Yttrium aluminum garnet coating on glass substrate

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J., E-mail: eduardo.nassar@unifran.edu.br

2016-02-15

Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu{sup 3+} onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min{sup −1} and evaporation led to deposition of different numbers of layers of the YAG:Eu{sup 3+} film onto the glass substrate from a YAG:Eu{sup 3+} powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu{sup 3+}. • The matrix was deposited as transparent films. • The YAG:Eu{sup 3+} was deposited by sol–gel process onto glass substrate.

Yttrium aluminum garnet coating on glass substrate

International Nuclear Information System (INIS)

Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J.

2016-01-01

Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu 3+ onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min −1 and evaporation led to deposition of different numbers of layers of the YAG:Eu 3+ film onto the glass substrate from a YAG:Eu 3+ powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu 3+ . • The matrix was deposited as transparent films. • The YAG:Eu 3+ was deposited by sol–gel process onto glass substrate.

Study of phase separation and crystallization phenomena in soda-lime borosilicate glass enriched in MoO3

International Nuclear Information System (INIS)

Magnin, M.

2009-09-01

Molybdenum oxide immobilization (MoO 3 , as fission product) is one of the major challenges in the nuclear glass formulation issues for high level waste solutions conditioning since many years, these solutions arising from spent nuclear fuel reprocessing. Phase separation and crystallisation processes may arise in molten glass when the MoO 3 content is higher than its solubility limit that may depend on glass composition. Molybdenum combined with other elements such as alkali and alkaline-earth may form crystalline molybdates, known as 'yellow phases' in nuclear glasses which may decrease the glass durability. In order to confine high level wastes (HLW) such as the fission product solutions arising from the reprocessing of high burn-up UOX-type nuclear spent fuels, a new glass composition (HLW glass) is being optimized. This work is devoted to the study of the origin and the mechanism of phase separation and crystallization phenomena induced by molybdenum oxide incorporation in the HLW glass. From microstructural and structural point of view, the molybdenum oxide behavior was studied in glass compositions belonging to the SiO 2 -B 2 O 3 - Na 2 O-CaO simplified system which constituted basis for the HLW glass formulation. The structural role of molybdenum oxide in borosilicate network explaining the phase separation and crystallization tendency was studied through the coupling of structural ( 95 Mo, 29 Si, 11 B, 23 Na MAS NMR, XRD) and microstructural (SEM, HRTEM) analysis techniques. The determination of phase separation (critical temperature) and crystallization (liquidus temperature) appearance temperatures by in situ viscosimetry and Raman spectroscopy experiments allowed us to propose a transformation scenario during melt cooling. These processes and the nature of the crystalline phases formed (CaMoO 4 , Na 2 MoO 4 ) that depend on the evolution of MoO 3 , CaO and B 2 O 3 contents were correlated with changes of sodium and calcium cations proportions in the

Structural study of glasses in the binary system NaPO{sub 3}-MoO{sub 3} by X-ray absorption spectroscopy at the Mo K and L{sub 3} edges

Energy Technology Data Exchange (ETDEWEB)

Poirier, Gael, E-mail: gael@unifal-mg.edu.br [Department of Science and Technology, UNIFAL-MG, Rua Corumba 72, CEP 37701-100, Pocos de Caldas, MG (Brazil); Cassanjes, Fabia C. [Department of Science and Technology, UNIFAL-MG, Rua Corumba 72, CEP 37701-100, Pocos de Caldas, MG (Brazil)

2010-04-15

Glasses were prepared in the binary system (100 - x)NaPO{sub 3}-xMoO{sub 3} with x varying from 0 to 50 mol%. An increase in the MoO{sub 3} concentration promotes a strong absorption in the visible and near infrared attributed to Mo reduction during glass synthesis. X-ray absorption measurements were performed at the Mo K and L{sub 3} edges to investigate both the coordination number and oxidation state of Mo in these glasses. The evolution of the pre-peak observed at the K edge suggests that Mo atoms are six-fold coordinated in these glasses. This hypothesis was confirmed by data obtained at the Mo-L{sub 3}-absorption edge. Since the final electronic states at the L{sub 3}-absorption edge are mostly orbitals of d-character which are splitted by the ligand field, the amplitude of the d-orbital splitting could be estimated and the related coordination number of Mo obtained. Finally, the oxidation state of Mo could be related with a change of the white line intensity at the Mo-L{sub 3} edge. These results confirm that the optical absorption in the visible is due to Mo reduction and that transparent samples prepared by slow cooling contain less reduced Mo species.

Investigation on nonlinear optical properties of MoS2 nanoflake, grown on silicon and quartz substrates

Science.gov (United States)

Bayesteh, S.; Mortazavi, S. Z.; Reyhani, A.

2018-03-01

In this study, MoS2 was directly synthesized by one-step thermal chemical vapour deposition (TCVD), on different substrates including Si/SiO2 and quartz, using MoO3 and sulfide powders as precursor. The XRD patterns demonstrate the high crystallinity of MoS2 on Si/SiO2 and quartz substrates. SEM confirmed the formation of MoS2 grown on both substrates. According to line width and frequency difference between the E1 2g and A1g in Raman spectroscopy, it is inferred that the MoS2 grown on Si/SiO2 substrate is monolayer and the MoS2 grown on quartz substrate is multilayer. Moreover, by assessment of MoS2 nanoflake band gap via UV-visible analysis, it verified the formation of few layer structures. In addition, the open-aperture and close-aperture Z-scan techniques were employed to study the nonlinear optical properties including nonlinear absorption and nonlinear refraction of the synthesized MoS2. All experiments were performed using a diode laser with a wavelength of 532 nm as light source. The monolayer MoS2 synthesized on Si/SiO2, display considerable two-photon absorption. However, the multilayer MoS2 synthesized on quartz displayed saturable absorption (SA). It is noticeable that both samples demonstrate obvious self-defocusing behaviour.

Electrical contacts on polyimide substrates for flexible thin film photovoltaic devices

Energy Technology Data Exchange (ETDEWEB)

Guillen, C.; Herrero, J

2003-05-01

Both frontal and back electrical contacts have been developed onto polyimide sheets (Kapton KJ[reg]) as alternative substrates to the conventional glasses, for application in lightweight and flexible thin film photovoltaic devices. Transparent and conductive indium tin oxide (ITO) thin films have been deposited by r.f.-magnetron sputtering as the frontal electrical contact. On the other hand, Mo, Cr and Ni layers have been prepared by e-gun evaporation for the back electrical connections. ITO films deposited onto polyimide have shown similar optical transmittance and higher electrical conductivity than onto glass substrates. The transmittance decreases and the conductivity increases after heating at 400 sign C in vacuum atmosphere. Mo, Cr and Ni layers deposited onto polyimide showed similar structure and electrical conductivity than onto conventional glasses. The properties of Mo and Cr layers remained unchanged after heating at 400 sign C in selenium atmosphere.

Structural investigations of borosilicate glasses containing MoO{sub 3} by MAS NMR and Raman spectroscopies

Energy Technology Data Exchange (ETDEWEB)

Caurant, D., E-mail: daniel-caurant@enscp.f [Laboratoire de Chimie de la Matiere Condensee de Paris, UMR-CNRS 7574, Ecole Nationale Superieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231 Paris (France); Majerus, O.; Fadel, E.; Quintas, A. [Laboratoire de Chimie de la Matiere Condensee de Paris, UMR-CNRS 7574, Ecole Nationale Superieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231 Paris (France); Gervais, C. [Laboratoire de Chimie de la Matiere Condensee de Paris, UMR-CNRS 7574, Universite Pierre et Marie Curie, 75252 Paris (France); Charpentier, T. [CEA, IRAMIS, Service Interdisciplinaire sur les Systemes Moleculaires et Materiaux, CEA Saclay, 91191 Gif-sur-Yvette (France); Neuville, D. [Physique des Mineraux et des Magmas, UMR-CNRS 7047, Institut de Physique du Globe, place Jussieu, 75252 Paris (France)

2010-01-01

High molybdenum concentration in glass compositions may lead to alkali and alkaline-earth molybdates crystallization during melt cooling that must be controlled particularly during the preparation of highly radioactive nuclear glassy waste forms. To understand the effect of molybdenum addition on the structure of a simplified nuclear glass and to know how composition changes can affect molybdates crystallization tendency, the structure of two glass series belonging to the SiO{sub 2}-B{sub 2}O{sub 3}-Na{sub 2}O-CaO-MoO{sub 3} system was studied by {sup 29}Si, {sup 11}B, {sup 23}Na MAS NMR and Raman spectroscopies by increasing MoO{sub 3} or B{sub 2}O{sub 3} concentrations. Increasing MoO{sub 3} amount induced an increase of the silicate network reticulation but no significant effect was observed on the proportion of BO{sub 4}{sup -} units and on the distribution of Na{sup +} cations in glass structure. By increasing B{sub 2}O{sub 3} concentration, a strong evolution of the distribution of Na{sup +} cations was observed that could explain the evolution of the nature of molybdate crystals (CaMoO{sub 4} or Na{sub 2}MoO{sub 4}) formed during melt cooling.

Influence of Mo on the structure of borosilicate glass for the immobilization of high level waste

International Nuclear Information System (INIS)

Petrov, I.; Dimitriev, Y.; Kashchieva, E.

2015-01-01

It has been shown that the classic multi-borosilicate glass with concentration of MoO 3 has a low melting in the range of 1300 to 1400 ° C, but for achieving of complete homogenization and vitrification it is required temperature above 1400 ° C. Under this temperature in all tested samples areas of crystallization were observed, due to incomplete vitrification processes. It is understood that in all multicomponent borosilicate glass featuring MoO 3 , occur micro vitrification processes, and at a concentration of MoO 3 above 20% - macro segregation; It has been shown that the introduction of Nd in compound borosilicate glass featuring MoO 3 is observed crystallization of the phase Na 0.5 Nd 0.5 Mo, and it has been also found that the phase Na 0.5 Nd 0.5 Mo 4 can be synthesized either by solid phase reaction or supercooled melt. The results of surveys show that It is possible to prevent the occurrence of liquid phase separation in the studied multicomponent glass. From a structural point of view, the cause of liquid phase separation is the result of structural incompatibility of molybdenum units with structural units borosilicate network since not been established links Mo-O-B-O and Mo-Si. From a thermodynamic point of view in the lamination multi windows may be due to overlapping areas of delamination in component binary and triple systems. From the kinetic point of view of course the liquid phase by settling, and crystallization may be due to imbalances conditions the cooling process, in the course of which flow various processes of imbalances metastable settling, followed by crystallization of molybdate phases

In-situ fabrication of MoSi2/SiC–Mo2C gradient anti-oxidation coating on Mo substrate and the crucial effect of Mo2C barrier layer at high temperature

International Nuclear Information System (INIS)

Liu, Jun; Gong, Qianming; Shao, Yang; Zhuang, Daming; Liang, Ji

2014-01-01

MoSi 2 /SiC–Mo 2 C gradient coating on molybdenum was in situ prepared with pack cementation process by two steps: (1) carburizing with graphite powder to obtain a Mo 2 C layer on Mo substrate, and (2) siliconizing with Si powder to get a composite MoSi 2 /SiC layer on the upper part of Mo 2 C layer. The microstructure and elemental distribution in the coating were investigated with scanning electron microscopy (SEM), backscattered electron (BSE), energy dispersive spectroscopy (EDS), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Cyclic oxidation tests (at 500 °C, 1200 °C, 1400 °C and 1600 °C) demonstrated excellent oxidation resistance for the gradient composite coating and the mass loss was only 0.23% in 60 min at 1600 °C. XRD, EPMA, thermal dynamic and phase diagram analyses indicated that the Mo 2 C barrier layer played the key role in slowing down the diffusion of C and Si toward inner Mo substrate at high temperature and principally this contributed to the excellent anti-oxidation for Mo besides the outer MoSi 2 /SiC composite layer.

Anisotropic MoS2 Nanosheets Grown on Self-Organized Nanopatterned Substrates.

Science.gov (United States)

Martella, Christian; Mennucci, Carlo; Cinquanta, Eugenio; Lamperti, Alessio; Cappelluti, Emmanuele; Buatier de Mongeot, Francesco; Molle, Alessandro

2017-05-01

Manipulating the anisotropy in 2D nanosheets is a promising way to tune or trigger functional properties at the nanoscale. Here, a novel approach is presented to introduce a one-directional anisotropy in MoS 2 nanosheets via chemical vapor deposition (CVD) onto rippled patterns prepared on ion-sputtered SiO 2 /Si substrates. The optoelectronic properties of MoS 2 are dramatically affected by the rippled MoS 2 morphology both at the macro- and the nanoscale. In particular, strongly anisotropic phonon modes are observed depending on the polarization orientation with respect to the ripple axis. Moreover, the rippled morphology induces localization of strain and charge doping at the nanoscale, thus causing substantial redshifts of the phonon mode frequencies and a topography-dependent modulation of the MoS 2 workfunction, respectively. This study paves the way to a controllable tuning of the anisotropy via substrate pattern engineering in CVD-grown 2D nanosheets. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Layer Dependence and Light Tuning Surface Potential of 2D MoS2 on Various Substrates.

Science.gov (United States)

Li, Feng; Qi, Junjie; Xu, Minxuan; Xiao, Jiankun; Xu, Yuliang; Zhang, Xiankun; Liu, Shuo; Zhang, Yue

2017-04-01

Here surface potential of chemical vapor deposition (CVD) grown 2D MoS 2 with various layers is reported, and the effect of adherent substrate and light illumination on surface potential of monolayer MoS 2 are investigated. The surface potential of MoS 2 on Si/SiO 2 substrate decreases from 4.93 to 4.84 eV with the increase in the number of layer from 1 to 4 or more. Especially, the surface potentials of monolayer MoS 2 are strongly dependent on its adherent substrate, which are determined to be 4.55, 4.88, 4.93, 5.10, and 5.50 eV on Ag, graphene, Si/SiO 2 , Au, and Pt substrates, respectively. Light irradiation is introduced to tuning the surface potential of monolayer MoS 2 , with the increase in light intensity, the surface potential of MoS 2 on Si/SiO 2 substrate decreases from 4.93 to 4.74 eV, while increases from 5.50 to 5.56 eV on Pt substrate. The I-V curves on vertical of monolayer MoS 2 /Pt heterojunction show the decrease in current with the increase of light intensity, and Schottky barrier height at MoS 2 /Pt junctions increases from 0.302 to 0.342 eV. The changed surface potential can be explained by trapped charges on surface, photoinduced carriers, charge transfer, and local electric field. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Mo-Fe substitution on glass forming ability, thermal stability, and hardness of Fe-C-B-Mo-Cr-W bulk amorphous alloys

Energy Technology Data Exchange (ETDEWEB)

Khalifa, Hesham E.; Cheney, Justin L. [University of California, San Diego Materials Science and Engineering Program, 9500 Gilman Drive, La Jolla, CA 92093-0411 (United States); Vecchio, Kenneth S. [University of California, San Diego Department of NanoEngineering, 9500 Gilman Drive, La Jolla, CA 92093-0411 (United States)], E-mail: kvecchio@ucsd.edu

2008-08-25

Amorphous Fe{sub 67-x}C{sub 10}B{sub 9}Mo{sub 7+x}Cr{sub 4}W{sub 3} (x = 1-7 at.%) plates with 640 {mu}m thickness were prepared by copper mold casting. The thermal properties and microstructural development during heat treatments were investigated by a combination of differential scanning calorimetry (DSC), differential thermal analysis, and X-ray diffractometry (XRD). The glass forming ability (GFA) and activation energy for crystallization have a distinct dependence on Mo content. Fe{sub 62}C{sub 10}B{sub 9}Mo{sub 12}Cr{sub 4}W{sub 3} is the best glass former in this study, demonstrating a supercooled liquid region, {delta}T{sub x} = 51 K, and an activation energy for crystallization, Q = 453 kJ/mol. The GFA of alloys in this system was governed by elastic strain optimization resulting directly from the variation in Mo content. Heat treatments were performed to demonstrate resistance to crystallization under typical processing conditions. Alloys in this system exhibited a three-phase evolution during crystallization. A second set of heat treatments was performed to identify each phase. Hardness data was collected at each of the heat treatment conditions, and a bulk metallic glasses (BMG)-derived composite containing a Mo-rich phase exhibited Vickers Hardness in excess of 2000. The fully amorphous alloys had an average hardness approaching 1500.

Investigation on nonlinear optical properties of MoS2 nanoflakes grown on silicon and quartz substrates

Science.gov (United States)

Bayesteh, Samaneh; Zahra Mortazavi, Seyedeh; Reyhani, Ali

2018-05-01

In this study, MoS2 nanoflakes were directly grown on different substrates—Si/SiO2 and quartz—by one-step thermal chemical vapor deposition using MoO3 and sulfide powders as precursors. Scanning electron microscopy and x-ray diffraction patterns demonstrated the formation of MoS2 structures on both substrates. Moreover, UV-visible and photoluminescence analysis confirmed the formation of MoS2 few-layer structures. According to Raman spectroscopy, by assessment of the line width and frequency shift differences between the and A 1g, it was inferred that the MoS2 grown on the silicon substrate was monolayer and that grown on the quartz substrate was multilayer. In addition, open-aperture and close-aperture Z-scan techniques were employed to study the nonlinear optical properties including nonlinear absorption and nonlinear refraction of the grown MoS2. All experiments were performed using a diode laser with a wavelength of 532 nm as the light source. It is noticeable that both samples demonstrate obvious self-defocusing behavior. The monolayer MoS2 grown on the silicon substrate displayed considerable two-photon absorption while, the multilayer MoS2 synthesized on the quartz exhibited saturable absorption. In general, few-layered MoS2 would be useful for the development of nanophotonic devices like optical limiters, optical switchers, etc.

Highly flexible, conductive and transparent MoO3/Ag/MoO3 multilayer electrode for organic photovoltaic cells

International Nuclear Information System (INIS)

Abachi, T.; Cattin, L.; Louarn, G.; Lare, Y.; Bou, A.; Makha, M.; Torchio, P.

