and Yb 3+ were prepared by a simple sol–gel method. The formation of MgGa 2 O 4 nanocrystals in the GCs was confirmed by the X-ray diffraction (XRD). Their morphology was investigated applying high-resolution transmission electron microscopy (HRTEM). Stark splitting of near infrared (NIR) and up-conversion (UC) emission implies that the Er 3+ is incorporated into MgGa 2 O 4 nanocrystals. The effect of the MgO, Ga 2 O 3 content and sintering temperature on the structure of the prepared samples was systematically studied. Under 980 nm excitation, intense UC and NIR emission (1530 nm) were observed in the MG-S GCs by efficient energy transfer from Yb 3+ to Er 3+ . The two-photon process was confirmed to be responsible for both the green and red UC emissions. - Highlights: • It is interesting that the CIE chromaticity coordinates of the several prepared CaMO 4 :Eu samples by a hydrothermal method are very close to the standard of white light.

Polarized spectroscopic properties of Er3+:Gd2SiO5 crystal and evaluation of Er3+:Yb3+:Gd2SiO5 crystal as a 1.55 μm laser medium

International Nuclear Information System (INIS)

Wang, H.; Huang, J.H.; Gong, X.H.; Chen, Y.J.; Lin, Y.F.; Luo, Z.D.; Huang, Y.D.

2016-01-01

An Er 3+ -doped Gd 2 SiO 5 single crystal with high optical quality has been grown by the Czochralski method. Polarized absorption and fluorescence spectra and fluorescence lifetime of the crystal were measured at room temperature. Intensity parameters, spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes were estimated on the basis of the Judd–Ofelt theory. Besides, potentiality of 1.55 μm laser emission in an Er 3+ –Yb 3+ co-doped Gd 2 SiO 5 crystal was evaluated.

Crystalline electric fields and magnetic properties of single-crystalline RNiC2 compounds R=Ho, Er and Tm

International Nuclear Information System (INIS)

Koshikawa, Y.; Onodera, H.; Kosaka, M.; Yamauchi, H.; Ohashi, M.; Yamaguchi, Y.

1997-01-01

Magnetometric investigations were performed on single-crystalline HoNiC 2 , ErNiC 2 and TmNiC 2 compounds. Susceptibility of HoNiC 2 shows no anomaly around T N , but a clear cusp appears at T t =2.9 K. Magnetization curves reveal that the anisotropy is relatively weak and that the Ho moments align not along any crystallographic axis. In addition to T N =8.5 K of ErNiC 2 , a new order-order transition at T t =3.6 K has been found. Although the Er moments align along the a-axis between T t and T N , it seems certain that the small moment-components along the b- and c-axes come into existence below T t . TmNiC 2 with T N =5.5 K has a strong uniaxial anisotropy along the a-axis. These results are discussed on the basis of competitions between the magnetic interactions and the crystal field effect which changes anomalously by the replacement of rare earth element. It has been found that the drastic change of crystal field occurs between HoNiC 2 and ErNiC 2 without any corresponding structural change. (orig.)

Radiochemical separations of target-like reaction products from Au-, Pt-, and Th-targets after irradiation with GeV protons

International Nuclear Information System (INIS)

Szweryn, B.; Bruechle, W.; Schausten, B.; Schaedel, M.

1988-08-01

Chemical separation procedures for separations of reaction products after spallation reactions with 2.6 GeV protons and heavy element targets are presented. To determine independent cross sections of individual isotopes the elements Au, Pt, Ir, Os, Re, W, Ta, Hf, (Lu, Yb, Tm, Er), (Gd, Eu, Sm), were separated from gold targets, Pt, Ir, Os, W, Ta, Hf, (Lu, Yb, Tm, Er), (Gd, Eu, Sm) from a platinum target and Au, Tl from a thorium target. (orig.)

Tuning from green to red the upconversion emission of Y{sub 2}O{sub 3}:Er{sup 3+}-Yb{sup 3+} nanophosphors

Energy Technology Data Exchange (ETDEWEB)

Diaz-Torres, L.A. [Centro de Investigaciones en Optica, Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (GEMANA), A. P. 1-948, Leon, GTO (Mexico); Salas, P.; Resendiz-L, E.; Rodriguez-Gonzalez, C. [Universidad Nacional Autonoma de Mexico, Centro de Fisica Aplicada y Tecnologia Avanzada, Apartado Postal 1-1010, Queretaro, QRO (Mexico); Oliva, J. [Conacyt-Facultad Ciencias Quimicas Universidad Autonoma de Coahuila, Saltillo, Coahuila (Mexico); Meza, O. [Benemerita Universidad Autonoma de Puebla, Instituto de Fisica, A.P. J-48, Centro Historico, PUE (Mexico)

2017-01-15

In this work, the structural, morphological and luminescent properties of Y{sub 2}O{sub 3} nanophosphors doped with Er{sup 3+} (1 mol%) and different Yb{sup 3+} concentrations (2-12 mol%) have been studied. Those nanophosphors were synthesized using a simple hydrothermal method. XRD analysis indicates that all the samples presented a pure cubic phase even for Yb concentrations as high as 12 mol%. In addition, SEM images show nanoparticles with quasi-spherical shapes with average sizes in the range of 300-340 nm. Photoluminescence measurements obtained after excitation at 967 nm revealed that our samples have strong green (563 nm) and red emissions (660 nm) corresponding to {sup 2}H{sub 11/2} + {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} transitions of Er{sup 3+} ions, respectively. We also observed that the green band is quenched and the red emission enhanced as the Yb concentration increases. In consequence, the CIE coordinates changed from (0.35, 0.64) in the green region to (0.59, 0.39) in the red region. Thus, the tuning properties of Y{sub 2}O{sub 3} nanophosphors suggest that they are good candidates for applications in lighting. (orig.)

Tuning crystal field symmetry of hexagonal NaY0.92Yb0.05Er0.03F4 by Ti4+ codoping for high-performance upconversion

International Nuclear Information System (INIS)

Yu, Han; Huang, Qingming; Ma, En; Zhang, Xinqi; Yu, Jianchang

2014-01-01

Highlights: • Upconversion emission of Er 3+ was obviously enhanced by Ti 4+ codoped in NaYF 4 . • The upconversion luminescence lifetime was also obviously prolonged. • Na + could be induced to occupy Y 3+ sites if Ti 4+ was codoped with appropriate concentration. • The crystal field asymmetry was enhanced for better upconversion performance. • Crystal growth was prevented and small-sized NaYF 4 were obtained. - Abstract: 378 nm, 408 nm and 521 nm upconversion emissions of Er 3+ ions were obviously enhanced by Ti 4+ codoped with Yb 3+ /Er 3+ in hexagonal NaYF 4 , and the corresponding upconversion luminescence lifetimes were also prolonged, especially for 378 nm and 408 nm emissions. X-ray powder diffraction, field emission scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy and upconversion emission spectra were employed to explore the relationships of the structure and properties. From these characterizations we made a novel discovery that Na + could be induced to occupy Y 3+ sites for establishing valence balance of the system if Ti 4+ ions were codoped with appropriate concentration. As a result the crystal field asymmetry of NaY 0.92 Yb 0.05 Er 0.03 F 4 was enhanced and then its upconversion properties were improved because the hypersensitive electron transition of Yb 3+ /Er 3+ ions was promoted greatly. At the same time, the crystal sizes of the codoped NaYF 4 became smaller because the crystal growth was prevented by more negative charges gathering at the crystal surface. This study provides an exploration of the relationship among impurity doping, structural changes and upconversion performance, which may be useful for design and synthesis of high-performance upconversion codoping materials

Up-conversion monodispersed spheres of NaYF4:Yb3+/Er3+: green and red emission tailoring mediated by heating temperature, and greatly enhanced luminescence by Mn2+ doping.

Science.gov (United States)

Zhu, Qi; Song, Caiyun; Li, Xiaodong; Sun, Xudong; Li, Ji-Guang

2018-04-09

Submicron sized, monodispersed spheres of Mn2+, Yb3+/Er3+ and Mn2+/Yb3+/Er3+ doped α-NaYF4 were easily autoclaved from mixed solutions of the component nitrates and ammonium fluoride (NH4F), in the presence of EDTA-2Na. Detailed characterizations of the resultant phosphors were obtained using XRD, Raman spectroscopy, FE-SEM, HR-TEM, STEM, PLE/PL spectroscopy, and fluorescence decay analysis. Finer structure and better crystal perfection was observed at a higher calcination temperature, and the spherical shape and excellent dispersion of the original particles was retained at temperatures up to 600 °C. Under the 980 nm infrared excitation, the Yb3+/Er3+-doped sample (calcined at 400 °C) exhibits a stronger green emission centered at ∼524 nm (2H11/2 → 4I15/2 transition of Er3+) and a weaker red emission centered at ∼657 nm (4F9/2 → 4I15/2 transition of Er3+). A 200 °C increase in the temperature from 400 °C to 600 °C resulted in the dominant red emission originating from the 4F9/2 → 4I15/2 transition of Er3+, instead of the previously dominant green one. Mn2+ doping induced a remarkable more enhanced intensity at ∼657 nm and ∼667 nm (red emission area) than that at ∼524 nm and ∼546 nm (green emission area), because of the non-radiative energy transfer between Mn2+ and Er3+. However, a poor thermal stability was induced by Mn2+ doping. The observed upconversion luminescence of the samples calcined at 400 °C and 600 °C followed the two photon process and the four photon process, respectively.

A ₂ TiO ₅ (A = Dy, Gd, Er, Yb) at High Pressure

Energy Technology Data Exchange (ETDEWEB)

Park, Sulgiye [Department of Geological Science, Stanford University, Stanford, California 94305, United States; Rittman, Dylan R. [Department of Geological Science, Stanford University, Stanford, California 94305, United States; Tracy, Cameron L. [Department of Geological Science, Stanford University, Stanford, California 94305, United States; Chapman, Karena W. [X-ray Science Division, Advanced Photon; Zhang, Fuxiang [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States; Park, Changyong [HPCAT, Carnegie Institution of Washington, Argonne, Illinois 60439, United States; Tkachev, Sergey N. [Center for Advanced Radiation Sources, University of Chicago, Chicago, Illinois 60637, United States; O’Quinn, Eric [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States; Shamblin, Jacob [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States; Lang, Maik [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States; Mao, Wendy L. [Department of Geological Science, Stanford University, Stanford, California 94305, United States; Stanford; amp, Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States; Ewing, Rodney C. [Department of Geological Science, Stanford University, Stanford, California 94305, United States

2018-02-07

The structural evolution of lanthanide A2TiO5 (A = Dy, Gd, Yb, and Er) at high pressure is investigated using synchrotron X-ray diffraction. The effects of A-site cation size and of the initial structure are systematically examined by varying the composition of the isostructural lanthanide titanates, and the structure of dysprosium titanate polymorphs (orthorhombic, hexagonal and cubic), respectively. All samples undergo irreversible high pressure phase transformations, but with different onset pressures depending on the initial structure. While individual phase exhibits different phase transformation histories, all samples commonly experience a sluggish transformation to a defect cotunnite-like (Pnma) phase for a certain pressure range. Orthorhombic Dy2TiO5 and Gd2TiO5 form P21am at pressures below 9 GPa and Pnma above 13 GPa. Pyrochlore-type Dy2TiO5 and Er2TiO5 as well as defect-fluorite-type Yb2TiO5 form Pnma at ~ 21 GPa, followed by Im-3m. Hexagonal Dy2TiO5 forms Pnma directly, although a small amount of remnants of hexagonal Dy2TiO5 is observed even at the highest pressure (~ 55 GPa) reached, indicating a kinetic limitations in the hexagonal Dy2TiO5 phase transformations at high pressure. Decompression of these materials leads to different metastable phases. Most interestingly, a high pressure cubic X-type phase (Im-3m) is confirmed using highresolution transmission electron microscopy on recovered pyrochlore-type Er2TiO5. The kinetic constraints on this metastable phase yield a mixture of both the X-type phase and amorphous domains upon pressure release. This is the first observation of an X-type phase for an A2BO5 composition at high pressure.

Near infrared and upconversion luminescence behaviour of Er{sup 3+}/Yb{sup 3+} codoped boro-tellurite glasses

Energy Technology Data Exchange (ETDEWEB)

Maheshvaran, K. [Department of Physics, Gandhigram Rural Institute - Deemed University, Gandhigram - 624302, India and Department of Physics, K.S. Rangasamy College of Technology, Trichengode - 637215 (India); Arunkumar, S., E-mail: mari-ram2000@yahoo.com; Vijayakumar, R., E-mail: mari-ram2000@yahoo.com; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute − Deemed University, Gandhigram - 624302 (India)

2014-04-24

The broadband NIR and upconversion luminescence behavior in a new series of Er{sup 3+}/Yb{sup 3+} codoped TeO{sub 2}-B{sub 2}O{sub 3}-SrO-BaO-Li{sub 2}O-LiF glasses have been studied exciting at a wavelength of 980 nm using semiconductor laser. A broadband emission is observed from 1450 to 1650 nm with a full width at half maximum (FWHM) around 165 nm in 0.5wt% Yb{sup 3+} ion content E0.5YLTB glass. The radiative parameters such as transition probability (A), stimulated emission cross-section (σ{sup E}), experimental and calculated branching ratios (β{sub R}), optical gain width (σ{sub p}×FWHM) and radiative lifetime (τ{sub cal}) have been calculated for the {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} NIR emission. Upconversion luminescence spectra of the prepared glasses have been studied and the ESA and ET processes have also been discussed and reported.

Rhodium-rich silicides RERh{sub 6}Si{sub 4} (RE=La, Nd, Tb, Dy, Er, Yb)

Energy Technology Data Exchange (ETDEWEB)

Vosswinkel, Daniel; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

2017-07-01

Polycrystalline RERh{sub 6}Si{sub 4} (RE=La, Nd, Tb, Dy, Er, Yb) samples can be synthesized by arc-melting of the elements. Single crystals of LaRh{sub 6}Si{sub 4}, NdRh{sub 6}Si{sub 4} and YbRh{sub 6}Si{sub 4} were synthesized from the elements in bismuth fluxes (non-reactive flux medium). The structures were refined on the basis of single-crystal X-ray diffractometer data: LiCo{sub 6}P{sub 4} type, P anti 6m2, a=700.56(3), c=380.55(1) pm, wR2=0.0257, 317 F{sup 2} values, 19 variables for LaRh{sub 6}Si{sub 4}, a=698.4(5), c=377.7(2) pm, wR2=0.0578, 219 F{sup 2} values, 19 variables for NdRh{sub 6}Si{sub 4} and a=696.00(3), c=371.97(1) pm, wR2=0.0440, 309 F{sup 2} values, 19 variables for YbRh{sub 6}Si{sub 4}. The rhodium and silicon atoms build up three-dimensional, covalently bonded [Rh{sub 6}Si{sub 4}]{sup δ-} polyanionic networks with Rh-Si distances ranging from 239 to 249 pm. The rare earth atoms fill larger cavities within channels of these networks and they are coordinated by six silicon and twelve rhodium atoms in the form of hexa-capped hexagonal prisms.

Thermal, Spectral and Laser Properties of Er3+:Yb3+:GdMgB₅O10: A New Crystal for 1.5 μm Lasers.

Science.gov (United States)

Huang, Yisheng; Yuan, Feifei; Sun, Shijia; Lin, Zhoubin; Zhang, Lizhen

2017-12-25

A novel laser crystal of Er 3+ :Yb 3+ :GdMgB₅O 10 with dimension of 26 × 16 × 12 mm³ was grown successfully from K₂Mo₃O 10 flux by the top seeded solution growth method. The thermal diffusivity and specific heat capacity were measured to calculate the thermal conductivity of the crystal. The absorption and fluorescence properties of the crystal at room temperature were investigated in detail. The Judd-Ofelt method was used to analyze the polarized absorption spectra. The emission cross-section of the ⁴I 13/2 →⁴I 15/2 transition was calculated by the Füchtbauer-Ladenburg formula and the relevant gain cross-sections were estimated. Continuous-wave laser output of 140 mW at 1569 nm with the slope efficiency of 17.8% was demonstrated in a plano-concave resonator. The results reveal that Er 3+ :Yb 3+ :GdMgB₅O 10 crystal is a promising material for 1.5 μm lasers.

Ridge optical waveguide in an Er3+/Yb3+ co-doped phosphate glass produced by He+ ion implantation combined with Ar+ ion beam etching

International Nuclear Information System (INIS)

Tan Yang; Chen Feng; Hu Lili; Xing Pengfei; Chen Yanxue; Wang Xuelin; Wang Keming

2007-01-01

This paper reports on the fabrication and characterization of a ridge optical waveguide in an Er 3+ /Yb 3+ co-doped phosphate glass. The He + ion implantation (at energy of 2.8 MeV) is first applied onto the sample to produce a planar waveguide substrate, and then Ar + ion beam etching (at energy of 500 eV) is carried out to construct rib stripes on the sample surface that has been deposited by a specially designed photoresist mask. According to a reconstructed refractive index profile of the waveguide cross section, the modal distribution of the waveguide is simulated by applying a computer code based on the beam propagation method, which shows reasonable agreement with the experimentally observed waveguide mode by using the end-face coupling method. Simulation of the incident He ions at 2.8 MeV penetrating into the Er 3+ /Yb 3+ co-doped phosphate glass substrate is also performed to provide helpful information on waveguide formation

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.

Hydrothermal synthesis of NaLuF4:153Sm,Yb,Tm nanoparticles and their application in dual-modality upconversion luminescence and SPECT bioimaging.

Science.gov (United States)

Yang, Yang; Sun, Yun; Cao, Tianye; Peng, Juanjuan; Liu, Ying; Wu, Yongquan; Feng, Wei; Zhang, Yingjian; Li, Fuyou

2013-01-01

Upconversion luminescence (UCL) properties and radioactivity have been integrated into NaLuF(4):(153)Sm,Yb,Tm nanoparticles by a facile one-step hydrothermal method, making these nanoparticles potential candidates for UCL and single-photon emission computed tomography (SPECT) dual-modal bioimaging in vivo. The introduction of small amount of radioactive (153)Sm(3+) can hardly vary the upconversion luminescence properties of the nanoparticles. The as-designed nanoparticles showed very low cytotoxicity, no obvious tissue damage in 7 days, and excellent in vitro and in vivo performances in dual-modal bioimaging. By means of a combination of UCL and SPECT imaging in vivo, the distribution of the nanoparticles in living animals has been studied, and the results indicated that these particles were mainly accumulated in the liver and spleen. Therefore, the concept of (153)Sm(3+)/Yb(3+)/Tm(3+) co-doped NaLuF(4) nanoparticles for UCL and SPECT dual-modality imaging in vivo of whole-body animals may serve as a platform for next-generation probes for ultra-sensitive molecular imaging from the cellular scale to whole-body evaluation. It also introduces an easy methodology to quantify in vivo biodistribution of nanomaterials which still needs further understanding as a community. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis and up-conversion emissions of Yb , Yb and Yb co-doped ...

Indian Academy of Sciences (India)

2017-09-23

Sep 23, 2017 ... Green/red UC emissions of Er3+, UV/blue/IR UC emissions of Tm3+, and UV UC emissions of Gd3+ ... In the last few decades, rare earth (RE) materials have been ... age, colour displays, IR sensors, environmental monitoring,.

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.

Infrared emissions in MgSrAl{sub 10}O{sub 17}:Er{sup 3+} phosphor co-doped with Yb{sup 3+}/Ba{sup 2+}/Ca{sup 2+} obtained by solution combustion route

Energy Technology Data Exchange (ETDEWEB)

Singh, Vijay, E-mail: vijayjiin2006@yahoo.com [Physical Chemistry, Institute for Pure and Applied Chemistry and Center of Interface Science, University of Oldenburg, 26129 Oldenburg (Germany); Kumar Rai, Vineet [Department of Applied Physics, Indian School of Mines, Dhanbad 826 004 (India); Venkatramu, V. [Department of Physics, Yogi Vemana University, Kadapa 516 003 (India); Chakradhar, R.P.S. [CSIR-National Aerospace, Bangalore 560 017 (India); Hwan Kim, Sang [Department of Chemical Engineering, Konkuk University, Seoul 143-701 (Korea, Republic of)

2013-02-15

An intense infrared emitting MgSrAl{sub 10}O{sub 17}:Er{sup 3+} phosphor co-doped with Yb{sup 3+}, Ba{sup 2+} and Ca{sup 2+} ions have been prepared by a solution combustion method. Phase purity of the derived compounds was confirmed by X-ray diffraction technique. The vibrational properties of MgSrAl{sub 10}O{sub 17} phosphor was studied by Fourier transform infrared spectroscopy. The broad and strong infrared emission of Er{sup 3+} ions at around 1.53 {mu}m was observed upon excitation at 980 nm. Effect of co-doping with the Yb{sup 3+}{sub ,} Ba{sup 2+} and Ca{sup 2+} ions on the infrared luminescence intensity of Er{sup 3+} ions and the mechanism responsible for the variation in the infrared intensity have been discussed. The results indicate that these materials may be suitable for the optical telecommunication window and wavelength division multiplexing applications. - Highlights: Black-Right-Pointing-Pointer The hexagonal phase of MgSrAl{sub 10}O{sub 17} could be obtained by the low temperature combustion method. Black-Right-Pointing-Pointer The broad and strong infrared emission of Er{sup 3+} ions at around 1.53 {mu}m was observed. Black-Right-Pointing-Pointer Effect of co-doping with the Yb{sup 3+}{sub ,} Ba{sup 2+} and Ca{sup 2+} ions on the infrared luminescence intensity of Er{sup 3+} were reported.

Optical thermometry based on green upconversion emission in Er3+/Yb3+ codoped BaGdF5 glass ceramics

Science.gov (United States)

Wu, Ting; Zhao, Shilong; Lei, Ruoshan; Huang, Lihui; Xu, Shiqing

2018-02-01

Er3+/Yb3+ codoped BaGdF5 glass ceramics have been prepared and used to develop a portable all-fiber temperature sensor based on fluorescence intensity ratio technique. XRD and TEM results affirm the generation of BaGdF5 nanocrystals in the borosilicate glass. Eu3+ ions are used as spectral probe to investigate external environment around rare earth (RE) ions. Intense green upconversion emissions from Er3+ ions are detected in the BaGdF5 glass ceramics and their intensity are enhanced about three orders of magnitude after heat treatment, which is attributed to the enrichment of RE ions in the BaGdF5 phase. Based on green upconversion emission from Er3+ ions, the temperature sensing property of the portable all-fiber temperature sensor is studied. The maximum absolute sensitivity is 15.5 × 10-4 K-1 at 567 K and the relative sensitivity is 1.28% K-1 at 298 K, respectively.

Influence of core size on the upconversion luminescence properties of spherical Gd2O3:Yb3+/Er3+@SiO2 particles with core-shell structures

International Nuclear Information System (INIS)

Zheng, Kezhi; Liu, Zhenyu; Liu, Ye; Song, Weiye; Qin, Weiping

2013-01-01

Spherical SiO 2 particles with different sizes (30, 80, 120, and 180 nm) have been coated with Gd 2 O 3 :Yb 3+ /Er 3+ layers by a heterogeneous precipitation method, leading to the formation of core-shell structural Gd 2 O 3 :Yb 3+ /Er 3+ @SiO 2 particles. The samples were characterized by using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, upconversion (UC) emission spectra, and fluorescent dynamical analysis. The obtained core-shell particles have perfect spherical shape with narrow size distribution. Under the excitation of 980 nm diode laser, the core-shell samples showed size-dependent upconversion luminescence (UCL) properties. The inner SiO 2 cores in core-shell samples were proved to have limited effect on the total UCL intensities of Er 3+ ions. The UCL intensities of core-shell particles were demonstrated much higher than the values obtained in pure Gd 2 O 3 :Yb 3+ /Er 3+ with the same phosphor volume. The dependence of the specific area of a UCL shell on the size of its inner SiO 2 particle was calculated and analyzed for the first time. It was confirmed that the surface effect came from the outer surfaces of emitting shells is dominant in influencing the UCL property in the core-shell samples. Three-photon UC processes for the green emissions were observed in the samples with small sizes of SiO 2 cores. The results of dynamical analysis illustrated that more nonradiative relaxation occurred in the core-shell samples with smaller SiO 2 core sizes

Thermal evolution of the spin ordering at the concomitant spin–orbital rearrangement temperature in RVO{sub 3} (R=Lu, Yb and Tm)

Energy Technology Data Exchange (ETDEWEB)

Sarkar, Tapati, E-mail: tapati.sarkar@angstrom.uu.se [Department of Engineering Sciences, Uppsala University, Box 534, SE-75121 Uppsala (Sweden); Ivanov, Sergey A. [Department of Engineering Sciences, Uppsala University, Box 534, SE-75121 Uppsala (Sweden); Center of Materials Science, Karpov Institute of Physical Chemistry, 105064 Moscow K-64 (Russian Federation); Bazuev, G.V. [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Science, 620999 Ekaterinburg GSP-145 (Russian Federation); Nordblad, Per; Mathieu, Roland [Department of Engineering Sciences, Uppsala University, Box 534, SE-75121 Uppsala (Sweden)

2016-07-01

Synthesis, crystal structure and magnetization measurements of phase pure polycrystalline RVO{sub 3} (R=Lu, Yb and Tm) are reported. The compounds were stabilized in the orthorhombic structure by thermal treatment of the respective precursors (RVO{sub 4}) in a reducing atmosphere. Special pressure treatment was carried out during the synthesis to ensure phase pure samples without secondary phases. Magnetization measurements reveal the presence of two spin ordering temperatures in the samples. Interestingly, at the lower spin ordering temperature, T{sub SO2}, the uncompensated excess moment of the antiferromagnetic spin structure has different field dependences above and below T{sub SO2}, causing a jump in the thermal evolution of the magnetization that changes sign with increasing field strength. This jump is associated with the reported magnetic and orbital rearrangement in the samples, and the different spin configurations in the C- and G-type antiferromagnetic structures. - Highlights: • Magnetization measurements of polycrystalline RVO{sub 3} (R=Lu, Yb, Tm) are reported. • The samples have two spin ordering temperatures, T{sub SO1} and T{sub SO2} (T{sub SO1}>T{sub SO2}). • A magnetic field dependent jump of the excess magnetization, ΔM is observed at T{sub SO2.} • The jump in ΔM is associated with magnetic and orbital rearrangement in the samples. • ΔM is probably affected by possible phase coexistence in the samples.

Structural and magnetic properties of two branches of the tripod-kagome-lattice family A2R3Sb3O14 (A = Mg, Zn; R = Pr, Nd, Gd, Tb, Dy, Ho, Er, Yb)

Science.gov (United States)

Dun, Z. L.; Trinh, J.; Lee, M.; Choi, E. S.; Li, K.; Hu, Y. F.; Wang, Y. X.; Blanc, N.; Ramirez, A. P.; Zhou, H. D.

2017-03-01

We present a systematic study of the structural and magnetic properties of two branches of the rare-earth tripod-kagome-lattice (TKL) family A2R3Sb3O14 (A = Mg, Zn; R = Pr, Nd, Gd, Tb, Dy, Ho, Er, Yb; here, we use abbreviation A-R, as in MgPr for Mg2Pr3Sb3O14 ), which complements our previously reported work on MgDy, MgGd, and MgEr [Z. L. Dun et al., Phys. Rev. Lett. 116, 157201 (2016), 10.1103/PhysRevLett.116.157201]. The present susceptibility (χdc, χac) and specific-heat measurements reveal various magnetic ground states, including the nonmagnetic singlet state for MgPr, ZnPr; long-range orderings (LROs) for MgGd, ZnGd, MgNd, ZnNd, and MgYb; a long-range magnetic charge ordered state for MgDy, ZnDy, and potentially for MgHo; possible spin-glass states for ZnEr, ZnHo; the absence of spin ordering down to 80 mK for MgEr, MgTb, ZnTb, and ZnYb compounds. The ground states observed here bear both similarities as well as striking differences from the states found in the parent pyrochlore systems. In particular, while the TKLs display a greater tendency towards LRO, the lack of LRO in MgHo, MgTb, and ZnTb can be viewed from the standpoint of a balance among spin-spin interactions, anisotropies, and non-Kramers nature of single-ion state. While substituting Zn for Mg changes the chemical pressure, and subtly modifies the interaction energies for compounds with larger R ions, this substitution introduces structural disorder and modifies the ground states for compounds with smaller R ions (Ho, Er, Yb).

Energy transfer characteristics of silicate glass doped with Er{sup 3+}, Tm{sup 3+}, and Ho{sup 3+} for ∼2 μm emission

Energy Technology Data Exchange (ETDEWEB)

Li, Ming; Liu, Xueqiang [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 Sciences, Beijing 100039 (China); Guo, Yanyan [College of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (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); Zhang, Junjie [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310 018 (China)

2013-12-28

A Er{sup 3+}/Tm{sup 3+}/Ho{sup 3+} tri-doped silicate glass with good thermal stability is prepared by melt-quenching method. Efficient ∼2 μm emission is observed under 808 nm laser excitation. It is found that the 2.0 μm emission of Ho{sup 3+} can be enhanced under the excitation at 808 nm by incorporating Er{sup 3+} and Tm{sup 3+}. Based on the measurement of absorption spectra, the Judd–Ofelt intensity parameters, radiation emission probability, and branching ratio are calculated to evaluate the spectroscopic properties simultaneously. The maximum value of emission cross section of Ho{sup 3+} is 3.54 × 10{sup −21} cm{sup 2} at 2008 nm. Additionally, the phonon assistance and the micro-parameters in the energy transfer process are quantitatively analyzed by using Dexter model. The energy transfer coefficient from Tm{sup 3+} to Ho{sup 3+} can reach as high as 21.44 × 10{sup −40} cm{sup 6}/s, respectively. The emission property together with good thermal property indicates that Er{sup 3+}/Tm{sup 3+}/Ho{sup 3+} tri-doped silicate glass is a potential kind of laser glass for efficient 2 μm laser.