2013-01-01

MoO 3 /Ag/MoO 3 (MAM) multilayer structures were deposited by vacuum evaporation on polyethylene terephthalate (PET) substrate. We demonstrate that, as in the case of glass substrate, the sheet resistance of such structures depends significantly on the Ag film deposition rate. When it is deposited between 0.2 and 0.4 nm/s, an Ag thickness of 11 nm allows achieving sheet resistance of 13 Ω/sq and an averaged transmission of 74%. A study of the influence of the PET substrate on the optimum MoO 3 thicknesses was done. A good qualitative agreement between the theoretical calculations of the variation of the optical transmittance of the MoO 3 /Ag/MoO 3 structures is obtained. The optimum MAM structures MoO 3 (17.5 nm)/Ag (11 nm)/MoO 3 (35 nm) has a factor of merit F M = 4.21 10 −3 (Ω/sq) −1 . Proven by the scotch test the MAM structures exhibit a good adhesion to the PET substrates. The MAM structures were also submitted to bending tests. For outer bending, the samples exhibit no variation of their resistance value, while for inner bending there is a small increase of the resistance of the MAM structures. However this increasing is smaller than that exhibited by Indium Tin Oxide. When the PET/MAM structures are used as anode in organic photovoltaic cells, it is shown that the need to use thicker Ag films inside the multilayer and to cover the MAM with Au to obtain promising Current density vs Voltage characteristics is due to the heating of the PET substrate during the deposition process. - Highlights: • MoO 3 /Ag/MoO 3 structures deposited on polyethylene terephthalate substrate. • MoO 3 /Ag/MoO 3 structures deposited by vacuum evaporation. • The Ag deposition rate influences the properties of the structures. • The MoO 3 /Ag/MoO 3 optimum structure has a factor of merit F M = 4.21 10 −3 (Ω/sq) −1 . • The MoO 3 /Ag/MoO 3 structures exhibit a high flexibility

EPR dosimetry of glass substrate of mobile phone LCDs

International Nuclear Information System (INIS)

Trompier, F.; Della Monaca, S.; Fattibene, P.; Clairand, I.

2011-01-01

Previous studies have shown that mineral glass from watches, windows and displays of personal electronic devices could be a suitable restrospective dosimeter in case of radiation accident. In this paper glass substrates of the window display of 100 mobile phones of different trademarks were analized by X-band cw-EPR before and after irradiation at 100 Gy. The objective of this study was to highlight some issues of EPR measurements of glass related to inter-sample variability of: i) signal line shape in irradiated and unirradiated glass; ii) signal intensity loss and line shape change with post-irradiation time; iii) signal changes induced by sample preparation and iv) signal changes induced by thermal annealing. Scope of the paper is to provide a phenomenological picture of the observed effects in order to give a warning about possible problems and to provide suggestions for future work. Explanation of the mechanisms and the causes leading to the observed effects was beyond the scope of this work. These preliminary results confirm that glass substrate of mobile phone displays should be considered as a fortuitous dosimeter in radiation accidents. However, albeit very promising, mineral glass presents a number of issues that should be thoroughly investigated and addressed in future work.

Layer-controlled large area MoS{sub 2} layers grown on mica substrate for surface-enhanced Raman scattering

Energy Technology Data Exchange (ETDEWEB)

Xu, Y.Y.; Yang, C. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Jiang, S.Z. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); State Key Lab of Crystal Materials Shandong University, Jinan 250100 (China); Man, B.Y., E-mail: byman@sdnu.edu.cn [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Liu, M.; Chen, C.S.; Zhang, C.; Sun, Z.C.; Qiu, H.W. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Li, H.S. [Department of Radiation Oncology, Key Laboratory of Radiation Oncology of Shandong Province, Shandong Cancer Hospital and Institute, Jinan 250117 (China); Feng, D.J. [College of Information Science and Engineering, Shandong University, Jinan 250100 (China); Zhang, J.X. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China)

2015-12-01

Highlights: • Layer-controlled large-area and continuous MoS{sub 2} atomic layers were obtained on mica substrate by thermally decomposing ammonium thiomolybdate at relatively low temperature. • The as-grown MoS{sub 2}/mica substrate was demonstrated to be suitable as a substrate for enhancing Raman signals without any modification and we even collected Raman signals of R6G as low as 10{sup −7} M. • Using the Raman peak of R6G at 1361 cm{sup −1} as a signature, Raman intensity showed an approximately linear increase with the increasing of the logarithm of R6G concentrations. - Abstract: Molybdenum disulfide has recently raised more and more interest due to its layer-related properties and potential applications in optoelectronics and electronics. Here, layer-controlled large-area and continuous MoS{sub 2} atomic layers were obtained on mica substrate by thermally decomposing ammonium thiomolybdate. The obtained MoS{sub 2} film is three layers uniformly. Because of the small lattice mismatch between MoS{sub 2} and mica, the epitaxial MoS{sub 2} film is well grown on the substrate. The as-grown MoS{sub 2}/mica substrate is demonstrated to be suitable as a substrate for enhancing Raman signals of adsorbed molecules without any modification, which even can compare with graphene and will expand the application of MoS{sub 2} to microanalysis.

In-situ fabrication of MoSi{sub 2}/SiC–Mo{sub 2}C gradient anti-oxidation coating on Mo substrate and the crucial effect of Mo{sub 2}C barrier layer at high temperature

Energy Technology Data Exchange (ETDEWEB)

Liu, Jun [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Gong, Qianming, E-mail: gongqianming@mail.tsinghua.edu.cn [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Shao, Yang; Zhuang, Daming [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Liang, Ji [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

2014-07-01

MoSi{sub 2}/SiC–Mo{sub 2}C gradient coating on molybdenum was in situ prepared with pack cementation process by two steps: (1) carburizing with graphite powder to obtain a Mo{sub 2}C layer on Mo substrate, and (2) siliconizing with Si powder to get a composite MoSi{sub 2}/SiC layer on the upper part of Mo{sub 2}C layer. The microstructure and elemental distribution in the coating were investigated with scanning electron microscopy (SEM), backscattered electron (BSE), energy dispersive spectroscopy (EDS), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Cyclic oxidation tests (at 500 °C, 1200 °C, 1400 °C and 1600 °C) demonstrated excellent oxidation resistance for the gradient composite coating and the mass loss was only 0.23% in 60 min at 1600 °C. XRD, EPMA, thermal dynamic and phase diagram analyses indicated that the Mo{sub 2}C barrier layer played the key role in slowing down the diffusion of C and Si toward inner Mo substrate at high temperature and principally this contributed to the excellent anti-oxidation for Mo besides the outer MoSi{sub 2}/SiC composite layer.

Characterization of Thin Walled Mo Tubing produced by FBCVD

Energy Technology Data Exchange (ETDEWEB)

Beaux, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-01-21

The goal of this report is to delineate the results of material characterization performed on Mo tubing produced via the fluidized bed chemical vapor deposition (FBCVD) method. Scanning electron microscopy (SEM) imaging reveals that small randomly oriented grains are achieved in the Mo deposition, but do not persist throughout the entire thickness of the material. Energy dispersive spectroscopy (EDS) reveals the Mo tubes contain residual chlorine and oxygen. EDS measurements on the tube surfaces separated from glass and quartz substrates reveal substrate material adhered to this surface. X-ray diffraction (XRD) revealed the presence of carbon contaminant in the form of Mo₂C and oxygen in the form of MoO₂. Combustion infrared detection (CID) and inert gas fusion (IGF) performed at Luvak Inc. was used to quantify weight percentages of oxygen and carbon in the tubes produced. Hardness value of the FBCVD Mo was found to be comparable to low carbon arc cast molybdenum.

Preparation, thermal stability, and magnetic properties of Fe-Zr-Mo-W-B bulk metallic glass

International Nuclear Information System (INIS)

Liu, D.Y.; Sun, W.S.; Wang, A.M.; Zhang, H.F.; Hu, Z.Q.

2004-01-01

A bulk metallic glass (BMG) cylinder of Fe 60 Co 8 Zr 10 Mo 5 W 2 B 15 with a diameter of 1.5 mm was prepared by copper mould casting of industrial raw materials. The amorphous state and the crystallization behavior were investigated by X-ray diffraction (XRD). The thermal stability parameters, such as glass transition temperature (T g ), crystallization temperature (T x ), supercooled liquid region (ΔT x ) between T g and T x , and reduced glass transition temperature T rg (T g /T m ) were measured by differential scanning calorimetry (DSC) to be 891, 950, 59 K, and 0.62, respectively. The crystallization process took place through a single stage, and involved crystallization of the phases α-Fe, ZrFe 2 , Fe 3 B, MoB 2 , Mo 2 FeB 2 , and an unknown phase, as determined by X-ray analysis of the sample annealed for 1.5 ks at 1023 K, 50 K above the DSC peak temperature of crystallization. Moessbauer spectroscopy was studied for this alloy. The spectra exhibit a broadened and asymmetric doublet-like structure that indicated paramagnetic behavior and a fully amorphous structure. α-Fe was found in the amorphous matrix for a cylinder with a diameter of 2.5 mm. The success of synthesis of the Fe-based bulk metallic glass from industrial materials is important for the future progress in research and practical application of new bulk metallic glasses

One-step femtosecond laser welding and internal machining of three glass substrates

Science.gov (United States)

Tan, Hua; Duan, Ji'an

2017-05-01

In this paper, it demonstrated one-step femtosecond laser welding and internal machining of three fused silica substrates in the optical- and non-optical-contact regimes by focusing 1030-nm laser pulses at the middle of the second substrate. Focusing laser pulses within the second glass in optical-contact and non-optical-contact samples induces permanent internal structural modification, leading to the three glass substrates bonding together simultaneously. The bonding mechanism is based on the internal modification of glass, and this mechanism is different from that of ordinary glass welding at the interface. Welding-spot size is affected by not only the gap distance (ablation effect) and heat transmission, but also by gravity through examining the sizes of the welding spots on the four contact welding surfaces. The maximum bonding strength of the lower interface (56.2 MPa) in the optical-contact regime is more than double that (27.6 MPa) in the non-optical-contact regime.

Use of a cobalt-based metallic glass for joining MoSi{sub 2} to stainless steel

Energy Technology Data Exchange (ETDEWEB)

Vaidya, R.U.; Rangaswamy, P.; Misra, A.; Gallegos, D.E.; Castro, R.G.; Petrovic, J.J. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.; Butt, D.P. [Florida Univ., Gainesville, FL (United States). Dept. of Materials Science and Engineering

2002-07-01

The successful use of a cobalt-based metallic glass in joining molybdenum disilicide (MoSi{sub 2}) to stainless steel 316L was demonstrated. Such joints are being investigated for sensor tube applications in glass melting operations. The cobalt-based metallic-glass (METGLAS{sup TM} 2714A) was found to wet the MoSi{sub 2} and stainless steel surfaces and provide high quality joints. Joining was completed at 1050 C for 60 minutes in two different ways; either by feeding excess braze into the braze gap upon heating or by constraining the MoSi{sub 2}/stainless steel assembly with an alumina (Al{sub 2}O{sub 3}) fixture during the heating cycle. These steps were necessary to ensure the production of a high quality void free joint. Post-brazing metallographic evaluations coupled with quantitative elemental analysis indicated the presence of a Co-Cr-Si ternary phase with CoSi and CoSi{sub 2} precipitates within the braze. The residual stresses in these molybdenum disilicide (MoSi{sub 2})/stainless steel 316 L joints were evaluated using X-ray diffraction and instrumented indentation techniques. These measurements revealed that significant differences are induced in the residual stresses in MoSi{sub 2} and stainless steel depending on the joining technique employed. Push-out tests were carried out on these joints to evaluate the joint strength. (orig.)

Patterned Electroplating of Micrometer Scale Magnetic Structures on Glass Substrates

NARCIS (Netherlands)

de Vries, A.H.B.; Kanger, Johannes S.; Krenn, Bea E.; van Driel, Roel

2004-01-01

This paper has developed a new method of micro patterned electroplating that enables the fabrication of micrometer scale magnetic structures on glass substrates. In contrast to other methods, the process as developed here leaves the surrounding substrate area untouched: that is there is no seed

Patterned electroplating of micrometer scale magnetic structures on glass substrates.

NARCIS (Netherlands)

de Vries, A.H.B.; Kanger, S.J.; Krenn, G.E.; van Driel, R.

2004-01-01

This paper has developed a new method of micro patterned electroplating that enables the fabrication of micrometer scale magnetic structures on glass substrates. In contrast to other methods, the process as developed here leaves the surrounding substrate area untouched: that is there is no seed

Rocking disc electro-deposition of copper films on Mo/MoSe{sub 2} substrates

Energy Technology Data Exchange (ETDEWEB)

Cummings, Charles Y.; Frith, Paul E. [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Zoppi, Guillaume; Forbes, Ian [Northumbria Photovoltaics Applications Centre, Northumbria University, NE1 8ST (United Kingdom); Rogers, Keith D. [Cranfield Health, Cranfield University, Shrivenham Campus, Swindon, SN6 8LA (United Kingdom); Lane, David W. [Department of Applied Science, Security and Resilience, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Marken, Frank, E-mail: F.Marken@bath.ac.uk [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

2011-08-31

A novel electro-deposition method based on a rocking disc system with {pi}/3 amplitude and variable frequency is introduced. Uniform copper films were deposited from a 0.1 M CuSO{sub 4}/3.0 M NaOH/0.2 M sorbitol bath directly onto 12.1 cm{sup 2} Mo/MoSe{sub 2} substrates with X-ray diffraction showing a thickness variation of {+-}5% over this area. Investigation of the mass transport conditions suggests (i) uniform diffusion over the sample, (ii) a rate of mass transport proportional to the square root of the rocking rate, and (iii) turbulent conditions, which are able to dislodge gas bubbles during electro-deposition.

Near-field enhanced femtosecond laser nano-drilling of glass substrate

International Nuclear Information System (INIS)

Zhou, Y.; Hong, M.H.; Fuh, J.Y.H.; Lu, L.; Lukyanchuk, B.S.; Wang, Z.B.

2008-01-01

Particle mask assisted near-field enhanced femtosecond laser nano-drilling of transparent glass substrate was demonstrated in this paper. A particle mask was fabricated by self-assembly of spherical 1 μm silica particles on the substrate surface. Then the samples were exposed to femtosecond laser (800 nm, 100 fs) and characterized by field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). The nano-hole array was found on the glass surface. The hole sizes were measured from 200 to 300 nm with an average depth of 150 nm and increased with laser fluence. Non-linear triple-photon absorption and near-field enhancement were the main mechanisms of the nano-feature formation. Calculations based on Mie theory shows an agreement with experiment results. More debris, however, was found at high laser fluence. This can be attributed to the explosion of silica particles because the focusing point is inside the 1 μm particle. The simulation predicts that the focusing point will move outside the particle if the particle size increases. The experiment performed under 6.84 μm silica particles verified that no debris was formed. And for all the samples, no cracks were found on the substrate surface because of ultra-short pulse width of femtosecond laser. This method has potential applications in nano-patterning of transparent glass substrate for nano-structure device fabrication

Inorganic Substrates and Encapsulation Layers for Transient Electronics

Science.gov (United States)

2014-07-01

as substrates and encapsulating materials, with demonstrated options that range from films of silk fibroin, polycaprolactone (PCL), polyglycolic...PDMS) (Dow Corning , USA) coated on glass slides to facilitate processing. SiO2 (~1 μm) was deposited by PECVD on these foils for electrical...with laminating the foils Fe, Mo, W, and Zn, ~10 μm thick (Goodfellow, USA) on glass slides coated with PDMS (Dow Corning Co., USA) as temporary

Wear Resistance of Nano Alumina Containing SiO2-B2O3-Na2O Glass-Ceramic on Steel Substrate

Directory of Open Access Journals (Sweden)

A. Faeghinia

2016-09-01

Full Text Available The experimental study has been carried out to investigate the tribological properties of nano Alumina reinforced glass-ceramic enamel. The mixtures of (5, 10, 15 wt.% nano alumina and glass powders have been air sprayed on stainless steel substrate.. The thixotropy, wetting angle and surface tension of used slurry were increased inherently by 15-wt.% nano alumina. By heat treating at 870-640-525 ºC, the homogeneous crystalline sodium silicate phase beside nano alumina was obtained in glass –ceramic coat. According to the EDAX results, the precipitated reduced Sb and Mo particles at the interface of enamel and steel caused to reasonable adherence of coat and steel. The dry sliding wear tests were carried out using pin on disk method. Results revealed the 0.01 mg wear rate by 30N load at 100 m for nano alumina bearing coats. The wear resistance increased by a factor of 10. According to SEM micrographs, the sliding load transfer by nano alumina particles occurred.

Improving yield of PZT piezoelectric devices on glass substrates

Science.gov (United States)

Johnson-Wilke, Raegan L.; Wilke, Rudeger H. T.; Cotroneo, Vincenzo; Davis, William N.; Reid, Paul B.; Schwartz, Daniel A.; Trolier-McKinstry, Susan

2012-10-01

The proposed SMART-X telescope includes adaptive optics systems that use piezoelectric lead zirconate titanate (PZT) films deposited on flexible glass substrates. Several processing constraints are imposed by current designs: the crystallization temperature must be kept below 550 °C, the total stress in the film must be minimized, and the yield on 1 cm2 actuator elements should be work, RF magnetron sputtering was used to deposit films since chemical solution deposition (CSD) led to warping of large area flexible glass substrates. A PZT 52/48 film that wasdeposited at 4 mTorr and annealed at 550 °C for 24 hours showed no detectable levels of either PbO or pyrochlore second phases. Large area electrodes (1cm x 1 cm) were deposited on 4" glass substrates. Initially, the yield of the devices was low, however, two methods were employed to increase the yield to near 100 %. The first method included a more rigorous cleaning to improve the continuity of the Pt bottom electrode. The second method was to apply 3 V DC across the capacitor structure to burn out regions of defective PZT. The result of this latter method essentially removed conducting filaments in the PZT but left the bulk of the material undamaged. By combining these two methods, the yield on the large area electrodes improved from < 10% to nearly 100%.

Scalable Patterning of MoS2 Nanoribbons by Micromolding in Capillaries.

Science.gov (United States)

Hung, Yu-Han; Lu, Ang-Yu; Chang, Yung-Huang; Huang, Jing-Kai; Chang, Jeng-Kuei; Li, Lain-Jong; Su, Ching-Yuan

2016-08-17

In this study, we report a facile approach to prepare dense arrays of MoS2 nanoribbons by combining procedures of micromolding in capillaries (MIMIC) and thermolysis of thiosalts ((NH4)2MoS4) as the printing ink. The obtained MoS2 nanoribbons had a thickness reaching as low as 3.9 nm, a width ranging from 157 to 465 nm, and a length up to 2 cm. MoS2 nanoribbons with an extremely high aspect ratio (length/width) of ∼7.4 × 10(8) were achieved. The MoS2 pattern can be printed on versatile substrates, such as SiO2/Si, sapphire, Au film, FTO/glass, and graphene-coated glass. The degree of crystallinity of the as-prepared MoS2 was discovered to be adjustable by varying the temperature through postannealing. The high-temperature thermolysis (1000 °C) results in high-quality conductive samples, and field-effect transistors based on the patterned MoS2 nanoribbons were demonstrated and characterized, where the carrier mobility was comparable to that of thin-film MoS2. In contrast, the low-temperature-treated samples (170 °C) result in a unique nanocrystalline MoSx structure (x ≈ 2.5), where the abundant and exposed edge sites were obtained from highly dense arrays of nanoribbon structures by this MIMIC patterning method. The patterned MoSx was revealed to have superior electrocatalytic efficiency (an overpotential of ∼211 mV at 10 mA/cm(2) and a Tafel slope of 43 mV/dec) in the hydrogen evolution reaction (HER) when compared to the thin-film MoS2. The report introduces a new concept for rapidly fabricating cost-effective and high-density MoS2/MoSx nanostructures on versatile substrates, which may pave the way for potential applications in nanoelectronics/optoelectronics and frontier energy materials.