Strong broad green UV-excited photoluminescence in rare earth (RE = Ce, Eu, Dy, Er, Yb) doped barium zirconate

Energy Technology Data Exchange (ETDEWEB)

Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Ciudad de Mexico, D. F. 07730 (Mexico); Meza, O. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico)

2011-10-25

Highlights: > Trivalent rare earth (RE) substitution on Zr{sup 4+} sites in BaZrO{sub 3} lead to band gap narrowing. > RE substitution lead to enhanced blue-green intrinsic emission of nanocrystalline BaZrO{sub 3} > Blue-green hue of BaZrO3:RE depends on RE dopant and excitation UV wavelength > BaZrO3: Dy{sup 3+} PL chromatic coordinates correspond to pure white color coordinates of CIE 1931 model - Abstract: The wet synthesis hydrothermal method at 100 deg. C was used to elaborate barium zirconate (BaZrO{sub 3}) unpurified with 0.5 mol% of different rare earth ions (RE = Yb, Er, Dy, Eu, Ce). Morphological, structural and UV-photoluminescence properties depend on the substituted rare earth ionic radii. While the crystalline structure of RE doped BaZrO{sub 3} remains as a cubic perovskite for all substituted RE ions, its band gap changes between 4.65 and 4.93 eV. Under 267 nm excitation the intrinsic green photoluminescence of the as synthesized BaZrO{sub 3}: RE samples is considerably improved by the substitution on RE ions. For 1000 deg. C annealed samples, under 267 nm, the photoluminescence is dominated by the intrinsic BZO emission. It is interesting to notice that Dy{sup 3+}, Er{sup 3+} and Yb{sup 3+} doped samples present whitish emissions that might be useful for white light generation under 267 nm excitation. CIE color coordinates are reported for all samples.

Synthesis and characterization of the novel rare earth orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Schildhammer, Daniel; Petschnig, Lucas L.; Fuhrmann, Gerda; Heymann, Gunter; Schottenberger, Herwig; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Tribus, Martina [Innsbruck Univ. (Austria). Inst. fuer Mineralogie und Petrographie

2016-02-01

The new mixed rare earth (RE) orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} were synthesized by a classical solid state reaction in an electrical furnace at 1200 C. As starting materials, the corresponding rare earth oxides and diammonium hydrogen phosphate were used. The powder diffraction analyses revealed that the new compounds Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} crystallize in a zircon-type structure being isostructural with the rare earth orthophosphate YPO{sub 4}. Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} crystallize in the tetragonal space group I4{sub 1}/amd (no. 141) with four formula units in the unit cell. The structural parameters based on Rietveld refinements are a = 687.27(2), c = 601.50(2) pm, V = 0.28412(1) nm{sup 3}, R{sub p} = 0.0143, and R{sub wp} = 0.0186 (all data) for Y{sub 0.5}Er{sub 0.5}PO{sub 4} and a = 684.61(2), c = 599.31(2) pm, V = 0.28089(2) nm{sup 3}, R{sub p} = 0.0242, and R{sub wp} = 0.0313 (all data) for Y{sub 0.5}Yb{sub 0.5}PO{sub 4}. Furthermore, the structure of Y{sub 0.5}Er{sub 0.5}PO{sub 4} was refined from single-crystal X-ray diffraction data: a = 687.78(5), c = 601.85(4) pm, V = 0.28470(5) nm{sup 3}, R{sub 1} = 0.0165, and wR{sub 2} = 0.0385 (all data). In both compounds, the rare earth metal ions are eightfold coordinated by oxygen atoms, forming two unique interlocking tetrahedra with two individual RE-O distances. The tetrahedral phosphate groups [PO{sub 4}]{sup 3-} are slightly distorted in both compounds. The individual rare earth ions share a common position (Wyckoff site 4a). The presence of two rare earth ions in the structures of the new orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} was additionally confirmed by single-crystal EDX spectroscopy revealing a ratio of 1:1.

Efficient green and red up-conversion emissions in Er/Yb co-doped TiO{sub 2} nanopowders prepared by hydrothermal-assisted sol–gel process

Energy Technology Data Exchange (ETDEWEB)

Salhi, Rached, E-mail: salhi_rached@yahoo.fr [Laboratoire de chimie industrielle, Ecole Nationale d’ingénieurs de Sfax, Université de Sfax, 3018 Sfax (Tunisia); Deschanvres, Jean-Luc [Laboratoire des Matériaux et du Génie Physique, 3 Parvis Louis Néel, BP 257, 38016 Grenoble (France)

2016-08-15

In this work, erbium and ytterbium co-doped titanium dioxide (Er–Yb:TiO{sub 2}) nanopowders have been successfully prepared by hydrothermal-assisted sol–gel method using supercritical drying of ethyl alcohol and annealing at 500 °C for 1 h. Nanopowders were prepared with fixed 5 mol% Erbium concentration and various Ytterbium concentrations of 5 and 10 mol%. The powders were characterized by studying their structural, morphology and photo-luminescent properties. The annealing treatment at 500 °C was found to enhance the crystallinity of the TiO{sub 2} anatase structure and the upconversion (UC) emission of the nanopowders. UC emissions were investigated under 980 nm excitation, and the Er–Yb:TiO{sub 2} nanopowders exhibited the intense green (520–570 nm) and red (640–690 nm) upconverted emissions of Er ions originating from an efficient Yb–Er energy transfer process. The absolute upconversion quantum yield (UC-QY) of each nanopowders was measured for the UC emissions centered at 525, 550 and 655 nm at varying excitation power densities. UC-QY analysis has revealed that 5 mol% Er–5 mol% Yb:TiO{sub 2} nanopowders possess the highest total quantum yield of 2.8±0.1% with a power density of 16.7 W/cm{sup 2}. These results make these nanopowders promising materials for efficient upconversion in photonic applications.

Spectrum fluctuations from regular and damped rotational structures in {sup 16}`8Yb and {sup 163}Tm nuclei

Energy Technology Data Exchange (ETDEWEB)

Herskind, B; Dossing, T; Ninel, N; Atac, A; Jensen, H J; Hagemann, G B; Lieder, R M; Maj, A; Nyberg, J; Piiparinen, M; Sugawara, M; Virtanen, A [Niels Bohr Inst., Copenhagen (Denmark); Leoni, S; Vigezzi, E; Bosetti, P; Bracco, A; Broglia, R A; Million, B [Milan Univ. (Italy); Matsuo, M [Kyoto Univ., Uji (Japan). Uji Research Center of Yukawa Inst. for Theoretical Physics; Bergstrom, M; Brockstedt, A; Carlsson, H; Ekstrom, P; Nordlund, A; Ryde, H [Lund Univ. (Sweden). Dept. of Physics; Jongman, J [Rijksuniversiteit Groningen (Netherlands). Kernfysisch Versneller Inst.; Ingebretsen, F; Tjom, P O [Oslo Univ. (Norway); Lonnroth, T [Aabo Akademi, Turku (Finland). Dept. of Physics

1992-08-01

A new method has been developed for analyzing fluctuations of count in two-dimensional gamma ray energy coincidence spectra of deformed nuclei formed in heavy ion fusion reactions. Most of the gamma decay cascades flow through regions of high level density, and the method is based upon assumptions about average properties of the excited states. Transition energies along discrete rotational bands are viewed as randomly selected from a continuous distribution of rotational frequencies and moments of inertia. For damped rotational motion, implying a mixing of the rotational bands, a random matrix model is assumed, leading to smooth energy spectra, and strong fluctuations of the transition strengths. The method is illustrated for {sup 168}Yb and {sup 163}Tm. 4 refs., 4 figs.

Study of the focusing effect of silica microspheres on the upconversion of Er3+–Yb3+ codoped glass ceramics

International Nuclear Information System (INIS)

Pérez-Rodríguez, C.; Imanieh, M.H.; Martín, L.L; Ríos, S.; Martín, I.R.; Yekta, Bijan Eftekhari

2013-01-01

Highlights: •Silica microspheres have been located on the surface of glass and glass ceramics samples codoped with Er and Yb. •Microspheres act as microlens of the 950 nm excitation light resulting in focalized excited regions in the samples with sizes under the micron. •Intense red upconversion is achieved in the focalized areas. •Microspheres collect the upconversion emission light, scoping with the together microlensing properties an enhancement of the detected signal in a 3x factor. •Performed Finite-Difference Time-Domain simulations predict the size of the focalized regions in good agreement with the experimental measurements. -- Abstract: The upconversion emission properties of Er 3+ –Yb 3+ codoped glass and glass ceramic samples with different Si/Al ratios and thermal treatments were analyzed by covering their surfaces with silica microspheres (3.8 μm diameter). A 950 nm laser beam is focused by the microspheres producing a set of photonic nanojets near the surface of the samples. After the upconversion processes of the Er 3+ ions located in each microsphere focus area, these ions emit light in the green and red regions. The red emission from each sample was measured, yielding an upconversion intensity in the focal areas three times higher than the emission from the bare substrate. To estimate the real size of the red emission area under a single microsphere, a deconvolution of the measured focal spots with the Point Spread Function of the experimental setup was performed, resulting in a Full Width at Half Maximum of 330 nm. The results obtained by Finite-Difference Time-Domain simulations are in good agreement with the experimental values

Broadened band C-telecom and intense upconversion emission of Er{sup 3+}/Yb{sup 3+} co-doped CaYAlO{sub 4} luminescent material obtained by an easy route

Energy Technology Data Exchange (ETDEWEB)

Perrella, R.V.; Schiavon, M.A. [Grupo de Pesquisa em Química de Materiais – (GPQM), Departamento de Ciências Naturais, Universidade Federal de São João del Rei (UFSJ), Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João del Rei, MG (Brazil); Pecoraro, E.; Ribeiro, S.J.L. [UNESP, Institute of Chemistry, P.O. Box 355, 14800-970 Araraquara, SP (Brazil); Ferrari, J.L., E-mail: ferrari@ufsj.edu.br [Grupo de Pesquisa em Química de Materiais – (GPQM), Departamento de Ciências Naturais, Universidade Federal de São João del Rei (UFSJ), Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João del Rei, MG (Brazil)

2016-10-15

This work reports on photoluminescence properties of Er{sup 3+}/Yb{sup 3+} co-doped CaYAlO{sub 4} in powder form, synthesized by an easy route using citric acid as ligand to form complex precursor. The 1.2 mol% of Yb{sup 3+} was fixed, while the amount of Er{sup 3+} changed in 0.5, 1.5 and 3 mol% in order to evaluate the photoluminescence properties as a function of the Er{sup 3+} concentration. The structural and thermal properties of the viscous solutions and powder materials obtained after the heat-treatment at 1000, 1100 and 1200 °C for 4 h were evaluated by XRD, FTIR and TG/DTA analysis. The results showed the formation of pure CaYAlO{sub 4} tetragonal crystalline phase after heat-treatment at 1100 °C and 1200 °C. Intense emission in the visible region under excitation at 980 nm was attributed to upconversion process, from Er{sup 3+} intra-configurational f–f transitions. The emissions were assigned to the transitions {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2} and {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} (green region), and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} (red region) energy levels. The ratio between emission band integrated areas assigned to the red and green emissions increased as a function of Er{sup 3+} concentration. Under excitation at 980 nm with 100 mW of power pump, the materials also showed intense and broadening emission with maximum at 1520 nm with FWHM of 84.74 nm for the sample CaYAlO{sub 4}:1.5% Er{sup 3+}/1.2% Yb{sup 3+} heat-treated at 1000 °C for 4 h. The photoluminescence properties showed that these materials are promising for use in C-telecom band as optical amplifier biological marker or/and solid-state laser devices under excitation at 980 nm.

Highly Efficient LiYF4:Yb(3+), Er(3+) Upconversion Single Crystal under Solar Cell Spectrum Excitation and Photovoltaic Application.

Science.gov (United States)

Chen, Xu; Xu, Wen; Song, Hongwei; Chen, Cong; Xia, Haiping; Zhu, Yongsheng; Zhou, Donglei; Cui, Shaobo; Dai, Qilin; Zhang, Jiazhong

2016-04-13

Luminescent upconversion is a promising way to harvest near-infrared (NIR) sunlight and transforms it into visible light that can be directly absorbed by active materials of solar cells and improve their power conversion efficiency (PCE). However, it is still a great challenge to effectively improve the PCE of solar cells with the assistance of upconversion. In this work, we demonstrate the application of the transparent LiYF4:Yb(3+), Er(3+) single crystal as an independent luminescent upconverter to improve the PCE of perovskite solar cells. The LiYF4:Yb(3+), Er(3+) single crystal is prepared by an improved Bridgman method, and its internal quantum efficiency approached to 5.72% under 6.2 W cm(-2) 980 nm excitation. The power-dependent upconversion luminescence indicated that under the excitation of simulated sunlight the (4)F(9/2)-(4)I(15/2) red emission originally results from the cooperation of a 1540 nm photon and a 980 nm photon. Furthermore, when the single crystal is placed in front of the perovskite solar cells, the PCE is enhanced by 7.9% under the irradiation of simulated sunlight by 7-8 solar constants. This work implies the upconverter not only can serve as proof of principle for improving PCE of solar cells but also is helpful to practical application.

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.

Spin reorientation behavior in Yb doped YMnO3

International Nuclear Information System (INIS)

Sharma, Neetika; Das, A.

2014-01-01

RMnO 3 with smaller rare-earths ions (R = Ho to Lu and Y) crystallize in the non-centrosymmetric hexagonal space group P6 3 cm. The magnetic structure of RMnO 3 compounds with (R=Er,Yb.Lu) are described by irreducible representations (IR) Γ 2,4 and Γ 1,3 for those with higher ionic radii (R=Ho,Y,Y-Er). Of recent the magnetic structure of YMnO 3 has been found to be better described by Γ 3 + Γ 4 IR. YbMnO 3 is another hexagonal manganite, with almost similar transition temperature, and basically shares all the physical properties of YMnO 3 , except for the magnetic structure. The magnetic structure of YbMnO 3 can be explained by Γ 2 or Γ 4 . The non collinear nature of magnetic ordering in these compounds arises due to the frustration inherent in these compounds. In this study we have probed the effect of a magnetic ion (Yb) on the magnetic structure of these frustrated isostructural compounds

Biocompatible Er, Yb co-doped fluoroapatite upconversion nanoparticles for imaging applications

Science.gov (United States)

Anjana, R.; K. M., Kurias; M. K., Jayaraj

2017-08-01

Upconversion luminescence, visible emission on infra red (IR) excitation was achieved in a biocompatible material, fluoroapatite. Fluoroapatite crystals are well known biomaterials, which is a component of tooth enamel. Also it can be considered as an excellent host material for lanthanide doping since the ionic radii of lanthanide is similar to that of calcium ion(Ca2+) hence successful incorporation of dopants within the lattice is possible. Erbium (Er), Ytterbium (Yb) co-doped fluorapatite (FAp) nanoparticles were prepared by precipitation method. The particles show intense visible emission when excited with 980 nm laser. Since upconversion luminescence is a multiphoton process the excitation power dependence on emission will give number of photons involved in the emission of single photon. Excitation power dependence studies show that two photons are involved in the emission of single photons. The value of slope was different for different emission peak because of the difference in intermediate energy level involved. The crystal structure and morphology of the particle were determined using X-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM). These particles with surface functionalisation can be used for live cell imaging.

Intense upconversion luminescence and effect of local environment for Tm3+/Yb3+ co-doped novel TeO2-BiCl3 glass system.

Science.gov (United States)

Wang, Guonian; Dai, Shixun; Zhang, Junjie; Wen, Lei; Yang, Jianhu; Jiang, Zhonghong

2006-05-15

We present the results of a study that uses theoretical and experimental methods to investigate the characteristics of the upconversion luminescence of Tm3+/Yb3+ codoped TeO2-BiCl3 glass system as a function of the BiCl3 fraction. These glasses are potentially important in the design of upconversion fiber lasers. Effect of local environment around Tm3+ on upconversion fluorescence intensity was analyzed by theoretical calculations. The structure and spectroscopic properties were investigated in the experiments by measuring the Raman spectra, IR transmission spectra, and absorption and fluorescence intensities at room temperature. The results indicate that blue luminescence quantum efficiency increases with increasing BiCl3 content from 10 to 60 mol%, which were interpreted by the increase of asymmetry of glass structure, decrease of phonon energy and removing of OH- groups.

Plasmonic enhancement in upconversion emission of La2O3:Er3+/Yb3+ phosphor via introducing silver metal nanoparticles

Science.gov (United States)

Tiwari, S. P.; Kumar, K.; Rai, V. K.

2015-11-01

In the present work, authors have synthesized silver (Ag) nanoparticle (NP) embedded La2O3:Er3+/Yb3+ powder phosphor. The synthesis method has resulted in silver oxide-lanthanum oxide composite material. Through subsequent heat treatment of sample in pellet form, the silver metal nanoparticles were formed. The presence of plasmonic Ag NPs in the matrix is confirmed by various techniques. Large enhancement in downconversion as well as upconversion emission intensity of Er3+ ions at various concentrations of Ag NPs is obtained. Large enhancement in the upconversion emission intensity is correlated to the reduction in decay time of 4S3/2 level in the presence of Ag NPs, and possible reasons for intensity enhancement are discussed. The application of phosphor in fingermark detection is demonstrated.

RESEARCH OF THERMO-OPTICAL INHOMOGENEITIES IN Yb-Er GLASS AT DIODE PUMPING

Directory of Open Access Journals (Sweden)

V. Khramov

2016-03-01

Full Text Available Subject of Research. Investigation method of thermo-optical distortions in solid-state lasers was developed and presented. The method can be easily used for research of small diameter (approximately 2 mm active elements. Method. The experimental method described in this paper is based on the registration of deviation of the energy center of the probe beam passing through the thermally stressed active element. Main Results. We have presented experimental results of the thermal lens optical power research in the active element made of Yb-Er glass pumped transversely by a laser diode in the following modes: without generating, free-running and Q-switching. We have submitted obtained dependences of the optical power on the pumping energy. The measurements have been performed for the two polarization components at two wavelengths (632.8 nm and 1550 nm showing the absence of explicit astigmatism of the thermal lens. Practical Relevance. Knowledge of the thermal regime of such lasers gives the possibility for more precise calculation of the resonator parameters in terms of the thermal lens occurrence.

Tuning crystal field symmetry of hexagonal NaY{sub 0.92}Yb{sub 0.05}Er{sub 0.03}F{sub 4} by Ti{sup 4+} codoping for high-performance upconversion

Energy Technology Data Exchange (ETDEWEB)

Yu, Han, E-mail: fjfzyh@fzu.edu.cn [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China); Huang, Qingming [Instrumentation Analysis and Research Center, Fuzhou University, Fuzhou, Fujian 350002 (China); Ma, En [Fujian Institue of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Zhang, Xinqi [Instrumentation Analysis and Research Center, Fuzhou University, Fuzhou, Fujian 350002 (China); Yu, Jianchang [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China)

2014-11-15

Highlights: • Upconversion emission of Er{sup 3+} was obviously enhanced by Ti{sup 4+} codoped in NaYF{sub 4}. • The upconversion luminescence lifetime was also obviously prolonged. • Na{sup +} could be induced to occupy Y{sup 3+} sites if Ti{sup 4+} was codoped with appropriate concentration. • The crystal field asymmetry was enhanced for better upconversion performance. • Crystal growth was prevented and small-sized NaYF{sub 4} were obtained. - Abstract: 378 nm, 408 nm and 521 nm upconversion emissions of Er{sup 3+} ions were obviously enhanced by Ti{sup 4+} codoped with Yb{sup 3+}/Er{sup 3+} in hexagonal NaYF{sub 4}, and the corresponding upconversion luminescence lifetimes were also prolonged, especially for 378 nm and 408 nm emissions. X-ray powder diffraction, field emission scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy and upconversion emission spectra were employed to explore the relationships of the structure and properties. From these characterizations we made a novel discovery that Na{sup +} could be induced to occupy Y{sup 3+} sites for establishing valence balance of the system if Ti{sup 4+} ions were codoped with appropriate concentration. As a result the crystal field asymmetry of NaY{sub 0.92}Yb{sub 0.05}Er{sub 0.03}F{sub 4} was enhanced and then its upconversion properties were improved because the hypersensitive electron transition of Yb{sup 3+}/Er{sup 3+} ions was promoted greatly. At the same time, the crystal sizes of the codoped NaYF{sub 4} became smaller because the crystal growth was prevented by more negative charges gathering at the crystal surface. This study provides an exploration of the relationship among impurity doping, structural changes and upconversion performance, which may be useful for design and synthesis of high-performance upconversion codoping materials.

Large scale preparation of up-converting YF3:YbEr nanocrystals with various sizes by solvothermal syntheses using ionic liquid bmimCl

Czech Academy of Sciences Publication Activity Database

Bartůněk, V.; Rak, J.; Pelánková, B.; Junková, J.; Mezlíková, M.; Král, V.; Kuchař, M.; Engstová, Hana; Ježek, Petr; Šmucler, R.

2016-01-01

Roč. 188, Aug (2016), s. 14-17 ISSN 0022-1139 R&D Projects: GA ČR(CZ) GA15-01897S; GA MŠk(CZ) LF14001; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : Yttrium fluoride * up-conversion * ionic liquids * BmimCl * YF3:YbEr * nanocrystals Subject RIV: BO - Biophysics Impact factor: 2.101, year: 2016

Spectral management and morphology evolution of β-NaGdF4:Yb3+,Er3+ by tuning the concentration of citric acid

Science.gov (United States)

Yao, Lu; Xu, Dekang; Lin, Hao; Yang, Shenghong; Zhang, Yueli

2018-05-01

β-NaGdF4:Yb3+,Er3+ upconversion (UC) particles were prepared by a facile hydrothermal process with assistance of citric acid (CA). The morphologies of β-NaGdF4 UC particles were controlled by changing the doses of CA in precursor. With an increase CA concentration in precursor, increase sizes of crystals were observed, resulting in the increasing of luminescence intensity. The energy transfer ET mechanism was analyzed in detail.

Neutron scattering study on R2PdSi3 (R=Ho,Er,Tm) compounds

International Nuclear Information System (INIS)

Tang, Fei

2010-01-01

Previous studies on the family of inter-metallic rare-earth compounds R 2 PdSi 3 revealed multifaceted magnetic properties, for instance, spin-glass like behavior. Experimental observations include: Signs of a crystallographic superstructure, complicated magnetic structures both in zero field and in applied magnetic fields as well as a generic phase in applied fields for compounds in the series with the heavy rare-earths R=Gd, Tb, Dy, Ho, Er and Tm. This thesis expands the studies on the magnetic properties of R 2 PdSi 3 employing mainly neutron scattering on single crystals with the focus on the compounds with R=Ho, Er and Tm. A detailed analysis of the crystallographic superstructure using modulation wave approach and group theory is presented. The resulting structure implies the existence of two different rare-earth sites with reduced symmetry and an arrangement of the different sites according to sequences as determined by the superstructure. It is shown that the reduced symmetry of the rare-earth sites is explicitly observed in the energy spectra of inelastic neutron scattering. The results on the magnetic structures and excitations are shown and discussed in the framework of the superstructure model. Specifically the generic phase in applied fields is interpreted as a direct consequence of the crystallographic superstructure. It is rather unusual that a crystallographic superstructure is playing such a decisive, and through the field dependence also tunable role in determining the magnetic properties as observed in R 2 PdSi 3 . The mediating interactions between the crystallographic part and the magnetic part of the system are discussed. (orig.)

Study of quantitative analysis of rare earth elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in soil samples by inductively couple plasma mass spectrometry

International Nuclear Information System (INIS)

Truong Duc Toan; Nguyen Giang; Vo Tran Quang Thai; Do Tam Nhan; Nguyen Le Anh; Nguyen Viet Duc; Luong Thi Tham; Truong Thi Phuong Mai

2015-01-01

Method for the determination of 16 rare earth elements (REEs) in soil samples without separating by inductively coupled plasma mass spectrometry (ICP-MS) has been studied at Dalat Nuclear Research Institute. The optimal conditions for ICP-MS NexION 300X with three modes: Standard, Collision (KED), and Reaction (DRC) have been studied on the Montana II soil reference material. The result analysis shows that: DRC mode only gives good analysis result for Sc, Y, La, Ce, Pr, Nd, Tm, Yb, and Lu; Standard mode exhibits good analysis results for all elements with error from 1.2 - 29.0% and KED mode is the best one with error less than 15%. The concentrations of elements in the soil samples of Cau Dat, Bao Loc, and Da Lat were determined, which concentrations of REEs in soil samples of Cau Dat are higher than that of the other areas in Lam Dong Province. (author)

Investigation of A = 152 radioactivities with mass-separated sources: Identification of /sup 152/Lu

International Nuclear Information System (INIS)

Toth, K.S.; Sousa, D.C.; Nitschke, J.M.; Wilmarth, P.A.

1987-01-01

Nuclides with A = 152 were produced in /sup 58/Ni bombardments of /sup 96/Ru and their decay properties were investigated following on-line mass separation. The isotope /sup 152/Lu (T/sub 1/2/ = 0.7 +- 0.1 s) was identified by γ rays in its β-decay daughter, /sup 152/Yb. Based on its decay characteristics, the parent state has a probable spin and parity assignment of (4,5,6 - ). Several new transitions were observed to follow the β decays of /sup 152/Yb and the /sup 152/Tm low-spin isomer; they established previously unknown levels in both /sup 152/Tm and /sup 152/Er. The additional γ rays in /sup 152/Yb decay reduce from 100% to 88% the direct feeding to the one excited state in /sup 152/Tm that had been known earlier. Nevertheless, the corresponding logft value is calculated to be 3.5, indicating that this is an allowed β transition which connects the 0 + parent with a 1 + excited state in /sup 152/Tm. By comparing the β-decay rates of /sup 148/Dy and /sup 152/Ho, and the α- and β-decay rates of /sup 152/Er, an α branch of 90 +- 4 % was deduced for /sup 152/Er

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.

Upconversion emission study of Er3+/Yb3+ doped barium titanate phosphor prepared by co-precipitation method

International Nuclear Information System (INIS)

Mahata, M.K.; Dey, R.; Kumar, K.; Rai, V.K.; Rai, S.B.

2012-01-01

In the present work we have successfully synthesized the Er 3+ , Yb 3+ doped barium titanate phosphor via co-precipitation synthesis method. Under 980 nm excitation, tri-color upconversion fluorescence has been observed. The Fourier Transform Infrared measurement was done to check the presence of organic impurities. In order to find out how many photons are involved in each emission band, the variation of UC emission intensity of the codoped phosphor is studied with increase in excitation power. Upconversion emission spectra show that as the annealing temperature of the powder is increased, intensity of red emission decreases and intensity of green emission increases due to the decrease in maximum phonon frequency of the host material. (author)

Anomalies of magnetoresistance of compounds with atomic clusters RB12 (R = Ho, Er, Tm, Lu)

International Nuclear Information System (INIS)

Sluchanko, N. E.; Bogach, A. V.; Glushkov, V. V.; Demishev, S. V.; Samarin, N. A.; Sluchanko, D. N.; Dukhnenko, A. V.; Levchenko, A. V.

2009-01-01

The magnetoresistance and magnetization of single-crystal samples of rare-earth dodecaborides RB 12 (R = Ho, Er, Tm, Lu) have been measured at low temperatures (1.8-35 K) in a magnetic field of up to 70 kOe. The effect of positive magnetoresistance that obeys the Kohler's rule Δρ/ρ = f(ρ(0, 300 K)H/ρ(0, T)) is observed for the nonmagnetic metal LuB 12 . In the magnetic dodecaborides HoB 12 , ErB 12 , and TmB 12 , three characteristic regimes of the magnetoresistance behavior have been revealed: the positive magnetoresistance effect similar to the case of LuB 12 is observed at T > 25 K; in the range T N ≤ T ≤ 15 K, the magnetoresistance becomes negative and depends quadratically on the external magnetic field; and, finally, upon the transition to the antiferromagnetic phase (T N ), the positive magnetoresistance is again observed and its amplitude reaches 150% for HoB 12 . It has been shown that the observed anomalies of negative magnetoresistance in the paramagnetic phase can be explained within the Yosida model of conduction electron scattering by localized magnetic moments. The performed analysis confirms the formation of spin-polaron states in the 5d band in the vicinity of rare-earth ions in paramagnetic and magnetically ordered phases of RB 12 and makes it possible to reveal a number of specific features in the transformation of the magnetic structure of the compounds under investigation

Spectroscopic studies of the energy transfer processes important to obtain holmium laser action in the Er:Tm:Ho:YLF

International Nuclear Information System (INIS)

Tarelho, Luiz Vicente Gomes

1995-01-01

There are several processes of energy transfer between Er, Tm and Ho ions in YLF crystal that could be evaluated using the Foerster-Dexter method. Energy transfer processes, important to understand Holmium laser action, were studied, specially involving the energy transfer between the first excited states of Er and Tm donors and Ho acceptor. The back-transfer processes were evaluated too in order to minimize the system losses. Another important process to understand Ho laser action in the host is the energy diffusion mechanism between donor ions due to excitation migration processes which take place before the energy transfer to Ho. The proposed model of energy transfer was developed to include the diffusion mechanism between donors in the absence and presence of the acceptors. The energy transfer probability was evaluated including the back-transfer processes besides the diffusion assistance. A laser medium model based on the fundamental spectroscopic parameters was used in order to determine the ideal donor acceptor concentrations in order to maximize the laser action of Ho at 2,1 μm. (author)

Study for optimizing the design of optical temperature sensor

Science.gov (United States)

Li, Panpan; Sun, Zhen; Shi, Ruixin; Liu, Guofeng; Fu, Zuoling; Wei, Yanling

2017-12-01

The correlations between temperature sensitivity (relative sensitivity Sr and absolute sensitivity Sa) and thermally coupled level gaps (ΔE) are vital but less-studied for potential applications in scientific research, industrial production, clinical medicine, and so on. We take YbPO4:Ln3+ (Ln = Tm3+, Ho3+, and Er3+) up-conversion phosphors as a case to study the relationships between temperature sensitivity (Sr, Sa) and ΔE. The results of various discussions, including the experimental data of temperature sensitivity based on YbPO4:Ln3+ (Ln = Tm3+, Ho3+, and Er3+) and theoretical derivation from original formulas, show that Sr and ΔE are linearly positive correlation, which is invalid for Sa. Noticeably, YbPO4:Tm3+ nanoparticles display intense near infrared red emission within the biological window, leading to great potential application in biological sensing and biological imaging. All the research studies would benefit the design of optical temperature sensing.

Study of the focusing effect of silica microspheres on the upconversion of Er{sup 3+}–Yb{sup 3+} codoped glass ceramics

Energy Technology Data Exchange (ETDEWEB)

Pérez-Rodríguez, C., E-mail: cjperez@ull.edu.es [Dpto. Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); Imanieh, M.H. [Department of Chemical and Environmental Engineering, University of Toledo, Toledo, OH (United States); Department of Materials, Ceramic Division, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Martín, L.L [Dpto. Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); Ríos, S. [Dpto. de Física Básica, Universidad de La Laguna, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); Martín, I.R. [Dpto. Física Fundamental y Experimental, Electrónica y Sistemas, Universidad de La Laguna, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); MALTA Consolider Team, Av. Astrofísico Francisco Sánchez, s/n E-38206 La Laguna, Tenerife (Spain); Yekta, Bijan Eftekhari [Department of Materials, Ceramic Division, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

2013-11-05

Highlights: •Silica microspheres have been located on the surface of glass and glass ceramics samples codoped with Er and Yb. •Microspheres act as microlens of the 950 nm excitation light resulting in focalized excited regions in the samples with sizes under the micron. •Intense red upconversion is achieved in the focalized areas. •Microspheres collect the upconversion emission light, scoping with the together microlensing properties an enhancement of the detected signal in a 3x factor. •Performed Finite-Difference Time-Domain simulations predict the size of the focalized regions in good agreement with the experimental measurements. -- Abstract: The upconversion emission properties of Er{sup 3+}–Yb{sup 3+} codoped glass and glass ceramic samples with different Si/Al ratios and thermal treatments were analyzed by covering their surfaces with silica microspheres (3.8 μm diameter). A 950 nm laser beam is focused by the microspheres producing a set of photonic nanojets near the surface of the samples. After the upconversion processes of the Er{sup 3+} ions located in each microsphere focus area, these ions emit light in the green and red regions. The red emission from each sample was measured, yielding an upconversion intensity in the focal areas three times higher than the emission from the bare substrate. To estimate the real size of the red emission area under a single microsphere, a deconvolution of the measured focal spots with the Point Spread Function of the experimental setup was performed, resulting in a Full Width at Half Maximum of 330 nm. The results obtained by Finite-Difference Time-Domain simulations are in good agreement with the experimental values.

Polarized spectroscopic properties of Er{sup 3+}:Gd{sub 2}SiO{sub 5} crystal and evaluation of Er{sup 3+}:Yb{sup 3+}:Gd{sub 2}SiO{sub 5} crystal as a 1.55 μm laser medium

Energy Technology Data Exchange (ETDEWEB)

Wang, H. [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Huang, J.H.; Gong, X.H.; Chen, Y.J.; Lin, Y.F.; Luo, Z.D. [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang, Y.D., E-mail: huyd@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2016-10-01

An Er{sup 3+}-doped Gd{sub 2}SiO{sub 5} single crystal with high optical quality has been grown by the Czochralski method. Polarized absorption and fluorescence spectra and fluorescence lifetime of the crystal were measured at room temperature. Intensity parameters, spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes were estimated on the basis of the Judd–Ofelt theory. Besides, potentiality of 1.55 μm laser emission in an Er{sup 3+}–Yb{sup 3+} co-doped Gd{sub 2}SiO{sub 5} crystal was evaluated.

Luminescent and laser properties of Yb Er:GdCa4O(BO3)3: a new crystal for eye-safe 1.5-μm lasers

Science.gov (United States)

Denker, B.; Galagan, B.; Ivleva, L.; Osiko, V.; Sverchkov, S.; Voronina, I.; Hellstrom, J. E.; Karlsson, G.; Laurell, F.

2004-09-01

We present for the first time 1.5-μm laser emission in Yb Er:GdCa4O(BO3)3 (GdCOB). The crystals were grown by the Czochralski method from platinum crucibles. Spectroscopic and laser tests of the crystals are described. A continuous-wave output power of 80 mW was achieved in a monolithic microchip cavity under laser-diode pumping.

Crystal structure of 4-RbHo(PO3)4, 4-RbTm(PO3)4 and 4-CsEr(PO3)4

International Nuclear Information System (INIS)

Maksimova, S.I.; Palkina, K.K.; Chibiskova, N.T.

1982-01-01

X-ray structural study of 4-RbLn(PO 3 ) 4 (Ln=Mo, Tm) and 4-CsEr(PO 3 ) 4 is carried out. The compounds are crystallized in monoclinic crystal system, sp. gr P2 1 /n. Parameters of their unit cell, atom coordinates, anisotropic heat parameters, interatomic distances and valent angles are given. 4-RbHo(PO 3 ) 4 , 4-RbTm(PO 3 ) 4 , 4-CsEr(PO 3 ) 4 are isostructural to previously studied TlNd(PO 3 ) and 4-RbNd(PO 3 ) 4 . Using as an example the structural type 4-M 1 Ln(PO 3 ) 4 it is shown that the change of the shortest distances Ln-Ln, M 1 -M 1 and M 1 -Ln, as well as of degree of polymorphous chain corrugation to a higher extent depends on rare earth atom dimensions, than on monovalent metal ion dimensions [ru

Scintillation properties of Nd{sup 3+}, Tm{sup 3+}, and Er{sup 3+} doped LuF{sub 3} scintillators in the vacuum ultra violet region

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Takayuki, E-mail: yanagida@imr.tohoku.ac.jp [New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Kawaguchi, Noriaki [Tokuyama Corporation Ltd., Shibuya 3-chome, Shibuya-ku, Tokyo 150-8383 Japan (Japan); Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Fukuda, Kentaro [Tokuyama Corporation Ltd., Shibuya 3-chome, Shibuya-ku, Tokyo 150-8383 Japan (Japan); Kurosawa, Shunsuke; Fujimoto, Yutaka; Futami, Yoshisuke; Yokota, Yuui [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Taniue, Kojiro [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwakecho, Sakyo, Kyoto, 606-8502 (Japan); Sekiya, Hiroyuki [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Hida, 506-1205 (Japan); Kubo, Hidetoshi [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwakecho, Sakyo, Kyoto, 606-8502 (Japan); Yoshikawa, Akira [New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Tanimori, Toru [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwakecho, Sakyo, Kyoto, 606-8502 (Japan)

2011-12-11

In order to develop novel vacuum ultra violet (VUV) emitting scintillators, we grew Nd 0.5%, Tm 0.5%, and Er 0.5% doped LuF{sub 3} scintillators by the {mu}-pulling down method, because LuF{sub 3} has a very wide band gap and Nd{sup 3+}, Tm{sup 3+}, and Er{sup 3+} luminescence centers show fast and intense 5d-4f emission in VUV region. Transmittance and X-ray induced radioluminescence were studied in these three samples using our original spectrometer made by Bunkou-Keiki company. In the VUV region, transmittance of 20-60% was achieved for all the samples. The emission peaks appeared at approximately 180, 165, and 164 nm for Nd{sup 3+}, Tm{sup 3+}, and Er{sup 3+} doped LuF{sub 3}, respectively. Using PMT R8778 (Hamamatsu), we measured their light yields under {sup 241}Am {alpha}-ray excitation. Compared with Nd:LaF{sub 3} scintillator, which has 33 photoelectrons/5.5 MeV {alpha}, Nd:LuF{sub 3} and Tm:LuF{sub 3} showed 900{+-}90 and 170{+-}20 ph/5.5 MeV-{alpha}, respectively. Only for the Nd doped one, we can detect {sup 137}Cs 662 keV {gamma}-ray photoabsorption peak and the light yield of 1200{+-}120 ph/MeV was measured. We also investigated their decay time profiles by picosecond pulse X-ray equipped streak camera, and the main decay component of Nd:LuF{sub 3} turned out to be 7.63 ns.

Near-yrast spectroscopy of 164Yb and neighbouring nuclei

International Nuclear Information System (INIS)

Jonsson, S.; Roy, H. and others.

1983-03-01

High-spin states in 164 Yb have been populated in the 152 Sm( 16 0,4n) and 150 Sm( 18 0,4n) reactions. From studies of γ-γ coincidences, γ-ray angular distributions and conversion electron measurements the level scheme has been constructed. The g-band and the S-band have been established to spin and parity 22(sup)+ and 26(sup)+, respectively, and the rotational sequences (π,α)=(-,1) 1 , (-,0) 1 and (-,0) 2 to 23(sup)-, 24(sup)- and 18(sup)-, respectively. The sidebands in 162 , 164 Er and 164 , 166 Yb are discussed. Constructed two-quasineutron configurations and cranked shell model (CSM) calculations are compared with the experimental results in 164 Yb. Residual interactions between quasiparticles in 164 Yb are calculated. Crossing frequencies and the gain in alignment are summarized for the Yb isotopes and the main features are discussed. (author)

Energy transfer between doubly doped Er3+, Tm3+and Ho3+ rare earth ions in SiO2 nanoparticles

CSIR Research Space (South Africa)

Dhlamini, MS

2011-04-01

Full Text Available + and Ho3+ ions are reported. Another emission peak in the near infra-red (NIR) region at 875 nm from Er3+ was also measured. Blue emission at 460 nm, red at 705 nm and a NIR peak in the region of 865 nmfrom Tm3+ were observed. Red, green and blue (RGB...

Specific features of magnetoresistance during the antiferromagnet—paramagnet transition in Tm1−xYbxB12

International Nuclear Information System (INIS)

Sluchanko, N. E.; Azarevich, A. N.; Bogach, A. V.; Glushkov, V. V.; Demishev, S. V.; Levchenko, A. V.; Filippov, V. B.; Shitsevalova, N. Yu.

2013-01-01

The transverse magnetoresistance Δρ/ρ(H, T) of Tm 1−x Yb x B 12 single crystals is studied in the ytterbium concentration range corresponding to the antiferromagnet-paramagnet transition in a magnetic field up to 80 kOe at low temperatures. A magnetic H-T phase diagram is constructed for the antiferromagnetic state of substitutional Tm 1−x Yb x B 12 solid solutions with x ≤ 0.1. The contributions to the magnetoresistance in the antiferromagnetic and paramagnetic phases of the dodecaborides under study are separated. Along with negative quadratic magnetoresistance -Δρ/ρ ∝ H 2 , the magnetically ordered phase of these compounds is found to have component Δρ/ρ ∝ H that linearly changes in a magnetic field. The negative contribution to the magnetoresistance of Tm 1−x Yb x B 12 is analyzed in terms of the Yosida model for a local magnetic susceptibility.

Lanthanide-doped Sr2YF7 nanoparticles: controlled synthesis, optical spectroscopy and biodetection

Science.gov (United States)

Yang, Yuhan; Tu, Datao; Zheng, Wei; Liu, Yongsheng; Huang, Ping; Ma, En; Li, Renfu; Chen, Xueyuan

2014-09-01

Sr2YF7, as an important matrix for trivalent lanthanide (Ln3+) ions to fabricate upconversion (UC) or downshifting (DS) phosphors, has been rarely reported. Herein, monodisperse and size-controllable tetragonal-phase Ln3+-doped Sr2YF7 nanoparticles (NPs) were synthesized via a facile thermal decomposition method. Upon excitation at 980 nm, UC luminescence properties of Sr2YF7:Ln3+/Yb3+ (Ln = Tm, Er) NPs were systematically surveyed. Particularly, after coating an inert Sr2YF7 shell, the UC luminescence intensities of Sr2YF7:Tm3+/Yb3+ and Sr2YF7:Er3+/Yb3+ NPs were enhanced by ~22 and 4 times, respectively. Furthermore, intense multicolor DS luminescence was also achieved in Ce3+/Tb3+ or Eu3+ doped Sr2YF7 NPs, with absolute quantum yields of 55.1% (Tb3+) and 11.2% (Eu3+). The luminescence lifetimes of 5D4 (Tb3+) and 5D0 (Eu3+) were determined to be 3.7 and 8.1 ms, respectively. By utilizing the long-lived luminescence of Ln3+ in these Sr2YF7 NPs, we demonstrated their application as sensitive heterogeneous time-resolved photoluminescence bioprobes to detect the protein of avidin and the tumor marker of the carcinoembryonic antigen (CEA) with their limits of detection down to 40.6 and 94.9 pM, and thus reveal the great potential of these Sr2YF7:Ln3+ nanoprobes in cancer diagnosis.Sr2YF7, as an important matrix for trivalent lanthanide (Ln3+) ions to fabricate upconversion (UC) or downshifting (DS) phosphors, has been rarely reported. Herein, monodisperse and size-controllable tetragonal-phase Ln3+-doped Sr2YF7 nanoparticles (NPs) were synthesized via a facile thermal decomposition method. Upon excitation at 980 nm, UC luminescence properties of Sr2YF7:Ln3+/Yb3+ (Ln = Tm, Er) NPs were systematically surveyed. Particularly, after coating an inert Sr2YF7 shell, the UC luminescence intensities of Sr2YF7:Tm3+/Yb3+ and Sr2YF7:Er3+/Yb3+ NPs were enhanced by ~22 and 4 times, respectively. Furthermore, intense multicolor DS luminescence was also achieved in Ce3+/Tb3+ or Eu3

Bulk glass ceramics containing Yb{sup 3+}/Er{sup 3+}: β-NaGdF{sub 4} nanocrystals: Phase-separation-controlled crystallization, optical spectroscopy and upconverted temperature sensing behavior

Energy Technology Data Exchange (ETDEWEB)

Chen, Daqin, E-mail: dqchen@fjirsm.ac.cn [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Wan, Zhongyi; Zhou, Yan [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Huang, Ping, E-mail: phuang@fjirsm.ac.cn [Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Zhong, Jiasong; Ding, Mingye [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Xiang, Weidong; Liang, Xiaojuan [College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035 (China); Ji, Zhenguo, E-mail: jizg@hdu.edu.cn [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)

2015-07-25

Highlights: • Hexagonal NaGdF{sub 4} nanocrystals embedded bulk glass ceramics were fabricated. • The incorporation of Ln{sup 3+} dopants into the β-NaGdF{sub 4} lattice was demonstrated. • Upconversion luminescence was highly intensified after glass crystallization. • Such glass ceramics had possible application in the optical temperature sensors. - Abstract: Lanthanide doped hexagonal β-NaGdF{sub 4} nanocrystals embedded transparent bulk glass ceramics were successfully fabricated via a phase-separation-controlled crystallization route. Elemental mapping in the scanning transmission electron microscope and optical spectroscopy analysis demonstrated the partition of the active centers into the β-NaGdF{sub 4} crystalline lattice. As a result, upconversion luminescence of the glass ceramic co-doped with Yb{sup 3+} and Er{sup 3+} is about 60 times as high as that of the precursor glass, attributing to the modification of Yb{sup 3+}/Er{sup 3+} surrounding from phase-separated amorphous nanoparticle to β-NaGdF{sub 4} crystalline lattice with low phonon energy and high crystallinity after crystallization. Furthermore, the temperature-dependent green upconversion emissions assigned to {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2} (520 nm) and {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} (540 nm) transitions were investigated, and the corresponding fluorescence intensity ratio of these two thermally coupled emitting-states greatly enhanced with increase of temperature. Using such fabricated glass ceramic as an optical thermometric medium, the maximum sensitivity reached as high as 0.0037 K{sup −1} at 580 K. It is expected that the investigated Er{sup 3+}/Yb{sup 3+} codoped glass ceramic might be a very promising candidate for accurate optical temperature sensors.

Structure-property relations in new fluorophosphate glasses singly- and co-doped with Er3+ and Yb3+

International Nuclear Information System (INIS)

Gonçalves, Tássia S.; Moreira Silva, Raphaell J.; Oliveira Junior, Marcos de; Ferrari, Cynthia R.; Poirier, Gäel Y.; Eckert, Hellmut; Camargo, Andrea S.S. de

2015-01-01

Rare earth (RE 3+ )-doped fluorophosphate glasses are among the most promising candidates for high-efficiency laser generation in the near-infrared spectral region. By proper choice of composition, these materials can combine the advantages of fluorides (low phonon energies, low refractive indices, extensive optical window, low hygroscopicity) and of oxides (high chemical and mechanical stability and high dopant solubility), resulting in enhancement of the RE 3+ emissive properties. In this work, we present the synthesis and structural/spectroscopic investigation of new glasses with composition 25BaF 2 25SrF 2 (30-x)Al(PO 3 ) 3 xAlF 3 (20-z)YF 3 :zREF 3 , where x = 20 or 15, RE = Er 3+ and/or Yb 3+ , z = 0.25–5.0 mol%. Results indicate considerable improvement of the emissive properties of both ions when compared to phosphate or even other fluorophosphate host compositions. Long excited state lifetimes (τ = 10 ms for the Er 3+ level 4 I 13/2 , and τ = 1.3 ms for the Yb 3+ level 2 F 5/2 ) imply high fluorescence quantum efficiencies η (up to 85% for both ions). Structural characterization by Raman and multinuclear solid state NMR spectroscopies indicate that the metaphosphate-type chain structure of the Al(PO 3 ) 3 vitreous framework is partially depolymerized and dominated by Q (0) and Q (1) units crosslinked by six-coordinate Al species. As revealed by 27 Al{ 31 P} rotational echo double resonance (REDOR) NMR results the average local aluminum environment of the x = 20 sample comprises 1.6 phosphate and 4.4 fluoride species. These results indicate a clear bonding preference between aluminum and phosphorus, which is consistent with the desired dominance of fluoride species in the local environment of the rare earth and alkaline earth atoms in these glasses. - Highlights: • New fluorophosphate glass composition with excellent photophysical properties. • Detailed structural insights by multinuclear solid state NMR. • Rare earth bonding preference to

Synthesis, characterization and upconversion emission properties of the nanocrystals of Yb3+/Er3+-codoped YF3-YOF-Y2O3 system

International Nuclear Information System (INIS)

Li Zhihua; Zheng Longzhen; Zhang Luning; Xiong Leyan

2007-01-01

Nanocrystalline Yb 3+ , Er 3+ -codoped fluoride (YF 3 ), oxyfluoride (YOF), and oxide (Y 2 O 3 ) phosphors have been synthesized by a facile pyrolysis of a yttrium trifluoroacetate precursor. YF 3 , YOF and Y 2 O 3 nanoparticles were demonstrated to be good host materials for lanthanides. Varied hosts led to different optical properties. Red, green, and blue up-conversion (UC) was observed upon excitation in the NIR spectral range in all synthesized compounds. The UC mechanisms were also analyzed

Optical emission spectrographic analysis of lutetium oxide for rare earth impurities

International Nuclear Information System (INIS)

Chandola, L.C.; Dixit, V.S.

1986-01-01

An optical emission spectrographic (OES) method has been developed for the analysis of high purity lutetium oxide to determine rare earths Er, Tm, Yb and Y. The spectra are excited by a d.c. arc run at 10 A current after mixing the sample with graphite buffer in the weight ratio 1:1. A 1200 grooves/mm grating blazed at 3300 A is used for dispersion and a Kodak SA-1 plate for recording the spectrum. The detection limit is 0.001 per cent for Tm, Yb and Y while it is 0.005 per cent for Er. The relative standard deviation of the method is ± 13.4 per cent. (author)

Highly scalable, resonantly cladding-pumped, Er-doped fiber laser with record efficiency.

Science.gov (United States)

Dubinskii, M; Zhang, J; Ter-Mikirtychev, V

2009-05-15

We report the performance of a resonantly cladding-pumped, Yb-free, Er-doped fiber laser. We believe this is the first reported resonantly cladding-pumped fiber-Bragg-grating-based, Er-doped, large-mode-area (LMA) fiber laser. The laser, pumped by fiber-coupled InGaAsP/InP laser diode modules at 1,532.5 nm, delivers approximately 48 W of cw output at 1,590 nm. It is believed to be the highest power ever reported from a Yb-free Er-doped LMA fiber. This fully integrated laser also has the optical-to-optical efficiency of approximately 57%, to the best of our knowledge, the highest efficiency reported for cladding-pumped unidirectionally emitting Er-doped laser.

Impact of firing temperature on multi-wavelength selective Stokes and anti-Stokes luminescent behavior by Gd2O2S:Er,Yb phosphor and its application in solar energy harvesting

Science.gov (United States)

Kataria, V.; Mehta, D. S.

2018-04-01

Erbium (Er3+)-ytterbium (Yb3+) doped gadolinium oxysulphide (Gd2O2S) phosphor has been developed via a facile method of solid-state flux fusion, and offers two-fold spectrum modification with highly intense Stokes and anti-Stokes shift. The effect of the firing cycle on the photoluminescent response and morphology of Gd2O2S:Er,Yb is scrutinized, wherein the firing temperature was varied (1000 °C-1250 °C), keeping firing time and all other parameters constant. Interestingly, the nanostructures fired below 1150 °C showed nanorods of diameter ~200 nm and length ~1-2 µm, whereas firing at 1150 °C and above rendered nanospheres with small diameter, ~350 nm. Highly bright upconversion (UC) emission was achieved even under an extremely low excitation power density of 800 µW cm-2 from a 980 nm laser, and was comfortably visible to the naked eye. The incident power dependent studies disclosed increase in UC-emission intensity with increasing excitation power and a quasi-linear dependence on excitation power density. Intense characteristic UC-emission of Er3+ excited states at 525 nm, 556 nm and 668 nm were observed, and the green emission band was found to be dominant over the red band in intensity. Concurrently, downconversion (DC) emission at 556 nm and 669 nm was also exhibited under ultraviolet excitation (285 nm and 380 nm), with the red band being more powerful than the green, unlike UC-emission. Firing temperature dependent studies divulged the dependence of luminescence intensity on the firing cycle of the luminophore and formation of the respective luminescent phase. The UC-emission intensity was found to be maximum for samples fired at 1150 °C, whereas samples fired at 1000 °C showed the highest DC-emission intensity. The excitation and emission profile of single Gd2O2S:Er,Yb phosphor lying in the desired spectral region and as a dual spectral converter marks its possible application for enhanced harvesting of sunlight.

Effect of thermal lens on beam quality and mode matching in LD pumped Er-Yb-codoped phosphate glass microchip laser

Energy Technology Data Exchange (ETDEWEB)

Liu Shujing; Song Feng; Cai Hong; Li Teng; Tian Bin; Wu Zhaohui; Tian Jianguo [Photonics Center, Nankai University, Tianjin 300071 (China); Key Laboratory of Advanced Technique and Fabrication for Weak-Light Nonlinear Photonics Materials (Ministry of Education), Nankai University, Tianjin 300457 (China)

2008-02-07

The theoretical values of the thermal focal length and laser beam waist are derived from the theoretical model and transformation theory, respectively. The values of thermal focal length, laser beam waist and the far field divergence angle were experimentally measured in a laser diode (LD) pumped erbium-ytterbium(Er-Yb)-codoped phosphate microchip glass laser. As an extension of thermal effect studies, we investigate the role of thermal lens on beam quality and the mode matching between the pump and the laser, which affects laser efficiency in TEM{sub 00} operation. The study shows that the experimental data are in good agreement with the theoretical predictions.

Spectral properties and anti-Stokes luminescence of TeO2-BaF2:Ho3+, Ho3+/Yb3+ ceramics and glass excited by 1.9-μm radiation of a Tm:LiYF4 laser

Science.gov (United States)

Savikin, A. P.; Egorov, A. S.; Budruev, A. V.; Perunin, I. Yu.; Krasheninnikova, O. V.; Grishin, I. A.

2017-07-01

We demonstrate the up-conversion of Tm:LiYF4 infrared (IR) laser radiation with 1908-nm wavelength into visible light with a spectral maximum at 650 nm by ceramics with a composition of (100 - x)TeO2- xBaF2 - 1 wt % HoF3- yYbF3, where x = 20, 30, or 40 mol % and y = 0 or 0.5 wt %. The samples of 60TeO2-40BaF2 - 1 wt % HoF3 - 0.5 wt % YbF3 exhibited anti-Stokes luminescence at a threshold radiation power density of 1.0-1.5 W cm-2.

BaYb2F8, a new radiation hard Cherenkov radiator for electromagnetic calorimeters

International Nuclear Information System (INIS)

Aseev, A.A.; Devitsin, E.G.; Komar, A.A.; Kozlov, V.A.; Hovsepyan, Yu.I.; Potashov, S.Yu.; Sokolovsky, K.A.; Uvarova, T.V.; Vasilchenko, V.G.

1992-01-01

Radiation hardness and optical properties of a new Cherenkov radiator, heavy fluoride BaYb 2 F 8 doped with various elements, have been studied. The above mentioned crystal has the density of 7 g/cm 3 , the radiation length is 1.28 cm and the Moliere radius 2.44 cm. High radiation hardness has been demonstrated for BaYb 2 F 8 doped with Tm, Pr, Tb. (orig.)

UV-assisted selective chemical etching of relief gratings in Er/Yb-codoped IOG1 phosphate glass

Energy Technology Data Exchange (ETDEWEB)

Pappas, C; Pissadakis, S [Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser, Vasilika Vouton, PO Box 1527, Heraklion 71 110, GREECE (Greece)

2007-04-15

The patterning of sub-micron periodicity Bragg reflectors in Er/Yb-codoped IOG1, phosphate glass is demonstrated. A high yield patterning technique is presented, wherein high volume damage is induced into the glass matrix by exposure to intense UV radiation, and subsequently a chemical development in a strong acid selectively etches the exposed areas. The grating reflectors were fabricated by employing an elliptical Talbot interferometer and the output of a 213nm, 150ps frequency quintupled Nd:YAG laser. The grating depth of the etched relief pattern in time was measured at fixed time intervals and the dependence is presented in upon the etching time and exposure conditions. The gratings fabricated are examined by atomic and scanning electron microscopy for revealing the topology of the relief structure. Gratings with period of the order of 500nm were fabricated, having a maximum depth of 60nm.

A facile synthesis approach and impact of shell formation on morphological structure and luminescent properties of aqueous dispersible NaGdF{sub 4}:Yb/Er upconversion nanorods

Energy Technology Data Exchange (ETDEWEB)

Ansari, Anees A., E-mail: aneesaansari@gmail.com [King Saud University, King Abdullah Institute for Nanotechnology (Saudi Arabia); Yadav, Ranvijay; Rai, S. B. [Banaras Hindu University, Department of Physics (India)

2016-12-15

A general facile synthesis approach was used for fabrication of highly emissive aqueous dispersible hexagonal phase upconversion luminescent NaGdF{sub 4}:Yb/Er nanorods (core NRs) through metal complex decomposition process. An inert NaGdF{sub 4} and porous silica layers were grafted surrounding the surface of each and every NRs to enhance their luminescence efficiency and colloidal dispersibility in aqueous environment. Optical properties in terms of band gap energy of core, core/shell, and silica-coated core/shell/SiO{sub 2} nanorods were observed to investigate the influence of surface coating, which was gradually decreased after surface coating because of increase crystalline size after growth of inert and silica shells. The inert shell formation before silica surface grafting, upconversion luminescence intensity was greatly improved by about 20 times, owing to the effective surface passivation of the seed core and, therefore, protection of Er{sup 3+} ion in the core from the nonradiative decay caused by surface defects. Moreover, after silica coating, core/shell nanorods shows strong upconversion luminescence property similar to the hexagonal upconversion core NRs. It is expected that these NaGdF{sub 4}:Yb/Er@NaGdF{sub 4}@SiO{sub 2} (core/shell/SiO{sub 2}) NRs including highly upconversion emissive and aqueous dispersible properties make them an ideal materials for various photonic-based potential applications such as in upconversion luminescent bioimaging, magnetic resonance imaging, and photodynamic therapy.

Structural and light up-conversion luminescence properties of Er{sup 3+}-Yb{sup 3+}-W{sup 6+} substituted Bi{sub 4}Ti{sub 3}O{sub 12}

Energy Technology Data Exchange (ETDEWEB)

Bokolia, Renuka, E-mail: renuka1274@gmail.com; Chauhan, Lalita; Sreenivas, K. [Department of Physics & Astrophysics, University of Delhi, Delhi-110007 (India); Rai, Vineet K. [Laser & Spectroscopy Laboratory, Department of Applied Physics, Indian School of Mines, Dhanbad 826 004, Jharkhand (India)

2016-05-23

The structural and light up-conversion (UC) luminescence properties of W{sup 6+} substituted Bi{sub 3.79}Er{sub 0.03}Yb{sub 0.18}Ti{sub 3-x}W{sub x}O{sub 12} (0 ≤ x ≤ 0.10) ceramics prepared by solid state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of single phase material with orthorhombic structure. A decrease in the lattice parameters and unit cell volume is observed with increasing W content. Strong UC luminescence at 527, 548 and 662 nm is seen under an excitation of 980 nm for an optimum W content (x = 0.06) and is attributed to the transitions {sup 2}H{sub 11/2} →{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} →{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} →{sup 4}I{sub 15/2} respectively. The improved UC luminescence is ascribed to the reduced defects such as oxygen vacancies and change in the crystal field around Er{sup 3+} ions due to B-site (Ti{sup 4+}) substitution with W{sup 6+} ions. Enhanced UC emission is observed for an optimum content of w{sup 6+} in the prepared composition Bi{sub 3.79}Er{sub 0.03}Yb{sub 0.18}Ti{sub 3-x}W{sub x}O{sub 12} for x = 0.06.

Specific heat of the chiral-soliton-lattice phase in Yb(Ni0.94Cu0.06)3Al9

Science.gov (United States)

Ninomiya, Hiroki; Sato, Takaaki; Inoue, Katsuya; Ohara, Shigeo

2018-05-01

We have studied the monoaxial-chiral helimagnet YbNi3Al9 and its-substituted analogue Yb(Ni0.94Cu0.06)3Al9. These compounds belong to a chiral space group R32. In Yb(Ni0.94Cu0.06)3Al9 with the magnetic ordering temperature TM = 6.4 K , only when the magnetic field is applied perpendicular to the helical axis, the chiral soliton lattice is observed below Hc = 10 kOe . YbNi3Al9 with TM = 3.4 K exhibits a metamagnetic transition at Hc = 1 kOe in 2 K. To study the formation of chiral helimagnetic state and chiral soliton lattice, we have measured the specific heat in magnetic fields applied parallel and perpendicular to the helical axis. In zero field, with decreasing temperature, specific heat shows λ-type phase transition from paramagnetic state to chiral helimagnetic one. At the temperature where the chiral soliton lattice emerges, we have found that the specific heat shows a sharp peak. In addition, at around the crossover between paramagnetic state and forced-ferromagnetic one, a broad maximum has been observed. We have determined the magnetic phase diagrams of YbNi3Al9 and Yb(Ni0.94Cu0.06)3Al9.