Gas microstrip detectors on polymer, silicon and glass substrates

International Nuclear Information System (INIS)

Barasch, E.F.; Demroff, H.P.; Drew, M.M.; Elliott, T.S.; Gaedke, R.M.; Goss, L.T.; Kasprowicz, T.B.; Lee, B.; Mazumdar, T.K.; McIntyre, P.M.; Pang, Y.; Smith, D.D.; Trost, H.J.; Vanstraelen, G.; Wahl, J.

1993-01-01

We present results on the performance of Gas Microstrip Detectors on various substrates. These include a 300 μm anode-anode pitch pattern on Tempax borosilicate glass and ABS/copolyether, a 200 μm pattern on Upilex ''S'' polyimide, Texin 4215, Tedlar, ion-implanted Kapton, orientation-dependent etched flat-topped silicon (''knife-edge chamber''), and iron-vanadium glass, and a 100 μm pitch pattern on Upilex ''S'' and ion-implanted Kapton. (orig.)

Printed electronic on flexible and glass substrates

Science.gov (United States)

Futera, Konrad; Jakubowska, Małgorzata; Kozioł, Grażyna

2010-09-01

Organic electronics is a platform technology that enables multiple applications based on organic electronics but varied in specifications. Organic electronics is based on the combination of new materials and cost-effective, large area production processes that provide new fields of application. Organic electronic by its size, weight, flexibility and environmental friendliness electronics enables low cost production of numerous electrical components and provides for such promising fields of application as: intelligent packaging, low cost RFID, flexible solar cells, disposable diagnostic devices or games, and printed batteries [1]. The paper presents results of inkjetted electronics elements on flexible and glass substrates. The investigations was target on characterizing shape, surface and geometry of printed structures. Variety of substrates were investigated, within some, low cost, non specialized substrate, design for other purposes than organic electronic.

Structural transformations in MoOx thin films grown by pulsed laser deposition

International Nuclear Information System (INIS)

Camacho-Lopez, M.A.; Haro-Poniatowski, E.; Escobar-Alarcon, L.

2004-01-01

In this work, laser-induced crystallization in MoO x thin films (1.8≤x≤2.1) is reported. This transformation involves a MoO x oxidation and subsequently a crystallization process from amorphous MoO 3 to crystalline αMoO 3 . For comparison purposes crystallization is induced thermally, in an oven, as well. The crystallization kinetics is monitored by Raman spectroscopy; a threshold in the energy density necessary to induce the phase transformation is determined in the case of photo-crystallization. This threshold depends on the type of substrate on which the film is deposited. For the thin films deposited on glass substrates, the structural transformation is from amorphous MoO x to the thermodynamically stable αMoO 3 crystalline phase. For the thin films deposited on Si(100) the structural transformation is from amorphous MoO x to a mixture of αMoO 3 and the thermodynamically unstable βMoO 3 crystalline phases. The structural transformations are also characterized by scanning electron microscopy and light-transmission experiments. (orig.)

Development of a High Precision Edge Alignment System for Touch-Panel Glass Substrates

Directory of Open Access Journals (Sweden)

Hau-Wei Lee

2014-06-01

Full Text Available There are two kinds of alignment systems, marked and unmarked. The glass substrate for touch panels is categorized as an unmarked work piece. Vision based glass substrate alignment (GSA relies on the edge of the glass. Traditional GSA systems compensate first for angular and then for linear error. This reduces alignment accuracy and increases alignment time and edge detection usually takes longer than 10 ms. This study proposes an effortless edge detection method. This method is very simple and can significantly reduce the time taken to detect the edge to about 6 ms using a 1.3 megapixel image. In this study, a floating center idea is used to control the glass substrate on a high precision coplanar XXY alignment stage. According to the method, users can set the rotation center anywhere as long as it is on the working (xy plane. Tolerance prognosis is also considered in this study to help the operator decide if the substrate is usable or should be rejected. The experimental results show alignment repeatability of the x, y, and θ axes to be 1 μm, 1 μm, and 5 arcsec, respectively.

High performance, transparent a-IGZO TFTs on a flexible thin glass substrate

International Nuclear Information System (INIS)

Lee, Gwang Jun; Jang, Jae Eun; Kim, Joonwoo; Kim, Jung-Hye; Jeong, Soon Moon; Jeong, Jaewook

2014-01-01

We investigated electrical properties of transparent amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with amorphous indium zinc oxide (a-IZO) transparent electrodes on a flexble thin glass substrate. The TFTs show a high field-effect mobility, a good subthreshold slope and a high on/off ratio owing to the high temperature thermal annealing process which cannot be applied to typical transparent polymer-based flexible substrates. Bias stress instability tests applying tensile stress concurrently with the bending radius of up to 40 mm indicated that mechanically and electrically stable a-IGZO TFTs can be fabricated on the transparent thin glass substrate. (paper)

Large-scale uniform ZnO tetrapods on catalyst free glass substrate by thermal evaporation method

Energy Technology Data Exchange (ETDEWEB)

Alsultany, Forat H., E-mail: foratusm@gmail.com [School of Physics, USM, 11800 Penang (Malaysia); Hassan, Z. [Institute of Nano-Optoelectronics Research and Technology Laboratory (INOR), USM, 11800 Penang (Malaysia); Ahmed, Naser M. [School of Physics, USM, 11800 Penang (Malaysia)

2016-07-15

Highlights: • Investigate the growth of ZnO-Ts on glass substrate by thermal evaporation method. • Glass substrate without any catalyst or a seed layer. • The morphology was controlled by adjusting the temperature of the material and the substrate. • Glass substrate was placed vertically in the quartz tube. - Abstract: Here, we report for the first time the catalyst-free growth of large-scale uniform shape and size ZnO tetrapods on a glass substrate via thermal evaporation method. Three-dimensional networks of ZnO tetrapods have needle–wire junctions, an average leg length of 2.1–2.6 μm, and a diameter of 35–240 nm. The morphology and structure of ZnO tetrapods were investigated by controlling the preparation temperature of each of the Zn powder and the glass substrate under O{sub 2} and Ar gases. Studies were carried out on ZnO tetrapods using X-ray diffraction, field emission scanning electron microscopy, UV–vis spectrophotometer, and a photoluminescence. The results showed that the sample grow in the hexagonal wurtzite structure with preferentially oriented along (002) direction, good crystallinity and high transmittance. The band gap value is about 3.27 eV. Photoluminescence spectrum exhibits a very sharp peak at 378 nm and a weak broad green emission.

Surface treatment of glass substrates for the preparation of long-lived carbon stripper foils

International Nuclear Information System (INIS)

Takeuchi, Suehiro; Takekoshi, Eiko

1981-02-01

Glass substrates having uniformly distributed microscopic grains on the surfaces are useful to make long-lived carbon stripper foils for heavy ions. A method of surface treatment of glass substrates to form the surface structure is described. This method consists of precipitation of glass components, such as soda, onto the surfaces in a hot and humid atmosphere and a fogging treatment of forming microscopic grains of the precipitated substances. Some results of studies on the treatment conditions are also presented. (author)

Strictly monolayer large continuous MoS2 films on diverse substrates and their luminescence properties

International Nuclear Information System (INIS)

Mohapatra, P. K.; Deb, S.; Singh, B. P.; Vasa, P.; Dhar, S.

2016-01-01

Despite a tremendous interest on molybdenum disulfide as a thinnest direct band gap semiconductor, single step synthesis of a large area purely monolayer MoS 2 film has not yet been reported. Here, we report a CVD route to synthesize a continuous film of strictly monolayer MoS 2 covering an area as large as a few cm 2 on a variety of different substrates without using any seeding material or any elaborate pretreatment of the substrate. This is achieved by allowing the growth to take place in the naturally formed gap between a piece of SiO 2 coated Si wafer and the substrate, when the latter is placed on top of the former inside a CVD reactor. We propose a qualitative model to explain why the MoS 2 films are always strictly monolayer in this method. The photoluminescence study of these monolayers shows the characteristic excitonic and trionic features associated with monolayer MoS 2 . In addition, a broad defect related luminescence band appears at ∼1.7 eV. As temperature decreases, the intensity of this broad feature increases, while the band edge luminescence reduces

Broadband anti-reflective and water-repellent coatings on glass substrates for self-cleaning photovoltaic cells

International Nuclear Information System (INIS)

Li, Xiaoyu; He, Junhui; Liu, Weiyi

2013-01-01

Graphical abstract: High performance broadband antireflective and water-repellent coatings were fabricated on glass substrates, which can improve the short-circuit current of solar cells as much as 6.6% in comparison with glass substrates without the coatings. - Highlights: • Broadband anti-reflective and water-repellent coatings were fabricated. • Transmittance increased to 99.0%, significantly higher than that of commercial solar glasses. • The performance of standard solar cells with the AR coating was enhanced as much as 6.6%. - Abstract: High performance broadband antireflective (AR) and water-repellent coatings were fabricated on glass substrates by assembly of silica nanoparticles and polyelectrolytes via the layer-by-layer (LbL) assembly technique, followed by calcination and hydrophobic modification. A porous poly(diallyladimethylammonium chloride) (PDDA)/20 nm SiO 2 nanoparticles (S-20) multilayer coating with AR property was prepared first. The maximum transmittance is as high as 99.0%, while that of the glass substrate is only 91.3%. After calcination and hydrophobic modification, the coating became water-repellent while maintaining the good AR property. Such water-repellent AR coatings can improve the short-circuit current of solar cells as much as 6.6% in comparison with glass substrates without the coatings. Scanning electron microscopy (SEM) was used to observe the morphology and thickness of coatings. Transmission spectra and reflection spectra were characterized by UV–vis spectrophotometer. The surface wettability was studied by a contact angle/interface system

Corrosion-resistant amorphous metallic films of Mo49Cr33B18 alloy

Science.gov (United States)

Ramesham, R.; Distefano, S.; Fitzgerald, D.; Thakoor, A. P.; Khanna, S. K.

1987-01-01

Corrosion-resistant amorphous metallic alloy films of Mo49Cr33B18 with a crystallization temperature of 590 C were deposited onto glass and quartz substrates by magnetron sputter-quench technique. The amorphous nature of the films was confirmed by their diffuse X-ray diffraction patterns. The deposited films are densely packed (zone T) and exhibit low stress and good adhesion to the substrate. Corrosion current of as-deposited coating of MoCrB amorphous metallic alloy is approximately three orders of magnitude less than the corrosion current of 304 stainless steel in 1N H2SO4 solution.

Application of NiMoNb adhesion layer on plasma-treated polyimide substrate for flexible electronic devices

Energy Technology Data Exchange (ETDEWEB)

Bang, S.-H.; Kim, K.-K.; Jung, H.-Y.; Kim, T.-H.; Jeon, S.-H. [Metal and Material Technology Group, R and D Center, LS Mtron Ltd., Gyeonggi 431-080 (Korea, Republic of); Seol, Jae-Bok, E-mail: zptkfm20@hanmail.net [Max-Planck-Insititut für Eisenforschung, Max-Planck-Str. 1, D-40237 Düsseldorf (Germany)

2014-05-02

A thin film, NiMoNb, was introduced as an adhesion layer between the Cu metal and the insulator polyimide substrate in a flexible Cu-clad laminated structure. Using 90° peel test, we evaluated the peel strength of the system as a function of the thickness of the adhesion layer. An increase in the NiMoNb thickness from 7 to 40 nm enhanced the peel strength of the deposited systems. After plasma treatment by the roll-to-roll method, the multilayer structure showed an outstanding peel strength of ∼ 529 N/m, even after thermal annealing at 150 °C for 168 h. We also studied the role of plasma treatment of the polyimide substrate on the adhesion strength and microstructure of a flexible Cu-clad laminated structure by peel strength, atomic force microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. These experimental observations showed that the plasma-treated polyimide substrate with the deposition of NiMoNb showed the enhanced adhesion of ∼ 656 N/m, because of the change of functional groups, which affected the bonding force and crystallinity of the thin films deposited on polyimide, rather than an increase in the surface roughness. - Highlights: • NiMoNb film on polyimide substrate was employed for higher peel strength. • Plasma-treated substrate enhances the peel strength of multilayer. • Even when annealed at 150 °C, plasma-treated films showed enhanced peel strength.

Application of NiMoNb adhesion layer on plasma-treated polyimide substrate for flexible electronic devices

International Nuclear Information System (INIS)

Bang, S.-H.; Kim, K.-K.; Jung, H.-Y.; Kim, T.-H.; Jeon, S.-H.; Seol, Jae-Bok

2014-01-01

A thin film, NiMoNb, was introduced as an adhesion layer between the Cu metal and the insulator polyimide substrate in a flexible Cu-clad laminated structure. Using 90° peel test, we evaluated the peel strength of the system as a function of the thickness of the adhesion layer. An increase in the NiMoNb thickness from 7 to 40 nm enhanced the peel strength of the deposited systems. After plasma treatment by the roll-to-roll method, the multilayer structure showed an outstanding peel strength of ∼ 529 N/m, even after thermal annealing at 150 °C for 168 h. We also studied the role of plasma treatment of the polyimide substrate on the adhesion strength and microstructure of a flexible Cu-clad laminated structure by peel strength, atomic force microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. These experimental observations showed that the plasma-treated polyimide substrate with the deposition of NiMoNb showed the enhanced adhesion of ∼ 656 N/m, because of the change of functional groups, which affected the bonding force and crystallinity of the thin films deposited on polyimide, rather than an increase in the surface roughness. - Highlights: • NiMoNb film on polyimide substrate was employed for higher peel strength. • Plasma-treated substrate enhances the peel strength of multilayer. • Even when annealed at 150 °C, plasma-treated films showed enhanced peel strength

Calcium and Zinc Containing Bactericidal Glass Coatings for Biomedical Metallic Substrates

Directory of Open Access Journals (Sweden)

Leticia Esteban-Tejeda

2014-07-01

Full Text Available The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3–SiO2–Na2O–ZnO and SiO2–Na2O–Al2O3–CaO–B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log.

Structural transformations in MoO{sub x} thin films grown by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Camacho-Lopez, M.A.; Haro-Poniatowski, E. [Departamento de Fisica, Laboratorio de Optica Cuantica, Universidad Autonoma Metropolitana Iztapalapa, Apdo. Postal 55-534, 09340, Mexico D. F. (Mexico); Escobar-Alarcon, L. [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, 11801, Mexico D. F. (Mexico)

2004-01-01

In this work, laser-induced crystallization in MoO{sub x} thin films (1.8{<=}x{<=}2.1) is reported. This transformation involves a MoO{sub x} oxidation and subsequently a crystallization process from amorphous MoO{sub 3} to crystalline {alpha}MoO{sub 3}. For comparison purposes crystallization is induced thermally, in an oven, as well. The crystallization kinetics is monitored by Raman spectroscopy; a threshold in the energy density necessary to induce the phase transformation is determined in the case of photo-crystallization. This threshold depends on the type of substrate on which the film is deposited. For the thin films deposited on glass substrates, the structural transformation is from amorphous MoO{sub x} to the thermodynamically stable {alpha}MoO{sub 3} crystalline phase. For the thin films deposited on Si(100) the structural transformation is from amorphous MoO{sub x} to a mixture of {alpha}MoO{sub 3} and the thermodynamically unstable {beta}MoO{sub 3} crystalline phases. The structural transformations are also characterized by scanning electron microscopy and light-transmission experiments. (orig.)

Binding of mouse immunoglobulin G to polylysine-coated glass substrate for immunodiagnosis

Science.gov (United States)

Vashist, Sandeep Kumar; Tewari, Rupinder; Bajpai, Ram Prakash; Bharadwaj, Lalit Mohan; Raiteri, Roberto

2006-12-01

We report a method for immobilizing mouse immunoglobulin G (IgG) on polylysine-coated glass substrate for immunodiagnostic applications. Mouse IgG molecules were immobilized on polylysine-coated glass substrate employing 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and protein A. The amino groups of the polylysine-coated glass slide were cross linked to the carboxyl groups of protein A employing EDC crosslinker. Protein A was employed as it binds to the constant Fc region of antibodies keeping their antigen binding sites on the variable F ab region free to bind to antigens. The qualitative analysis of surface immobilized mouse IgG was done by fluorescent microscopy employing fluorescein isothiocyanate (FITC) labeled mouse IgG molecules. The immobilization densities of protein A and mouse IgG were determined by 3, 3', 4, 4'-tetramethyl benzidine (TMB) substrate assay employing horse radish peroxidise labelled molecules and were found to be 130 +/- 17 ng/cm2 and 596 +/- 31 ng/cm2 respectively. The biomolecular coatings analyzed by atomic force microscopy (AFM) were found to be uniform.

Impact of optical properties of front glass substrates on Cu(In,Ga)Se{sub 2} solar cells using lift-off process

Energy Technology Data Exchange (ETDEWEB)

Tamura, Akihiro, E-mail: ro005080@ed.ritsumei.ac.jp [College of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-0058 (Japan); Abe, Yasuhiro [Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Shiga 525-0058 (Japan); Minemoto, Takashi [College of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-0058 (Japan)

2013-11-01

Transmittance of a front glass is one of the important factors in the development of high efficiency superstrate-type Cu(In,Ga)Se{sub 2} (CIGS) solar cells. In this study, we investigated the impact of optical properties of the front glass on the solar cell performance of the CIGS solar cells fabricated using the lift-off process. First, optical properties of quartz substrates and soda-lime glass (SLG) substrates with various thicknesses were investigated. Although optical properties of the SLG substrates depend on the thickness, those of the quartz substrates hardly depend on the thickness. Secondly, the superstrate-type CIGS solar cells were fabricated using 1-mm-thick SLG or 1-mm-thick quartz substrates. As a result, the short-circuit current density of the superstrate-type CIGS solar cell with 1-mm-thick quartz substrate was approximately 7% higher than that with 1-mm-thick SLG substrate, and its conversion efficiency was 7.1%. The external quantum efficiency of the solar cells was also improved using the quartz substrate as a front glass because transmittance and absorptance of the quartz substrate were superior to those of the SLG substrate. We therefore conclude that optical properties of the front glasses play an important role in the improvement of the superstrate-type solar cells. - Highlights: • Superstrate type Cu(In,Ga)Se{sub 2} solar cells are fabricated by lift-off process. • Various glasses are used as front glass for lift-off. • The impact of optical properties of the glasses on cell performance is investigated. • Quartz front glass gives 7% higher short-circuit current than soda-lime glass. • High transmittance is desired for front glass.

Scalable Patterning of MoS2Nanoribbons by Micromolding in Capillaries

KAUST Repository

Hung, Yu-Han

2016-07-27

In this study, we report a facile approach to prepare dense arrays of MoS2 nanoribbons by combining procedures of micromolding in capillaries (MIMIC) and thermolysis of thiosalts ((NH4)2MoS4) as the printing ink. The obtained MoS2 nanoribbons had a thickness reaching as low as 3.9 nm, a width ranging from 157 to 465 nm, and a length up to 2 cm. MoS2 nanoribbons with an extremely high aspect ratio (length/width) of ∼7.4 × 108 were achieved. The MoS2 pattern can be printed on versatile substrates, such as SiO2/Si, sapphire, Au film, FTO/glass, and graphene-coated glass. The degree of crystallinity of the as-prepared MoS2 was discovered to be adjustable by varying the temperature through postannealing. The high-temperature thermolysis (1000 °C) results in high-quality conductive samples, and field-effect transistors based on the patterned MoS2 nanoribbons were demonstrated and characterized, where the carrier mobility was comparable to that of thin-film MoS2. In contrast, the low-temperature-treated samples (170 °C) result in a unique nanocrystalline MoSx structure (x ≈ 2.5), where the abundant and exposed edge sites were obtained from highly dense arrays of nanoribbon structures by this MIMIC patterning method. The patterned MoSx was revealed to have superior electrocatalytic efficiency (an overpotential of ∼211 mV at 10 mA/cm2 and a Tafel slope of 43 mV/dec) in the hydrogen evolution reaction (HER) when compared to the thin-film MoS2. The report introduces a new concept for rapidly fabricating cost-effective and high-density MoS2/MoSx nanostructures on versatile substrates, which may pave the way for potential applications in nanoelectronics/optoelectronics and frontier energy materials. © 2016 American Chemical Society.

Morphology and transmittance of porous alumina on glass substrate

Energy Technology Data Exchange (ETDEWEB)

Guo Peitao, E-mail: guopeitao@hotmail.com [Wuhan University of Technology. Wuhan (China); Xia Zhilin [Wuhan University of Technology. Wuhan (China); Key Laboratory of Low Dimensional Materials and Application Technology, Xiangtan University, Ministry of Education, Xiangtan (China); Xue Yiyu [Wuhan University of Technology. Wuhan (China); Huang Caihua [China Three Gorges University, Yichang (China); Zhao Lixin [Wuhan University of Technology. Wuhan (China)

2011-02-01

The porous optical film has higher threshold of laser-induced damage than densified films, for the study of mechanism of laser-induced damage of porous optical film with ordered pore structure. Porous anodic alumina (PAA) film with high transmittance on glass substrate has been prepared. Aluminum film was deposited on glass substrate by means of resistance and electron beam heat (EBH) evaporation. Porous alumina was prepared in oxalic acid solution under different anodizing conditions. At normal incidence, the optical transmittance spectrum over 300-1000 nm spectra region was obtained by spectrophotometer. SEM was introduced to analysis the morphology of the porous alumina film. The pore aperture increased with the increase of anodizing voltage, which resulted in a rapid decrease of the pore concentration and the optical thickness of porous alumina film. Damage morphology of porous alumina film is found to be typically defects initiated, and the defect is the pore presented on the film.

Conductive stability of graphene on PET and glass substrates under blue light irradiation

Science.gov (United States)

Cao, Xueying; Liu, Xianming; Li, Xiangdi; Lei, Xiaohua; Chen, Weimin

2018-01-01

Electrical properties of graphene transparent conductive film under visible light irradiation are investigated. The CVD-grown graphene on Polyethylene Terephthalate (PET) and glass substrates for flexible and rigid touch screen display application are chosen for research. The resistances of graphene with and without gold trichloride (AuCl3) doping are measured in vacuum and atmosphere environment under blue light irradiation. Results show that the conductivities of all samples change slowly under light irradiation. The change rate and degree are related to the substrate material, doping, environment and lighting power. Graphene on flexible PET substrate is more stable than that on rigid glass substrate. Doping can improve the electrical conductivity but induce instability under light irradiation. Finally, the main reason resulting in the graphene resistance slowly increasing under blue light irradiation is analyzed.

Development of Fe-B Based Bulk Metallic Glasses: Morphology of Residual Phases in Fe50Ni16Mo6B18Zr10 Glass

Directory of Open Access Journals (Sweden)

Tiburce A. Aboki

2013-04-01

Full Text Available Iron-boron based bulk metallic glasses (BMG development has been initiated using Fe40Ni38Mo4B18 as precursor. Addition of zirconium up to 10 atomic % along with the reduction of Ni proportion improves the glass forming ability (GFA, which is optimum when Ni is suppressed in the alloy. However melting instability occurred during the materials fabrication resulting in the formation of residual crystalline phases closely related to the amorphous phase. Microstructure study shows an evolution from amorphous structure to peculiar acicular structure, particularly for Fe50Ni16Mo6B18Zr10, suggesting the amorphous structure as interconnected atomic sheets like “atomic mille feuilles” whose growth affects the alloys’ GFA.

Strictly monolayer large continuous MoS{sub 2} films on diverse substrates and their luminescence properties

Energy Technology Data Exchange (ETDEWEB)

Mohapatra, P. K.; Deb, S.; Singh, B. P.; Vasa, P.; Dhar, S., E-mail: dhar@phy.iitb.ac.in [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India)

2016-01-25

Despite a tremendous interest on molybdenum disulfide as a thinnest direct band gap semiconductor, single step synthesis of a large area purely monolayer MoS{sub 2} film has not yet been reported. Here, we report a CVD route to synthesize a continuous film of strictly monolayer MoS{sub 2} covering an area as large as a few cm{sup 2} on a variety of different substrates without using any seeding material or any elaborate pretreatment of the substrate. This is achieved by allowing the growth to take place in the naturally formed gap between a piece of SiO{sub 2} coated Si wafer and the substrate, when the latter is placed on top of the former inside a CVD reactor. We propose a qualitative model to explain why the MoS{sub 2} films are always strictly monolayer in this method. The photoluminescence study of these monolayers shows the characteristic excitonic and trionic features associated with monolayer MoS{sub 2}. In addition, a broad defect related luminescence band appears at ∼1.7 eV. As temperature decreases, the intensity of this broad feature increases, while the band edge luminescence reduces.

Origin of the n -type and p -type conductivity of MoS 2 monolayers on a SiO 2 substrate

KAUST Repository

Dolui, Kapildeb

2013-04-02

Ab initio density functional theory calculations are performed to study the electronic properties of a MoS2 monolayer deposited over a SiO 2 substrate in the presence of interface impurities and defects. When MoS2 is placed on a defect-free substrate, the oxide plays an insignificant role since the conduction band top and the valence band minimum of MoS2 are located approximately in the middle of the SiO2 band gap. However, if Na impurities and O dangling bonds are introduced at the SiO2 surface, these lead to localized states, which modulate the conductivity of the MoS2 monolayer from n- to p-type. Our results show that the conductive properties of MoS2 deposited on SiO 2 are mainly determined by the detailed structure of the MoS 2/SiO2 interface, and suggest that doping the substrate can represent a viable strategy for engineering MoS2-based devices. © 2013 American Physical Society.

Superhydrophobic ZnAl double hydroxide nanostructures and ZnO films on Al and glass substrates

Energy Technology Data Exchange (ETDEWEB)

De, Debasis, E-mail: debasis.de@bcrec.ac.in [Electronics and Instrumentation Engineering Department, Dr. B C Roy Engineering College, Durgapur, West Bengal 713206 (India); Sarkar, D.K. [Centre Universitaire de Recherche sur l' Aluminium (CURAL), L' Université du Québec à Chicoutimi, 555 Blvd. Université, Chicoutimi, Saguenay, Québec G7H 2B1 (Canada)

2017-01-01

Superhydrophobic nanostructured ZnAl: layered double hydroxides (LDHs) and ZnO films have been fabricated on Al and glass substrates, respectively, by a simple and cost effective chemical bath deposition technique. Randomly oriented hexagonal patterned of ZnAl: LDHs thin nanoplates are clearly observed on Al-substrate in the scanning electron microscopic images. The average size of these hexagonal plates is ∼4 μm side and ∼30 nm of thickness. While on the glass substrate, a oriented hexagonal patterned ZnO nanorods (height ∼5 μm and 1 μm diameter) are observed and each rod is further decorated throughout the top few nanometers with several nanosteps. At the top of the nanorod, a perfectly hexagonal patterned ZnO surface with ∼250 nm sides is observed. The tendency to form hexagonal morphological features is due to the hexagonal crystal structure of ZnO confirmed from X-ray diffraction patterns and transmission electron microscopy image. The ZnAl: LDHs and/or ZnO coated substrates have been passivated by using stearic acid (SA) molecules. Infrared spectra of passivated ZnAl: LDHs coated substrates confirm the presence of SA. X-ray diffraction pattern also corroborates the results of infrared spectrum. The contact angle of the as prepared samples is zero. The superhydrophobicity is achieved by observing contact angle of ∼161° with a hysteresis of ∼4° for Al-substrate. On the glass substrate, a higher contact angle of ∼168° with a lower hysteresis of ∼3° is observed. A lower surface roughness of ∼4.93 μm is measured on ZnAl: LDHs surface layer on the Al substrate as compare to a higher surface roughness of 6.87 μm measured on ZnO layer on glass substrate. The superhydrophobicity of passivated nanostructured films on two different substrates is observed due to high surface roughness and low surface energy. - Highlights: • ZnAl: layered double hydroxides (LDHs) nanoplates are fabricated on Al substrate. • ZnO nanorods are fabricated on

Growth-substrate induced performance degradation in chemically synthesized monolayer MoS{sub 2} field effect transistors

Energy Technology Data Exchange (ETDEWEB)

Amani, Matin; Chin, Matthew L.; Mazzoni, Alexander L.; Burke, Robert A.; Dubey, Madan, E-mail: madan.dubey.civ@mail.mil [Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, Maryland 20723 (United States); Najmaei, Sina; Ajayan, Pulickel M.; Lou, Jun [Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005 (United States)

2014-05-19

We report on the electronic transport properties of single-layer thick chemical vapor deposition (CVD) grown molybdenum disulfide (MoS{sub 2}) field-effect transistors (FETs) on Si/SiO{sub 2} substrates. MoS{sub 2} has been extensively investigated for the past two years as a potential semiconductor analogue to graphene. To date, MoS{sub 2} samples prepared via mechanical exfoliation have demonstrated field-effect mobility values which are significantly higher than that of CVD-grown MoS{sub 2}. In this study, we will show that the intrinsic electronic performance of CVD-grown MoS{sub 2} is equal or superior to that of exfoliated material and has been possibly masked by a combination of interfacial contamination on the growth substrate and residual tensile strain resulting from the high-temperature growth process. We are able to quantify this strain in the as-grown material using pre- and post-transfer metrology and microscopy of the same crystals. Moreover, temperature-dependent electrical measurements made on as-grown and transferred MoS{sub 2} devices following an identical fabrication process demonstrate the improvement in field-effect mobility.

Photo- and Electrochromic Properties of Activated Reactive Evaporated MoO3 Thin Films Grown on Flexible Substrates

Directory of Open Access Journals (Sweden)

K. Hari Krishna

2008-01-01

Full Text Available The molybdenum trioxide (MoO3 thin films were grown onto ITO-coated flexible Kapton substrates using plasma assisted activated reactive evaporation technique. The film depositions were carried out at constant glow power and oxygen partial pressures of 8 W and 1×10−3 Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. The MoO3 thin films prepared at a substrate temperature of 523 K were found to be composed of uniformly distributed nanosized grains with an orthorhombic structure of α-MoO3. These nanocrystalline MoO3 thin films exhibited higher optical transmittance of about 80% in the visible region with an evaluated optical band gap of 3.29 eV. With the insertion of 12.5 mC/cm2, the films exhibited an optical modulation of 40% in the visible region with coloration efficiency of 22 cm2/C at the wavelength of 550 nm. The MoO3 films deposited at 523 K demonstrated better photochromic properties and showed highest color center concentration for the irradiation time of 30 minutes at 100 mW/cm2.

MoS2 solid-lubricating film fabricated by atomic layer deposition on Si substrate

Science.gov (United States)

Huang, Yazhou; Liu, Lei; Lv, Jun; Yang, Junjie; Sha, Jingjie; Chen, Yunfei

2018-04-01

How to reduce friction for improving efficiency in the usage of energy is a constant challenge. Layered material like MoS2 has long been recognized as an effective surface lubricant. Due to low interfacial shear strengths, MoS2 is endowed with nominal frictional coefficient. In this work, MoS2 solid-lubricating film was directly grown by atomic layer deposition (ALD) on Si substrate using MoCl5 and H2S. Various methods were used to observe the grown MoS2 film. Moreover, nanotribological properties of the film were observed by an atomic force microscope (AFM). Results show that MoS2 film can effectively reduce the friction force by about 30-45% under different loads, indicating the huge application value of the film as a solid lubricant. Besides the interlayer-interfaces-sliding, the smaller capillary is another reason why the grown MoS2 film has smaller friction force than that of Si.

Coating extracellular matrix proteins on a (3-aminopropyl)triethoxysilane-treated glass substrate for improved cell culture.

Science.gov (United States)

Masuda, Hiro-taka; Ishihara, Seiichiro; Harada, Ichiro; Mizutani, Takeomi; Ishikawa, Masayori; Kawabata, Kazushige; Haga, Hisashi

2014-01-01

We demonstrate that a (3-aminopropyl)triethoxysilane-treated glass surface is superior to an untreated glass surface for coating with extracellular matrix (ECM) proteins when used as a cell culture substrate to observe cell physiology and behavior. We found that MDCK cells cultured on untreated glass coated with ECM removed the coated ECM protein and secreted different ECM proteins. In contrast, the cells did not remove the coated ECM protein when seeded on (3-aminopropyl)triethoxysilane-treated (i.e., silanized) glass coated with ECM. Furthermore, the morphology and motility of cells grown on silanized glass differed from those grown on non-treated glass, even when both types of glass were initially coated with laminin. We also found that cells on silanized glass coated with laminin had higher motility than those on silanized glass coated with fibronectin. Based on our results, we suggest that silanized glass is a more suitable cell culture substrate than conventional non-treated glass when coated by ECM for observations of ECM effects on cell physiology.

Adhesion energies of 2D graphene and MoS{sub 2} to silicon and metal substrates

Energy Technology Data Exchange (ETDEWEB)

Torres, Jorge; Liu, Pei; Yun, Minhee [Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, PA (United States); Zhu, Yisi [Materials Science Division, Argonne National Lab, Lemont, IL (United States); Lim, Seong Chu [Department of Energy Science, Sungkyunkwan University (SKKU), Suwon (Korea, Republic of); Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon (Korea, Republic of)

2018-01-15

In this paper, results for the adhesion energy of graphene and MoS{sub 2} to silicon based and metal substrates using the intercalation of nanoparticles method are presented. In this method, nanoparticles are dispersed onto the substrates before transferring the 2D material onto the substrate. This causes a blister to form, the width and height of which can be measured by AFM. Using a simple model then allows for the adhesion energy to be found. The substrates tested are SiO{sub 2}, Si{sub 3}N{sub 4}, gold, and platinum. Gold is found to have the highest adhesion energy per area of 7687.10 and 1207.26 mJ m{sup -2} for graphene and MoS{sub 2} respectively. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Morphologies of CaMoO4 crystals in simulated nuclear waste disposal glass

NARCIS (Netherlands)

Li, D.; Sengers, E.G.F.; Janssen, F.J.J.G.; Waal, de H.

1992-01-01

Two kinds of morphologies of CaMoO4 crystals in K3 glass heat-treated between 850 and 1120 K are presented. One kind of morphol. is rather special. It is elongated in 1 direction. The cross section normal to the longer direction is a cross with 2 perpendicular arms of the same length. Application to

Low Power Consumption Complementary Inverters with n-MoS2 and p-WSe2 Dichalcogenide Nanosheets on Glass for Logic and Light-Emitting Diode Circuits.

Science.gov (United States)

Jeon, Pyo Jin; Kim, Jin Sung; Lim, June Yeong; Cho, Youngsuk; Pezeshki, Atiye; Lee, Hee Sung; Yu, Sanghyuck; Min, Sung-Wook; Im, Seongil

2015-10-14

Two-dimensional (2D) semiconductor materials with discrete bandgap become important because of their interesting physical properties and potentials toward future nanoscale electronics. Many 2D-based field effect transistors (FETs) have thus been reported. Several attempts to fabricate 2D complementary (CMOS) logic inverters have been made too. However, those CMOS devices seldom showed the most important advantage of typical CMOS: low power consumption. Here, we adopted p-WSe2 and n-MoS2 nanosheets separately for the channels of bottom-gate-patterned FETs, to fabricate 2D dichalcogenide-based hetero-CMOS inverters on the same glass substrate. Our hetero-CMOS inverters with electrically isolated FETs demonstrate novel and superior device performances of a maximum voltage gain as ∼27, sub-nanowatt power consumption, almost ideal noise margin approaching 0.5VDD (supply voltage, VDD=5 V) with a transition voltage of 2.3 V, and ∼800 μs for switching delay. Moreover, our glass-substrate CMOS device nicely performed digital logic (NOT, OR, and AND) and push-pull circuits for organic light-emitting diode switching, directly displaying the prospective of practical applications.

Low-temperature synthesis of 2D MoS2 on a plastic substrate for a flexible gas sensor.

Science.gov (United States)

Zhao, Yuxi; Song, Jeong-Gyu; Ryu, Gyeong Hee; Ko, Kyung Yong; Woo, Whang Je; Kim, Youngjun; Kim, Donghyun; Lim, Jun Hyung; Lee, Sunhee; Lee, Zonghoon; Park, Jusang; Kim, Hyungjun

2018-05-08

The efficient synthesis of two-dimensional molybdenum disulfide (2D MoS2) at low temperatures is essential for use in flexible devices. In this study, 2D MoS2 was grown directly at a low temperature of 200 °C on both hard (SiO2) and soft substrates (polyimide (PI)) using chemical vapor deposition (CVD) with Mo(CO)6 and H2S. We investigated the effect of the growth temperature and Mo concentration on the layered growth by Raman spectroscopy and microscopy. 2D MoS2 was grown by using low Mo concentration at a low temperature. Through optical microscopy, Raman spectroscopy, X-ray photoemission spectroscopy, photoluminescence, and transmission electron microscopy measurements, MoS2 produced by low-temperature CVD was determined to possess a layered structure with good uniformity, stoichiometry, and a controllable number of layers. Furthermore, we demonstrated the realization of a 2D MoS2-based flexible gas sensor on a PI substrate without any transfer processes, with competitive sensor performance and mechanical durability at room temperature. This fabrication process has potential for burgeoning flexible and wearable nanotechnology applications.