Spectroscopic properties and energy levels of Yb{sup 3+} ion in huntite structure

Energy Technology Data Exchange (ETDEWEB)

Malakhovskii, A.V. [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation)], E-mail: malakha@iph.krasn.ru; Sukhachev, A.L. [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Gnatchenko, S.L.; Kachur, I.S.; Piryatinskaya, V.G. [B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, 61103 Kharkov (Ukraine); Temerov, V.L.; Krylov, A.S.; Edelman, I.S. [L.V. Kirensky Institute of Physics, Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation)

2009-05-12

Temperature dependence of Yb{sup 3+} optical absorption spectrum has been studied in crystals Yb{sub x}Tm{sub 1-x}Al{sub 3}(BO{sub 3}){sub 4} (x = 0.1, 0.2 and 1) in the temperature range 1.7-293 K. The spectra of the crystals appeared to be practically identical for the studied ytterbium concentrations. Raman scattering spectrum of YbAl{sub 3}(BO{sub 3}){sub 4} crystal has been measured. Group theory analysis of the optical absorption spectra is made, and new energy structure of the ground and excited states of Yb{sup 3+} ion, based on the experimental data obtained, is presented. Transformation of the local environment of Yb{sup 3+} ion depending on temperature has been found out. Spectrum of luminescence has been calculated from the absorption spectrum by reciprocity method with the use of the proposed energy structure.

K-shell absorption jump factors and jump ratios in elements between Tm ( Z = 69) and Os ( Z = 76) derived from new mass attenuation coefficient measurements

Science.gov (United States)

Kaya, Necati; Tıraşoğlu, Engin; Apaydın, Gökhan; Aylıkcı, Volkan; Cengiz, Erhan

2007-08-01

The K-shell absorption jump factors and jump ratios were derived from new mass attenuation coefficients measured using an energy dispersive X-ray fluorescence (EDXRF) spectrometer for Tm, Yb elements being Tm 2O 3, Yb 2O 3 compounds and pure Lu, Hf, Ta, W, Re and Os. The measurements, in the region 56-77 keV, were done in a transmission geometry utilizing the K α1 , K α2 , K β1 and K β2 X- rays from different secondary source targets (Yb, Ta, Os, W, Re and Ir, etc.) excited by the 123.6 keV γ-photons from an 57Co annular source and detected by an Ultra-LEGe solid state detector with a resolution of 150 eV at 5.9 keV. Experimental results have been compared with theoretically calculated values. The measured values of Tm, Yb, Lu, Hf, Ta, W, Re and Os are reported here for the first time.

K-shell absorption jump factors and jump ratios in elements between Tm (Z = 69) and Os (Z = 76) derived from new mass attenuation coefficient measurements

International Nuclear Information System (INIS)

Kaya, Necati; Tirasoglu, Engin; Apaydin, Goekhan; Aylikci, Volkan; Cengiz, Erhan

2007-01-01

The K-shell absorption jump factors and jump ratios were derived from new mass attenuation coefficients measured using an energy dispersive X-ray fluorescence (EDXRF) spectrometer for Tm, Yb elements being Tm 2 O 3 , Yb 2 O 3 compounds and pure Lu, Hf, Ta, W, Re and Os. The measurements, in the region 56-77 keV, were done in a transmission geometry utilizing the K α1 , K α2 , K β1 and K β2 X- rays from different secondary source targets (Yb, Ta, Os, W, Re and Ir, etc.) excited by the 123.6 keV γ-photons from an 57 Co annular source and detected by an Ultra-LEGe solid state detector with a resolution of 150 eV at 5.9 keV. Experimental results have been compared with theoretically calculated values. The measured values of Tm, Yb, Lu, Hf, Ta, W, Re and Os are reported here for the first time

Magnetism of cyano-bridged Ln3+-M3+ complexes. Part II: one-dimensional complexes (Ln3+ = Eu, Tb, Dy, Ho, Er, Tm; M3+ = Fe or Co) with bpy as blocking ligand.

Science.gov (United States)

Figuerola, Albert; Ribas, Joan; Casanova, David; Maestro, Miguel; Alvarez, Santiago; Diaz, Carmen

2005-10-03

The reaction of Ln(NO3)3(aq) with K3[Fe(CN)6] or K3[Co(CN)6] and 2,2'-bipyridine in water/ethanol led to 13 one-dimensional complexes: trans-[M(CN)4(mu-CN)2Ln(H2O)4(bpy)]n.4nH2O.1.5nbpy (Ln = Eu3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Lu3+; M = Fe3+, Co3+). The structures for [EuFe]n (1), [TbFe]n (2), [DyFe]n (3), [HoFe]n (4), [ErFe]n (5), [TmFe]n (6), [LuFe]n (7), [EuCo]n (8), [TbCo]n (9), [DyCo]n (10), [HoCo]n (11), [ErCo]n (12), and [TmCo]n (13) have been solved: they crystallize in the triclinic space group P and are isomorphous. They exhibit a supramolecular architecture created by the interplay of coordinative, hydrogen bonding, and pi-pi interactions. A stereochemical study of the eight-vertex polyhedra of the lanthanide ions, based on continuous shape measures, is presented. The Ln3+-Fe3+ interaction is antiferromagnetic in [DyFe]n and [TbFe]n. For [EuFe]n, [HoFe]n, [ErFe]n, and [TmFe]n, there is no sign of any significant interaction. The magnetic behavior of [DyFe]n suggests the onset of weak long-range ferromagnetic ordering at 2.5 K.

Fingermark detection on non-porous and semi-porous surfaces using NaYF4:Er,Yb up-converter particles.

Science.gov (United States)

Ma, Rongliang; Bullock, Elicia; Maynard, Philip; Reedy, Brian; Shimmon, Ronald; Lennard, Chris; Roux, Claude; McDonagh, Andrew

2011-04-15

This article describes the first use of an anti-Stokes material, or up-converter, for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes materials can absorb long-wavelength light and emit light at a shorter wavelength. This property is unusual in both natural and artificial materials and so fingermark detection techniques based on anti-Stokes luminescence are potentially sensitive and selective. Latent fingermarks on luminescent and non-luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with sodium yttrium tetrafluoride doped with erbium and ytterbium (NaYF(4):Er,Yb) by dry powder, wet powder, and cyanoacrylate staining techniques. This study illustrates the potential of up-converter phosphors for the detection of latent fingermarks. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Critical evaluation and thermodynamic optimisation of the Si-RE systems: Part II. Si-RE system (RE = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y)

International Nuclear Information System (INIS)

Kim, Junghwan; Jung, In-Ho

2015-01-01

Highlights: • The (Si-RE) (RE = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y) systems have been reviewed. • The thermodynamic optimization of the (Si-RE) systems have been performed. • Systematic changes and similarities in the (Si-RE) systems were found. • The systematic approach resolved inconsistencies in the experimental data. • The systematic approach was used to assess the unexplored phase diagrams. - Abstract: A critical evaluation and optimisation of all available phase diagrams and thermodynamic data of the (Si-RE) (RE = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y) systems was conducted to obtain reliable thermodynamic functions of all the phases in the system. In the thermodynamic modelling, a systematic analysis involving the similarity and periodicity observed in the lanthanide series was applied to resolve inconsistencies in the experimental data and to estimate the unknown thermodynamic properties and phase equilibria data. In particular, the phase diagrams and thermodynamic properties of (Si-Tm) and (Si-Lu) systems which are rarely investigated can be predicted from this approach. Systematic trends in thermodynamic properties of solid and liquid phases and phase diagram of the entire (Si-RE) systems were summarized

Miljøundersøgelser ved Kvanefjeldet 2001

DEFF Research Database (Denmark)

Asmund, G.

jordarter' (La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu) Af de mange grundstoffer, der er undersøgt er det kun 'Sjældne jordarter', zirkonium, niobium og thorium, der viser forhøjelser i forhold til baggrundsværdier og samtidigt er stærkt forhøjede i det vand, der siver ud fra minen. Imidlertid fandtes denne...

Near-barrier Fusion Evaporation and Fission of 28Si+174Yb and 32S+170Er

Science.gov (United States)

Wang, Dongxi; Lin, Chengjian; Jia, Huiming; Ma, Nanru; Sun, Lijie; Xu, Xinxing; Yang, Lei; Yang, Feng; Zhang, Huanqiao; Bao, Pengfei

2017-11-01

Fusion evaporation residues and fission fragments have been measured, respectively, at energies around the Coulomb barrier for the 28Si+174Yb and 32S+170Er systems forming the same compound nucleus 202Po. The excitation function of fusion evaporation, fission as well as capture reactions were deduced. Coupled-channels analyses reveal that couplings to the deformations of targets and the two-phonon states of projectiles contribute much to the enhancement of capture cross sections at sub-barrier energies. The mass and total kinetic energy of fission fragments were deduced by the time-difference method assuming full momentum transfer in a two-body kinematics. The mass-energy and mass-angle distributions were obtained and no obvious quasi-fission components were observed in this bombarding energy range. Further, mass distributions of fission fragments were fitted to extract their widths. Results show that the mass widths decrease monotonically with decreasing energy, but might start to increase when Ec.m./VB < 0.95 for both systems.

Accurate thermometry based on the red and green fluorescence intensity ratio in NaYF4: Yb, Er nanocrystals for bioapplication.

Science.gov (United States)

Liu, Lixin; Qin, Feng; Lv, Tianquan; Zhang, Zhiguo; Cao, Wenwu

2016-10-15

A biological temperature measurement method based on the fluorescence intensity ratio (FIR) was developed to reduce uncertainty. The upconversion luminescence of NaYF4:Yb, Er nanocrystals was studied as a function of temperature around the physiologically relevant range of 300-330 K. We found that the green-green FIR Fe and red-green FIR (I660/I540) varied linearly as temperature increased. The thermometric uncertainties using the two FIRs were discussed and were determined to be almost constant at 0.6 and 0.09 K for green-green and red-green, respectively. The lower thermometric uncertainty comes from the intense signal-to-noise ratio of the measured FIRs owing to their comparable fluorescence intensities.

Neutron scattering study on R{sub 2}PdSi{sub 3} (R=Ho,Er,Tm) compounds

Energy Technology Data Exchange (ETDEWEB)

Tang, Fei

2010-12-14

Previous studies on the family of inter-metallic rare-earth compounds R{sub 2}PdSi{sub 3} revealed multifaceted magnetic properties, for instance, spin-glass like behavior. Experimental observations include: Signs of a crystallographic superstructure, complicated magnetic structures both in zero field and in applied magnetic fields as well as a generic phase in applied fields for compounds in the series with the heavy rare-earths R=Gd, Tb, Dy, Ho, Er and Tm. This thesis expands the studies on the magnetic properties of R{sub 2}PdSi{sub 3} employing mainly neutron scattering on single crystals with the focus on the compounds with R=Ho, Er and Tm. A detailed analysis of the crystallographic superstructure using modulation wave approach and group theory is presented. The resulting structure implies the existence of two different rare-earth sites with reduced symmetry and an arrangement of the different sites according to sequences as determined by the superstructure. It is shown that the reduced symmetry of the rare-earth sites is explicitly observed in the energy spectra of inelastic neutron scattering. The results on the magnetic structures and excitations are shown and discussed in the framework of the superstructure model. Specifically the generic phase in applied fields is interpreted as a direct consequence of the crystallographic superstructure. It is rather unusual that a crystallographic superstructure is playing such a decisive, and through the field dependence also tunable role in determining the magnetic properties as observed in R{sub 2}PdSi{sub 3}. The mediating interactions between the crystallographic part and the magnetic part of the system are discussed. (orig.)

New strategies invonving upconverting nanoparticles for determining moderate temperatures by luminescence thermometry

Energy Technology Data Exchange (ETDEWEB)

Savchuk, Ol.A. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), c/Marcellí Domingo s/n E-43007, Tarragona (Spain); Carvajal, J.J., E-mail: joanjosep.carvajal@urv.cat [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), c/Marcellí Domingo s/n E-43007, Tarragona (Spain); Pujol, M.C.; Massons, J. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), c/Marcellí Domingo s/n E-43007, Tarragona (Spain); Haro-González, P. [Fluorescence Imaging Group, Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, E-28049 Madrid (Spain); Martínez, O.; Jiménez, J. [GdS-Optronlab, Departamento Física Materia Condensada, Universidad de Valladolid, Edificio I+D, Paseo de Belén 11, 47011 Valladolid (Spain); Aguiló, M.; Díaz, F. [Física i Cristallografia de Materials i Nanomaterials (FiCMA-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), c/Marcellí Domingo s/n E-43007, Tarragona (Spain)

2016-01-15

Here we analyze alternative luminescence thermometry techniques to FIR, such as intensity ratio luminescence thermometry between the emission arising from two electronic levels that are not necessarily thermally coupled, but that show different evolutions with temperature, and lifetime luminescence nanothermometry in (Ho,Tm,Yb):KLu(WO{sub 4}){sub 2} and (Er,Yb):NaY{sub 2}F{sub 5}O nanoparticles. (Ho,Tm,Yb):KLu(WO{sub 4}){sub 2} nanoparticles exhibited a maximum relative sensitivity of 0.61% K{sup −1}, similar to that achievable in Er-doped systems, which are the upconverting systems presenting the highest sensitivity. From another side, (Er,Yb):NaY{sub 2}F{sub 5}O nanocrystals show great potentiality as thermal sensors at the nanoscale for moderate temperatures due to the incorporation of additional non-radiative relaxation mechanisms that shorten the emission lifetime generated by the oxygen present in the structure when compared to (Er,Yb):NaYF{sub 4} nanoparticles exhibiting the highest upconversion efficiency. We used those nanoparticles for ex-vivo temperature determination by laser induced heating in chicken breast using lifetime-based thermometry. The results obtained indicate that these techniques might constitute alternatives to FIR with potential applications for the determination of moderate temperatures, with sensitivities comparable to those that can be achieved by FIR or even higher. - Highlights: • Other nanothermometry techniques than FIR proposed with upconversion nanoparticles. • Energy transfer between different lanthanide ions can be used for thermometry. • Lifetime measurements can constitute also a tool for temperature determination.

Transparent infrared-emitting CeF3:Yb-Er polymer nanocomposites for optical applications.

Science.gov (United States)

Tan, Mei Chee; Patil, Swanand D; Riman, Richard E

2010-07-01

Bright infrared-emitting nanocomposites of unmodified CeF(3):Yb-Er with polymethyl-methacrylate (PMMA) and polystyrene (PS), which offer a vast range of potential applications, which include optical amplifiers, waveguides, laser materials, and implantable medical devices, were developed. For the optical application of these nanocomposites, it is critical to obtain highly transparent composites to minimize absorption and scattering losses. Preparation of transparent composites typically requires powder processing approaches that include sophisticated particle size control, deagglomeration, and dispersion stabilization methods leading to an increase in process complexity and processing steps. This work seeks to prepare transparent composites with high solids loading (>5 vol%) by matching the refractive index of the inorganic particle with low cost polymers like PMMA and PS, so as to circumvent the use of any complex processing techniques or particle surface modification. PS nanocomposites were found to exhibit better transparency than the PMMA nanocomposites, especially at high solids loading (>/=10 vol%). It was found that the optical transparency of PMMA nanocomposites was more significantly affected by the increase in solids loading and inorganic particle size because of the larger refractive index mismatch of the PMMA nanocomposites compared to that of PS nanocomposites. Rayleigh scattering theory was used to provide a theoretical estimate of the scattering losses in these ceramic-polymer nanocomposites.

Upconversion luminescence and blackbody radiation in tetragonal YSZ co-doped with Tm(3+) and Yb(3+).

Science.gov (United States)

Soares, M R N; Ferro, M; Costa, F M; Monteiro, T

2015-12-21

Lanthanide doped inorganic nanoparticles with upconversion luminescence are of utmost importance for biomedical applications, solid state lighting and photovoltaics. In this work we studied the downshifted luminescence, upconversion luminescence (UCL) and blackbody radiation of tetragonal yttrium stabilized zirconia co-doped with Tm(3+) and Yb(3+) single crystals and nanoparticles produced by laser floating zone and laser ablation in liquids, respectively. The photoluminescence (PL) and PL excitation (PLE) were investigated at room temperature (RT). PL spectra exhibit the characteristic lines in UV, blue/green, red and NIR regions of the Tm(3+) (4f(12)) under resonant excitation into the high energy (2S+1)LJ multiplets. Under NIR excitation (980 nm), the samples placed in air display an intense NIR at ∼800 nm due to the (1)G4→(3)H5/(3)H4→(3)H6 transitions. Additionally, red, blue/green and ultraviolet UCL is observed arising from higher excited (1)G4 and (1)D2 multiplets. The power excitation dependence of the UCL intensity indicated that 2-3 low energy absorbed photons are involved in the UCL for low power levels, while for high powers, the identified saturation is dependent on the material size with a enhanced effect on the NPs. The temperature dependence of the UCL was investigated for single crystals and targets used in the ablation. An overall increase of the integrated intensity was found to occur between 12 K and the RT. The thermally activated process is described by activation energies of 10 meV and 30 meV for single crystals and targets, respectively. For the NPs, the UCL was found to be strongly sensitive to pressure conditions. Under vacuum conditions, instead of the narrow lines of the Tm(3+), a wide blackbody radiation was detected, responsible for the change in the emission colour from blue to orange. This phenomenon is totally reversible when the NPs are placed at ambient pressure. The UCL/blackbody radiation in the nanosized material exhibits

Use of ERS-2 Sar and Landsat TM Images for Geological Mapping and Mineral Exploration Of Sol Hamid Area, South Eastern Desert, Egypt

International Nuclear Information System (INIS)

Ramadan, T.M.

2003-01-01

Sol hamid area is chiefy occupied by neo proterozoic rocks, partly covered by miocene sediments and recent sand sheets and dunes. The neo proterozoic rocks include ophiolitic ultramafic to mafic rocks, meta volcano-sedimentary rocks, meta volcanics, gabbros-diorite rocks, granodiorites, biotite granites and alkali granites. Magnesite, chromite, iron ores, manganese and barite ore deposits are hosted in different at the study area. ERS-2 SAR data enabled to obtain an image that reveals some buried fluvial features beneath the surface cover of desert sand. These features are not observable in Landsat TM image of similar resolution. In this work, Principal Component Analysis (PCA) technique was used for merging ERS-2 SAR and Landsat TM images to make use of the potential of data fusion technique of image processing in the interpretation of geological features. This procedure has resulted in enhancing subsurface structure such as faults that control distribution of several deposits in the study area. This study represents an example to demonstrate the utility of merging various remote sensing data for exploring mineral deposits in arid region

Enhancement of the up-conversion luminescence from NaYF{sub 4}:Yb{sup 3+},Tb{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Hölsä, Jorma, E-mail: jholsa@utu.fi [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf), Turku (Finland); Universidade de São Paulo, Instituto de Química, São Paulo-SP (Brazil); Laihinen, Tero [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Laamanen, Taneli; Lastusaari, Mika [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf), Turku (Finland); Pihlgren, Laura [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Graduate School of Materials Research (GSMR), Turku (Finland); Rodrigues, Lucas C.V. [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Universidade de São Paulo, Instituto de Química, São Paulo-SP (Brazil); Soukka, Tero [University of Turku, Department of Biochemistry, FI-20014 Turku (Finland)

2014-04-15

The synthesis conditions of the Yb{sup 3+} and Tb{sup 3+} co-doped NaYF{sub 4} were optimized by reducing the number of washings to include only ethanol. The avoidance of the loss of amorphous NaF prior to post-annealing of the as-prepared materials resulted in the enhancement of the otherwise rather weak up-conversion from Tb{sup 3+} by 1–2 orders of magnitude. At the same time, the temperature of formation of the hexagonal NaRF{sub 4} phase with high up-conversion could be lowered by 100 °C down to 350 °C. This improvement in up-conversion was concluded to result from the better stoichiometry of the material without washing with water. The deficit of Na{sup +} would result in the excess of fluoride which, although not as fatal to the luminescence as the fluoride vacancies, has serious implications to the up-conversion intensity. A further enhancement in the up-conversion luminescence was observed to be due to the Er{sup 3+} ion impurity frequently associated with high-concentration Yb{sup 3+} materials. The mechanism involving the unintentional Er{sup 3+} sensitizer and the resonance energy transfer in the Yb{sup 3+}–Er{sup 3+}–Tb{sup 3+} co-doped NaYF{sub 4} were discussed based on the energy level schemes of the Yb{sup 3+}, Er{sup 3+}, and Tb{sup 3+} ions in NaYF{sub 4}.

Sol-Gel Derived Active Material for Yb Thin-Disk Lasers.

Science.gov (United States)

Almeida, Rui M; Ribeiro, Tiago; Santos, Luís F

2017-09-02

A ytterbium doped active material for thin-disk laser was developed based on aluminosilicate and phosphosilicate glass matrices containing up to 30 mol% YbO 1.5 . Thick films and bulk samples were prepared by sol-gel processing. The structural nature of the base material was assessed by X-ray diffraction and Raman spectroscopy and the film morphology was evidenced by scanning electron microscopy. The photoluminescence (PL) properties of different compositions, including emission spectra and lifetimes, were also studied. Er 3+ was used as an internal reference to compare the intensities of the Yb 3+ PL peaks at ~ 1020 nm. The Yb 3+ PL lifetimes were found to vary between 1.0 and 0.5 ms when the Yb concentration increased from 3 to 30 mol%. Based on a figure of merit, the best active material selected was the aluminosilicate glass composition 71 SiO₂-14 AlO 1.5 -15 YbO 1.5 (in mol%). An active disk, ~ 36 μm thick, consisting of a Bragg mirror, an aluminosilicate layer doped with 15 mol% Yb and an anti-reflective coating, was fabricated.

In-beam gamma spectroscopy of 155Tm

International Nuclear Information System (INIS)

Raut, R.; Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S.; Mukherjee, A.; Saha Sarkar, M.; Goswami, A.; Bhowal, S.; Ganguly, G.; Muralithar, S.; Singh, R.P.

2005-01-01

The observation of superdeformation in 154 Er has pronounced the possibility of observation of high spin phenomena in the neighbouring isotones. There has been a paucity of data on 155 Tm till day. The present work proposes to extend the level scheme of 155 Tm and thus established the systematics therein

Effects of Er{sup 3+} and Yb{sup 3+} doping on structural and non-linear optical properties of LiNaSO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Palmero, I.C. [Departamento de Fisica Basica, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Gonzalez-Silgo, C. [Departamento de Fisica Fundamental II, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Torres, M.E. [Departamento de Fisica Basica, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Marrero-Lopez, D. [Departamento de Quimica Inorganica, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Rivera-Lopez, Fernando [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain)], E-mail: frivera@ull.es; Haro-Gonzalez, P. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38200, San Cristobal de la Laguna, Santa Cruz de Tenerife (Spain); Solans, X. [Departament de Cristallografia, Universitat de Barcelona, E-08028, Barcelona (Spain)

2008-05-15

We have characterized LiNaSO{sub 4} crystals doped with rare earth (RE) (Er{sup 3+} and Yb{sup 3+}) to give new insights about their structural properties relations. The samples were analyzed by X-ray single crystal diffraction and differential thermal analysis. The non-centrosymmetry was confirmed second-harmonic generation. Inductively coupled plasma (ICP) and emission experiments confirmed the nominal concentrations of the REs. Crystallographic data and two empirical models were employed to understand the structural modifications by substitution of the Na site which reduces, monotonically, the non-linear optical coefficients and the temperature of the phase transition in these crystals.

Infrared to near-infrared and visible upconversion mechanisms in LiYF 4: Yb3+, Ho3+

NARCIS (Netherlands)

Martín-Rodríguez, R.; Meijerink, A.|info:eu-repo/dai/nl/075044986

2014-01-01

Upconversion materials have regained interest in recent years due to their potential to enhance the efficiency of solar cells. The research has focused on lanthanide based upconverters, especially Er3+- and Yb 3+-doped materials. In this paper we report Ho3+ and Yb3+ upconversion after excitation

Near infrared emission and multicolor tunability of enhanced upconversion emission from Er{sup 3+}–Yb{sup 3+} co-doped Nb{sub 2}O{sub 5} nanocrystals embedded in silica-based nanocomposite and planar waveguides for photonics

Energy Technology Data Exchange (ETDEWEB)

Aquino, Felipe Thomaz [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo. Av. Bandeirantes, 3900, CEP 14040-901 Ribeirão Preto, SP (Brazil); Ferrari, Jefferson Luis [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo. Av. Bandeirantes, 3900, CEP 14040-901 Ribeirão Preto, SP (Brazil); Grupo de Pesquisa em Química de Materiais – (GPQM), Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João Del Rei, MG (Brazil); Maia, Lauro June Queiroz [Grupo Física de Materiais, Instituto de Física, Universidade Federal de Goiás, Campus II, C.P. 131, CEP 74001-970, Goiânia, GO (Brazil); Ribeiro, Sidney José Lima [Institute of Chemistry- São Paulo State University- UNESP, Araraquara, SP 14800-900 (Brazil); Ferrier, Alban [PSL Research University, Chimie ParisTech - CNRS, Institut de Recherche de Chimie Paris, 75005 Paris (France); Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France); and others

2016-02-15

This work reports on the Yb{sup 3+} ion addition effect on the near infrared emission and infrared-to-visible up conversion from planar waveguides based on Er{sup 3+}–Yb{sup 3+} co-doped Nb{sub 2}O{sub 5} nanocrystals embedded in SiO{sub 2}-based nanocomposite prepared by a sol–gel process with controlled crystallization in situ. Planar waveguides and xerogels containing Si/Nb molar ratio of 90:10 up to 50:50 were prepared. Spherical-like orthorhombic or monoclinic Nb{sub 2}O{sub 5} nanocrystals were grown in the amorphous SiO{sub 2}-based host depending on the niobium content and annealing temperature, resulting in transparent glass ceramics. Crystallization process was intensely affected by rare earth content increase. Enhancement and broadening of the NIR emission has been achieved depending on the rare earth content, niobium content and annealing temperature. Effective Yb{sup 3+}→Er{sup 3+} energy transfer and a high-intensity broad band emission in the near infrared region assigned to the Er{sup 3+} ions {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition, and longer {sup 4}I{sub 13/2} lifetimes were observed for samples containing orthorhombic Nb{sub 2}O{sub 5} nanocrystals. Intense green and red emissions were registered for all Er{sup 3+}–Yb{sup 3+} co-doped waveguides under 980 nm excitation, assigned to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2} (525 nm),{sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} (545nm) and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} (670 nm) transitions, respectively. Different relative green and red intensities emissions were observed, depending upon niobium oxide content and the laser power. Upconversion dynamics were determined by the photons number, evidencing that ESA or ETU mechanisms are probably occurring. The 1931 CIE chromaticity diagrams indicated interesting color tunability based on the waveguides composition and pump power. The nanocomposite waveguides are promising materials for photonic applications as optical amplifiers and

Effect of Gallium and Indium Co-Substituting on Upconversion Properties of Er/Yb:Yttrium Aluminum Garnet Powders Prepared by the Co-Precipitation Method.

Science.gov (United States)

Zhang, Wei; Liang, Yun-Ling; Hu, Zheng-Fa; Feng, Zu-Yong; Lun, Ma; Zhang, Xiu-ping; Sheng, Xia; Liu, Qian; Luo, Jie

2016-04-01

Gallium and Indium co-substituted Yb, Er:YAG was fabricated through the chemical co-precipitation method. The formation process and structure of the Ga3+ and In3+ substituted phosphor powders were characterized by the X-ray diffraction, thermo-gravimetry analyzer, infrared spectra, and X-ray photoelectron spectroscopy, and the effects of Ga3+ and In3+ concentration on the luminescence properties were investigated by spectrum. The results showed that the blue shift occurred after the substitution of Ga3+ and In3+ for Al3+ in matrix, and the intensity of emission spectrum was affected by the concentration of Ga3+ and In3+.

Crystal electric field splitting of R{sup 3+}-ions in pure and Co- and Cu-doped RNi{sub 2}B{sub 2}C (R=Ho, Er, Tm)

Energy Technology Data Exchange (ETDEWEB)

Gasser, U.; Allenspach, P.; Henggeler, W.; Zolliker, M.; Furrer, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

From the crystal-electric-field (CEF) splitting of the R{sup 3+}-ions, the CEF parameters of RNi{sub 2}B{sub 2}C (R=Ho, Er, Tm) were deduced. In order to get information about the influence of the variation of the density of states (DOS) at the Fermi level (E{sub F}), CEF spectroscopy measurements with Co- and Cu-doped ErNi{sub 2}B{sub 2}C-samples were performed. (author) 1 fig., 1 tab., 1 ref.

Multifunctional Optical Sensors for Nanomanometry and Nanothermometry: High-Pressure and High-Temperature Upconversion Luminescence of Lanthanide-Doped Phosphates-LaPO4/YPO4:Yb3+-Tm3.

Science.gov (United States)

Runowski, Marcin; Shyichuk, Andrii; Tymiński, Artur; Grzyb, Tomasz; Lavín, Víctor; Lis, Stefan

2018-05-23

Upconversion luminescence of nano-sized Yb 3+ and Tm 3+ codoped rare earth phosphates, that is, LaPO 4 and YPO 4 , has been investigated under high-pressure (HP, up to ∼25 GPa) and high-temperature (293-773 K) conditions. The pressure-dependent luminescence properties of the nanocrystals, that is, energy red shift of the band centroids, changes of the band ratios, shortening of upconversion lifetimes, and so forth, make the studied nanomaterials suitable for optical pressure sensing in nanomanometry. Furthermore, thanks to the large energy difference (∼1800 cm -1 ), the thermalized states of Tm 3+ ions are spectrally well-separated, providing high-temperature resolution, required in optical nanothermometry. The temperature of the system containing such active nanomaterials can be determined on the basis of the thermally induced changes of the Tm 3+ band ratio ( 3 F 2,3 → 3 H 6 / 3 H 4 → 3 H 6 ), observed in the emission spectra. The advantage of such upconverting optical sensors is the use of near-infrared light, which is highly penetrable for many materials. The investigated nanomanometers/nanothermometers have been successfully applied, as a proof-of-concept of a novel bimodal optical gauge, for the determination of the temperature of the heated system (473 K), which was simultaneously compressed under HP (1.5 and 5 GPa).