Glass substrates crosslinked with tetracycline-imprinted polymeric silicate and CdTe quantum dots as fluorescent sensors

Energy Technology Data Exchange (ETDEWEB)

Chao, Mu-Rong [Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Hu, Chiung-Wen [Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Chen, Jian-Lian, E-mail: cjl@mail.cmu.edu.tw [School of Pharmacy, China Medical University, No. 91 Hsueh-Shih Road, Taichung 40402, Taiwan (China)

2016-06-21

A fluorescence-based sensor that combines the merits of quantum dots (QDs) and molecularly imprinted polymers (MIPs) was first fabricated on a glass substrate via a sol–gel route. Some of the key performance factors, including silane selection, substrate etching, the reaction times of glass silanization and sol–gel polymerization, and the times and methods used for template stripping and loading, were discussed and determined. After fabricating the sensor on either a 3-aminopropyltriethoxysilane (APS) or a 3-mercaptopropyltriethoxysilane (MPS) modified glass substrate, APS showed a much better performance than MPS as both the capping reagent of QDs and the functional monomer of tetracycline-templated MIPs. The APS-QDs on APS-modified glass had a higher imprinted factor (IF = 5.6), a lower LOD (2.1 μM, 3σ), and a more stable signal (2.8%, n = 10 at 70 μM) than those on the MPS-modified glass (IF = 5.2, LOD = 6.5 μM, stability = 6.2%). Furthermore, the recoveries of tetracycline (70 μM) from BSA (133 μg/mL) and FBS (0.66 ppt) by the APS-modified glass were 98% (RSD = 3.5%, n = 5) and 97% (RSD = 5.7%), respectively. For the MPS-modified glass, recoveries of 95% (RSD = 7.2%) and 89% (RSD = 8.7%) were observed at 67 μg/mL of BSA and 0.33 ppt of FBS, respectively. - Highlights: • QD-MIP composites were first built on a glass substrate through a sol–gel route. • Two silanes were evaluated as both a surface modifier and a functional capping monomer. • Fluorescence enhancement by template on glass was different from quenching in solution.

Low-temperature deposition of ZnO thin films on PET and glass substrates by DC-sputtering technique

International Nuclear Information System (INIS)

Banerjee, A.N.; Ghosh, C.K.; Chattopadhyay, K.K.; Minoura, Hideki; Sarkar, Ajay K.; Akiba, Atsuya; Kamiya, Atsushi; Endo, Tamio

2006-01-01

The structural, optical and electrical properties of ZnO thin films (260 - 490 nm thick) deposited by direct-current sputtering technique, at a relatively low-substrate temperature (363 K), onto polyethylene terephthalate and glass substrates have been investigated. X-ray diffraction patterns confirm the proper phase formation of the material. Optical transmittance data show high transparency (80% to more than 98%) of the films in the visible portion of solar radiation. Slight variation in the transparency of the films is observed with a variation in the deposition time. Electrical characterizations show the room-temperature conductivity of the films deposited onto polyethylene terephthalate substrates for 4 and 5 h around 0.05 and 0.25 S cm -1 , respectively. On the other hand, for the films deposited on glass substrates, these values are 8.5 and 9.6 S cm -1 for similar variation in the deposition time. Room-temperature conductivity of the ZnO films deposited on glass substrates is at least two orders of magnitude higher than that of ZnO films deposited onto polyethylene terephthalate substrates under identical conditions. Hall-measurements show the maximum carrier concentration of the films on PET and glass substrate around 2.8 x 10 16 and 3.1 x 10 2 cm -3 , respectively. This report will provide newer applications of ZnO thin films in flexible display technology

Stress-induced light scattering method for the detection of latent flaws on fine polished glass substrates.

Science.gov (United States)

Sakata, Y; Sakai, K; Nonaka, K

2014-08-01

Fine polishing techniques, such as the chemical mechanical polishing treatment, are one of the most important technique to glass substrate manufacturing. Mechanical interaction in the form of friction occurs between the abrasive and the substrate surface during polishing, which may cause formation of latent flaws on the glass substrate surface. Fine polishing-induced latent flaws may become obvious during a subsequent cleaning process if glass surfaces are corroded away by chemical interaction with the cleaning liquid. Latent flaws thus reduce product yield. In general, non-destructive inspection techniques, such as the light-scattering methods, used to detect foreign matters on the glass substrate surface. However, it is difficult to detect latent flaws by these methods because the flaws remain closed. Authors propose a novel inspection technique for fine polishing-induced latent flaws by combining the light scattering method with stress effects, referred to as the stress-induced light scattering method (SILSM). SILSM is able to distinguish between latent flaws and particles on the surface. In this method, samples are deformed by an actuator and stress effects are induced around the tips of latent flaws. Due to the photoelastic effect, the refractive index of the material around the tip of a latent flaw is changed. This changed refractive index is in turn detected by a cooled charge-coupled device camera as variations in light scattering intensity. In this report, surface latent flaws are detected non-destructively by applying SILSM to glass substrates, and the utility of SILSM evaluated as a novel inspection technique.

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

Energy Technology Data Exchange (ETDEWEB)

Janek, Joanna, E-mail: janek.joanna@gmail.com; Sołtys, Marta; Żur, Lidia; Pietrasik, Ewa; Pisarska, Joanna; Pisarski, Wojciech A.

2016-09-01

Series of lead-free borate glasses with different oxide modifiers and lanthanide ions were prepared. The effect of oxide modifiers MO (M = Ca, Sr, Ba) on spectroscopic properties of trivalent Ln{sup 3+} (Ln = Eu, Er, Pr) were systematically investigated. Especially, the luminescence spectra of Ln{sup 3+}-doped lead-free borate glasses are presented and discussed in relation to the impact of selective components (CaO, SrO and BaO). Several spectroscopic parameters, such as the fluorescence intensity ratio R/O (Eu{sup 3+}) and measured luminescence lifetimes for the {sup 5}D{sub 0} (Eu{sup 3+}), {sup 4}I{sub 13/2} (Er{sup 3+}) and {sup 1}D{sub 2} (Pr{sup 3+}) excited states of lanthanide ions were analyzed in details. The research proved that spectroscopic properties of trivalent Ln{sup 3+} depend significantly on kind of presence oxide modifiers MO (M = Ca, Sr, Ba) in glass host matrices. - Highlights: • Luminescence of Ln{sup 3+}-doped borate glasses was presented and discussed. • Effect of glass modifiers on spectroscopic properties of rare earths was studied. • Measured luminescence lifetimes of Ln{sup 3+} (Ln = Eu, Er, Pr) were analyzed. • Luminescence intensity ratios R/O (Eu{sup 3+}) were determined.

Comparison study of ITO thin films deposited by sputtering at room temperature onto polymer and glass substrates

International Nuclear Information System (INIS)

Guillen, C.; Herrero, J.

2005-01-01

Indium tin oxide (ITO) thin films have been grown simultaneously onto glass and polymer substrates at room temperature by sputtering from ceramic target. The structure, morphology and electro-optical characteristics of the ITO/glass and ITO/polymer samples have been analyzed by X-ray diffraction, atomic force microscopy, four-point electrical measurements and spectrophotometry. In the selected experimental conditions, the polycrystalline ITO coating shows higher average grain size and higher conductivity, with similar visible transmittance, onto the polymer than onto the glass substrate

Electronic conductivity in glasses of the TeO sub 2 -V sub 2 O sub 5 -MoO sub 3 system

Energy Technology Data Exchange (ETDEWEB)

Lebrun, N.; Levy, M; Souquet, J.L. (URA D1213-E.N.S.E.E.G., Saint Martin d' Heres (France). Laboratoire d' Ionique et d' Electrochimie du Solide)

1990-08-01

Conductivity and redox potential on glasses of the TeO{sub 2}-V{sub 2}O{sub 5}-MoO{sub 3} system have been measured. For temperatures between 20 to 200 pC, the electronic conductivity proceed by an activated mechanism. Variations of the pre-exponential factor interpreted by the small polaron theory indicate that only the vanadium ions are involved in the conduction mechanism. Cyclic voltamperometry measurements performed on TeO{sub 2}V{sub 2}O{sub 4}-MoO{sub 3} glasses as working electrode show that at 1 V difference between the V{sup +V}/V{sup +IV} and Mo{sup +I}/Mo{sup +V} redox potentials exists in the glassy material. This correspondend to an energy gap which may be to large to allow the electron transition from vanadium to molybdenum ions. (author). 13 refs.; 4 figs.; 1 tab.

A comparative study of Co thin film deposited on GaAs (1 0 0) and glass substrates

International Nuclear Information System (INIS)

Sharma, A.; Brajpuriya, R.; Tripathi, S.; Jain, D.; Dubey, R.; Shripathi, T.; Chaudhari, S.M.

2006-01-01

The structural, magnetic and transport properties of Co/GaAs (1 0 0) and Co/glass thin films have been investigated. The structural measurements reveal the crystalline nature of Co thin film grown on GaAs, while microcrystalline nature in case of glass substrate. The film grown on GaAs shows higher coercivity (49.0 G), lower saturation magnetization (3.65 x 10 -4 ) and resistivity (8 μΩ cm) values as compared to that on glass substrate (22 G, 4.77 x 10 -4 and 18 μΩ cm). The grazing incidence X-ray reflectivity and photoemission spectroscopy results show the interaction between Co and GaAs at the interface, while the Co layer grown on glass remains unaffected. These observed results are discussed and interpreted in terms of different growth morphologies and structures of as grown Co thin film on both substrates

Chemical states of molybdenum in radioactive waste glass

International Nuclear Information System (INIS)

Ishiguro, Katsuhiko; Kawanishi, Nobuo; Nagaki, Hiroshi; Naito, Aritsune

1982-01-01

In order to confirm an expectation that the chemical state of molybdenum in glass reflects the phase separation tendency of the yellow solid from the melt of borosilicate glass, simulated waste glasses were prepared, and ESCA analysis was performed using a commercially available electron spectrometer (PHI550 E) with an excitation source consisting of Mg Kα-ray. The effects of the concentration of Mo and FE 2 O 3 and the melting atmosphere (oxidizing or reducing) in which the samples were prepared on the chemical state of Mo and the solubility of MoO 3 were examined. From the observation of Mo spectra, it was shown that Mo in waste glass had several valencies, e.g., Mo(3), Mo(4), Mo(5) and Mo(6), while Mo in the yellow solid separated from the melts exhibited hexa-valent state, the peak intensity of higher valencies increased relatively with the increase of MoO 3 concentration, but the chemical state of Mo did not change remarkably around the solubility limit of MoO 3 , the melting atmosphere influenced on the Mo state in the waste glass, the peak intensity of Mo(6) increased relatively with the increasing Fe 2 O 3 concentration, and Mo in devitrified glass exhibited hexa-valent state. (Yoshitake, I.)

Probing the chemistry of adhesion between a 316L substrate and spin-on-glass coating

DEFF Research Database (Denmark)

Lampert, Felix; Kadkhodazadeh, Shima; Kasama, Takeshi

2018-01-01

Hydrogen silsesquioxane ([HSiO3/2]n) based "spin-on-glass" has been deposited on 316L substrate and cured in Ar/H2 gas atmosphere at 600 ºC to form a continuous surface coating with sub-micrometer thickness. The coating functionality depends primarily on the adhesion to the substrate, which...... is largely affected by the chemical interaction at the interface between the coating and the substrate. We have investigated this interface by transmission electron microscopy and electron energy loss spectroscopy. The analysis identified a 5-10 nm thick interaction zone containing signals from O, Si, Cr....... In agreement with computational thermodynamics, it is proposed that the spin-on-glass forms a chemically bonded silicate-rich interaction zone with the substrate. It was further suggested that this zone is composed of a corundum-type oxide at the substrate surface, followed by an olivine-structure intermediate...

Interpretation of dc and ac conductivity of Ag2O–SeO2–MoO3 glass-nanocomposite-semiconductor

International Nuclear Information System (INIS)

Bhattacharya, Sanjib; Kundu, Ranadip; Das, Anindya Sundar; Roy, Debasish

2015-01-01

Highlights: • Polaron hopping. • Dc and ac conductivity. • Mott's model and Greave's model. • Ag 2 MoO 4 , Ag 2 Mo 2 O 7 and Ag 6 Mo 10 O 33 nanoparticles and SeO 3 and SeO 4 nanoclusters. • XRD and FESEM studies. - Abstract: A new type of semiconducting glass-nanocomposites 0.3Ag 2 O–0.7 (xMoO 3 –(1 − x) SeO 2 ) is prepared by melt-quenching route. The formation of Ag 2 MoO 4 , Ag 2 Mo 2 O 7 and Ag 6 Mo 10 O 33 nanoparticles and SeO 3 and SeO 4 nanoclusters in glass-nanocomposites has been confirmed from X-ray diffraction (XRD) and field emission scanning electron microscopic (FESEM) studies. Fourier transform infrared (FTIR) spectroscopy is employed to find out Se−O stretching vibration as well as stretching vibrations of Mo 2 O 7 2− ions. The dc conductivity of them is studied on the light of polaron hopping approach in a wide temperature range. At low temperatures, variable range hopping model (Mott's model) is employed to analyze the conductivity data. Greave's model is used to predict temperature dependent variable range hopping in the high temperature region. Frequency dependent ac conductivity is well explained on the basis of tunneling. I–V characteristics of the as-prepared samples have also been investigated

Characteristics of Schottky-barrier source/drain metal-oxide-polycrystalline thin-film transistors on glass substrates

International Nuclear Information System (INIS)

Jung, Seung-Min; Cho, Won-Ju; Jung, Jong-Wan

2012-01-01

Polycrystalline-silicon (poly-Si) Schottky-barrier thin-film transistors (SB-TFTs) with Pt-silicided source /drain junctions were fabricated on glass substrates, and the electrical characteristics were examined. The amorphous silicon films on glass substrates were converted into high-quality poly-Si by using excimer laser annealing (ELA) and solid phase crystallization (SPC) methods. The crystallinity of poly-Si was analyzed by using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis. The silicidation process was optimized by measuring the electrical characteristics of the Pt-silicided Schottky diodes. The performances of Pt-silicided SB-TFTs using poly-Si films on glass substrates and crystallized by using ELA and SPC were demonstrated. The SB-TFTs using the ELA poly-Si film demonstrated better electrical performances such as higher mobility (22.4 cm 2 /Vs) and on/off current ratio (3 x 10 6 ) and lower subthreshold swing value (120 mV/dec) than the SPC poly-Si films.

Protective amorphous carbon coatings on glass substrates

Science.gov (United States)

Silins, Kaspars; Baránková, Hana; Bardos, Ladislav

2017-11-01

Thick amorphous carbon films were deposited by the Magnets-in-Motion (M-M) rf linear hollow cathode at varying acetylene contents in Ar in a hybrid PVD/PE-CVD process directly on glass substrates. The hollow cathode plates manufactured from graphite were used as the PVD target. The measurements show that the films can reach thickness of up to 50 μm at deposition rates of up to 2.5 μm/min. Scratch test measurements confirm that well adhering films several μm thick can be achieved at C2H2 contents of up to 0.5%.

Development of MoOx thin films as back contact buffer for CdTe solar cells in substrate configuration

International Nuclear Information System (INIS)

Gretener, C.; Perrenoud, J.; Kranz, L.; Baechler, C.; Yoon, S.; Romanyuk, Y.E.; Buecheler, S.; Tiwari, A.N.

2013-01-01

Molybdenum oxide compounds exhibit unique electrical and optical properties depending on oxygen vacancy concentration and composition and therefore, have recently attracted a lot of attention as a hole transport layer in various devices. In this work CdTe solar cells in substrate configuration were grown with evaporated MoO x back contact buffer layers and efficiencies of up to 10% could be achieved without using Cu in the back contact processing. The buffer layer – at the CdTe/back contact interface – in the finished cell was found to consist of MoO 2 phase instead of the expected MoO 3 phase as observed in as-deposited or annealed MoO x layers without CdTe deposition. In order to obtain MoO x buffer layers with desired stoichiometry, MoO x thin films were deposited by radio-frequency sputtering under different growth conditions. The chemical phase, composition, microstructure and optical properties of such layers were studied for their possible use in CdTe solar cells. - Highlights: ► MoO x is used as a back contact buffer in CdTe solar cells in substrate configuration. ► Efficiency of 10.0% was achieved without the addition of Cu. ► The back contact buffer in the finished device consists only of MoO 2 . ► Phases and microstructure of MoO x can be controlled by sputtering conditions

Laser deposition of (Cu + Mo) alloying reinforcements on AA1200 substrate for corrosion improvement

CSIR Research Space (South Africa)

Popoola, API

2011-10-01

Full Text Available Poor corrosion performance of aluminium alloys in marine environment has been a subject of intensive research recently. Aluminium substrate was alloyed with a combination of two metallic powders (Cu + Mo) using an Nd: YAG solid state laser...

Comparative studies on p-type CuI grown on glass and copper substrate by SILAR method

Energy Technology Data Exchange (ETDEWEB)

Dhere, Sunetra L.; Latthe, Sanjay S. [Air Glass Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India); Kappenstein, Charles [University of Poitiers, Laboratory of Catalysis in Organic Chemistry, LA CCO, UMR CNRS 6503, Poitiers-86000 (France); Mukherjee, S.K. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400085, Maharashtra India (India); Rao, A. Venkateswara, E-mail: avrao2012@gmail.com [Air Glass Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004, Maharashtra (India)

2010-04-01

Depending upon the method of synthesis and the nature of substrate surface, there is variation in the physico-chemical properties of the material. Cuprous iodide films are deposited at room temperature on the glass and copper substrates by a simple SILAR method and the obtained results are compared. The p-type material with optical band gap 2.88 eV is found to be possessing face-centered cubic crystal structure with lattice parameter 6.134 A. We observed irregular particles for the CuI film on the glass substrate while patterned arrays of micro-rods with cabbage like tips on copper substrate, for the same preparative conditions. Also, the material deposited on copper is showing superhydrophobic nature (contact angle {approx}156{sup o}) while that on glass it is hydrophilic (contact angle {approx}88{sup o}). We have characterized the thin films by X-ray diffraction, scanning electron microscopy, surface roughness and contact angle measurement, thermoelectric power measurement and optical studies. This hydrophobic, p-type material with wide band gap will be helpful in the development of optoelectronic devices.