Hydrothermal synthesis, characterization and up/down-conversion luminescence of barium rare earth fluoride nanocrystals

International Nuclear Information System (INIS)

Jia, Li-Ping; Zhang, Qiang; Yan, Bing

2014-01-01

Graphical abstract: Lanthanide ions doped bare earth rare earth fluoride nanocrystals are synthesized by hydrothermal technology and characterized. The down/up-conversion luminescence of them are discussed. - Highlights: • Mixed hydrothermal system H 2 O–OA (EDA)–O-A(LO-A) is used for synthesis. • Barium rare earth fluoride nanocrystals are synthesized comprehensively. • Luminescence for down-conversion and up-conversion are obtained for these systems. - Abstract: Mixed hydrothermal system H 2 O–OA (EDA)–O-A(LO-A) is developed to synthesize barium rare earth fluorides nanocrystals (OA = oleylamine, EDA = ethylenediamine, O-A = oleic acid and LO-A = linoleic acid). They are presented as BaREF 5 (RE = Ce, Pr, Nd, Eu, Gd, Tb, Dy, Y, Tm, Lu) and Ba 2 REF 7 (RE = La, Sm, Ho, Er, Yb). The influence of reaction parameters (rare earth species, hydrothermal system and temperature) is checked on the phase and shape evolution of the fluoride nanocrystals. It is found that reaction time and temperature of these nanocrystals using EDA (180 °C, 6 h) is lower than those of them using OA (220 °C, 10 h). The photoluminescence properties of these fluorides activated by some rare earth ions (Nd 3+ , Eu 3+ , Tb 3+ ) are studied, and especially up-conversion luminescence of the four fluoride nanocrystal systems (Ba 2 LaF 7 :Yb, Tm(Er), Ba 2 REF 7 :Yb, Tm(Er) (RE = Gd, Y, Lu)) is observed

Synthesis and up-conversion white light emission of RE{sup 3+}-doped lutetium oxide nanocubes as a single compound

Energy Technology Data Exchange (ETDEWEB)

Hu Shanshan [School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yang Jun, E-mail: jyang@swu.edu.cn [School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Li Chunxia [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Lin Jun, E-mail: jlin@ciac.jl.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2012-04-16

Highlights: Black-Right-Pointing-Pointer Uniform and dispersive cubic precursor can be synthesized by sample hydrothermal process. Black-Right-Pointing-Pointer Hydrothermal precursor could transform to Lu{sub 2}O{sub 3}:RE{sup 3+} with its original cubic morphology. Black-Right-Pointing-Pointer Nearly equal intensities of blue, green, and red emissions under single 980 nm laser. Black-Right-Pointing-Pointer Lu{sub 2}O{sub 3}:RE{sup 3+} show bright white light emission, clearly visible to the naked eyes. Black-Right-Pointing-Pointer Chromaticity coordinate is very close to the standard equal energy white light illuminate. - Abstract: Uniform and dispersive Lu{sub 2}O{sub 3}:Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+} nanocubes have been successfully synthesized by hydrothermal process with subsequent calcination at 900 Degree-Sign C. The as-formed RE{sup 3+}-doped lutetium oxide precursor via the hydrothermal process, as a template, could transform to RE{sup 3+}-doped Lu{sub 2}O{sub 3} with their original cubic morphology and slight shrinkage in the size after post-annealing process. The formation mechanism for the lutetium oxide precursor cubes has been proposed. Under single wavelength diode laser excitation of 980 nm, the as-obtained Lu{sub 2}O{sub 3}:3%Yb{sup 3+}/0.5%Er{sup 3+}/0.3%Tm{sup 3+} nanocubes show nearly equal intensities of blue (Tm{sup 3+}: {sup 1}G{sub 4} {yields} {sup 3}H{sub 6}), green (Er{sup 3+}: ({sup 2}H{sub 11/2}, {sup 4}S{sub 3/2}) {yields} {sup 4}I{sub 15/2}), and red (Er{sup 3+}: {sup 4}F{sub 9/2} {yields} {sup 4}I{sub 15/2}) emissions, which produces bright white light emission, clearly visible to the naked eyes. The main pathways to populate the upper emitting states come from the energy-transfer processes from Yb{sup 3+} to Tm{sup 3+}/Er{sup 3+}, respectively. The chromaticity coordinate of the Lu{sub 2}O{sub 3}:3%Yb{sup 3+}/0.5%Er{sup 3+}/0.3%Tm{sup 3+} sample is calculated to be about x = 0.3403 and y = 0.3169, which falls exactly within the

Laser-diode-excited blue upconversion in Tm3+/Yb3+ -codoped TeO2-Ga2O3-R2O (R=Li, Na, K) glasses.

Science.gov (United States)

Zhao, Chun; Zhang, Qinyuan; Yang, Gangfeng; Jiang, Zhonghong

2008-01-01

This paper reports on intense blue upconversion in Tm(3+)/Yb(3+) codoped TeO(2)-Ga(2)O(3)-R(2)O(R=Li, Na, K) glasses upon excitation with commercial available laser diode (LD). Effects of alkali ions on the Raman spectra, thermal stability and spectroscopic properties of the tellurite-gallium glasses have also been investigated. Energy transfer and the involved upconversion mechanisms have been discussed. Intense blue upconversion emission centered at 476 nm along with a weak red emission at 650 nm has been observed upon excitation of 977 nm LD, assigned to the transitions of 1G4-->3H6, and 1G4-->3H4 and/or 3F(2,3)-->3H6 of Tm(3+), respectively. The blue upconversion intensity has a cubelike dependence on incident pump laser power, indicating a three-photon process. However, a quadratic dependence of the 476 nm upconversion intensity on the incident pump laser power has been observed when samples under excitation of 808 nm LD due to a two-photon absorption process. Enhanced upconversion luminescence have been observed with replacing K(+) for Na(+) and Li(+).

Structure-property relations in new fluorophosphate glasses singly- and co-doped with Er{sup 3+} and Yb{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Gonçalves, Tássia S.; Moreira Silva, Raphaell J.; Oliveira Junior, Marcos de; Ferrari, Cynthia R. [Physics Institute of São Carlos, University of São Paulo, São Carlos, SP 13566-590 (Brazil); Poirier, Gäel Y. [Science and Technology Institute, Federal University of Alfenas, Poços de Caldas, MG 37715-400 (Brazil); Eckert, Hellmut, E-mail: eckert@ifsc.usp.br [Physics Institute of São Carlos, University of São Paulo, São Carlos, SP 13566-590 (Brazil); Physical Chemistry Institute, Westfälische Wilhelms Universität Münster, Münster D-48149 (Germany); Camargo, Andrea S.S. de, E-mail: andreasc@ifsc.usp.br [Physics Institute of São Carlos, University of São Paulo, São Carlos, SP 13566-590 (Brazil)

2015-05-01

Rare earth (RE{sup 3+})-doped fluorophosphate glasses are among the most promising candidates for high-efficiency laser generation in the near-infrared spectral region. By proper choice of composition, these materials can combine the advantages of fluorides (low phonon energies, low refractive indices, extensive optical window, low hygroscopicity) and of oxides (high chemical and mechanical stability and high dopant solubility), resulting in enhancement of the RE{sup 3+} emissive properties. In this work, we present the synthesis and structural/spectroscopic investigation of new glasses with composition 25BaF{sub 2}25SrF{sub 2}(30-x)Al(PO{sub 3}){sub 3}xAlF{sub 3}(20-z)YF{sub 3}:zREF{sub 3}, where x = 20 or 15, RE = Er{sup 3+} and/or Yb{sup 3+}, z = 0.25–5.0 mol%. Results indicate considerable improvement of the emissive properties of both ions when compared to phosphate or even other fluorophosphate host compositions. Long excited state lifetimes (τ = 10 ms for the Er{sup 3+} level {sup 4}I{sub 13/2}, and τ = 1.3 ms for the Yb{sup 3+} level {sup 2}F{sub 5/2}) imply high fluorescence quantum efficiencies η (up to 85% for both ions). Structural characterization by Raman and multinuclear solid state NMR spectroscopies indicate that the metaphosphate-type chain structure of the Al(PO{sub 3}){sub 3} vitreous framework is partially depolymerized and dominated by Q{sup (0)} and Q{sup (1)} units crosslinked by six-coordinate Al species. As revealed by {sup 27}Al{"3"1P} rotational echo double resonance (REDOR) NMR results the average local aluminum environment of the x = 20 sample comprises 1.6 phosphate and 4.4 fluoride species. These results indicate a clear bonding preference between aluminum and phosphorus, which is consistent with the desired dominance of fluoride species in the local environment of the rare earth and alkaline earth atoms in these glasses. - Highlights: • New fluorophosphate glass composition with excellent photophysical properties. �

Comparative study on upconversion luminescence and temperature sensing of α- and β-NaYF{sub 4}:Yb{sup 3+}/Er{sup 3+} nano-/micro-crystals derived from a microwave-assisted hydrothermal route

Energy Technology Data Exchange (ETDEWEB)

Tong, Lili [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Li, Xiangping, E-mail: lixp@dlmu.edu.cn [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Hua, Ruinian [College of Life Science, Dalian Nationalities University, Dalian 116600 (China); Li, Xuejing; Zheng, Hui; Sun, Jiashi; Zhang, Jinsu; Cheng, Lihong [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Chen, Baojiu, E-mail: chenmbj@sohu.com [Department of Physics, Dalian Maritime University, Dalian 116026 (China)

2015-11-15

Yb{sup 3+}/Er{sup 3+} co-doped α- and β-phase NaYF{sub 4} nano-/micro-crystals were prepared through a microwave-assisted hydrothermal route. The crystal structure and microscopic morphology of the samples were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Frequency upconverted emissions from the two thermally coupled excited state {sup 2}H{sub 11/2} and {sup 4}S{sub 3/2} levels of Er{sup 3+} in both phases of phosphors were recorded at temperatures ranging from room temperature to 573 K under 980 nm infrared laser excitation. The time scanning upconversion spectra were investigated in detail to reveal the thermal effect induced by laser irradiation and the luminescent thermal stability of the two phases NaYF{sub 4} polycrystals. Comparison of the upconversion luminescence and the sensitivity between the two phases NaYF{sub 4} polycrystals indicated that β-phase NaYF{sub 4} won much stronger luminescent intensity, better luminescent thermal stability, and higher temperature sensitivity. - Highlights: • Yb{sup 3+}/Er{sup 3+} codoped NaYF{sub 4} were prepared by a microwave-assisted hydrothermal route. • The UC luminescence and temperature sensing properties were studied. • Comparison of the UCL and the sensitivity between α- and β-phase samples were done. • Thermal effect and UCL thermo-stability were studied by time scanning UCL spectra. • β-phase sample won much better luminescent and temperature sensing properties.

Effect of various surfactants on changes in the emission color chromaticity in upconversion YVO4: Yb3+, Er3+ nanoparticles

Science.gov (United States)

Woźny, Przemysław; Szczeszak, Agata; Lis, Stefan

2018-02-01

YVO4: Yb3+,Er3+ upconverting nanocrystals were synthesized via a hydrothermal method using different compounds as surfactants. Structure and morphology of the nanocrystals were investigated by X-ray diffraction and transmission electron microscopy. Tetragonal crystal structure of the nanocrystals appeared irrespective of the type of surfactant used. The average crystallite size was estimated by TEM images. The obtained products were composed of small nanoparticles, in the size range of 10-60 nm, depending on the surfactant used. The morphology of the nanoparticles was also regulated by the type of surfactant. Spectroscopic analysis of the materials obtained was carried out by measuring the emission and excitation spectra and the intensity of luminescence as a function of laser energy and luminescence decays. The nanocrystals prepared exhibited a green upconversion emission attributed to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+, under NIR (985 nm) pulse laser irradiation, and their emission lifetimes were in the range 3.84-4.90 μs. On the basis of the spectroscopic investigation, the upconversion mechanism was proposed and chromaticity coordinates were calculated. Surfactants were found to influence on chromaticity of luminescence.

Structural relative stabilities and pressure-induced phase transitions for lanthanide trihydrides REH{sub 3} (RE=Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu)

Energy Technology Data Exchange (ETDEWEB)

Kong Bo, E-mail: kong79@yeah.net [National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Zhang Lin, E-mail: zhanglinbox@263.net [National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China); Chen Xiangrong [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Zeng Tixian [College of Physics and Electronic Information, China West Normal University, Nanchong 637002 (China); Cai Lingcang [National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China)

2012-06-15

The structures, structural relative stabilities, pressure-induced phase transitions, and equations of state for lanthanide trihydrides REH{sub 3} (RE=Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu) are systematically studied using ab initio calculations under a core state model (CSM). The obtained ground-state parameters, such as lattice constants and bulk modulus, agree well with the available data. Among the P6{sub 3}/mm, P3-bar c1, and P6{sub 3}cm structures, the P6{sub 3}cm structure is found to be the most stable structure for lanthanide trihydride via the comparison of the calculated total energies. With the help of Birch-Murnaghan equation of state, the structural transitions from hexagonal to cubic for REH{sub 3} (RE=Sm, Gd, Ho, Er, and Lu) under pressure are affirmed; especially, the similar behavior of REH{sub 3} (RE= Tb, Dy, and Tm) is reasonably predicted for the first time by this means. For the transitions, the repulsive interactions of H-H atoms may play an important role in terms of the analysis of the structures in the vicinity of the theoretical phase transition.

Magnetic anomaly in superconducting TmRh4B4

International Nuclear Information System (INIS)

Smith, J.L.; Huang, C.Y.; Tsou, J.J.; Ho, J.C.

1978-01-01

The magnetic and superconducting properties of TmRh 4 B 4 (which becomes superconducting at 9.6 K) by means of ac and dc magnetic susceptibility and specific heat measurements are investigated. At 10.7 K, an ac susceptibility peak similar to those found in spin glasses has been observed. In addition, a pronounced specific heat peak has been observed at 11.4 K. The susceptibility peak is essentially unaffected by substitution of 1% Lu or Er for the Tm, but it diminishes when much larger amounts of Er are substituted. The physical origin of this anomalous peak will be discussed

Enhancement of single particle rare earth doped NaYF4: Yb, Er emission with a gold shell

International Nuclear Information System (INIS)

Li, Ling; Green, Kory; Hallen, Hans; Lim, Shuang Fang

2015-01-01

Upconversion of infrared light to visible light has important implications for bioimaging. However, the small absorption cross-section of rare earth dopants has limited the efficiency of these anti-Stokes nanomaterials. We present enhanced excitation absorption and single particle fluorescent emission of sodium yttrium fluoride, NaYF 4 : Yb, Er based upconverting nanoparticles coated with a gold nanoshell through surface plasmon resonance. The single gold-shell coated nanoparticles show enhanced absorption in the near infrared, enhanced total emission intensity, and increased green relative to red emission. We also show differences in enhancement between single and aggregated gold shell nanoparticles. The surface plasmon resonance of the gold-shell coated nanoparticle is shown to be dependent on the shell thickness. In contrast to other reported results, our single particle experimental observations are corroborated by finite element calculations that show where the green/red emission enhancement occurs, and what portion of the enhancement is due to electromagnetic effects. We find that the excitation enhancement and green/red emission ratio enhancement occurs at the corners and edges of the doped emissive core. (paper)

Optical Amplification at 1525 nm in BaYF5: 20% Yb3+, 2% Er3+ Nanocrystals Doped SU-8 Polymer Waveguide

Directory of Open Access Journals (Sweden)

Pengcheng Zhao

2014-01-01

Full Text Available We demonstrated optical amplification in BaYF5: 20% Yb3+, 2% Er3+ (BYF nanocrystals doped polymer waveguide. BYF nanocrystals with an average size of ∼13 nm were synthesized by a high-boiling solvent process. Intense 1.53 μm fluorescence was obtained in the nanocrystals under excitation at 980 nm. An optical polymer waveguide was fabricated by using BYF nanocrystals doped SU-8 polymer as the core material. A relative optical gain of ∼10.4 dB at 1525 nm was achieved in a 1.1 cm long waveguide for an input signal power of ∼0.09 mW and a pump power of ∼212 mW.

Transport of NaYF4:Er3+, Yb3+ up-converting nanoparticles into HeLa cells

International Nuclear Information System (INIS)

Sikora, Bożena; Fronc, Krzysztof; Kamińska, Izabela; Wojciechowski, Tomasz; Sobczak, Kamil; Minikayev, Roman; Paszkowicz, Wojciech; Elbaum, Danek; Koper, Kamil; Stępień, Piotr; Szewczyk, Sebastian; Paterczyk, Bohdan

2013-01-01

An effective, simple and practically useful method to incorporate fluorescent nanoparticles inside live biological cells was developed. The internalization time and concentration dependence of a frequently used liposomal transfection factor (Lipofectamine 2000) was studied. A user friendly, one-step technique to obtain water and organic solvent soluble Er 3+ and Yb 3+ doped NaYF 4 nanoparticles coated with polyvinylpyrrolidone was obtained. Structural analysis of the nanoparticles confirmed the formation of nanocrystals of the desired sizes and spectral properties. The internalization of NaYF 4 nanoparticles in HeLa cervical cancer cells was determined at different nanoparticle concentrations and for incubation periods from 3 to 24 h. The images revealed a redistribution of nanoparticles inside the cell, which increases with incubation time and concentration levels, and depends on the presence of the transfection factor. The study identifies, for the first time, factors responsible for an effective endocytosis of the up-converting nanoparticles to HeLa cells. Thus, the method could be applied to investigate a wide range of future ‘smart’ theranostic agents. Nanoparticles incorporated into the liposomes appear to be very promising fluorescent probes for imaging real-time cellular dynamics. (paper)

Transport of NaYF4:Er3+, Yb3+ up-converting nanoparticles into HeLa cells

Science.gov (United States)

Sikora, Bożena; Fronc, Krzysztof; Kamińska, Izabela; Koper, Kamil; Szewczyk, Sebastian; Paterczyk, Bohdan; Wojciechowski, Tomasz; Sobczak, Kamil; Minikayev, Roman; Paszkowicz, Wojciech; Stępień, Piotr; Elbaum, Danek

2013-06-01

An effective, simple and practically useful method to incorporate fluorescent nanoparticles inside live biological cells was developed. The internalization time and concentration dependence of a frequently used liposomal transfection factor (Lipofectamine 2000) was studied. A user friendly, one-step technique to obtain water and organic solvent soluble Er3+ and Yb3+ doped NaYF4 nanoparticles coated with polyvinylpyrrolidone was obtained. Structural analysis of the nanoparticles confirmed the formation of nanocrystals of the desired sizes and spectral properties. The internalization of NaYF4 nanoparticles in HeLa cervical cancer cells was determined at different nanoparticle concentrations and for incubation periods from 3 to 24 h. The images revealed a redistribution of nanoparticles inside the cell, which increases with incubation time and concentration levels, and depends on the presence of the transfection factor. The study identifies, for the first time, factors responsible for an effective endocytosis of the up-converting nanoparticles to HeLa cells. Thus, the method could be applied to investigate a wide range of future ‘smart’ theranostic agents. Nanoparticles incorporated into the liposomes appear to be very promising fluorescent probes for imaging real-time cellular dynamics.

Lifetimes Measurements in 160Yb,162Yb,164Yb,166Yb,168Yb

International Nuclear Information System (INIS)

Araddad, S. Y.; El-barouni, A. M.; Rateb, G. M.; Mosbah, D. S.; Elahrash, M. S.; Sergiwa, S. M.

2004-01-01

From our measurements of the lifetimes of high spin states in 168 Yb along with the published lifetime data for the nearby even even ytterbium isotopes, 160-168 Yb using the Recoil Distance Method (RDM) and the Doppler Shift Attenuation Method (DSAM) present a great opportunity to probe systematically the relationship between the nuclear shape changes and the reduction in collectivity. (authors)

Color tunability in green, red and infra-red upconversion emission in Tm{sup 3+}/Yb{sup 3+}/Ho{sup 3+} co-doped CeO{sub 2} with potential application for improvement of efficiency in solar cells

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Luiz G.A.; Rocha, Leonardo A.; Buarque, Juliana M.M. [Laboratório de Materiais Inorgânicos Fotoluminescentes e Polímeros Biodegradáveis (LAFOP), Grupo de Pesquisa em Química de Materiais – (GPQM), Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João Del Rei, MG (Brazil); Gonçalves, Rogéria Rocha [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, USP, Av. Bandeirantes, 3900, 14040-901 Ribeirão Preto, SP (Brazil); Nascimento Jr, Clébio S. [Laboratório de Química Teórica e Computacional – (LQTC), Departamento de Ciências Naturais, Universidade Federal de São João del-Rei, Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João del-Rei, MG (Brazil); and others

2015-03-15

The preparation of Tm{sup 3+}/Yb{sup 3+}/Ho{sup 3+} co-doped CeO{sub 2} prepared by the precipitation method using ammonium hydroxide as a precursor is presented. By X-ray diffraction the materials show the phase-type of fluorite structure and the crystallite sizes were calculated by the Scherrer's equation. No other phase was observed evincing that the rare earth ions were inserted into the fluorite phase as substitutional or interstitial dopants. The microstrain calculated by the Williamson–Hall method do not show significant changes in their values, indicating that the inclusion of rare earths does not causes structural changes in the CeO{sub 2} used as a host matrix. All material showed intense upconversion emission at red and green region under excitation with diode laser at 980 nm. The color of emission changes from green to red with increasing excitation power pump. The materials showed suitable photoluminescent properties for applications as a laser source, solar cells, and great emitter at 800 nm. - Highlights: • Tm{sup 3+}/Yb{sup 3+}/Ho{sup 3+} co-doped CeO{sub 2} prepared by the simple way. • Intense upconversion emission regions and the tunability of emission color by the laser power pump. • The materials showed suitable photoluminescent properties for different applications.

Crystal fields in Sc, Y, and the heavy-rare-earth metals Tb, Dy, Ho, Er, Tm, and Lu

International Nuclear Information System (INIS)

Touborg, P.

1977-01-01

Experimental investigations of the magnetic poperties of dilute alloys of the rare-earth solutes Tb, Dy, Ho, Er, and Tm in the nonmagnetic hosts Lu, Y, and Sc have been performed. These measurements, which include and supplement earlier published results, have been analyzed and crystal-field parameters for all these 15 alloy systems deduced. The consistency of the parameters was confirmed by a variety of magnetic measurements, including neutron spectroscopy. Crystal-field parameters have also been derived for the ions in pure magnetic rare-earth metals and their alloys using the results for the dilute alloys supplemented with paramagnetic measurements up to high temperatures on the concentrated systems. Mean values and standard deviations of the higher-order crystal-field parameters for all Y and Lu alloys are B 40 /β = 6.8 +- 0.9 K, B 60 /γ = 13.6 +- 0.7 K, and B 66 /γ = (9.7 +- 1.1) B 60 /γ. These values: with the inaccuracies somewhat increased: are expected to be representative also for the magnetic rare-earth metals. For rare-earth ions in the Sc host the values B 40 /β = 9.9 +- 1.9 K, B 60 /γ = 19.8 +- 1.5 K, and B 66 /γ = (9.4 +- 0.9) B 60 /γ were deduced. B 20 /α is a host-sensitive parameter which has the average values of -102.7, -53.4, and 29.5 K for rare-earth ions in Y, Lu, and Sc, respectively. There is also evidence that this parameter varies with the solute. B 20 /α for ions in the pure magnetic rare-earth metals and their alloys shows a linear variation with c/a ratio characteristic of each ion. The results indicate a contribution from anisotropic exchange to the high-temperature paramagnetic anisotropy of approximately 20% for Tb, Dy, Ho, and Er, and approximately 10% for Tm

Emission bands of phosphorus and calculation of band structure of rare earth phosphides

International Nuclear Information System (INIS)

Al'perovich, G.I.; Gusatinskij, A.N.; Geguzin, I.I.; Blokhin, M.A.; Torbov, V.I.; Chukalin, V.I.; AN SSSR, Moscow. Inst. Novykh Khimicheskikh Problem)

1977-01-01

The method of x-ray emission spectroscopy has been used to investigate the electronic structure of monophosphides of rare-earth metals (REM). The fluorescence K bands of phosphorus have been obtained in LaP, PrP, SmP, GdP, TbP, DyP, HoP, ErP, TmP, YbP, and LuP and also the Lsub(2,3) bands of phosphorus in ErP, TmP, YbP, and LuP. Using the Green function technique involving the muffin-tin potential, the energy spectrum for ErP has been calculated in the single-electron approximation. The hystogram of electronic state distribution N(E) is compared with the experimental K and Lsub(2,3) bands of phosphorus in ErP. The agreement between the main details of N(E) and that of x-ray spectra allows to state that the model used provides a good description of the electron density distribution in crystals of REM monophosphides. In accordance with the character of the N(E) distribution the compounds under study are classified as semimetals or semiconductors with a very narrow forbidden band

The modulation of upconversion in BaTiO{sub 3}:Yb{sup 3+}, Er{sup 3+} inverse opal structures

Energy Technology Data Exchange (ETDEWEB)

Tan, Tianya; Han, Yazhou; Zhang, Chunyu; Ji, Yanan; Zhang, Fan; Chen, Qiang; Wang, Chun; Mei, Yong; Xu, Panfeng; Li, Lina [College of Physics, Liaoning University, Shenyang 110036 (China); Zhu, Yongsheng, E-mail: yongshengzhu0001@163.com [College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061 (China); Wang, Jiwei, E-mail: jiweiwang6688@yahoo.com [College of Physics, Liaoning University, Shenyang 110036 (China)

2017-03-15

Under 980 nm excitation, it is observed that green upconversion emission is suppressed whereas red emission is enhanced when the photonic band gap (PBG) covers the spectral region of green emission in the BaTiO{sub 3}: Yb{sup 3+}, Er{sup 3+} inverse opal structure. The investigation of the PBG effect on upconversion dynamics reveals that the population of the low level {sup 4}I{sub 13/2} is increased by both cross relaxation and energy back transfer processes when spontaneous emission of higher levels is suppressed. Then, following energy transfer or excited state absorption processes starting from {sup 4}I{sub 13/2}, the intensity of red emission is enhanced. The ratio of 525 nm versus 550 nm emission presents the temperature of samples when the PBG complete or absent covers the green emission band. However, the branching ratio deviates the temperature index in condition of a part of overlap between PBG and green emission band.

Up-converter nanophosphor Y2O2S:Er,Yb aminofunctionalized containing or not spherical silica conjugated with BSA

International Nuclear Information System (INIS)

Gelamos, Joao Paulo; Laranja, Marlon Larry; Alvino, Karla Cristina Lombardi; Camacho, Sabrina Alessio; Pires, Ana Maria

2009-01-01

This work reports on the study of the nanophosphor Y 2 O 2 S:Er(2%),Yb(1%) obtained from polymeric resin to be evaluated as fluorescent label with suitable features to conjugate with bio-molecules for bioassay up-converting phosphor technology (UPT) application. A conjugation protocol between bovine serum albumin (BSA) and the aminofunctionalized nanophosphor containing or not spherical silica was established. UV-vis results indicated an effective conjugation between nanophosphor particles and the protein. Up-conversion measurements under 980 nm excitation performed for samples before and after aminofunctionalization showed that nanophosphor particles luminescence features keep unchanged in all cases. All results suggest that the adapted protocol is feasible to provide a nanoparticle-protein effective conjugation preserving nanophosphor optical features. The presence of spherical silica can be considered advantageous to increase conjugation efficiency. Therefore, the developed procedure is applicable for future conjugations between the chosen nanophosphor and the streptavidin protein that takes part in the well known self-recognition system avidin-biotin.

Studies on up-gradation of Erbium from a heavy fraction of rare earths with EHEHPA

International Nuclear Information System (INIS)

Singh, D.K.; Anitha, M.; Yadav, K.K.; Kotekar, M.K.; Vijayalakshmi, R.; Singh, H.

2014-01-01

Erbium is an important heavy rare earth element, which finds wide applications. Recently, use of Erbium oxide as structural coating material in fusion reactor has stimulated the interest in obtaining Erbium in pure form. The separation of Erbium from other rare earths such as Dy, Ho, Y, Yb, Tm etc is very difficult due to low separation factor owing to their similar chemical properties. Additionally due to very low concentration ( 2 O 3 : 1.09, Dy 2 O 3 : 58.07, Er 2 O 3 : 22.0, Ho 2 O 3 : 13.33, Yb 2 O 3 : 4.74, Tm 2 O 3 :0.67 is obtained during purification of Y by Aliquat 336 from thiocyanate medium. In the present investigation this HRE fraction is taken as the feed material for up-gradation of Er by an acidic extractant namely 2 ethyl hexyl - 2 ethyl hexyl phosphonic acid (EHEHPA)

Judd-Ofelt analysis and temperature dependent upconversion luminescence of Er{sup 3+}/Yb{sup 3+} codoped Gd{sub 2}(MoO{sub 4}){sub 3} phosphor

Energy Technology Data Exchange (ETDEWEB)

Lu, Hongyu [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Gao, Yachen [College of Electronic Engineering, Heilongjiang University, Harbin 150080 (China); Hao, Haoyue; Shi, Guang [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Li, Dongyu [Department of Physics, Lingnan Normal University, Zhanjiang 524048 (China); Song, Yinglin [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Wang, Yuxiao, E-mail: wangyx@hit.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Zhang, Xueru, E-mail: xrzhang@hit.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China)

2017-06-15

Although lanthanide doped luminescent materials have been extensively investigated, a quantitative analysis of how temperature affects upconversion luminescence is still incomplete. The Gd{sub 2}(MoO{sub 4}){sub 3}:Er{sup 3+}/Yb{sup 3+} phosphor is synthetized by sol-gel method. Based on the absorption spectra of Er{sup 3+} ions, J-O intensity parameters and radiative transition probabilities are computed to estimate the optical properties. In view of ion-phonon interaction, the phonon-assisted energy transfer and multiphonon relaxation are responsible for the temperature dependent luminescence. Additionally, cross relaxation probability for {sup 4}I{sub 11/2}+{sup 4}I{sub 11/2}→{sup 4}I{sub 15/2}+{sup 4}F{sub 7/2} is determined to be 240 s{sup −1} through quantitative simulation of ion-ion interaction. These meaningful results are of vital values for the field of laser crystal and optical temperature sensing.