Comparative studies on p-type CuI grown on glass and copper substrate by SILAR method

International Nuclear Information System (INIS)

Dhere, Sunetra L.; Latthe, Sanjay S.; Kappenstein, Charles; Mukherjee, S.K.; Rao, A. Venkateswara

2010-01-01

Depending upon the method of synthesis and the nature of substrate surface, there is variation in the physico-chemical properties of the material. Cuprous iodide films are deposited at room temperature on the glass and copper substrates by a simple SILAR method and the obtained results are compared. The p-type material with optical band gap 2.88 eV is found to be possessing face-centered cubic crystal structure with lattice parameter 6.134 A. We observed irregular particles for the CuI film on the glass substrate while patterned arrays of micro-rods with cabbage like tips on copper substrate, for the same preparative conditions. Also, the material deposited on copper is showing superhydrophobic nature (contact angle ∼156 o ) while that on glass it is hydrophilic (contact angle ∼88 o ). We have characterized the thin films by X-ray diffraction, scanning electron microscopy, surface roughness and contact angle measurement, thermoelectric power measurement and optical studies. This hydrophobic, p-type material with wide band gap will be helpful in the development of optoelectronic devices.

Effect of MoSi2 Content on Dry Sliding Tribological Properties of Zr-Based Bulk Metallic Glass Composites

Science.gov (United States)

Liu, Longfei; Yang, Jun

2017-12-01

Zr55Cu30Al10Ni5 bulk metallic glass and its composites were prepared by suction casting into a copper mold. The effect of MoSi2 content on the tribological behavior of Zr55Cu30Al10Ni5 BMG was studied by using a high-speed reciprocating friction and wear tester. The results indicate that the friction coefficient and wear resistance of the BMGs can be improved by a certain amount of crystalline phase induced by MoSi2 content from 1 to 3% and deteriorated with MoSi2 content of 4%. The wear mechanism of both the metallic glass and its composite is abrasive wear. The mechanism of crystalline phase-dependent tribological properties of the composite was discussed based on the wear track and mechanical properties in the present work. The wear behavior of Zr55Cu30Al10Ni5 BMG and its composite indicates that a good combination of the toughness and the hardness can make the composite be well wear resistant.

Bonding strength of glass-ceramic trabecular-like coatings to ceramic substrates for prosthetic applications.

Science.gov (United States)

Chen, Qiang; Baino, Francesco; Pugno, Nicola M; Vitale-Brovarone, Chiara

2013-04-01

A new approach based on the concepts of quantized fracture mechanics (QFM) is presented and discussed in this paper to estimate the bonding strength of trabecular-like coatings, i.e. glass-ceramic scaffolds mimicking the architecture of cancellous bone, to ceramic substrates. The innovative application of glass-derived scaffolds as trabecular-like coatings is proposed in order to enhance the osteointegration of prosthetic ceramic devices. The scaffolds, prepared by polymeric sponge replication, are joined to alumina substrates by a dense glass-ceramic coating (interlayer) and the so-obtained 3-layer constructs are investigated from micro-structural, morphological and mechanical viewpoints. In particular, the fracture strengths of three different crack propagation modes, i.e. glass-derived scaffold fracture, interface delamination or mixed fracture, are predicted in agreement with those of experimental mechanical tests. The approach proposed in this work could have interesting applications towards an ever more rational design of bone tissue engineering biomaterials and coatings, in view of the optimization of their mechanical properties for making them actually suitable for clinical applications. Copyright © 2012 Elsevier B.V. All rights reserved.

Design and fabrication of directional diffractive device on glass substrate for multiview holographic 3D display

Science.gov (United States)

Su, Yanfeng; Cai, Zhijian; Liu, Quan; Zou, Wenlong; Guo, Peiliang; Wu, Jianhong

2018-01-01

Multiview holographic 3D display based on the nano-grating patterned directional diffractive device can provide 3D images with high resolution and wide viewing angle, which has attracted considerable attention. However, the current directional diffractive device fabricated on the photoresist is vulnerable to damage, which will lead to the short service life of the device. In this paper, we propose a directional diffractive device on glass substrate to increase its service life. In the design process, the period and the orientation of the nano-grating at each pixel are carefully calculated accordingly by the predefined position of the viewing zone, and the groove parameters are designed by analyzing the diffraction efficiency of the nano-grating pixel on glass substrate. In the experiment, a 4-view photoresist directional diffractive device with a full coverage of pixelated nano-grating arrays is efficiently fabricated by using an ultraviolet continuously variable spatial frequency lithography system, and then the nano-grating patterns on the photoresist are transferred to the glass substrate by combining the ion beam etching and the reactive ion beam etching for controlling the groove parameters precisely. The properties of the etched glass device are measured under the illumination of a collimated laser beam with a wavelength of 532nm. The experimental results demonstrate that the light utilization efficiency is improved and optimized in comparison with the photoresist device. Furthermore, the fabricated device on glass substrate is easier to be replicated and of better durability and practicability, which shows great potential in the commercial applications of 3D display terminal.

Nucleation of microwave plasma CVD diamond on molybdenum (Mo) substrate

International Nuclear Information System (INIS)

Inderjeet, K.; Ramesh, S.

2000-01-01

Molybdenum is a metal, which is gaining increasing significance in industrial applications. The main use of Mo is as all alloying element added in small amounts to steel, irons and non- ferrous alloys in order to enhance the strength, toughness and wear resistance. Mo is also vastly being employed in the automotive and aircraft industries, mainly due to its low coefficient of friction. Diamond, on be other hand, is a unique material for innumerable applications because of its usual combination of physical and chemical properties. Several potential applications can be anticipated for diamond in many sectors including electronics, optics, as protective corrosion resistant coatings, cutting tools, etc. With the enhancement in science and technology, diamond microcrystals and thin films are now being produced from the vapour phase by a variety of chemical vapour deposition (CVD) techniques; such as microwave plasma CVD. With such technology being made available, it is envisage that diamond-coated molybdenum would further enhance the performance and to open up new avenue for Mo in various industries. Therefore, it is the aim of the present work to study the nucleation and growth of diamond particles on Mo surface by employing microwave plasma CVD (MAPCVD). In the present work, diamond deposition was carried out in several stages by varying the deposition distance. The nucleation and growth rate were studied using scanning electron microscopy (SEM). In addition, the existence of diamond was verified by X-ray diffraction (XRD) analysis. It has been found that the nucleation and growth rate of diamond particles were influenced by the deposition height between the substrate and plasma. Under the optimum condition, well defined diamond crystallites distributed homogeneously throughout the surface, could be obtained. Some of the important parameters controlling the deposition and growth of diamond particles on Mo surface are discussed. (author)

Process parameter impact on properties of sputtered large-area Mo bilayers for CIGS thin film solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Badgujar, Amol C.; Dhage, Sanjay R., E-mail: dhage@arci.res.in; Joshi, Shrikant V.

2015-08-31

Copper indium gallium selenide (CIGS) has emerged as a promising candidate for thin film solar cells, with efficiencies approaching those of silicon-based solar cells. To achieve optimum performance in CIGS solar cells, uniform, conductive, stress-free, well-adherent, reflective, crystalline molybdenum (Mo) thin films with preferred orientation (110) are desirable as a back contact on large area glass substrates. The present study focuses on cylindrical rotating DC magnetron sputtered bilayer Mo thin films on 300 mm × 300 mm soda lime glass (SLG) substrates. Key sputtering variables, namely power and Ar gas flow rates, were optimized to achieve best structural, electrical and optical properties. The Mo films were comprehensively characterized and found to possess high degree of thickness uniformity over large area. Best crystallinity, reflectance and sheet resistance was obtained at high sputtering powers and low argon gas flow rates, while mechanical properties like adhesion and residual stress were found to be best at low sputtering power and high argon gas flow rate, thereby indicating a need to arrive at a suitable trade-off during processing. - Highlights: • Sputtering of bilayer molybdenum thin films on soda lime glass • Large area deposition using rotating cylindrical direct current magnetron • Trade of sputter process parameters power and pressure • High uniformity of thickness and best electrical properties obtained • Suitable mechanical and optical properties of molybdenum are achieved for CIGS application.

β-Irradiation Effects on the Formation and Stability of CaMoO4 in a Soda Lime Borosilicate Glass Ceramic for Nuclear Waste Storage.

Science.gov (United States)

Patel, Karishma B; Boizot, Bruno; Facq, Sébastien P; Lampronti, Giulio I; Peuget, Sylvain; Schuller, Sophie; Farnan, Ian

2017-02-06

Molybdenum solubility is a limiting factor to actinide loading in nuclear waste glasses, as it initiates the formation of water-soluble crystalline phases such as alkali molybdates. To increase waste loading efficiency, alternative glass ceramic structures are sought that prove resistant to internal radiation resulting from radioisotope decay. In this study, selective formation of water-durable CaMoO 4 in a soda lime borosilicate is achieved by introducing up to 10 mol % MoO 3 in a 1:1 ratio to CaO using a sintering process. The resulting homogeneously dispersed spherical CaMoO 4 nanocrystallites were analyzed using electron microscopy, X-ray diffraction (XRD), Raman and electron paramagnetic resonance (EPR) spectroscopies prior to and post irradiation, which replicated internal β-irradiation damage on an accelerated scale. Following 0.77 to 1.34 GGy of 2.5 MeV electron radiation CaMoO 4 does not exhibit amorphization or significant transformation. Nor does irradiation induce glass-in-glass phase separation in the surrounding amorphous matrix, or the precipitation of other molybdates, thus proving that excess molybdenum can be successfully incorporated into a structure that it is resistant to β-irradiation proportional to 1000 years of storage without water-soluble byproducts. The CaMoO 4 crystallites do however exhibit a nonlinear Scherrer crystallite size pattern with dose, as determined by a Rietveld refinement of XRD patterns and an alteration in crystal quality as deduced by anisotropic peak changes in both XRD and Raman spectroscopy. Radiation-induced modifications in the CaMoO 4 tetragonal unit cell occurred primarily along the c-axis indicating relaxation of stacked calcium polyhedra. Concurrently, a strong reduction of Mo 6+ to Mo 5+ during irradiation is observed by EPR, which is believed to enhance Ca mobility. These combined results are used to hypothesize a crystallite size alteration model based on a combination of relaxation and diffusion

Continuous depth-sensing nano-mechanical characterization of living, fixed and dehydrated cells attached on a glass substrate

Energy Technology Data Exchange (ETDEWEB)

Yang, Yun-Ta; Liao, Jiunn-Der; Chang, Chia-Wei [Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China); Lin, Chou-Ching K [Department of Neurology, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China); Ju, Ming-Shaung, E-mail: jdliao@mail.ncku.edu.tw [Department of Mechanical Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China)

2010-07-16

Continuous depth-sensing nano-indentation on living, fixed and dehydrated fibroblast cells was performed using a dynamic contact module and vertically measured from a pre-contact state to the glass substrate. The nano-indentation tip-on-cell approaches took advantage of finding a contact surface, followed by obtaining a continuous nano-mechanical profile along the nano-indentation depths. In the experiment, serial indentations from the leading edge, i.e., the lamellipodium to nucleus regions of living, fixed and dehydrated fibroblast cells were examined. Nano-indentations on a living cell anchored upon glass substrate were competent in finding the tip-on-cell contact surfaces and cell heights. For the result on the fixed and the dehydrated cells, cellular nano-mechanical properties were clearly characterized by continuous harmonic contact stiffness (HCS) measurements. The relations of HCS versus measured displacement, varied from the initial tip-on-cell contact to the glass substrate, were presumably divided into three stages, respectively induced by cellular intrinsic behavior, the substrate-dominant property, and the substrate property. This manifestation is beneficial to elucidate how the underlying substrate influences the interpretation of the nano-mechanical property of thin soft matter on a hard substrate. These findings, based upon continuous depth-sensing nano-indentations, are presumably valuable as a reference to related work, e.g., accomplished by atomic force microscopy.

Continuous depth-sensing nano-mechanical characterization of living, fixed and dehydrated cells attached on a glass substrate

International Nuclear Information System (INIS)

Yang, Yun-Ta; Liao, Jiunn-Der; Chang, Chia-Wei; Lin, Chou-Ching K; Ju, Ming-Shaung

2010-01-01

Continuous depth-sensing nano-indentation on living, fixed and dehydrated fibroblast cells was performed using a dynamic contact module and vertically measured from a pre-contact state to the glass substrate. The nano-indentation tip-on-cell approaches took advantage of finding a contact surface, followed by obtaining a continuous nano-mechanical profile along the nano-indentation depths. In the experiment, serial indentations from the leading edge, i.e., the lamellipodium to nucleus regions of living, fixed and dehydrated fibroblast cells were examined. Nano-indentations on a living cell anchored upon glass substrate were competent in finding the tip-on-cell contact surfaces and cell heights. For the result on the fixed and the dehydrated cells, cellular nano-mechanical properties were clearly characterized by continuous harmonic contact stiffness (HCS) measurements. The relations of HCS versus measured displacement, varied from the initial tip-on-cell contact to the glass substrate, were presumably divided into three stages, respectively induced by cellular intrinsic behavior, the substrate-dominant property, and the substrate property. This manifestation is beneficial to elucidate how the underlying substrate influences the interpretation of the nano-mechanical property of thin soft matter on a hard substrate. These findings, based upon continuous depth-sensing nano-indentations, are presumably valuable as a reference to related work, e.g., accomplished by atomic force microscopy.

High temperature creep deformation of glass-phase containing MoSi sub 2 sintered compacts. Glass so wo fukumu MoSi sub 2 shoketsutai no koon henkei

Energy Technology Data Exchange (ETDEWEB)

Shobu, K.; Watanabe, T.; Tani, E. (Government Industrial Research Inst., Kyushu, Saga (Japan))

1991-07-25

As such deformation mechanisms as diffusion, grain boundary sliding and motion of dislocation are known for high temperature deformation of polycrystallines, these atomic theoretical mechanism and quantitative side are not resolved perfectly. In this report, high temperature plasticity of sintered MoSi {sub 2} containing glass phase was examined and obtained some results shown as follows: its transient feature was same as usually observed one; and according to observe its structure, the deformation mechanism was mainly based on grain boundary sliding, and viscous flow of glass phase and diffusion therethrough; stress feature in deformation was shown a transient phenomenon at about 10MPa, and stress index approached to 3 under low stress and to 1 under high stress, in other words stress feature was controlled by viscous flow under high stress and by grain boundary sliding under low stress; and the stress index of grain boundary sliding was supposed to be 3 at low inclined angle and responsive grain boundary and 2 at high inclined angle. 4 refs., 5 figs.

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

Science.gov (United States)

Pat, Suat; Özen, Soner; Korkmaz, Şadan

2018-01-01

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

F2-laser patterning of indium tin oxide (ITO) thin film on glass substrate

International Nuclear Information System (INIS)

Xu, M.Y.; Li, J.; Herman, P.R.; Lilge, L.D.

2006-01-01

This paper reports the controlled micromachining of 100 nm thick indium tin oxide (ITO) thin films on glass substrates with a vacuum-ultraviolet 157 nm F 2 laser. Partial to complete film removal was observed over a wide fluence window from 0.49 J/cm 2 to an optimized single pulse fluence of 4.5 J/cm 2 for complete film removal. Optical microscopy, atomic force microscopy, and energy dispersive X-ray analysis show little substrate or collateral damage by the laser pulse which conserved the stoichiometry, optical transparency and electrical conductivity of ITO coating adjacent to the trenches. At higher fluence, a parallel micron sized channel can be etched in the glass substrate. The high photon energy and top-hat beam homogenized optical system of the F 2 laser opens new means for direct structuring of electrodes and microchannels in biological microfluidic systems or in optoelectronics. (orig.)

Seebeck coefficient of synthesized Titanium Dioxide thin film on FTO glass substrate

Science.gov (United States)

Usop, R.; Hamed, N. K. A.; Megat Hasnan, M. M. I.; Ikeda, H.; Sabri, M. F. M.; Ahmad, M. K.; Said, S. M.; Salleh, F.

2018-04-01

In order to fabricate a thermoelectric device on glass substrate for harvesting waste heat energy through house appliances, the Seebeck coefficient of translucent TiO2 thin film was investigated. The TiO2 thin film was synthesized by using hydrothermal method with F-SnO2 coated glass as substrate. From scanning electron microscopy analysis, the synthesized TiO2 thin film was found to be in nanometer-scale rod structure with a thickness of 4 µm. The Seebeck coefficient was measured in the temperature range of 300 – 400 K. The Seebeck coefficient is found to be in negative value which shows that synthesized film is an n-type semiconductor material, and is lower than the value of bulk-size material. This reduction in Seebeck coefficient of TiO2 thin film is likely due to the low dimensional effect and the difference of carrier concentration.

Anisotropic surroundings effects on photo absorption of partially embedded Au nanospheroids in silica glass substrate

Energy Technology Data Exchange (ETDEWEB)

Meng, Xuan; Shibayama, Tamaki, E-mail: shiba@qe.eng.hokudai.ac.jp; Watanabe, Seiichi [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060–8628 (Japan); Yu, Ruixuan; Ishioka, Junya [Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060–8628 (Japan)

2015-02-15

The influence of a directly adjacent or an anisotropic surrounding medium alters the plasmonic properties of a nanoparticle because it provides a mechanism for symmetry breaking of the scattering. Given the success of ion irradiation induced embedment of rigid metallic nanospheroids into amorphous substrate, it is possible to examine the effect of the silica glass substrate on the plasmonic properties of these embedded nanospheroids. In this work presented here, discrete dipole approximation (DDA) calculations for the Au nanospheroids’ optical properties were performed based on 3–dimensional (3D) configuration extracted from planar SEM micrographs and cross–sectional TEM micrographs of the Au nanospheroids partially embedded in the silica glass, and the well–matched simulations with respect to the experimental measurements could demonstrate the dielectric constant at the near surface of silica glass decreased after Ar–ion irradiation.

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

International Nuclear Information System (INIS)

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

2011-12-01

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

Order and disorder in the local and long-range structure of the spin-glass pyrochlore, Tb{sub 2}Mo{sub 2}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yu; Huq, Ashfia; Booth, Corwin H.; Ehlers, Georg; Greedan, John E.; Gardner, Jason S.