Development of solvent extraction process for erbium purification

International Nuclear Information System (INIS)

Singh, D.K.; Anitha, M.; Vijayalakshmi, R.; Chakravartty, J.K.

2016-01-01

Erbium an important heavy rare earth (HRE) finds valuable application in space and nuclear energy technology. High purity erbium oxide is used as coating material for test blanket module of fusion reactor to prevent the tritium permeation. The total concentration of HRE (including Er) in only proven resource of rare earths in Indian monazite mineral is < 0.05%. Its separation from such a low concentration and also from host of other chemically similar elements like Y, Dy, Ho, Yb, Tm etc is quite difficult and challenging. A solvent extraction process employing PC88A and Aliquat336 has been developed for the purification of erbium oxide from two types of HRE fractions having % composition; (i) Y 2 O 3 : 0.18, Tb 4 O 7 : 0.28, Dy 2 CO 2 : 47.07, Er 2 O 3 : 35.03, HO 2 O 3 : 10.11, Yb 2 O 3 : 5.88, Tm 2 O 3 : 1.43 and (ii) Dy 2 O 3 : 6.39, Er 2 O 3 : 49.43, HO 2 O 3 : 10.43, Tm 2 O 3 : 2.7, Y 2 O 3 : 24.08, Yb 2 O 3 : 6.96. PC88A was used to process low Y content concentrate from chloride medium whereas Aliquat336 was found to be suitable in thiocynate medium to treat the concentrate with high Y content. Effects of process variables such as acidity, extractant concentration, total oxide concentration in feed, number of stages, phase ratio, scrubbing agent were investigated for both the systems

NaGd(MoO4)2 nanocrystals with diverse morphologies: controlled synthesis, growth mechanism, photoluminescence and thermometric properties.

Science.gov (United States)

Li, Anming; Xu, Dekang; Lin, Hao; Yang, Shenghong; Shao, Yuanzhi; Zhang, Yueli

2016-08-10

Pure tetragonal phase, uniform and well-crystallized sodium gadolinium molybdate (NaGd(MoO4)2) nanocrystals with diverse morphologies, e.g. nanocylinders, nanocubes and square nanoplates have been selectively synthesized via oleic acid-mediated hydrothermal method. The phase, structure, morphology and composition of the as-synthesized products are studied. Contents of both sodium molybdate and oleic acid of the precursor solutions are found to affect the morphologies of the products significantly, and oleic acid plays a key role in the morphology-controlled synthesis of NaGd(MoO4)2 nanocrystals with diverse morphologies. Growth mechanism of NaGd(MoO4)2 nanocrystals is proposed based on time-dependent morphology evolution and X-ray diffraction analysis. Morphology-dependent down-shifting photoluminescence properties of NaGd(MoO4)2: Eu(3+) nanocrystals, and upconversion photoluminescence properties of NaGd(MoO4)2: Yb(3+)/Er(3+) and Yb(3+)/Tm(3+) nanoplates are investigated in detail. Charge transfer band in the down-shifting excitation spectra shows a slight blue-shift, and the luminescence intensities and lifetimes of Eu(3+) are decreased gradually with the morphology of the nanocrystals varying from nanocubes to thin square nanoplates. Upconversion energy transfer mechanisms of NaGd(MoO4)2: Yb(3+)/Er(3+), Yb(3+)/Tm(3+) nanoplates are proposed based on the energy level scheme and power dependence of upconversion emissions. Thermometric properties of NaGd(MoO4)2: Yb(3+)/Er(3+) nanoplates are investigated, and the maximum sensitivity is determined to be 0.01333 K(-1) at 285 K.

Near infrared emission of TbAG:Ce{sup 3+},Yb{sup 3+} phosphor for solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Meshram, N. D., E-mail: meshramnileshsd@gmail.com [Shri. Mathuradas Mohota College of Science, Sakkardara Square, Nagpur-440009 (India); Yadav, P. J., E-mail: yadav.pooja75@yahoo.in [Department of Electronics, Nagpur University campus, Nagpur-440010 (India); Pathak, A. A., E-mail: aapathak@yahoo.com [National power Training Institute, South ambazari road, Nagpur-440022 (India); Joshi, C. P., E-mail: charusheela-4253@yahoo.co.in [Ramdeobaba College of Engineering and Management, Katol road, Gittikhadan Nagpur-440012 (India); Moharil, S. V., E-mail: svmoharil@yahoo.com [Department of Physics, Nagpur University campus, Nagpur-440010 (India)

2016-05-06

Luminescent materials doped with rare earth ions are used for many devices such as optical amplifiers in telecommunication, phosphors for white light emitting diodes (LEDs), displays, and so on. Recently, they also have attracted a great interest for photovoltaic applications to improve solar cell efficiency by modifying solar spectrum. Crystal silicon (c-Si) solar cells most effectively convert photons of energy close to the semiconductor band gap. The mis-match between the incident solar spectrum and the spectral response of solar cells is one of the main reasons to limit the cell efficiency. The efficiency limit of the c-Si has been estimated to be 29% by Shockley and Queisser. However, this limit is estimated to be improved up to 38.4% by modifying the solar spectrum by a quantum cutting (down converting) phosphor which converts one photon of high energy into two photons of lower energy. The phenomenon such as the quantum cutting or the down conversion of rare earth ions have been investigated since Dexter reported the possibility of a luminescent quantum yield greater than unity in 1957. In the past, the quantum cutting from a vacuum ultraviolet photon to visible photons for Pr{sup 3+}, Gd{sup 3+},Gd{sup 3+}–Eu{sup 3+}, and Er{sup 3+}–Tb{sup 3+} had been studied. Recently, a new quantum cutting phenomenon from visible photon shorter than 500 nm to two infrared photons for Tb{sup 3+}–Yb{sup 3+}, Pr{sup 3+}–Yb{sup 3+}, and Tm{sup 3+}–Yb{sup 3+} has been reported. The Yb{sup 3+} ion is suitable as an acceptor and emitter because luminescent quantum efficiency of Yb{sup 3+} is close to 100% and the energy of the only excited level of Yb{sup 3+} (1.2 eV) is roughly in accordance with the band gap of Si (1.1 eV). In addition, the Ce{sup 3+}-doped Tb{sub 3}Al{sub 5}O{sub 12} (TbAG), used as a phosphor for white LED, has broad absorption bands in the range of 300–500 nm due to strong ligand field and high luminescent quantum efficiency. Therefore, the

Benefits of Silica Core-Shell Structures on the Temperature Sensing Properties of Er,Yb:GdVO4 Up-Conversion Nanoparticles.

Science.gov (United States)

Savchuk, Oleksandr A; Carvajal, Joan J; Cascales, C; Aguiló, M; Díaz, F

2016-03-23

We studied the temperature-dependent luminescence of GdVO4 nanoparticles co-doped with Er(3+) (1 mol %) and Yb(3+) (20 mol %) and determined their thermal sensing properties through the fluorescence intensity ratio (FIR) technique. We also analyzed how a silica coating, in a core-shell structure, affects the temperature sensing properties of this material. Spectra were recorded in the range of biological temperatures (298-343 K). The absolute sensitivity for temperature determination calculated for the core-shell nanoparticles is double the one calculated for bare nanoparticles, achieving a thermal resolution of 0.4 K. Moreover, silica-coated nanoparticles show good dispersibility in different solvents, such as water, DMSO, and methanol. Also, they show good luminescence stability without interactions with solvent molecules. Furthermore, we also observed that the silica coating shell prevents progressive heating of the nanoparticles during prolonged excitation periods with the 980 nm laser, preventing effects on their thermometric applications.

Novel fluorescence adjustable photonic crystal materials

Science.gov (United States)

Zhu, Cheng; Liu, Xiaoxia; Ni, Yaru; Fang, Jiaojiao; Fang, Liang; Lu, Chunhua; Xu, Zhongzi

2017-11-01

Novel photonic crystal materials (PCMs) with adjustable fluorescence were fabricated by distributing organic fluorescent powders of Yb0.2Er0.4Tm0.4(TTA)3Phen into the opal structures of self-assembled silica photonic crystals (PCs). Via removing the silica solution in a constant speed, PCs with controllable thicknesses and different periodic sizes were obtained on glass slides. Yb0.2Er0.4Tm0.4(TTA)3Phen powders were subsequently distributed into the opal structures. The structures and optical properties of the prepared PCMs were investigated. Finite-difference-time-domain (FDTD) calculation was used to further analyze the electric field distributions in PCs with different periodic sizes while the relation between periodic sizes and fluorescent spectra of PCMs was discussed. The results showed that the emission color of the PCMs under irradiation of 980 nm laser can be easily adjusted from green to blue by increasing the periodic size from 250 to 450 nm.

Spectroscopy and energy level location of the trivalent lanthanides in LiYP4O12

International Nuclear Information System (INIS)

Dorenbos, P.; Shalapska, T.; Stryganyuk, G.; Gektin, A.; Voloshinovskii, A.

2011-01-01

The excitation and emission properties of the lanthanides Ce 3+ , Pr 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Tb 3+ , Er 3+ , Tm 3+ , and Yb 3+ in LiYP 4 O 12 were studied by vacuum ultra-violet spectroscopy at 10 K. It provides information on the energies of 4f-5d excitation and emission bands. In the case of Er 3+ spin forbidden emission was observed. Charge transfer excitation bands were identified for Eu 3+ , Sm 3+ , Tm 3+ , and Yb 3+ , and in the case of Yb 3+ charge transfer luminescence is observed. All data appear to be consistent with each other and have been used to construct a level scheme showing the location of the energy levels of all trivalent and divalent lanthanides in LiYP 4 O 12 . - Research Highlights: → The spectroscopy of most of the trivalent lanthanides in LiYP 4 O 12 is presented for the first time. → Charge transfer luminescence of Yb3+ is reported. → We demonstrate that the energy of the first 4f-5d transition and the charge transfer band agree with predictive models. → For the first time a scheme with the location of all lanthanide states (divalent and trivalent ) w.r.t. de-valence and conduction band of LIP 4 O 12 is presented.

Luminescence properties of Tm3+ ions single-doped YF3 materials in an unconventional excitation region.

Science.gov (United States)

Chen, Yuan; Liu, Qing; Lin, Han; Yan, Xiaohong

2018-05-01

According to the spectral distribution of solar radiation at the earth's surface, under the excitation region of 1150 to 1350 nm, the up-conversion luminescence of Tm 3+ ions was investigated. The emission bands were matched well with the spectral response region of silicon solar cells, achieved by Tm 3+ ions single-doped yttrium fluoride (YF 3 ) phosphor, which was different from the conventional Tm 3+ /Yb 3+ ion couple co-doped materials. Additionally, the similar emission bands of Tm 3+ ions were achieved under excitation in the ultraviolet region. It is expected that via up-conversion and down-conversion routes, Tm 3+ -sensitized materials could convert photons to the desired wavelengths in order to reduce the energy loss of silicon solar cells, thereby enhancing the photovoltaic efficiency. Copyright © 2018 John Wiley & Sons, Ltd.

Evaluating the performance of the ORTECR DetectiveTM for emergency urine bioassay

International Nuclear Information System (INIS)

Li, C.; Ko, R.; Moodie, G.; Kramer, G. H.

2011-01-01

The performance of the ORTEC R Detective TM as a field deployable tool for emergency urine bioassay of 137 Cs, 60 Co, 192 Ir, 169 Yb and 75 Se was evaluated against ANSI N13.30. The tested activity levels represent 10 % RL (reference level) and 1 % RL defined by [Li C., Vlahovich S., Dai X., Richardson R. B., Daka J. N. and Kramer G. H. Requirements for radiation emergency urine bioassay techniques for the public and first responders. Health Phys (in press, 99(5), 702-707 (2010)]. The tests were conducted for both single radionuclide and mixed radionuclides at two geometries, one conventional geometry (CG) and one improved geometry (IG) which improved the MDAs (minimum detectable amounts) by a factor of 1.6-2.7. The most challenging radionuclide was 169 Yb. The measurement of the mixture radionuclides for 169 Yb at the CG did not satisfy the ANSI N13.30 requirements even at 10 % RL. At 1 % RL, 169 Yb and 192 Ir were not detectable at either geometry, while the measurement of 60 Co in the mixed radionuclides satisfied the ANSI N13.30 requirements only at the IG. (authors)

High-pressure synthesis and characterization of the effective pseudospin S =1 /2 XY pyrochlores R2P t2O7 (R =Er ,Yb )

Science.gov (United States)

Cai, Y. Q.; Cui, Q.; Li, X.; Dun, Z. L.; Ma, J.; dela Cruz, C.; Jiao, Y. Y.; Liao, J.; Sun, P. J.; Li, Y. Q.; Zhou, J. S.; Goodenough, J. B.; Zhou, H. D.; Cheng, J.-G.

2016-01-01

We report on the high-pressure syntheses and detailed characterizations of two effective pseudospin S =1 /2 XY pyrochlores E r2P t2O7 and Y b2P t2O7 via x-ray/neutron powder diffraction, dc and ac magnetic susceptibility, and specific-heat measurements down to 70 mK. We found that both compounds undergo long-range magnetic transitions at TN ,C≈0.3 K , which are ascribed to an antiferromagnetic- and ferromagnetic-type order for E r2P t2O7 and Y b2P t2O7 , respectively, based on the field dependence of their transition temperatures as well as the systematic comparisons with other similar pyrochlores R2B2O7 (R =Er ,Yb ;B =Sn ,Ti ,Ge ). The observed TN of E r2P t2O7 is much lower than that expected from the relationship of TN versus the ionic radius of B4 + derived from the series of E r2B2O7 , while the TC of Y b2P t2O7 is the highest among the series of ferromagnetic compounds Y b2B2O7 (B =Sn ,Pt ,Ti ). Given the monotonic variation of the lattice constant as a function of the B -cation size across these two series of R2B2O7 (R =Er ,Yb ), the observed anomalous values of TN ,C in the Pt-based XY pyrochlores imply that another important factor beyond the nearest-neighbor R -R distance is playing a role. In light of the anisotropic exchange interactions Jex={Jz z,J±,J±±,Jz ± } for the S =1 /2 XY pyrochlores, we have rationalized these observations by considering a weakened (enhanced) antiferromagnetic planar J± (ferromagnetic Ising-like Jz z) due to strong Pt 5 d -O 2 p hybridization within the plane perpendicular to the local [111] direction.

Transport and magnetic properties of new heavy-fermion antiferromagnet YbNi{sub 3}Al{sub 9}

Energy Technology Data Exchange (ETDEWEB)

Ohara, S; Yamashita, T; Mori, Y; Sakamoto, I, E-mail: ohara.shigeo@nitech.ac.jp [Department of Engineering Physics, Electronics and Mechanics, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

2011-01-01

We have synthesized a new Yb-based Kondo-lattice compound YbNi{sub 3}Al{sub 9}. This compound crystallizes in a trigonal ErNi{sub 3}Al{sub 9}-type structure (space group R32), in which the Yb-ion is arranged in a two-dimensional honey-comb lattice perpendicular to the c-axis. We report the first measurements of electrical resistivity and magnetization for single-crystalline samples of YbNi{sub 3}Al{sub 9}. The electrical resistivity of YbNi{sub 3}Al{sub 9} is characteristic of the typical properties of heavy-fermion antiferromagnets with a Neel temperature of T{sub N} = 3.4 K. The transport and magnetic properties exhibit large anisotropy in the low-temperature region owing to an interplay among the crystalline-electric-field effect, the Ruderman-Kittel-Kasuya-Yoshida interaction, and the Kondo effect. Below T{sub N}, the metamagnetic transition is observed at a very low magnetic field of around 1 kOe with the field applied along the a-axis. The magnetic structure of YbNi{sub 3}Al{sub 9} is highly sensitive to the applied magnetic field.

Luminescence of Er3+ doped double lead halide crystals under X-ray, UV, VIS and IR excitation

Science.gov (United States)

Serazetdinov, A. R.; Smirnov, A. A.; Pustovarov, V. A.; Isaenko, L. I.

2017-09-01

Er3+ doped double lead halide crystals incorporate a number of properties making them interesting for practical use in light conducting materials. X-ray excited luminescence (XRL) spectra, photoluminescence (PL) spectra in region of 1.5-3.5 eV, photoluminescence excitation (PLE) spectra (2.75-5 eV) and anti-stokes luminescence (ASL) spectra were measured at room temperature in KPb2Cl5 (KPC) and RbPb2Br5 (RPB) matrices doped with Er3+ (1%) ions and in KPC doped with Er3++ Yb3+ ions(1:3 ratio concentration). Intraconfigurational f→f transitions are observed in Er3+ ions in most of the cases. The concrete spectrum form is strongly dependent on the excitation energy. Under 980 nm excitation upper Er3+ levels are excited, showing upconversional processes. In case of 313 nm (UV) and 365 nm (VIS) excitation self trapped exciton luminescence was detected in RPB crystal. Additional Yb3+ doping ions strongly increase quantum yield under 980 nm excitation and this doping cause insignificant influence on quantum yield under VIS or UV excitation.

A modified energy transfer model for determination of upconversion emission of β-NaYF{sub 4}:Yb,Er: Role of self-quenching effect

Energy Technology Data Exchange (ETDEWEB)

Zhu, Hongyuan [The Key Laboratory of Biomedical Information Engineering, Ministry of Education, School of Life Science and Technology, Xi' an Jiaotong University, Xi’an 710049 (China); Bioinspired Engineering and Biomechanics Center (BEBC), Xi’an Jiaotong University, Xi’an 710049 (China); Lin, Min, E-mail: minlin@mail.xjtu.edu.cn [The Key Laboratory of Biomedical Information Engineering, Ministry of Education, School of Life Science and Technology, Xi' an Jiaotong University, Xi’an 710049 (China); Bioinspired Engineering and Biomechanics Center (BEBC), Xi’an Jiaotong University, Xi’an 710049 (China); Jin, Guorui [The Key Laboratory of Biomedical Information Engineering, Ministry of Education, School of Life Science and Technology, Xi' an Jiaotong University, Xi’an 710049 (China); Bioinspired Engineering and Biomechanics Center (BEBC), Xi’an Jiaotong University, Xi’an 710049 (China); Lu, Tian Jian [Bioinspired Engineering and Biomechanics Center (BEBC), Xi’an Jiaotong University, Xi’an 710049 (China); Xu, Feng [The Key Laboratory of Biomedical Information Engineering, Ministry of Education, School of Life Science and Technology, Xi' an Jiaotong University, Xi’an 710049 (China); Bioinspired Engineering and Biomechanics Center (BEBC), Xi’an Jiaotong University, Xi’an 710049 (China)

2017-05-15

A modified energy transfer model by incorporating self-quenching effect is introduced to determine upconversion emission of β-NaYF{sub 4}:Yb,Er. The simulation results agree well with existing experimental results, demonstrating the critical role of self-quenching effect in upconversion emission. Our results confirm that a 4.4-fold increase of green upconversion and 86-fold increase in the intensity of red upconversion emission could be realized by suppressing self-quenching. In addition, the optimal doping concentrations for integral emission intensity are found to be independent of excitation power, while the green to red ratio is found to rely significantly on excitation power. Our model offers mechanistic insight into upconversion emission processes and provides inspirations in improving upconversion emission efficiency through optimization of energy transfer pathways in different types of matrix sub-lattice.

Defects and color centers in SrTiD/sub 3/ monocrystals. [Pr, Nb Sm, Er, Tm additions

Energy Technology Data Exchange (ETDEWEB)

Kulagin, N A

1983-11-01

Results are presented of investigation into crystal defects of nominally pure and activated SrTiO/sub 3/ monocrystals. It is shown that blue and yellow colour of the crystals is caused bt transition of some Ti/sup 4 +/ ions to Ti/sup 3 +/ which takes place against the background of essential change in the phase composition of crystals. Ions of iron group (Cr, Fe, Co, Ni) in SrTiO/sub 3/ mainly form centres Me/sup 3 +/:(O/sup 2 -/)/sub 6/ with compensation of charge deficit by anion vacancies. Ti/sup 3 +/ ions serve as compensators at non-isovalent substitution for SrTiO/sub 3/:REI/sup 3 +/ (Pr, Nd, Er, Tm). It is shown that the presence of impurity in concentration up to 10/sup -1/ % does not affect the temperature of the phase transformation in the range of 106 K.

Absorption Spectra Of Rbcl:Yb Rbbr:Yb And Rbi:Yb Crystals ...

African Journals Online (AJOL)

Single crystals of rubidium chloride, bromide and iodide were doped with substitutional divalent ytterbium, Yb ions, by heating them in ytterbium atmosphere. The absorption spectra of the Yb doped crystals were measured at room and liquid nitrogen temperatures. The spectra were found to consist of intense broad ...

TmDOTA-tetraglycinate encapsulated liposomes as pH-sensitive LipoCEST agents.

Directory of Open Access Journals (Sweden)

Ana Christina L Opina

Full Text Available Lanthanide DOTA-tetraglycinate (LnDOTA-(gly₄⁻ complexes contain four magnetically equivalent amide protons that exchange with protons of bulk water. The rate of this base catalyzed exchange process has been measured using chemical exchange saturation transfer (CEST NMR techniques as a function of solution pH for various paramagnetic LnDOTA-(gly₄⁻ complexes to evaluate the effects of lanthanide ion size on this process. Complexes with Tb(III, Dy(III, Tm(III and Yb(III were chosen because these ions induce large hyperfine shifts in all ligand protons, including the exchanging amide protons. The magnitude of the amide proton CEST exchange signal differed for the four paramagnetic complexes in order, Yb>Tm>Tb>Dy. Although the Dy(III complex showed the largest hyperfine shift as expected, the combination of favorable chemical shift and amide proton CEST linewidth in the Tm(III complex was deemed most favorable for future in vivo applications where tissue magnetization effects can interfere. TmDOTA-(gly₄⁻ at various concentrations was encapsulated in the core interior of liposomes to yield lipoCEST particles for molecular imaging. The resulting nanoparticles showed less than 1% leakage of the agent from the interior over a range of temperatures and pH. The pH versus amide proton CEST curves differed for the free versus encapsulated agents over the acidic pH regions, consistent with a lower proton permeability across the liposomal bilayer for the encapsulated agent. Nevertheless, the resulting lipoCEST nanoparticles amplify the CEST sensitivity by a factor of ∼10⁴ compared to the free, un-encapsulated agent. Such pH sensitive nano-probes could prove useful for pH mapping of liposomes targeted to tumors.

Structure, photo- and triboluminescence of the lanthanoid dibenzoylmethanates: HNEt3[Ln(dbm)4

International Nuclear Information System (INIS)

Akerboom, Sebastiaan; Meijer, Michael S.; Siegler, Maxime A.; Fu, Wen Tian; Bouwman, Elisabeth

2014-01-01

A series of lanthanoid coordination compounds with the general formula HNEt 3 [Ln(dbm) 4 ] (Ln=La, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb; dbm=dibenzoylmethanate) has been prepared and characterized. In addition, single crystals with Ln=La, Nd and Sm were obtained. Single crystal X-ray diffraction studies reveal that the compounds with Ln=La and Nd crystallize in the P2 1 /c space group, while the Sm-compound crystallizes in the Pc space group. Based on powder XRD data, the compounds with Ln=Eu–Yb can be described with a monoclinic cell. Photoluminescence studies indicate that compounds with Ln=Sm and Eu exhibit bright photoluminescence characteristic of the lanthanoid ion upon excitation in the near UV range. Furthermore, HNEt 3 [Sm(dbm) 4 ] has been identified as a novel triboluminescent compound. -- Highlights: • The compounds HNEt 3 [Ln(dbm) 4 ], Ln=La, Nd, Sm, Eu, Tb, Dy, Ho Er, Tm, and Yb, have been prepared and their photophysical properties have been studied. • Crystal structures of HNEt 3 [La(dbm) 4 ], HNEt 3 [Nd(dbm) 4 ] and HNEt 3 [Sm(dbm) 4 ] are reported for the first time. • A novel, brightly triboluminescent Sm compound is reported

Spin re-orientation in heavy fermion system α - YbAl1 - x FexB4

Science.gov (United States)

Wu, Shan; Broholm, C.; Kuga, K.; Suzuki, Shintaro; Nakatsuji, S.; Mourigal, M.; Stone, M.; Tian, Wei; Qiu, Y.; Rodriguez-Rivera, Jose

Non centro-symmetric α - YbAlB4 has a heavy Fermi liquid ground state and shares many characteristics with centro-symmetric β - YbAlB4 . Both isomorphs display intermediate valence, associated with a fluctuation scale of T0 = 200 K and a Kondo lattice scale of T* = 8 K. Unlike β - YbAlB4 , α - YbAlB4 is at the boundary of a transition from a Fermi liquid metallic state to an antiferromagnetic (AFM) insulating state, driven by Fe substitution of Al. Magnetization and specific heat measurements reveal two different antiferromagnetic phases with TN = 9 K and TN = 2 K for Fe concentration above and below x =0.07. We report single crystal neutron scattering experiments on Fe doped YbAlB4 with x =0.035 and x =0.125. While the ordering wave vector is identical, k -> = (1 , 0 , 0) , the spin orientation switches from c to a with increasing Fe concentration. This suggests different anisotropic hybridization between 4f and conduction electrons that we confirmed by determining the crystal field levels. Supported by DOE, BES through DE-FG02-08ER46544.

A near-infrared luminescent Mn2+-doped NaYF4:Yb,Tm/Fe3+ upconversion nanoparticles redox reaction system for the detection of GSH/Cys/AA.

Science.gov (United States)

Zhang, Liping; Ling, Bo; Wang, Lun; Chen, Hongqi

2017-09-01

An upconversion luminescence method was developed for the determination of glutathione (GSH), L-cysteine (Cys) or L-ascorbic acid (AA) based on redox reaction. We synthesized poly(acrylic acid) (PAA)-modified Mn 2+ -doped NaYF 4 :Yb,Tm upconversion nanoparticles (UCNPs), and the luminescence of these UCNPs was effectively quenched due to their carboxyl groups coordinating with Fe 3+ to form a UCNPs/Fe 3+ system. GSH, Cys or AA reduced Fe 3+ to Fe 2+ , which induced the luminescence recovery of the UCNPs. Under the optimized conditions, wide linear concentration ranges from 0.25-300μM for GSH, 0.5-875μM for Cys and 0.5-350μM for AA were found, and the detection limits (3S/K) were 0.2μM, 0.5μM and 0.2μM, respectively. Thus, the UCNPs/Fe 3+ system was successfully applied for sensing GSH, Cys or AA. Copyright © 2017 Elsevier B.V. All rights reserved.

Rare earth-rich cadmium compounds RE{sub 10}TCd{sub 3} (RE = Y, Tb, Dy, Ho, Er, Tm, Lu; T = Rh, Pd, Ir, Pt) with an ordered Co{sub 2}Al{sub 5}-type structure

Energy Technology Data Exchange (ETDEWEB)

Block, Theresa; Klenner, Steffen; Heletta, Lukas; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

2018-04-01

Eighteen new rare earth-rich intermetallic phases RE{sub 10}TCd{sub 3} (RE = Y, Tb, Dy, Ho, Er, Tm, Lu; T = Rh, Pd, Ir, Pt) were obtained by induction melting of the elements in sealed niobium ampoules followed by annealing in muffle furnaces. All samples were characterized by X-ray powder diffraction. The structures of four representatives were refined from single-crystal X-ray diffractometer data: ordered Co{sub 2}Al{sub 5} type, P6{sub 3}/mmc, a = 951.2(1), c = 962.9(2) pm, wR = 0.0460, 595 F{sup 2} values, 20 parameters for Er{sub 10}RhCd{sub 3}; a = 945.17(4), c = 943.33(4), wR = 0.0395, 582 F{sup 2} values, 21 parameters for Lu{sub 9.89}PdCd{sub 3.11}; a = 964.16(6), c = 974.93(6) pm, wR = 0.0463, 614 F{sup 2} values, 21 parameters for Y{sub 10}Ir{sub 1.09}Cd{sub 2.91}; a = 955.33(3), c = 974.56(3) pm, wR = 0.0508, 607 F{sup 2} values, 22 refined parameters for Dy{sub 9.92}IrCd{sub 3.08}. Refinements of the occupancy parameters revealed small homogeneity ranges resulting from RE/Cd, respectively T/Cd mixing. The basic building units of the RE{sub 10}TCd{sub 3} phases are transition metal-centered RE{sub 6} trigonal prisms (TP) that are condensed with double-pairs of empty RE{sub 6} octahedra via common triangular faces. A second type of rods is formed by slightly distorted RE3 rate at Cd{sub 6}RE{sub 6} icosahedra which are condensed via Cd{sub 3} triangular faces. The shortest interatomic distances occur for RE-T, compatible with strong covalent bonding interactions. Temperature dependent magnetic susceptibility measurements were performed for RE{sub 10}RhCd{sub 3} (RE = Dy-Tm, Lu), RE{sub 10}IrCd{sub 3} (RE = Er, Tm, Lu) and RE{sub 10}PtCd{sub 3} (RE = Y, Lu). While Y{sub 10}PtCd{sub 3} and Lu{sub 10}TCd{sub 3} (T = Rh, Ir, Pt) show Pauli paramagnetic behavior, the compounds containing paramagnetic rare earth elements show Curie-Weiss behavior (the experimental magnetic moments indicate stable trivalent RE{sup 3+}) and magnetic ordering at low temperatures

Synthesis and Characterization of Upconversion Fluorescent Yb3+, Er3+ Doped CsY2F7 Nano- and Microcrystals

Directory of Open Access Journals (Sweden)

Helmut Schäfer

2009-01-01

Full Text Available Cs Y2F7: 78%   Y3+, 20%   Yb3+, 2%   Er3+ nanocrystals with a mean diameter of approximately 8 nm were synthesized at   185°C in the high boiling organic solvent N-(2-hydroxyethyl-ethylenediamine (HEEDA using ammonium fluoride, the rare earth chlorides and a solution of caesium alkoxide of N-(2-hydroxyethyl-ethylenediamine in HEEDA. In parallel with this approach, a microwave assisted synthesis was carried out which forms nanocrystals of the same material, about 50 nm in size, in aqueous solution at 200∘C/8 bar starting from ammonium fluoride, the rare earth chlorides, and caesium fluoride. In case of the nanocrystals, derived from the HEEDA synthesis, TEM images reveal that the particles are separated but have a broad size distribution. Also an occurred heat-treatment of these nanocrystals (600∘C for 45 minutes led to bulk material which shows highly efficient light emission upon continuous wave (CW excitation at 978 nm. Besides the optical properties, the structure and the morphology of the three products were investigated by means of powder XRD and Rietveld method.

Spectral evidence for multi-pathway contribution to the upconversion pathway in NaYF4:Yb3+,Er3+ phosphors.

Science.gov (United States)

Cho, Youngho; Song, Si Won; Lim, Soo Yeong; Kim, Jae Hun; Park, Chan Ryang; Kim, Hyung Min

2017-03-08

Although upconversion phosphors have been widely used in nanomedicine, laser engineering, bioimaging, and solar cell technology, the upconversion luminescence mechanism of the phosphors has been fiercely debated. A comprehensive understanding of upconversion photophysics has been significantly impeded because the number of photons incorporated in the process in different competitive pathways could not be resolved. Few convincing results to estimate the contribution of each of the two-, three-, and four-photon channels of near-infrared (NIR) energy have been reported in yielding upconverted visible luminescence. In this study, we present the energy upconversion process occurring in NaYF 4 :Yb 3+ ,Er 3+ phosphors as a function of excitation frequency and power density. We investigated the upconversion mechanism of lanthanide phosphors by comparing UV/VIS one-photon excitation spectra and NIR multi-photon spectra. A detailed analysis of minor transitions in one-photon spectra and luminescence decay enables us to assign electronic origins of individual bands in multi-photon upconversion luminescence and provides characteristic transitions representing the corresponding upconversion channel. Furthermore, we estimated the quantitative contribution of multiple channels with respect to irradiation power and excitation energy.

Yb valence state in Yb{sub 5}Rh{sub 4}Ge{sub 10}

Energy Technology Data Exchange (ETDEWEB)

Sato, Hitoshi; Arita, Masashi; Shimada, Kenya; Namatame, Hirofumi; Taniguchi, Masaki [Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima (Japan); Utsumi, Yuki [Synchrotron SOLEIL, L' Orme des Merisiers, Gif-sur-Yvette (France); Katoh, Kenichi [Department of Applied Physics, National Defense Academy, Yokosuka (Japan); Mimura, Kojiro [Graduate School of Engineering, Osaka Prefecture University, Sakai (Japan); Ueda, Shigenori [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, Hyogo (Japan); Quantum Beam Unit, National Institute for Materials Science, Tsukuba (Japan); Yamaoka, Hitoshi [RIKEN SPring-8 Center, Hyogo (Japan); Rousuli, Awabaikeli [Graduate School of Science, Hiroshima University, Higashi-Hiroshima (Japan); Umeo, Kazunori [NBARD, Hiroshima University, Higashi-Hiroshima (Japan)

2017-06-15

Temperature- and pressure-dependent Yb valence state in Yb{sub 5}Rh{sub 4}Ge{sub 10} has been investigated by means of Yb 3d hard X-ray photoemission spectroscopy (HAXPES) and Yb L{sub 3} absorption spectroscopy (XAS). The mean Yb valence derived from the Yb 3d HAXPES is estimated to be ∝2.78 at 300 K and decreases to ∝2.74 at 20 K. On the other hand, the Yb valence deduced from the Yb L{sub 3} XAS at 300 K is almost constant with ∝2.81 in the pressure range between 9.2 and 34.7 GPa. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Security printing of covert quick response codes using upconverting nanoparticle inks

Science.gov (United States)

Meruga, Jeevan M.; Cross, William M.; May, P. Stanley; Luu, QuocAnh; Crawford, Grant A.; Kellar, Jon J.

2012-10-01

Counterfeiting costs governments and private industries billions of dollars annually due to loss of value in currency and other printed items. This research involves using lanthanide doped β-NaYF4 nanoparticles for security printing applications. Inks comprised of Yb3+/Er3+ and Yb3+/Tm3+ doped β-NaYF4 nanoparticles with oleic acid as the capping agent in toluene and methyl benzoate with poly(methyl methacrylate) (PMMA) as the binding agent were used to print quick response (QR) codes. The QR codes were made using an AutoCAD file and printed with Optomec direct-write aerosol jetting®. The printed QR codes are invisible under ambient lighting conditions, but are readable using a near-IR laser, and were successfully scanned using a smart phone. This research demonstrates that QR codes, which have been used primarily for information sharing applications, can also be used for security purposes. Higher levels of security were achieved by printing both green and blue upconverting inks, based on combinations of Er3+/Yb3+ and Tm3+/Yb3+, respectively, in a single QR code. The near-infrared (NIR)-to-visible upconversion luminescence properties of the two-ink QR codes were analyzed, including the influence of NIR excitation power density on perceived color, in term of the CIE 1931 chromaticity index. It was also shown that this security ink can be optimized for line width, thickness and stability on different substrates.

Security printing of covert quick response codes using upconverting nanoparticle inks

International Nuclear Information System (INIS)

Meruga, Jeevan M; Cross, William M; Crawford, Grant A; Kellar, Jon J; Stanley May, P; Luu, QuocAnh

2012-01-01

Counterfeiting costs governments and private industries billions of dollars annually due to loss of value in currency and other printed items. This research involves using lanthanide doped β-NaYF 4 nanoparticles for security printing applications. Inks comprised of Yb 3+ /Er 3+ and Yb 3+ /Tm 3+ doped β-NaYF 4 nanoparticles with oleic acid as the capping agent in toluene and methyl benzoate with poly(methyl methacrylate) (PMMA) as the binding agent were used to print quick response (QR) codes. The QR codes were made using an AutoCAD file and printed with Optomec direct-write aerosol jetting ® . The printed QR codes are invisible under ambient lighting conditions, but are readable using a near-IR laser, and were successfully scanned using a smart phone. This research demonstrates that QR codes, which have been used primarily for information sharing applications, can also be used for security purposes. Higher levels of security were achieved by printing both green and blue upconverting inks, based on combinations of Er 3+ /Yb 3+ and Tm 3+ /Yb 3+ , respectively, in a single QR code. The near-infrared (NIR)-to-visible upconversion luminescence properties of the two-ink QR codes were analyzed, including the influence of NIR excitation power density on perceived color, in term of the CIE 1931 chromaticity index. It was also shown that this security ink can be optimized for line width, thickness and stability on different substrates. (paper)

First principle studies of electronic and magnetic properties of Lanthanide-Gold (RAu) binary intermetallics

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Sardar [Center for Computational Materials Science, University of Malakand, Chakdara, 18800 Pakistan (Pakistan); Department of Chemistry, University of Malakand, Chakdara, 18800 Pakistan (Pakistan); Ahmad, Rashid, E-mail: rashmad@gmail.com [Center for Computational Materials Science, University of Malakand, Chakdara, 18800 Pakistan (Pakistan); Department of Chemistry, University of Malakand, Chakdara, 18800 Pakistan (Pakistan); Jalali-Asadabadi, S. [Department of Physics, Faculty of Sciences, University of Isfahan (UI), Hezar Gerib Avenue, Isfahan 81746-73441 (Iran, Islamic Republic of); Ali, Zahid [Center for Computational Materials Science, University of Malakand, Chakdara, 18800 Pakistan (Pakistan); Department of Physics, University of Malakand, Chakdara, 18800 Pakistan (Pakistan); Ahmad, Iftikhar [Center for Computational Materials Science, University of Malakand, Chakdara, 18800 Pakistan (Pakistan); Vice Chancellor, Abbott Abad University of Science and Technology, Abbott Abad (Pakistan)

2017-01-15

In this article we explore the electronic and magnetic properties of RAu intermetallics (R=Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) for the first time. These properties are calculated by using GGA, GGA+U and hybrid density functional theory (HF) approaches. Our calculations show that HF provides superior results, consistent to the experimentally reported data. The chemical bonding between rare-earth and gold atoms within these compounds are explained on the basis of spin dependent electronic clouds in different planes, which shows predominantly ionic and metallic nature between Au and R atoms. The Cohesive energies of RAu compounds show direct relation with the melting points. Spin-dependent electronic band structure demonstrates that all these compounds are metallic in nature. The magnetic studies show that HoAu and LuAu are stable in non-magnetic structure, PrAu is stable in ferromagnetic phase and CeAu, NdAu, SmAu, GdAu, TbAu, DyAu, ErAu, TmAu, YbAu are anti-ferromagnetic materials.

Crystal growth and spectroscopic characterization of Yb3+:LiTaO3

International Nuclear Information System (INIS)

Gruber, John B.; Allik, Toomas H.; Sardar, Dhiraj K.; Yow, Raylon M.; Scripsick, Michael; Wechsler, Barry

2006-01-01

Spectroscopic properties are presented for Yb 3+ incorporated into single crystals of LiTaO 3 grown by the top-seeded solution growth method. From an analysis of the absorption and fluorescence spectra, we are able to determine the Stark-level components of the 2 F 7/2 (the ground-state multiplet manifold) and the 2 F 5/2 (the excited-state multiplet manifold of Yb 3+ (4f 13 )). The room-temperature fluorescence lifetime of 2 F 5/2 is 678μs as measured on a thin sample to reduce possibilities for reabsorption. Spectral comparisons of Yb 3+ -doped LiTaO 3 and LiNbO 3 are drawn. The crystal-field splitting of Yb 3+ (4f 13 ) in both crystal hosts is modeled using a set of crystal-field splitting parameters, B nm , determined from a recent spectroscopic analysis of Er 3+ (4f 11 ) in LiNbO 3 . Without adjustment of the B nm parameters, the model predicts the Stark-level energy and the symmetry label for each level in reasonable agreement with the experimental values. Less photorefractive than its niobate cousin, LiTaO 3 has potential for use in numerous integrated electro-optical circuits and devices

Spectral shapes and a beta-gamma directional correlation in the beta decay of 172Tm (Jpi = 2-)

DEFF Research Database (Denmark)

Gregers Hansen, P.; Loft Nielsen, H.; Wilsky, K.

1966-01-01

The isotope 172Tm populates the 0+, 2+ and 4+ states of the 172Yb ground-state rotational band directly in beta decay. The shapes and intensities of the three beta groups have been measured by means of a six-gap magnetic spectrometer operated in coincidence with a Nal(Tl) crystal. The experimenta...

Structural morphology, upconversion luminescence and optical thermometric sensing behavior of Y2O3:Er(3+)/Yb(3+) nano-crystalline phosphor.

Science.gov (United States)

Joshi, C; Dwivedi, A; Rai, S B

2014-08-14

Infrared-to-visible upconverting rare earths Er(3+)/Yb(3+) co-doped Y2O3 nano-crystalline phosphor samples have been prepared by solution combustion method followed by post-heat treatment at higher temperatures. A slight increase in average crystallite size has been found on calcinations verified by X-ray analysis. Transmission electron microscopy (TEM) confirms the nano-crystalline nature of the as-prepared and calcinated samples. Fourier transform infrared (FTIR) analysis shows the structural changes in as-prepared and calcinated samples. Upconversion and downconversion emission recorded using 976 and 532 nm laser sources clearly demonstrates a better luminescence properties in the calcinated samples as compared to as-prepared sample. Upconversion emission has been quantified in terms of standard chromaticity diagram (CIE) showing a shift in overall upconversion emission of as-prepared and calcinated samples. Temperature sensing behaviour of this material has also been investigated by measurement of fluorescence intensity ratio (FIR) of various signals in green emission in the temperature range of 315 to 555 K under 976 nm laser excitation. Copyright © 2014 Elsevier B.V. All rights reserved.

Alloying of Yb-Cu and Yb-Ag utilizing liquid ammonia metal solutions of ytterbium

International Nuclear Information System (INIS)

Imamura, H.; Yoshimura, T.; Sakata, Y.

2003-01-01

In the course of the studies on preparation of novel compounds using the dissolution of Eu or Yb metals in liquid ammonia, the formation of Yb-Cu and Yb-Ag intermetallic films has been found. When Cu or Ag metal powders were placed in a reactor containing a solution of Yb metal in liquid ammonia, the dissolved Yb readily react with the Cu or Ag metal particles to form surface alloy compounds. X-ray diffraction of Yb-Cu showed that upon thermal treatment above 673 K, the Yb metal deposited on the Cu particles reacted together to be transformed into the YbCu 6.5 intermetallic compound. A characteristic endothermic peak at 749 K, due to alloying of Yb-Cu, was observed by the differential scanning calorimeter measurements. By use of the high reactivity of liquid ammonia metal solutions of ytterbium, it was found that the ytterbium intermetallic films were readily formed under mild conditions. Yb-Cu and Yb-Ag exhibited enhanced catalytic activity for the hydrogenation of ethene as a result of alloying

Synthesis of Halide- and Solvent free metal borohydrides

DEFF Research Database (Denmark)

Grinderslev, Jakob; Møller, Kasper Trans; Jensen, Torben René

chloride or LiBH4 is present in the sample. The synthesis pathway has been shown to work for most of the already known metal borohydrides, M = Na, Ca, Sr, Ba, Y, La, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, but also new borohydrides are formed, M = Pr, Nd and Lu. Besides new compounds, new polymorphs...

Thermal stability of LiNaR2F8 compounds (R=Ho-Lu, Y)

International Nuclear Information System (INIS)

Fedorov, P.P.; Medvedeva, L.V.; Bondareva, O.S.; Sobolev, B.P.

1990-01-01

Monoclinic pseudorhombic compound mentioned in the title are investigated. It is determined, that the compounds are stable within temperature narrow range: Ho - 575-693 degC, Er - 566-712deg C, Tm - 560-710 deg C, Yb - less than 685 deg C, Y - 580-712 deg C. Triangulation of LiF-NaF-YF 3 system is carried out

Contribution for study on positron annihilation in tris (dipivaloilmethanates) lanthanides (III)

International Nuclear Information System (INIS)

Ribeiro e Silva, M.E.S.

1988-01-01

Some data on life time of positron and annihilation by Doppler effect in tris (dipivaloilmethanates) lanthanides (III), Ln (dpm) 3 , and Ln = Eu, Gd, Dy, Ho, Er, Tm and Yb are shown. Some results from positronium (Ps) in complexes except Eu (dpm) 3 , chemical aspects and properties of positron and positronium are evaluated. (M.J.C.) [pt

Synthesis of Multicolor Core/Shell NaLuF4:Yb3+/Ln3+@CaF2 Upconversion Nanocrystals

Directory of Open Access Journals (Sweden)

Hui Li

2017-02-01

Full Text Available The ability to synthesize high-quality hierarchical core/shell nanocrystals from an efficient host lattice is important to realize efficacious photon upconversion for applications ranging from bioimaging to solar cells. Here, we describe a strategy to fabricate multicolor core @ shell α-NaLuF4:Yb3+/Ln3+@CaF2 (Ln = Er, Ho, Tm upconversion nanocrystals (UCNCs based on the newly established host lattice of sodium lutetium fluoride (NaLuF4. We exploited the liquid-solid-solution method to synthesize the NaLuF4 core of pure cubic phase and the thermal decomposition approach to expitaxially grow the calcium fluoride (CaF2 shell onto the core UCNCs, yielding cubic core/shell nanocrystals with a size of 15.6 ± 1.2 nm (the core ~9 ± 0.9 nm, the shell ~3.3 ± 0.3 nm. We showed that those core/shell UCNCs could emit activator-defined multicolor emissions up to about 772 times more efficient than the core nanocrystals due to effective suppression of surface-related quenching effects. Our results provide a new paradigm on heterogeneous core/shell structure for enhanced multicolor upconversion photoluminescence from colloidal nanocrystals.

Spectroscopic analysis of LiTmF4

DEFF Research Database (Denmark)

Christensen, H.P.

1979-01-01

The absorption spectra of Tm3+ in LiTmF4 have been measured at 2, 10, 30, and 50 K in the spectral interval 4000-25 000 cm-1. The energy levels of the ground-state configuration were calculated by diagonalizing the Hamiltonian of the electron-electron interaction, the spin-orbit coupling......+, and Er3+ in LiLnF4, and they follow a common trend. The intensities of the transitions from the ground state were calculated in the Judd-Ofelt scheme, fitting six complex intensity parameters A(kqλ) for best agreement with the experimentally observed intensities. The model was only able to give a rough...

Core/shell structured NaYF4:Yb3+/Er3+/Gd+3 nanorods with Au nanoparticles or shells for flexible amorphous silicon solar cells

International Nuclear Information System (INIS)

Li, Z Q; Li, X D; Liu, Q Q; Chen, X H; Sun, Z; Huang, S M; Liu, C; Ye, X J

2012-01-01

A simple approach for preparing near-infrared (NIR) to visible upconversion (UC) NaYF 4 :Yb/Er/Gd nanorods in combination with gold nanostructures has been reported. The grown UC nanomaterials with Au nanostructures have been applied to flexible amorphous silicon solar cells on the steel substrates to investigate their responses to sub-bandgap infrared irradiation. Photocurrent–voltage measurements were performed on the solar cells. It was demonstrated that UC of NIR light led to a 16-fold to 72-fold improvement of the short-circuit current under 980 nm illumination compared to a cell without upconverters. A maximum current of 1.16 mA was obtained for the cell using UC nanorods coated with Au nanoparticles under 980 nm laser illumination. This result corresponds to an external quantum efficiency of 0.14% of the solar cell. Mechanisms of erbium luminescence in the grown UC nanorods were analyzed and discussed. (paper)

Study of the decay scheme of 159Tm

International Nuclear Information System (INIS)

Aguer, Pierre; Bastin, Genevieve; Chin Fan Liang; Libert, Jean; Paris, Pierre; Peghaire, Alain

1975-01-01

The energy levels of 159 Er have been investigated from the decay of 159 Tm (T(1/2)=9mn). Samples were obtained by (p,xn) reaction and on-line separation through Isocele facility. A level scheme is proposed with 24 levels between 0 and 1.3MeV [fr

Sirt3-Mediated Autophagy Contributes to Resveratrol-Induced Protection against ER Stress in HT22 Cells

Directory of Open Access Journals (Sweden)

Wen-Jun Yan

2018-02-01

Full Text Available Endoplasmic reticulum (ER stress occurring in stringent conditions is critically involved in neuronal survival and death. Resveratrol is a non-flavonoid polyphenol that has neuroprotective effects against many neurological disorders. Here, we investigated the potential protective effects of resveratrol in an in vitro ER stress model mimicked by tunicamycin (TM treatment in neuronal HT22 cells. We found that TM dose-dependently decreased cell viability and increased apoptosis, which were both significantly attenuated by resveratrol treatment. Resveratrol markedly reduced the expression or activation of ER stress-associated factors, including GRP78, CHOP, and caspase-12. The results of immunocytochemistry and western blot showed that resveratrol promoted autophagy in TM-treated cells, as evidenced by increased LC3II puncta number, bcelin1 expression and LC3II/LC3I ratio. Pretreatment with the autophagy inhibitor chloroquine could reduce the protective effects of resveratrol. In addition, the expression of Sirt3 protein and its downstream enzyme activities were significantly increased in resveratrol-treated HT22 cells. To confirm the involvement of Sirt3-mediated mechanisms, siRNA transfection was used to knockdown Sirt3 expression in vitro. The results showed that downregulation of Sirt3 could partially prevented the autophagy and protection induced by resveratrol after TM treatment. Our study demonstrates a pivotal role of Sirt3-mediated autophagy in mediating resveratrol-induced protection against ER stress in vitro, and suggests the therapeutic values of resveratrol in ER stress-associated neuronal injury conditions.

TU-H-CAMPUS-TeP3-04: Probing the Dose Enhancement Due to a Clinically-Relevant Concentration of Gold Nanoparticles and Yb-169 Gamma Rays Using PRESAGE Dosimeters

Energy Technology Data Exchange (ETDEWEB)

Cho, J [UT MD Anderson Cancer Center, Houston, TX (United States); Oklahoma State University, Stillwater, OK (United States); Alqathami, M; Cho, S [UT MD Anderson Cancer Center, Houston, TX (United States); Reynoso, F [UT MD Anderson Cancer Center, Houston, TX (United States); Washington University School of Medicine, St. Louis, MO (United States)

2016-06-15

Purpose: To probe physical evidences of the dose enhancement due to a low/clinically-relevant concentration of gold nanoparticles (GNPs) and Yb-169 gamma rays using PRESAGE dosimeters. Methods: A PRESAGE cuvette was placed at approximately 2 mm above the plane containing three novel Yb-169 brachytherapy seeds (3.2, 3.2, and 5.3 mCi each). Two types of PRESAGE dosimeters were used – plain PRESAGEs (controls) and PRESAGEs loaded with 0.02 wt. % of GNPs (GNP-PRESAGEs). Each PRESAGE dosimeter was irradiated with different time durations (0 to 24 hours) to deliver 0, 4, 8, 16 and 24 Gy of dose. For a reference/comparison, both types of PRESAGEs were also irradiated using 250 kVp x-rays with/without Er-filter to deliver 0, 3, 10, and 30 Gy of dose. Er-filter was used to emulate Yb-169 spectrum using 250 kVp x-rays. The absorption spectra of PRESAGEs were measured using a UV spectrophotometer and used to determine the corresponding optical densities (ODs). Results: GNP-PRESAGEs exposed to Yb-169 sources showed ∼65% increase in ODs compared with controls. When exposed to Er-filtered and unfiltered 250 kVp x-rays, they produced smaller increases in ODs, ∼41% and ∼37%, respectively. There was a linear relationship between ODs and delivered doses with a goodness-of-fit (R2) greater than 0.99. Conclusion: A notable increase in the ODs (∼65%) was observed for GNP-PRESAGEs irradiated by Yb-169 gamma rays. Considering the observed OD increases, it was highly likely that Yb-169 gamma rays were more effective than both Er-filtered and unfiltered 250 kVp x-rays, in terms of producing the dose enhancement. Due to several unknown factors (e.g., possible difference in the dose response of GNP-PRESAGEs vs. PRESAGEs), however, a further investigations is necessary to establish the feasibility of quantifying the exact amount of macroscopic or microscopic/local GNP-mediated dose enhancement using PRESAGE or similar volumetric dosimeters. Supported by DOD/PCRP grant W81XWH-12

Photosensitivity of the Er/Yb-Codoped Schott IOG1 Phosphate Glass Using 248 nm, Femtosecond, and Picosecond Laser Radiation

International Nuclear Information System (INIS)

Pissadakis, S.; Michelakaki, I.

2009-01-01

The effect of 248 nm laser radiation, with pulse duration of 5 picoseconds, 500 femtosecond, and 120 femtosecond, on the optical properties and the Knoop hardness of a commercial Er/Yb-codoped phosphate glass is presented here. Refractive index changes of the order of few parts of 10-4 are correlated with optical absorption centers induced in the glass volume, using Kramers-Kroning relationship. Accordingly, substantially lower refractive index changes are measured in volume Bragg gratings inscribed in the glass, indicating that, in addition to the optical density changes, volume dilation changes of negative sign may also be associated with the 248 nm ultrafast irradiation. The Knoop hardness experimental results reveal that the glass matrix undergoes an observable initial hardening and then a reversing softening and volume dilation process for modest accumulated energy doses, where the Knoop hardness follows a nonmonotonic trend. Comparative results on the Knoop hardness trend are also presented for the case of 193 nm excimer laser radiation. The above findings denote that the positive or negative evolution of refractive index changes induced by the 248 0nm ultrafast radiation in the glass is dominated by the counteraction of the color center formation and the volume modification effects.

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

Neutron diffraction studies of magnetic ordering in superconducting ErNi2B2C and TmNi2B2C in an applied magnetic field

DEFF Research Database (Denmark)

Toft, Katrine Nørgaard

The field-induced magnetic structures of ErNi2B2C and TmNi2B2C in are especially interesting because the field suppresses the superconducting order parameter and therefore the magnetic properties can be studied while varying the strength ofsuperconductivity. ErNi2B2C: For magnetic fields along all.......483,0,0). The appearance of the QN phase wasinitially believed to be caused by the suppression of superconductivity. This suppression should make it favorable to create a magnetic order with a Q-vector determined by the maximum in the magnetic susceptibility at the Fermi surface nesting vector QN.The phase diagram...... three symmetry directions, the observed magnetic structures have a period corresponding to the Fermi surface nesting structure. The phase diagrams present all the observed magnetic structures.Two results remain unresolved: 1. When applying the magnetic field along [010], the minority domain (QNB = (0,Q...

Electronic and crystal structure, EPR and magnetic investigations of YF{sub 3}:1%RE (RE = Pr, Ho, Er and Tm) and LaF{sub 3}:1%Pr nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Talik, E., E-mail: talik@us.edu.pl [Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice (Poland); Zajdel, P.; Guzik, A.; Skrzypek, D. [Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice (Poland); Lipińska, L.; Michalska, M. [Institute of Electronic Materials Technology, ul. Wólczyńska 133, 01-919 Warszawa (Poland)

2014-12-15

Highlights: • The thermal decomposition method was successfully applied for the first time in order to obtain the good quality nanocrystals of YF{sub 3}:1%RE. • For YF{sub 3}:1%Pr and LaF{sub 3}:1%Pr extra phase PrF{sub 3} was found. • The XPS energy gap is about 10 eV. • Surface contamination can be responsible for the deterioration of the optical properties of the composites. - Abstract: A new chemical synthesis route by a thermal decomposition of nitrates and acetates, preceded by solution displacement reaction, was successfully applied to obtain the YF{sub 3}:1%RE (RE = Pr, Ho, Er and Tm) and LaF{sub 3}:1%Pr nanocrystals. The samples were characterized by the following methods: X-ray diffraction, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), magnetic susceptibility thermal dependence measurements and electron paramagnetic resonance (EPR). The obtained YF{sub 3}:1%RE (RE = Pr, Ho, Er and Tm) materials crystallized with orthorhombic symmetry, whilst LaF{sub 3}:1%Pr exhibits hexagonal structure. Chemical composition determined by EDX, XPS and magnetic measurements was close to nominal formula. SEM images show the nanometric size of the grains. Surface contamination can be suggested to be responsible for the deterioration of the optical properties of the composites.

NIR-induced highly sensitive detection of latent finger-marks by NaYF4:Yb,Er upconversion nanoparticles in a dry powder state

Science.gov (United States)

Wang, Meng; Li, Ming; Yang, Mingying; Zhang, Xiaomei; Yu, Aoyang; Zhu, Ye; Qiu, Penghe; Mao, Chuanbin

2016-01-01

The most commonly found fingermarks at crime scenes are latent and, thus, an efficient method for detecting latent fingermarks is very important. However, traditional developing techniques have drawbacks such as low detection sensitivity, high background interference, complicated operation, and high toxicity. To tackle this challenge, we employed fluorescent NaYF4:Yb,Er upconversion nanoparticles (UCNPs), which can fluoresce visible light when excited by 980 nm human-safe near-infrared light, to stain the latent fingermarks on various substrate surfaces. The UCNPs were successfully used as a novel fluorescent label for the detection of latent fingermarks with high sensitivity, low background, high efficiency, and low toxicity on various substrates including non-infiltrating materials (glass, marble, aluminum alloy sheets, stainless steel sheets, aluminum foils, and plastic cards), semi-infiltrating materials (floor leathers, ceramic tiles, wood floor, and painted wood), and infiltrating materials such as various types of papers. This work shows that UCNPs are a versatile fluorescent label for the facile detection of fingermarks on virtually any material, enabling their practical applications in forensic sciences. PMID:27818741

tmRDB (tmRNA database)

DEFF Research Database (Denmark)

Zwieb, Christian; Gorodkin, Jan; Knudsen, Bjarne

2003-01-01

Maintained at the University of Texas Health Science Center at Tyler, Texas, the tmRNA database (tmRDB) is accessible at the URL http://psyche.uthct.edu/dbs/tmRDB/tmRDB.html with mirror sites located at Auburn University, Auburn, Alabama (http://www.ag.auburn.edu/mirror/tmRDB/) and the Bioinforma......Maintained at the University of Texas Health Science Center at Tyler, Texas, the tmRNA database (tmRDB) is accessible at the URL http://psyche.uthct.edu/dbs/tmRDB/tmRDB.html with mirror sites located at Auburn University, Auburn, Alabama (http......://www.ag.auburn.edu/mirror/tmRDB/) and the Bioinformatics Research Center, Aarhus, Denmark (http://www.bioinf.au.dk/tmRDB/). The tmRDB collects and distributes information relevant to the study of tmRNA. In trans-translation, this molecule combines properties of tRNA and mRNA and binds several proteins to form the tmRNP. Related RNPs are likely...

Beta-delayed proton activities: 147Dy and 149Er

International Nuclear Information System (INIS)

Toth, K.S.; Moltz, D.M.; Schloemer, E.C.; Cable, M.D.; Avignone, F.T. III; Ellis-Akovali, Y.A.

1984-01-01

The present paper discusses mainly the β-delayed proton spectra of 147 Dy and of the hitherto unknown isotope, 149 Er. However, following the submittal of the abstract for this conference we have now observed delayed protons following the decay of 145 Dy. Additionally, we have identified a 0.5-s delayed-proton emitter and tentatively assign it to the new isotope, 151 Yb

The new 157Tm isotope, Tsub(1/2)=(3.6+-0.3) min

International Nuclear Information System (INIS)

Latuszynski, A.; Mikulski, J.; Potempa, A.W.; Zielinski, A.; Zuber, K.; Penev, I.; Zuber, J.