2011-02-11

To understand the origin of the spin-glass state in molybdate pyrochlores, the structure of Tb{sub 2}Mo{sub 2}O{sub 7} is investigated using two techniques: the long-range lattice structure was measured using neutron powder diffraction (NPD), and local structure information was obtained from the extended x-ray absorption fine structure (EXAFS) technique. While the long-range structure appears generally well ordered, enhanced mean-squared site displacements on the O(1) site and the lack of temperature dependence of the strongly anisotropic displacement parameters for both the Mo and O(1) sites indicate some disorder exists. Likewise, the local structure measurements indicate some Mo-Mo and Tb-O(1) nearest-neighbor disorder exists, similar to that found in the related spin-glass pyrochlore, Y{sub 2}Mo{sub 2}O{sub 7}. Although the freezing temperature in Tb{sub 2}Mo{sub 2}O{sub 7}, 25 K, is slightly higher than in Y{sub 2}Mo{sub 2}O{sub 7}, 22 K, the degree of local pair distance disorder is actually less in Tb{sub 2}Mo{sub 2}O{sub 7}. This apparent contradiction is considered in light of the interactions involved in the freezing process.

Selective formation of GaN-based nanorod heterostructures on soda-lime glass substrates by a local heating method.

Science.gov (United States)

Hong, Young Joon; Kim, Yong-Jin; Jeon, Jong-Myeong; Kim, Miyoung; Choi, Jun Hee; Baik, Chan Wook; Kim, Sun Il; Park, Sung Soo; Kim, Jong Min; Yi, Gyu-Chul

2011-05-20

We report on the fabrication of high-quality GaN on soda-lime glass substrates, heretofore precluded by both the intolerance of soda-lime glass to the high temperatures required for III-nitride growth and the lack of an epitaxial relationship with amorphous glass. The difficulties were circumvented by heteroepitaxial coating of GaN on ZnO nanorods via a local microheating method. Metal-organic chemical vapor deposition of ZnO nanorods and GaN layers using the microheater arrays produced high-quality GaN/ZnO coaxial nanorod heterostructures at only the desired regions on the soda-lime glass substrates. High-resolution transmission electron microscopy examination of the coaxial nanorod heterostructures indicated the formation of an abrupt, semicoherent interface. Photoluminescence and cathodoluminescence spectroscopy was also applied to confirm the high optical quality of the coaxial nanorod heterostructures. Mg-doped GaN/ZnO coaxial nanorod heterostructure arrays, whose GaN shell layers were grown with various different magnesocene flow rates, were further investigated by using photoluminescence spectroscopy for the p-type doping characteristics. The suggested method for fabrication of III-nitrides on glass substrates signifies potentials for low-cost and large-size optoelectronic device applications.

Selective formation of GaN-based nanorod heterostructures on soda-lime glass substrates by a local heating method

Energy Technology Data Exchange (ETDEWEB)

Hong, Young Joon; Kim, Yong-Jin [Department of Materials Science and Engineering, POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Jeon, Jong-Myeong; Kim, Miyoung; Choi, Jun Hee [Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Baik, Chan Wook; Kim, Sun Il; Park, Sung Soo; Kim, Jong Min [Frontier Research Laboratory, Samsung Advanced Institute of Technology, PO Box 111, Kiheung 446-712 (Korea, Republic of); Yi, Gyu-Chul, E-mail: joonie.choi@samsung.com, E-mail: gcyi@snu.ac.kr [National Creative Research Initiative Center for Semiconductor Nanorods, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

2011-05-20

We report on the fabrication of high-quality GaN on soda-lime glass substrates, heretofore precluded by both the intolerance of soda-lime glass to the high temperatures required for III-nitride growth and the lack of an epitaxial relationship with amorphous glass. The difficulties were circumvented by heteroepitaxial coating of GaN on ZnO nanorods via a local microheating method. Metal-organic chemical vapor deposition of ZnO nanorods and GaN layers using the microheater arrays produced high-quality GaN/ZnO coaxial nanorod heterostructures at only the desired regions on the soda-lime glass substrates. High-resolution transmission electron microscopy examination of the coaxial nanorod heterostructures indicated the formation of an abrupt, semicoherent interface. Photoluminescence and cathodoluminescence spectroscopy was also applied to confirm the high optical quality of the coaxial nanorod heterostructures. Mg-doped GaN/ZnO coaxial nanorod heterostructure arrays, whose GaN shell layers were grown with various different magnesocene flow rates, were further investigated by using photoluminescence spectroscopy for the p-type doping characteristics. The suggested method for fabrication of III-nitrides on glass substrates signifies potentials for low-cost and large-size optoelectronic device applications.

Self-powdering and nonlinear optical domain structures in ferroelastic β'-Gd2(MoO4)3 crystals formed in glass

International Nuclear Information System (INIS)

Tsukada, Y.; Honma, T.; Komatsu, T.

2009-01-01

Ferroelastic β'-Gd 2 (MoO 4 ) 3 , (GMO), crystals are formed through the crystallization of 21.25Gd 2 O 3 -63.75MoO 3 -15B 2 O 3 glass (mol%), and two scientific curious phenomena are observed. (1) GMO crystals formed in the crystallization break into small pieces with a triangular prism or pyramid shape having a length of 50-500 μm spontaneously during the crystallizations in the inside of an electric furnace, not during the cooling in air after the crystallization. This phenomenon is called 'self-powdering phenomenon during crystallization' in this paper. (2) Each self-powdered GMO crystal grain shows a periodic domain structure with different refractive indices, and a spatially periodic second harmonic generation (SHG) depending on the domain structure is observed. It is proposed from polarized micro-Raman scattering spectra and the azimuthal dependence of second harmonic intensities that GMO crystals are oriented in each crystal grain and the orientation of (MoO 4 ) 2- tetrahedra in GMO crystals changes periodically due to spontaneous strains in ferroelastic GMO crystals. - Graphical abstract: This figure shows the polarized optical photograph at room temperature for a particle (piece) obtained by a heat treatment of the glass at 590 deg. C for 2 h in an electric furnace in air. This particle was obtained through the self-powdering behavior in the crystallization of glass. The periodic domain structure is observed. Ferroelastic β'-Gd 2 (MoO 4 ) 3 crystals are formed in the particle, and second harmonic generations are detected, depending on the domain structure.

Luminescent properties of CaTiO3:Pr thin-film phosphor deposited on ZnO/ITO/glass substrate

International Nuclear Information System (INIS)

Chung, Sung Mook; Han, Sang Hyuk; Song, Kuk Hyun; Kim, Eung Soo; Kim, Young Jin

2005-01-01

Red-emitting CaTiO 3 :Pr phosphor thin films were deposited on glass, ZnO/ITO/glass, and ITO/glass substrates by RF magnetron sputtering. The effects of various substrates and heat treatment on the structural and luminous properties were investigated. The films deposited on ZnO/ITO/glass exhibited superior crystallinity and more enhanced PL and CL properties compared with those on ITO/glass. The intermediate ZnO layer between phosphor film and ITO contributed to the growing behaviors and the roughening of CaTiO 3 :Pr phosphor thin films, and consequently, to the excellent luminescence. The luminescent properties of the films were improved by following heat-treatment due to a combination of factors, namely the transformation from amorphous to poly crystalline phases, the activation of the activators, and the elimination of microdefects

Single Phase Melt Processed Powellite (Ba,Ca) MoO{sub 4} For The Immobilization Of Mo-Rich Nuclear Waste

Energy Technology Data Exchange (ETDEWEB)

Brinkman, Kyle [Savannah River Site (SRS), Aiken, SC (United States); Marra, James [Savannah River Site (SRS), Aiken, SC (United States); Fox, Kevin [Savannah River Site (SRS), Aiken, SC (United States); Reppert, Jason [Savannah River Site (SRS), Aiken, SC (United States); Crum, Jarrod [Paci fic Northwest National Laboratory , Richland, WA (United States); Tang, Ming [Los Alamos National Laboratory , Los Alamos, NM (United States)

2012-09-17

Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO{sub 4} crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO{sub 4} and CaMoO{sub 4} were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In-situ electron irradiation studies indicated that both CaMoO{sub 4} and BaMoO{sub 4} powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 X 10{sup 13} Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m{sup 2}).

Raman band intensities of tellurite glasses.

Science.gov (United States)

Plotnichenko, V G; Sokolov, V O; Koltashev, V V; Dianov, E M; Grishin, I A; Churbanov, M F

2005-05-15

Raman spectra of TeO2-based glasses doped with WO3, ZnO, GeO2, TiO2, MoO3, and Sb2O3 are measured. The intensity of bands in the Raman spectra of MoO3-TeO2 and MoO3-WO3-TeO2 glasses is shown to be 80-95 times higher than that for silica glass. It is shown that these glasses can be considered as one of the most promising materials for Raman fiber amplifiers.

Electrophoretic deposition (EPD) of multi-walled carbon nano tubes (MWCNT) onto indium-tin-oxide (ITO) glass substrates

International Nuclear Information System (INIS)

Mohd Roslie Ali; Shahrul Nizam Mohd Salleh

2009-01-01

Full text: Multi-Walled Carbon Nano tubes (MWCNT) were deposited onto Indium-Tin-Oxide (ITO)-coated glass substrates by introducing the use of Electrophoretic Deposition (EPD) as the method. The Multi-Walled Carbon Nano tubes (MWCNT) were dispersed ultrasonically in ethanol and sodium hydroxide (NaOH) to form stable suspension. The addition of Sodium Hydroxide in ethanol can stabilize the suspension, which was very important step before the deposition take place. Two substrates of Indium-Tin-Oxide(ITO)-coated glass placed in parallel facing each other (conductive side) into the suspension. The deposition occurs at room temperature, which the distance fixed at 1 cm between both electrodes and the voltage level applied was fixed at 400 V, respectively. The deposition time also was fixed at 30 minutes. The deposited ITO-Glass with Multi-Walled Carbon Nano tubes (MWCNT) will be characterized using Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM), and Raman Microscope. The images of SEM shows that the Multi -Walled Carbon Nano tubes (MWCNT) were distributed uniformly onto the surface of ITO-Glass. The deposited ITO-Glass with Multi-Walled Carbon Nano tubes (MWCNT) could be the potential material in various practical applications such as field emission devices, fuel cells, and super capacitors. Electrophoretic deposition (EPD) technique was found to be an efficient technique in forming well distribution of Multi-Walled Carbon Nano tubes (MWCNT) onto ITO-Glass substrates, as proved in characterization methods, in which the optimum conditions will play the major role. (author)

Atomic layer deposition of two dimensional MoS{sub 2} on 150 mm substrates

Energy Technology Data Exchange (ETDEWEB)

Valdivia, Arturo; Conley, John F., E-mail: jconley@eecs.oregonstate.edu [School of EECS, Oregon State University, Corvallis, Oregon 97331 (United States); Tweet, Douglas J. [Sharp Labs of America, Camas, Washington 98607 (United States)

2016-03-15

Low temperature atomic layer deposition (ALD) of monolayer to few layer MoS{sub 2} uniformly across 150 mm diameter SiO{sub 2}/Si and quartz substrates is demonstrated. Purge separated cycles of MoCl{sub 5} and H{sub 2}S precursors are used at reactor temperatures of up to 475 °C. Raman scattering studies show clearly the in-plane (E{sup 1}{sub 2g}) and out-of-plane (A{sub 1g}) modes of MoS{sub 2}. The separation of the E{sup 1}{sub 2g} and A{sub 1g} peaks is a function of the number of ALD cycles, shifting closer together with fewer layers. X-ray photoelectron spectroscopy indicates that stoichiometry is improved by postdeposition annealing in a sulfur ambient. High resolution transmission electron microscopy confirms the atomic spacing of monolayer MoS{sub 2} thin films.

Origin of the n -type and p -type conductivity of MoS 2 monolayers on a SiO 2 substrate

KAUST Repository

Dolui, Kapildeb; Rungger, Ivan; Sanvito, Stefano

2013-01-01

Ab initio density functional theory calculations are performed to study the electronic properties of a MoS2 monolayer deposited over a SiO 2 substrate in the presence of interface impurities and defects. When MoS2 is placed on a defect

Characterization of TiO2 Thin Films on Glass Substrate Growth Using DC Sputtering Technique

International Nuclear Information System (INIS)

Agus Santoso; Tjipto Sujitno; Sayono

2002-01-01

It has been fabricated and characterization a TiO 2 thin films deposited on glass substrate using DC sputtering technique. Fabrication of TiO 2 thin films were carried out at electrode voltage 4 kV, sputtering current 5 mA, vacuum pressure 5 x 10 -4 torr, deposition time 150 minutes, and temperature of the substrate were varied from 150 -350 o C, while as a gas sputter was argon. The results was tested their micro structure using SEM, and crystal structure using XRD and found that the crystal structure of TiO 2 powder before deposited on glass substrate was rutile and anatase with orientation (110) and (200) for anatase and (100) and (111) rutile structure. While the crystal structure which deposited at temperature 150 o C and deposition time 2.5 hours was anatase with orientation (001) and (200). (author)

Development of MoO{sub x} thin films as back contact buffer for CdTe solar cells in substrate configuration

Energy Technology Data Exchange (ETDEWEB)

Gretener, C., E-mail: christina.gretener@empa.ch [Laboratory for Thin Films and Photovoltaics, Empa — Swiss Federal Laboratories for Materials Science and Technology, Überlandstr. 129, 8600 Dübendorf (Switzerland); Perrenoud, J.; Kranz, L.; Baechler, C. [Laboratory for Thin Films and Photovoltaics, Empa — Swiss Federal Laboratories for Materials Science and Technology, Überlandstr. 129, 8600 Dübendorf (Switzerland); Yoon, S. [Laboratory for Solid State Chemistry and Catalysis, Empa — Swiss Federal Laboratories for Materials Science and Technology, Überlandstr. 129, 8600 Dübendorf (Switzerland); Romanyuk, Y.E.; Buecheler, S.; Tiwari, A.N. [Laboratory for Thin Films and Photovoltaics, Empa — Swiss Federal Laboratories for Materials Science and Technology, Überlandstr. 129, 8600 Dübendorf (Switzerland)

2013-05-01

Molybdenum oxide compounds exhibit unique electrical and optical properties depending on oxygen vacancy concentration and composition and therefore, have recently attracted a lot of attention as a hole transport layer in various devices. In this work CdTe solar cells in substrate configuration were grown with evaporated MoO{sub x} back contact buffer layers and efficiencies of up to 10% could be achieved without using Cu in the back contact processing. The buffer layer – at the CdTe/back contact interface – in the finished cell was found to consist of MoO{sub 2} phase instead of the expected MoO{sub 3} phase as observed in as-deposited or annealed MoO{sub x} layers without CdTe deposition. In order to obtain MoO{sub x} buffer layers with desired stoichiometry, MoO{sub x} thin films were deposited by radio-frequency sputtering under different growth conditions. The chemical phase, composition, microstructure and optical properties of such layers were studied for their possible use in CdTe solar cells. - Highlights: ► MoO{sub x} is used as a back contact buffer in CdTe solar cells in substrate configuration. ► Efficiency of 10.0% was achieved without the addition of Cu. ► The back contact buffer in the finished device consists only of MoO{sub 2}. ► Phases and microstructure of MoO{sub x} can be controlled by sputtering conditions.

Remote and direct plasma regions for low-temperature growth of carbon nanotubes on glass substrates for display applications

International Nuclear Information System (INIS)

Tabatabaei, M K; Ghafouri fard, H; Koohsorkhi, J; Khatami, S; Mohajerzadeh, S

2011-01-01

A novel method for growing carbon nanotubes (CNTs) on glass substrates is introduced in this study. A two-stage plasma was used to achieve low-temperature and vertically aligned CNTs. Ni deposited on indium tin oxide/glass substrate was used as the catalyst and hydrogen and acetylene were used as gas feeds. In this investigation a new technique was developed to grow vertically aligned CNTs at temperatures below 400 deg. C while CNT growth by plasma-enhanced chemical vapour deposition required high temperatures. Low-temperature growth of vertically aligned CNTs was suitable for the fabrication of micro-lens and self-oriented displays on glass substrates. Also, we have reported a new configuration for CNT-based display by means of controlling the refractive index of liquid crystal around the CNT by applying a proper voltage to the top and bottom array.

Semi-transparent photovoltaic glazing based on electrodeposited CIGS solar cells on patterned molybdenum/glass substrates

Science.gov (United States)

Sidali, Tarik; Bou, Adrien; Coutancier, Damien; Chassaing, Elisabeth; Theys, Bertrand; Barakel, Damien; Garuz, Richard; Thoulon, Pierre-Yves; Lincot, Daniel

2018-03-01

In this paper, a new way of preparing semi-transparent solar cells using Cu(In1-xGax)Se2 (CIGS) chalcopyrite semiconductors as absorbers for BIPV applications is presented. The key to the elaboration process consists in the co-electrodeposition of Cu-In-Ga mixed oxides on submillimetric hole-patterned molybdenum substrate, followed by thermal reduction to metallic alloys and selenisation. This method has the advantage of being a selective deposition technique where the thin film growth is carried out only on Mo covered areas. Thus, after annealing, the transparency of the sample is always preserved, allowing light to pass through the device. A complete device (5 × 5 cm2) with 535 μm diameter holes and total glass aperture of around 35% shows an open circuit voltage (VOC) of 400 mV. Locally, the I-V curves reveal a maximum efficiency of 7.7%, VOC of 460 mV, JSC of 24 mA.cm-2 in an area of 0.1 cm2 with 35% aperture. This efficiency on the semi-transparent area is equivalent to a record efficiency of 11.9% by taking into account only the effective area.

Synthesis of functionally graded bioactive glass-apatite multistructures on Ti substrates by pulsed laser deposition

International Nuclear Information System (INIS)

Tanaskovic, D.; Jokic, B.; Socol, G.; Popescu, A.; Mihailescu, I.N.; Petrovic, R.; Janackovic, Dj.

2007-01-01

Functionally graded glass-apatite multistructures were synthesized by pulsed laser deposition on Ti substrates. We used sintered targets of hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 , or bioglasses in the system SiO 2 -Na 2 O-K 2 O-CaO-MgO-P 2 O 5 with SiO 2 content of either 57 wt.% (6P57) or 61 wt.% (6P61). A UV KrF* (λ = 248 nm, τ > 7 ns) excimer laser source was used for the multipulse laser ablation of the targets. The hydroxyapatite thin films were obtained in H 2 O vapors, while the bioglass layers were deposited in O 2 . Thin films of 6P61 were deposited in direct contact with Ti, because Ti and this glass have similar thermal expansion behaviors, which ensure good bioglass adhesion to the substrate. This glass, however, is not bioactive, so yet more depositions of 6P57 bioglass and/or hydroxyapatite thin films were performed. All structures with hydroxyapatite overcoating were post-treated in a flux of water vapors. The obtained multistructures were characterized by various techniques. X-ray investigations of the coatings found small amounts of crystalline hydroxyapatite in the outer layers. The scanning electron microscopy analyses revealed homogeneous coatings with good adhesion to the Ti substrate. Our studies showed that the multistructures we had obtained were compatible with further use in biomimetic metallic implants with glass-apatite coating applications

Ti substrate coated with composite Cr–MoO2 coatings as highly selective cathode materials in hypochlorite production

International Nuclear Information System (INIS)

Lačnjevac, U.Č.; Jović, B.M.; Gajić-Krstajić, Lj.M.; Kovač, J.; Jović, V.D.; Krstajić, N.V.