1975-01-01

The new isotope 157 Tm was discovered, and its half-life Tsub(1/2) (3.6+-0.3)min was measured. On the basis of the balance of energies and intensities of γ-transitions occurring in the 157 Tm decay a number of excited states of the 157 Er nucleus with energies of 110.2; 241.3; 357.3 and 457.1 keV were found. (author)

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

The rare earth elements like La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and the heavy metals like Mg, V, Cr, Mn, Fe, Cu, Zn, U, Th were analysed by using standard analytical methods. The Post-Archean Australian Shale composition was used to normalise the rare earth elements. It was found that the sediments ...

Preparation, thermogravimetric study and infrared spectra of rare earth acetates

International Nuclear Information System (INIS)

Graehlert, X.; Starke, M.

1992-01-01

The anhydrous and the hydrated acetates of Ho, Er, Tm, Yb and Lu have been prepared. The compounds obtained have been investigated by thermogravimetric analysis and infrared spectroscopy. The thermal decomposition of the rare earth acetates may proceed via various steps. It depends on both the number of crystal water molecules in the acetates and the rare earth element's behaviour. (orig.)

Crystal Chemistry and Photocatalytic Properties of RE4S4Te3 (RE = Gd, Ho, Er, Tm): Experimental and Theoretical Investigations.

Science.gov (United States)

Chi, Yang; Rong, Liang-Zhen; Suen, Nian-Tzu; Xue, Huai-Guo; Guo, Sheng-Ping

2018-04-25

Reported are the synthesis and structural characterization of a new series of ternary rare-earth mix-chalcogenides RE 4 S 4 Te 3 (RE = Gd, Ho, Er, Tm) that have been obtained from high-temperature solid state reactions. These compounds crystallize in Ho 4 S 4 Te 2.68 structure types with monoclinic C2/ m and/or orthorhombic Immm space groups. The space group variation within this series is due to the position disorder along the Te plane (Te to TeA and TeB). The structural relationship and change between these two space groups are analyzed. It is realized that these compounds are all photocatalytic active under simulated sunlight. The trend of their photocatalytic activities and photocurrent responses is well-explained by using theoretical calculation as well as dipole moment analysis.

High-efficiency 2 μm Tm-doped fiber laser

International Nuclear Information System (INIS)

Dvornikov, D.

2013-01-01

Full text: Tm doped fiber laser operating in so called 'eye safe' wavelength region and designed in a MOPA configuration has been demonstrated. Large-mode-area fiber design and availability of high-brightness, high-power pump diodes at 795 nm made possible maximum output power of 25 W achieved at incident pump power of 72 W resulting in optical conversion efficiency about 35%. An important factor that led to an interest in 2 μm Tm-doped lasers is significantly broader spectral tunability of Tm-doped fibers compared to Yb-doped fibers, spanning wavelengths from below 1850 nm to beyond 2100 nm, corresponding to more than 200 nm of available bandwidth. This wavelength region covers the water absorption peaks around 1940 nm, making these lasers a valuable tool for precise medical procedures including noninvasive surgery, as well as several atmospheric transmission windows that are useful for remote sensing, laser radar and range-finding. This work was carried out as part of the EU funded Joint Operational Programme 'Black Sea Basin 2007-2013' and project 2.2.1.74459.339, MIS-ETC 1443 'Research networking for the environmental monitoring and mitigation of adverse ecological effects in the Black Sea Basin (BSB Net-Eco)'.

Investigation of chemical bond characteristics, thermal expansion coefficients and bulk moduli of alpha-R2MoO6 and R2Mo2O7 (R = rare earths) by using a dielectric chemical bond method.

Science.gov (United States)

Li, Huaiyong; Zhang, Siyuan; Zhou, Shihong; Cao, Xueqiang

2009-09-01

Theoretical researches are performed on the alpha-R2MoO6 (R = Y, Gd, Tb Dy, Ho, Er, Tm and Yb) and pyrochlore-type R2Mo2O7 (R = Y, Nd, Sm, Gd, Tb and Dy) rare earth molybdates by using chemical bond theory of dielectric description. The chemical bonding characteristics and their relationship with thermal expansion property and compressibility are explored. The calculated values of linear thermal expansion coefficient (LTEC) and bulk modulus agree well with the available experimental values. The calculations reveal that the LTECs and the bulk moduli do have linear relationship with the ionic radii of the lanthanides: the LTEC decreases from 6.80 to 6.62 10(-6)/K and the bulk modulus increases from 141 to 154 GPa when R goes in the order Gd, Tb Dy, Ho, Er, Tm, and Yb in the alpha-R2MoO6 series; while in the R2Mo2O7 series, the LTEC ranges from 6.80 to 6.61 10(-6)/K and the bulk modulus ranges from 147 to 163 GPa when R varies in the order Nd, Sm, Gd, Tb and Dy. Copyright 2008 Wiley Periodicals, Inc.

SU-E-T-359: Emulation of Yb-169 Gamma-Ray Spectrum Using Metal-Filtered 250 KVp X-Rays for Pre-Clinical Studies of Gold Nanoparticle-Aided Radiation Therapy

International Nuclear Information System (INIS)

Reynoso, F; Cho, S

2015-01-01

Purpose: To develop an external beam surrogate of the Yb-169 brachytherapy source applying a filter-based spectrum modulation technique to 250 kVp x-rays. In-vitro/vivo studies performed with the modulated 250 kVp beam will help gauge the benefits of implementing gold nanoparticle-aided radiotherapy with the Yb-169 source. Methods: A previously validated MCNP5 model of the Phillips RT-250 orthovoltage unit was used to obtain the percentage depth dose (PDD) and filtered photon spectra for a variety of filtration and irradiation conditions. Photon spectra were obtained using the average flux F4 tally in air right after all collimation. A 30 x 30 x 30 cm 3 water phantom was used to compute the PDD along the central axis (CAX) under the standards conditions of a 10 x 10 cm 2 field size at 50 cm SSD. Cylindrical cells of 4 cm in diameter and the energy deposition F6 tally were used along the CAX to score the doses down to 20 cm depth. The number of particle history was set to 2 x 10 8 in order to keep the relative uncertainty within each cell < 0.3%. The secondary electron spectrum within a gold-loaded tissue due to each photon spectrum was also calculated using EGSnrc and compared with that due to Yb-169 gamma rays. Results: Under the practical constraints for the spectrum modulation task, 250 kVp x-rays filtered by a 0.25 mm Erbium (Er) foil produced the best match with Yb-169 gamma rays, in terms of PDD and, more importantly, secondary electron spectrum. Conclusion: Modulation of 250kVp x-ray spectrum by an Er-filter was found effective in emulating the gamma ray spectrum of Yb-169. Possible benefits as predicted from the current MC model such as enhanced radiosensitization with the Er-filtered beam (as a surrogate of Yb-169) was confirmed with a separate in-vitro study. Supported by DOD/PCRP grant W81XWH-12-1-0198

Color-tunable up-conversion emission of luminescent-plasmonic, core/shell nanomaterials – KY{sub 3}F{sub 10}:Yb{sup 3+},Tm{sup 3+}/SiO{sub 2}-NH{sub 2}/Au

Energy Technology Data Exchange (ETDEWEB)

Runowski, Marcin, E-mail: runowski@amu.edu.pl

2017-06-15

Multifunctional luminescent-plasmonic KY{sub 3}F{sub 10}:Yb{sup 3+},Tm{sup 3+}/SiO{sub 2}-NH{sub 2}/Au nanomaterials were successfully obtained. The lanthanide-doped fluoride nanoparticles (NPs), synthesized under hydrothermal conditions exhibited bright blue up-conversion luminescence (λ{sub ex}=980 nm). Such lanthanide nanocrystals (20–40 nm) were coated with amine modified silica shell, forming core/shell nanostructures. Their surface was further uniformly covered with ultra-small gold NPs (4–7 nm). The as-prepared luminescent-plasmonic core/shell nanomaterials exhibited tunable up-conversion emission, due to the interactions between plasmonic and luminescent phases. The emission of Tm{sup 3+} ion was affected by the surface Au NPs, which exhibited strong plasmonic absorption in the visible range (450–650 nm). The increasing amount of the surface Au NPs, led to the significant alterations in a ratio of the Tm{sup 3+} emission bands. The NIR band ({sup 3}H{sub 4}→{sup 3}H{sub 6}) was unchanged, whereas the ratio and relative intensity of the bands in a visible range ({sup 1}G{sub 4}→{sup 3}H{sub 6} and {sup 1}G{sub 4}→{sup 3}F{sub 4}) was altered. This led to the significant change of the emission spectra shape and influenced color of emission, tuning it from bright blue to blue-violet. The products obtained were characterized by transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), powder X-ray diffraction (XRD), UV–vis absorption spectroscopy and luminescence spectroscopy (excitation/emission spectra and luminescence decay curves).

Enhanced green upconversion by controlled ceramization of Er3+–Yb3+ co-doped sodium niobium tellurite glass–ceramics for low temperature sensors

International Nuclear Information System (INIS)

Suresh Kumar, J.; Pavani, K.; Graça, M.P.F.; Soares, M.J.

2014-01-01

Highlights: • Upconversion luminescence improved in glass–ceramics compared to host glass. • Judd–Ofelt and radiative parameters calculated. • NIR decay curve results concur the results of improved luminescence. • Temperature dependent upconversion support the use of materials for sensors. - Abstract: Tellurite based glasses are well-known for their upconversion properties besides having a disadvantage of low mechanical strength dragging them away from practical applications. The present work deals with preparation of sodium niobium tellurite (SNT) glasses using melt quenching method, in which small quantities of boron and silicon in the form of oxides are added to improve their mechanical properties. Controlled heat treatment is performed to ceramize the prepared glasses based on the thermal data given by DTA. XRD and SEM profiles of the glass–ceramics which confirmed the formation of crystalline monoclinic Sodium Tellurium Niobium Oxide (Na 1.4 Nb 3 Te 4.9 O 18 ) phase (JCPDS card No. 04–011-7556). Upconversion measurements in the visible region were made for the prepared Er 3+ –Yb 3+ co-doped glasses and glass–ceramics with 980 nm laser excitation varying the laser power and concentration of Er 3+ ions. Results showed that the upconversion luminescence intensity was enhanced by ten times in SNT glass–ceramics compared to that in the SNT glasses. Decay curves give evidence of high performance of glass–ceramics compared to glasses due to ceramization and structural changes. Temperature dependent visible upconversion was performed to test the ability of efficient SNT glass–ceramic at low temperatures and variation of upconversion intensities was studied

Enhancement of Cerenkov luminescence imaging by dual excitation of Er(3+,Yb(3+-doped rare-earth microparticles.

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Xiaowei Ma

Full Text Available Cerenkov luminescence imaging (CLI has been successfully utilized in various fields of preclinical studies; however, CLI is challenging due to its weak luminescent intensity and insufficient penetration capability. Here, we report the design and synthesis of a type of rare-earth microparticles (REMPs, which can be dually excited by Cerenkov luminescence (CL resulting from the decay of radionuclides to enhance CLI in terms of intensity and penetration.Yb(3+- and Er(3+- codoped hexagonal NaYF4 hollow microtubes were synthesized via a hydrothermal route. The phase, morphology, and emission spectrum were confirmed for these REMPs by power X-ray diffraction (XRD, scanning electron microscopy (SEM, and spectrophotometry, respectively. A commercial CCD camera equipped with a series of optical filters was employed to quantify the intensity and spectrum of CLI from radionuclides. The enhancement of penetration was investigated by imaging studies of nylon phantoms and nude mouse pseudotumor models.the REMPs could be dually excited by CL at the wavelengths of 520 and 980 nm, and the emission peaks overlaid at 660 nm. This strategy approximately doubled the overall detectable intensity of CLI and extended its maximum penetration in nylon phantoms from 5 to 15 mm. The penetration study in living animals yielded similar results.this study demonstrated that CL can dually excite REMPs and that the overlaid emissions in the range of 660 nm could significantly enhance the penetration and intensity of CL. The proposed enhanced CLI strategy may have promising applications in the future.

Optical properties of Mg2+, Yb3+, and Ho3+ tri-doped LiNbO3 crystals

Science.gov (United States)

Dai, Li; Liu, Chun-Rui; Tan, Chao; Yan, Zhe-Hua; Xu, Yu-Heng

2017-04-01

A series of LiNbO3 crystals tri-doped with Mg{}2+, Yb{}3+, and Ho{}3+ are grown by the conventional Czochraski technique. The concentrations of Mg{}2+, Yb{}3+, and Ho{}3+ ions in Mg:Yb:Ho:LiNbO3 crystals are measured by using an inductively coupled plasma atomic emission spectrometry. The x-ray diffraction is proposed to determine the lattice constant and analyze the internal structure of the crystal. The light-induced scattering of Mg:Yb:Ho:LiNbO3 crystal is quantitatively described via the threshold effect of incident exposure energy flux. The exposure energy ({E}{{r}}) is calculated to discuss the optical damage resistance ability. The exposure energy of Mg(7 mol):Yb:Ho:LiNbO3 crystal is 709.17 J/cm2, approximately 425 times higher than that of the Mg(1 mol):Yb:Ho:LiNbO3 crystal in magnitude. The blue, red, and very intense green bands of Mg:Yb:Ho:LiNbO3 crystal are observed under the 980-nm laser excitation to evaluate the up-conversion emission properties. The dependence of the emission intensity on pumping power indicates that the up-conversion emission is a two-photon process. The up-conversion emission mechanism is discussed in detail. This study indicates that Mg:Yb:Ho:LiNbO3 crystal can be applied to the fabrication of new multifunctional photoluminescence devices. Project supported by the National Natural Science Foundation of China (Grant No. 51301055), the Youth Science Fund of Heilongjiang Province, China (Grant No. QC2015061), the Special Funds of Harbin Innovation Talents in Science and Technology Research, China (Grant No. 2015RQQXJ045 ), and the Science Funds for the Young Innovative Talents of Harbin University of Science and Technology, China (Grant No. 201501).

Comparative decay analysis of 179Re* and 189Au* formed in the reactions 20Ne+159Tb, 169Tm with Elab=8 MeV/A

International Nuclear Information System (INIS)

Manpreet Kaur; Singh, BirBikram

2016-01-01

The heavy ion induced reactions lead to the formation of composite systems, which subsequently decay because of high excitation energy and angular momentum. The study of decaying composite system facilitates to explore the number of nuclear characteristics and the reaction dynamics. The medium mass composite systems 164 Yb*, 176,182,188,196 Pt* and 200,202 Pb* have been studied successfully within the framework of dynamical cluster decay model (DCM). These studies show the emission of light particles, LP (or evaporation residues, ER), intermediate mass fragments, IMF, heavy mass fragments, HMF and symmetric fragments, SF along with signatures of quasi-fission, qf, process in their decay path. The decay of medium mass composite system 179 Re* has also been studied within DCM. In the present work, we investigate the comparative decay of two medium mass composite systems 179 Re* and 189 Au formed in the reactions with same projectile ( 20 Ne) having same E lab (or same E/A) on two different targets 159 Tb and 169 Tm, for which the experimental data is available

Thermodynamic properties of thulium and ytterbium in fused NaCl-KCl-CsCl eutectic

Energy Technology Data Exchange (ETDEWEB)

Novoselova, A., E-mail: A.Novoselova@ihte.uran.ru [Institute of High-Temperature Electrochemistry, Ural Division, Russian Academy of Science, S. Kovalevskaya Str., 22, Ekaterinburg 620990 (Russian Federation); Smolenski, V. [Institute of High-Temperature Electrochemistry, Ural Division, Russian Academy of Science, S. Kovalevskaya Str., 22, Ekaterinburg 620990 (Russian Federation)

2011-07-15

Research highlights: > Tm and Yb chloride compounds as fission products. > The investigation of electrochemical properties of lanthanides. > Determination of the apparent standard redox potentials of the couple Ln(III)/Ln(II) in fused NaCl-KCl-CsCl eutectic at (823 to 973) K. > The calculation of the basic thermodynamic properties of redox reaction in molten salt. - Abstract: This work presents the results of a study of the Tm{sup 3+}/Tm{sup 2+} and Yb{sup 3+}/Yb{sup 2+} couple redox potentials vs. Cl{sup -}/Cl{sub 2} reference electrode at the temperature range (823 to 973) K in fused NaCl-KCl-CsCl eutectic by direct potentiometric method. Initial concentrations of TmCl{sub 3} and YbCl{sub 3} in solvents did not exceed 5.0 mol%. Basic thermodynamic properties of the reactions TmCl{sub 2(l)} + 1/2 Cl{sub 2(g)} {r_reversible} TmCl{sub 3(l)} and YbCl{sub 2(l)} + 1/2 Cl{sub 2(g)} {r_reversible} YbCl{sub 3(l)} were calculated using the temperature dependencies of apparent standard potentials of the couples E{sub Tm{sup 3+}/Tm{sup 2+*}} and E{sub Yb{sup 3+}/Yb{sup 2+*}}.

Multiple Temperature-Sensing Behavior of Green and Red Upconversion Emissions from Stark Sublevels of Er3+

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Baosheng Cao

2015-12-01

Full Text Available Upconversion luminescence properties from the emissions of Stark sublevels of Er3+ were investigated in Er3+-Yb3+-Mo6+-codoped TiO2 phosphors in this study. According to the energy levels split from Er3+, green and red emissions from the transitions of four coupled energy levels, 2H11/2(I/2H11/2(II, 4S3/2(I/4S3/2(II, 4F9/2(I/4F9/2(II, and 2H11/2(I + 2H11/2(II/4S3/2(I + 4S3/2(II, were observed under 976 nm laser diode excitation. By utilizing the fluorescence intensity ratio (FIR technique, temperature-dependent upconversion emissions from these four coupled energy levels were analyzed at length. The optical temperature-sensing behaviors of sensing sensitivity, measurement error, and operating temperature for the four coupled energy levels are discussed, all of which are closely related to the energy gap of the coupled energy levels, FIR value, and luminescence intensity. Experimental results suggest that Er3+-Yb3+-Mo6+-codoped TiO2 phosphor with four pairs of energy levels coupled by Stark sublevels provides a new and effective route to realize multiple optical temperature-sensing through a wide range of temperatures in an independent system.

Tuning the sensitivity of lanthanide-activated NIR nanothermometers in the biological windows.

Science.gov (United States)

Cortelletti, P; Skripka, A; Facciotti, C; Pedroni, M; Caputo, G; Pinna, N; Quintanilla, M; Benayas, A; Vetrone, F; Speghini, A

2018-02-01

Lanthanide-activated SrF 2 nanoparticles with a multishell architecture were investigated as optical thermometers in the biological windows. A ratiometric approach based on the relative changes in the intensities of different lanthanide (Nd 3+ and Yb 3+ ) NIR emissions was applied to investigate the thermometric properties of the nanoparticles. It was found that an appropriate doping with Er 3+ ions can increase the thermometric properties of the Nd 3+ -Yb 3+ coupled systems. In addition, a core containing Yb 3+ and Tm 3+ can generate light in the visible and UV regions upon near-infrared (NIR) laser excitation at 980 nm. The multishell structure combined with the rational choice of dopants proves to be particularly important to control and enhance the performance of nanoparticles as NIR nanothermometers.

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)

Transportin-1-dependent YB-1 nuclear import

International Nuclear Information System (INIS)

Mordovkina, Daria A.; Kim, Ekaterina R.; Buldakov, Ilya A.; Sorokin, Alexey V.; Eliseeva, Irina A.; Lyabin, Dmitry N.; Ovchinnikov, Lev P.

2016-01-01

The DNA/RNA-binding protein YB-1 (Y-box binding protein 1) performs multiple functions both in the cytoplasm and the nucleus of the cell. Generally localized to the cytoplasm, under certain conditions YB-1 is translocated to the nucleus. Here we report for the first time a transport factor that mediates YB-1 nuclear import – transportin-1. The YB-1/transportin-1 complex can be isolated from HeLa cell extract. Nuclear import of YB-1 and its truncated form YB-1 (1-219) in in vitro transport assay was diminished in the presence of a competitor substrate and ceased in the presence of transportin-1 inhibitor M9M. Inhibitors of importin β1 had no effect on YB-1 transport. Furthermore, transport of YB-1 (P201A/Y202A) and YB-1 (1–219) (P201A/Y202A) bearing inactivating mutations in the transportin-1-dependent nuclear localization signal was practically abolished. Together, these results indicate that transportin-1 mediates YB-1 nuclear translocation. - Highlights: • Transportin-1 mediates YB-1 nuclear import. • YB-1 nuclear translocation is diminished in the presence of transportin-1 inhibitors. • Mutations in the PY motif of YB-1 NLS prevent its translocation to the nucleus.

Effect of fluence on the lattice site of implanted Er and implantation induced strain in GaN

CERN Document Server

Wahl, U; Decoster, S; Vantomme, A; Correi, J G

2009-01-01

A GaN thin film was implanted with 5 × 1014 cm−2 of 60 keV stable 166Er, followed by the implantation of 2 × 1013 cm−2 radioactive 167Tm (t1/2 = 9.3 d) and an annealing sequence up to 900 °C. The emission channeling (EC) technique was applied to assess the lattice location of Er following the Tm decay from the conversion electrons emitted by 167mEr, which showed that more than 50% of 167mEr occupies substitutional Ga sites. The results are briefly compared to a 167mEr lattice location experiment in a GaN sample not pre-implanted with 166Er. In addition, high-resolution X-ray diffraction (HRXRD) was used to characterize the perpendicular strain in the high-fluence implanted film. The HRXRD experiments showed that the Er implantation resulted in an increase of the c-axis lattice constant of the GaN film around 0.5–0.7%. The presence of significant disorder within the implanted region was corroborated by the fact that the EC patterns for off-normal directions exhibit a pronounced angular broadening of t...

Rare earths refining by vacuum sublimation method

International Nuclear Information System (INIS)

Rytus, N.N.

1983-01-01

The process of rare earths refining by the sUblimation; method in high and superhigh oil-free vacuum, is investigated. The method is effective for rare earths obtaining and permits to prepare metal samples with a high value of electric resistance ratio γ=RsUb(298 K)/Rsub(4.2 K). The estimation of general purity is performed for Sm, Eu, Yb, Tm, Dy, Ho, Er and Se

Kondo effect and heavy fermions in Yb compounds

International Nuclear Information System (INIS)

Bonville, P.

1987-01-01

The Kondo properties of Yb dilute alloys and intermetallics have been investigated using Moessbauer spectroscopy on 170 Yb. In the dilute alloys AuYb and LaBe 13 Yb, the Kondo logarithmic anomaly of the impurity relaxation rate has been detected, and in the concentrated Yb compounds YbBe 13 , YbP and YbAs, and YbCuAl, the manifestations of the interplay between the Kondo effect and the magnetic ordering due to the RKKY interaction have been characterized

General synthesis and structural evolution of a layered family of Ln8(OH)20Cl4 x nH2O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y).

Science.gov (United States)

Geng, Fengxia; Matsushita, Yoshitaka; Ma, Renzhi; Xin, Hao; Tanaka, Masahiko; Izumi, Fujio; Iyi, Nobuo; Sasaki, Takayoshi

2008-12-03

The synthesis process and crystal structure evolution for a family of stoichiometric layered rare-earth hydroxides with general formula Ln(8)(OH)(20)Cl(4) x nH(2)O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y; n approximately 6-7) are described. Synthesis was accomplished through homogeneous precipitation of LnCl(3) x xH(2)O with hexamethylenetetramine to yield a single-phase product for Sm-Er and Y. Some minor coexisting phases were observed for Nd(3+) and Tm(3+), indicating a size limit for this layered series. Light lanthanides (Nd, Sm, Eu) crystallized into rectangular platelets, whereas platelets of heavy lanthanides from Gd tended to be of quasi-hexagonal morphology. Rietveld profile analysis revealed that all phases were isostructural in an orthorhombic layered structure featuring a positively charged layer, [Ln(8)(OH)(20)(H(2)O)(n)](4+), and interlayer charge-balancing Cl(-) ions. In-plane lattice parameters a and b decreased nearly linearly with a decrease in the rare-earth cation size. The interlamellar distance, c, was almost constant (approximately 8.70 A) for rare-earth elements Nd(3+), Sm(3+), and Eu(3+), but it suddenly decreased to approximately 8.45 A for Tb(3+), Dy(3+), Ho(3+), and Er(3+), which can be ascribed to two different degrees of hydration. Nd(3+) typically adopted a phase with high hydration, whereas a low-hydration phase was preferred for Tb(3+), Dy(3+), Ho(3+), Er(3+), and Tm(3+). Sm(3+), Eu(3+), and Gd(3+) samples were sensitive to humidity conditions because high- and low-hydration phases were interconvertible at a critical humidity of 10%, 20%, and 50%, respectively, as supported by both X-ray diffraction and gravimetry as a function of the relative humidity. In the phase conversion process, interlayer expansion or contraction of approximately 0.2 A also occurred as a possible consequence of absorption/desorption of H(2)O molecules. The hydration difference was also evidenced by refinement results. The number of coordinated water

X-ray fluorescence analysis of ytterbium oxide/oxalate for rare earth impurities

International Nuclear Information System (INIS)

Chandola, L.C.; Khanna, P.P.; Thomas, A.

1982-01-01

An XRF method for the determination of Ho, Er, Tm, Lu and Y oxides in Yb 2 O 3 is described. 450 mg sample in the oxalate form is mixed with 150 mg boric acid binding material and pressed into 1.25 inch diameter pellet over a supporting pellet of boric acid. The sample is irradiated by X-rays from a tungsten tube and the fluorescent X-rays are dispersed by a LiF(200) crystal in a Philips PW 1220 semiautomatic X-ray fluorescence spectrometer. The intensities of characteristic X-rays of the impurity elements are measured by a flow proportional counter or a scintillation counter. The lowest determination limit is 0.005% for Ho, Er, Tm and Y and 0.01% for Lu. Calculations for theoretical detection limit, standard deviation and uncertainty are done and presented. (author)

Multispectral Emissions of Lanthanide-Doped Gadolinium Oxide Nanophosphors for Cathodoluminescence and Near-Infrared Upconversion/Downconversion Imaging

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Doan Thi Kim Dung

2016-09-01

Full Text Available Comprehensive imaging of a biological individual can be achieved by utilizing the variation in spatial resolution, the scale of cathodoluminescence (CL, and near-infrared (NIR, as favored by imaging probe Gd2O3 co-doped lanthanide nanophosphors (NPPs. A series of Gd2O3:Ln3+/Yb3+ (Ln3+: Tm3+, Ho3+, Er3+ NPPs with multispectral emission are prepared by the sol-gel method. The NPPs show a wide range of emissions spanning from the visible to the NIR region under 980 nm excitation. The dependence of the upconverting (UC/downconverting (DC emission intensity on the dopant ratio is investigated. The optimum ratios of dopants obtained for emissions in the NIR regions at 810 nm, 1200 nm, and 1530 nm are applied to produce nanoparticles by the homogeneous precipitation (HP method. The nanoparticles produced from the HP method are used to investigate the dual NIR and CL imaging modalities. The results indicate the possibility of using Gd2O3 co-doped Ln3+/Yb3+ (Ln3+: Tm3+, Ho3+, Er3+ in correlation with NIR and CL imaging. The use of Gd2O3 promises an extension of the object dimension to the whole-body level by employing magnetic resonance imaging (MRI.

Luminescent properties of LuAG:Yb and YAG:Yb single crystalline films grown by Liquid Phase Epitaxy method

International Nuclear Information System (INIS)

Zorenko, Yu; Zorenko, T.; Gorbenko, V.; Voznyak, T.; Popielarski, P.; Batentschuk, M.; Osvet, A.; Brabec, Ch; Kolobanov, V.; Spasky, D.; Fedorov, A.

2016-01-01

In this work, investigation of the spectroscopic parameters of the luminescence of Yb"3"+ ions in single crystalline films of Lu_3Al_5O_1_2 and Y_3Al_5O_1_2 garnets was performed using the synchrotron radiation excitation with the energy in the range of Yb"3"+ charge transitions (CT), exciton range and the onset of interband transitions of these garnets. The basic spectroscopic parameters of the Yb"3"+ CT luminescence in LuAG and YAG hosts were determined and summarized with taking into account the differences in the band gap structure of these garnets. - Highlights: • Single crystalline films of Yb doped LuAG and YAG garnets were grown by LPE method. • Yb"3"+ luminescence of LuAG:Yb and YAG:Yb film were studied using synchrotron radiation. • Basic parameters of Yb"3"+ charge transfer luminescence in LuAG and YAG were determined.

Cross sections for fast-neutron interaction with ytterbium isotopes

International Nuclear Information System (INIS)

Luo, Junhua; Liu, Rong; Jiang, Li; Ge, Suhong; Liu, Zhenlai; Sun, Guihua

2013-01-01

Highlights: ► The cross sections for the (n,x) reactions on ytterbium isotopes have been measured. ► Mono-energetic neutron beams using the D + T reaction; Energies: 13.5 and 14.8 MeV. ► Neutron cross-section measurements by means of the activation technique. ► Reference reactions 93 Nb(n,2n) 92m Nb and 27 (n,α) 24 Na. ► Data for 172 Yb(n,p) 172 Tm and 176 Yb(n,d * ) 175 Tm are reported for the first time. - Abstract: Measurements of (n,2n), (n,p), and (n,d * ) (The expression (n,d * ) cross section used in this work includes a sum of (n,d), (n,np) and (n,pn) cross sections.) reaction cross-sections on ytterbium isotopes have been carried out in the range of 13.5–14.8 MeV using the activation technique. The monoenergetic neutron beams were produced via the 3 H(d,n) 3 He reaction. The neutron energies of different directions were determined using the Nb/Zr method. Samples were activated along with along with Nb and Al monitor foils to determine the incident neutron flux. Data are reported for the following reactions: 168 Yb(n,2n) 167 Yb, 170 Yb(n,2n) 169m+g Yb, 176 Yb(n,2n) 175m+g Yb, 172 Yb(n,p) 172 Tm, 173 Yb(n,p) 173 Tm, 176 Yb(n,d * ) 175 Tm, 174 Yb(n,p) 174 Tm, and 176 Yb(n,p) 176 Tm. The experimentally deduced cross-sections are compared with the existing experimental data. Furthermore, theoretical statistical model, based on the Hauser–Feshbach formalism, have been carried out using the HFTT