2013-01-01

Highlights: ► Composite Cr–MoO 2 coatings were prepared by electrodeposition onto mild steel and Ti substrates. ► Ti/Cr–MoO 2 electrodes were investigated as cathode materials for the hypochlorite production. ► Selectivity of electrodes increased with the increase of the content of MoO 2 in the coating. ► The current efficiency for the HER exceeded 97% at the best cathode. ► The suppression of hypochlorite reduction is caused by the presence of Cr 2 O 3 at the surface. -- Abstract: The aim of this work was to investigate the possibility of preparation of the composite Cr–MoO 2 coatings onto steel and titanium substrates as cathode materials with high selective properties which imply the suppression of hypochlorite reduction as a side reaction during hypochlorite commercial production. The electrodes were prepared by simultaneous deposition of chromium and suspended MoO 2 particles on titanium substrate from acid chromium (VI) bath. The current efficiency for electrodeposition of the composite coatings did not vary significantly with the concentration of suspended MoO 2 particles. The content of molybdenum in the deposits was relatively low (0.2–1.5 at.%) and increased with increasing the concentration of suspended MoO 2 particles in the bath, in the range from 0 to 10 g dm −3 . With further increase in the concentration of MoO 2 , the content of molybdenum in the coating varied insignificantly. X-ray photoelectron spectroscopy-XPS and EDS analysis were applied to analyze elemental composition and chemical bonding of elements on the surface and in the sub-surface region of obtained coatings. When the concentration of MoO 2 particles in the bath was raised above 5 g dm −3 , the appearance of the coating changed from the typical pure chromium deposit to needle-like deposit with the appearance of black inclusions on the surface. XPS analysis and corresponding Cr 2p spectra showed the presence of chromium oxide, probably Cr 2 O 3 with Cr(3

Ultra-high carrier mobility InSb film by rapid thermal annealing on glass substrate

Directory of Open Access Journals (Sweden)

Charith Jayanada Koswaththage

2016-11-01

Full Text Available InSb films were deposited on both mica and glass substrates using thermal evaporation and subjected to FA or RTA. Crystallinity, composition and electrical properties were investigated. High Hall electron mobility as high as 25,000 cm2/(Vs was obtained with the capped InSb film by keeping the In:Sb ratio after RTA at 520°C for 30 sec or more without adopting epitaxial growth on glass.

Effect of plasma voltage on sulfurization of α-MoO{sub 3} nanostructured thin films

Energy Technology Data Exchange (ETDEWEB)

Kumar, Prabhat, E-mail: prabhat89k@gmail.com; Singh, Megha; Sharma, Rabindar K.; Reddy, G. B. [Thin Film Laboratory, Physics Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016 (India)

2016-05-06

In this report, the effect of plasma voltage on plasma assisted sulfurization (PAS) of vertically aligned molybdenum trioxide (α- MoO{sub 3}) nanoflakes (NFs) on glass substrates has been studied systematically. MoO{sub 3} NFs were deposited using plasma assisted sublimation process. These nanoflakes were subjected to H{sub 2}S/Ar plasma at two different plasma voltages 600 and 1000 volts; to study the effect of plasma ionization on degree of sulfurization of MoO{sub 3} into MoS{sub 2}. XRD and Raman analysis show that film sulfurized at 1000 volts have relatively higher degree of conversion into MoS{sub 2}, as more intense peaks of MoS{sub 2} and MoO{sub 2} are obtained than that sulfurized at 600 volts. HRTEM of sulfurized film shows that outer surface of nanoflake has been converted into MoS{sub 2} (4-5 monolayers). Meanwhile, MoO{sub 3} was reduced into MoO{sub 2} as confirmed by XRD and Raman results. All the observed results are well in consonance with each other.

CVD synthesis of large-area, highly crystalline MoSe2 atomic layers on diverse substrates and application to photodetectors.

Science.gov (United States)

Xia, Jing; Huang, Xing; Liu, Ling-Zhi; Wang, Meng; Wang, Lei; Huang, Ben; Zhu, Dan-Dan; Li, Jun-Jie; Gu, Chang-Zhi; Meng, Xiang-Min

2014-08-07

Synthesis of large-area, atomically thin transition metal dichalcogenides (TMDs) on diverse substrates is of central importance for the large-scale fabrication of flexible devices and heterojunction-based devices. In this work, we successfully synthesized a large area of highly-crystalline MoSe2 atomic layers on SiO2/Si, mica and Si substrates using a simple chemical vapour deposition (CVD) method at atmospheric pressure. Atomic force microscopy (AFM) and Raman spectroscopy reveal that the as-grown ultrathin MoSe2 layers change from a single layer to a few layers. Photoluminescence (PL) spectroscopy demonstrates that while the multi-layer MoSe2 shows weak emission peaks, the monolayer has a much stronger emission peak at ∼ 1.56 eV, indicating the transition from an indirect to a direct bandgap. Transmission electron microscopy (TEM) analysis confirms the single-crystallinity of MoSe2 layers with a hexagonal structure. In addition, the photoresponse performance of photodetectors based on MoSe2 monolayer was studied for the first time. The devices exhibit a rapid response of ∼ 60 ms and a good photoresponsivity of ∼ 13 mA/W (using a 532 nm laser at an intensity of 1 mW mm(-2) and a bias of 10 V), suggesting that MoSe2 monolayer is a promising material for photodetection applications.

Effect of Si on the glass-forming ability, thermal stability and magnetic properties of Fe-Co-Zr-Mo-W-B alloys

Energy Technology Data Exchange (ETDEWEB)

Wang, W.-M. [Institute for Metallic Materials, IFW Dresden, P.O. 270016, Dresden D-01171 (Germany); Key Lab of Liquid Structure and Heredity of Materials, Shandong University, Jinan 250061 (China); Gebert, A. [Institute for Metallic Materials, IFW Dresden, P.O. 270016, Dresden D-01171 (Germany)], E-mail: a.gebert@ifw-dresden.de; Roth, S.; Kuehn, U.; Schultz, L. [Institute for Metallic Materials, IFW Dresden, P.O. 270016, Dresden D-01171 (Germany)

2008-07-14

This paper presents investigations on the effect of Si on the glass-forming ability, thermal stability and magnetic properties of the Fe-Co-Zr-Mo-W-B samples (group I: Fe{sub 60}Co{sub 8}Zr{sub 10}Mo{sub 5}W{sub 2}B{sub 15-x}Si{sub x}, 1 {<=} x {<=} 4; group II: Fe{sub 60}Co{sub 8}Zr{sub 10-x}Mo{sub 5}W{sub 2}B{sub 15}Si{sub x}, 0 {<=} x {<=} 4; group III: Fe{sub 60}Co{sub 8}Zr{sub 8}Mo{sub 5}W{sub 2}B{sub 17-x}Si{sub x}, 0 {<=} x {<=} 2) prepared by melt spinning, injection casting, and centrifugal casting methods. It is found that the glass-forming ability (GFA) of the alloys in group I is more deteriorated than that in group II, and that the alloys in group III can be cast into the rods of 1-3 mm diameter without crystalline reflections in their XRD patterns. For the amorphous ribbons and rods, a non-monotonic change of the nearest neighbour distance r{sub 1} with increasing Si content c{sub Si} was detected, which is parallel to that of the glass transition and crystallization temperatures T{sub g} and T{sub x}, but opposite to that of the magnetization at room temperature M{sub RT} and the Curie temperature T{sub c}. This correlation can be interpreted by a structure model presuming that iron atoms appear simultaneously in two types of local structures in the amorphous samples.

Properties of carbides, nitrides and carbonitrides based on Ti and Mo multicomponent layers

Energy Technology Data Exchange (ETDEWEB)

Kozlowski, J.; Markowski, J.; Prajzner, A.; Zdanowski, J. [Politechnika Wroclawska (Poland). Inst. Technologii Elektronowej

1998-01-01

Coating have been produced by bias activated reactive evaporation method (BARE) [1] on polished HSS steel and Corning glass substrates. Titanium and molybdenum were co-evaporated using a special two-hearth electron gun with separate Ti and Mo evaporation sources. Various chemical compositions were obtained by means of heating time control of respective materials. The working gases were nitrogen, acetylene and a 1:1 mixture of both. The investigation of properties of layers with various chemical compositions covered samples: TiC, TiCN, TiN, (Ti,Mo)C, (Ti,Mo)CN, (Ti,Mo)N, MoC, MoCN, MoN. The chemical film compositions were determined using the energy-dispersive X-ray analysis (EDAX) method. Vickers hardness measurements were made. The structures of the deposited layers were examined by means of X-ray diffraction. The electrical measurements of the deposited layers covered resistivity ({rho}) and temperature coefficient of resistivity (TCR). It has been found that the measurements of electrical properties may be very sensitive indicators of the layer composition and structure. (orig.) 5 refs.

Phase Separation and Crystallization in soda-lime borosilicate glass enriched in MoO{sub 3} studied by in situ Raman spectroscopy at high temperature

Energy Technology Data Exchange (ETDEWEB)

Magnin, M.; Schuller, S.; Advocat, T. [CEA Valrho, DEN/DTCD/SCDV, Laboratoire d' Etude de Base sur les Verres, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Caurant, D.; Majerus, O. [Laboratoire de Chimie de la Matiere Condensee de Paris- LCMCP - UMR-CNRS 7574, Ecole Nationale Superieure de Chimie de Paris - ENSCP, Paristech, 75231 Paris (France); Ligny, D. de [Laboratoire de Physico-Chimie des Materiaux Luminescents- LPCML - UMR-CNRS 5620, Universite Claude Bernard Lyon1, 69622 Villeurbanne (France)

2008-07-01

Phase separation and crystallisation processes may arise in molten glass when the MoO{sub 3} content exceeds its solubility limit. Molybdenum combined with other elements such as alkali and alkaline-earth may form crystalline molybdates, known as 'yellow phases' in nuclear glasses. In order to establish the sequence of phase separation and crystallization processes occurring during the cooling of the melt, a non-radioactive simplified glass composition was chosen in the SiO{sub 2}-B{sub 2}O{sub 3}-Na{sub 2}O-CaO system, with 2 mol.% MoO{sub 3}. Various cooling scenarios were tested: cooling by air blowing, quenching between two copper plates and cooling on metallic plate. The resulting glass specimens were then characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy in temperature. These observations made it possible to determine the sequence and the appearance temperature of phenomena upon cooling: first, a phase separation occurs, (small droplets dispersed in the molten glass) followed by molybdates crystallization inside the droplets. (authors)

Sputtering of silicon and glass substrates with polyatomic molecular ion beams generated from ionic liquids

Energy Technology Data Exchange (ETDEWEB)

Takeuchi, Mitsuaki, E-mail: m-takeuchi@kuee.kyoto-u.ac.jp; Hoshide, Yuki; Ryuto, Hiromichi; Takaoka, Gikan H. [Photonics and Electronics Science and Engineering Center, Kyoto University, Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan)

2016-03-15

The effect of irradiating 1-ethyl-3-methylimidazolium positive (EMIM{sup +}) or dicyanamide negative (DCA{sup –}) ion beams using an ionic liquid ion source was characterized concerning its sputtering properties for single crystalline Si(100) and nonalkaline borosilicate glass substrates. The irradiation of the DCA{sup –} ion beam onto the Si substrate at an acceleration voltage of 4 and 6 kV exhibited detectable sputtered depths greater than a couple of nanometers with an ion fluence of only 1 × 10{sup 15} ions/cm{sup 2}, while the EMIM{sup +} ion beam produced the same depths with an ion fluence 5 × 10{sup 15} ions/cm{sup 2}. The irradiation of a 4 kV DCA{sup –} ion beam at a fluence of 1 × 10{sup 16} ions/cm{sup 2} also yields large etching depths in Si substrates, corresponding to a sputtering yield of Si/DCA{sup – }= 10, and exhibits a smoothed surface roughness of 0.05 nm. The interaction between DCA{sup –} and Si likely causes a chemical reaction that relates to the high sputtering yield and forms an amorphous C-N capping layer that results in the smooth surface. Moreover, sputtering damage by the DCA{sup –} irradiation, which was estimated by Rutherford backscattering spectroscopy with the channeling technique, was minimal compared to Ar{sup +} irradiation at the same condition. In contrast, the glass substrates exhibited no apparent change in surface roughnesses when sputtered by the DCA{sup –} irradiation compared to the unirradiated glass substrates.

Atomic layer deposition and post-growth thermal annealing of ultrathin MoO3 layers on silicon substrates: Formation of surface nanostructures

Science.gov (United States)

Liu, Hongfei; Yang, Ren Bin; Yang, Weifeng; Jin, Yunjiang; Lee, Coryl J. J.

2018-05-01

Ultrathin MoO3 layers have been grown on Si substrates at 120 °C by atomic layer deposition (ALD) using molybdenum hexacarbonyl [Mo(CO)6] and ozone (O3) as the Mo- and O-source precursors, respectively. The ultrathin films were further annealed in air at Tann = 550-750 °C for 15 min. Scanning-electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy have been employed to evaluate the morphological and elemental properties as well as their evolutions upon annealing of the thin films. They revealed an interfacial SiOx layer in between the MoO3 layer and the Si substrate; this SiOx layer converted into SiO2 during the annealing; and the equivalent thickness of the MoO3 (SiO2) layer decreased (increased) with the increase in Tann. Particles with diameters smaller than 50 nm emerged at Tann = 550 °C and their sizes (density) were reduced (increased) by increasing Tann to 650 °C. A further increase of Tann to 750 °C resulted in telephone-cord-like MoO3 structures, initiated from isolated particles on the surface. These observations have been discussed and interpreted based on temperature-dependent atomic interdiffusions, surface evaporations, and/or melting of MoO3, which shed new light on ALD MoO3 towards its electronic applications.

Substrate effect on the growth of monolayer dendritic MoS2 on LaAlO3 (100) and its electrocatalytic applications

Science.gov (United States)

Li, Cong; Zhang, Yu; Ji, Qingqing; Shi, Jianping; Chen, Zhaolong; Zhou, Xiebo; Fang, Qiyi; Zhang, Yanfeng

2016-09-01

In accommodating the rapid development of two-dimensional (2D) nanomaterials, chemical vapor deposition (CVD) has become a powerful tool for their batch production with desirable characteristics, such as high crystal quality, large domain size, and tunable domain shape. The crystallinity and morphology of the growth substrates usually play a crucial role in the CVD synthesis of high-quality monolayer MoS2, a kind of 2D layered material which has ignited huge interest in nanoelectronics, optoelectronics and energy harvesting, etc. Herein, by utilizing a low-pressure chemical vapor deposition (LPCVD) system, we demonstrate a regioselective synthesis of monolayer MoS2 on the corrugated single-crystal LaAlO3 (100) with twin crystal domains induced by the second-order phase transition. Unique dendritic morphologies with tunable nucleation densities were obtained in different regions of the undulated substrate, presenting a strong substrate modulation effect. Interestingly, the exposure of abundant active edge sites along with the rather high nucleation density makes the monolayer dendritic MoS2 a good electrocatalyst for hydrogen evolution reaction (HER), particularly featured by a rather high exchange current density (70.4 μA cm-2). Furthermore, uniform monolayer MoS2 films can also be obtained and transferred to arbitrary substrates. We believe that this work provides a new growth system for the controllable synthesis of 2D layered materials with unique dendritic morphologies, as well as its great application potential in energy conversion and harvesting.

Solution growth of microcrystalline silicon on amorphous substrates

Energy Technology Data Exchange (ETDEWEB)

Heimburger, Robert

2010-07-05

material is proposed. MoSi{sub 2} thin films on glass, produced by annealing near-stoichiometric Mo-Si multilayers, are shown to resist solution contact. Subsequent investigation of feasibility of the vapor-liquid-solid mechanism revealed the success of indium microdroplet formation to be determined by both, the multilayer deposition parameters and the substrate temperature during indium deposition. Steady-state solution growth at 610 C was utilized to enlarge silicon seed crystals to diameters of up to 200 {mu}m. The grown material has been subject of characterization regarding the crystallinity, orientation and purity. Additionally, morphological anomalies are considered. The outgrown material was found to be bound by {l_brace}111{r_brace} facets. Many of these microcrystallites contain at least two twin domains. Twin-assisted growth at formed re-entrant edges promotes high growth rates even at low supersaturation. Additionally, many crystallites exhibit hoppers at the center of their facets. This is explained by a solute concentration inhomogeneity within the diffusion boundary layer of the nutrient solution leading to solute depletion at the facet centers and to morphological instability. The feasibility of the process for growth of microcrystalline silicon on glass has been shown in principle. Nevertheless, limitations exist regarding the achievable crystalline solidity ratio and the size of crystallites grown under stable conditions. (orig.)

Alkali passivation mechanism of sol-gel derived TiO2-SiO2 films coated on soda-lime-silica glass substrates

Energy Technology Data Exchange (ETDEWEB)

Matsuda, A; Matsuno, Y; Katayama, S; Tsuno, T [Nippon Steel Glass Co. Ltd., Tokyo (Japan); Toge, N; Minami, T [University of Osaka Prefecture, Osaka (Japan). College of Engineering

1992-09-01

TiO2-SiO2 films prepared by the sol-gel method serves as an effective alkali passivation layer on a soda-lime-silica glass substrate and the film is superior to a sol-gel derived pure SiO2 film from the view point of weathering resistance improvement. To clarify the reason, alkali passivation mechanism of sol-gel derived TiO2-SiO2 glass films with different TiO2 contents coated on a soda-lime-silica glass substrate was studied by SIMS (secondary ion mass spectroscopy) and XPS (X-ray photoelectron spectroscopy) analyses, and compared with the results of a sol-gel derived pure SiO2 film. As a result, the following conclusions were obtained: An increase in TiO2 content in the TiO2 SiO2 film increases the sodium concentration in the film, which was induced by sodium migration from the glass substrate during the heat-treatment. Because of the presence of sodium the TiO2 -SiO2 films serve not as a barrier but as an effective getter of alkali ions and thereby effectively improve the weathering resistance Of the glass substrate. 10 refs., 6 figs.

Influence of annealing temperature on the nanostructure TiO2-SnO2 prepared by electron gun method on the glass substrate and the aluminum/glass

Directory of Open Access Journals (Sweden)

N Beigmohammadi

2013-09-01

Full Text Available  TiO2-SnO2 thin films were coated on glass and Al / glass substrates by electron gun method. In coating process, the vacuum was 1.5×10-5 torr. Then, films were annealed at 450, 500 and 550 ˚ C. The crystallographic structure and film morphology were investigated by means of XRD and SEM. The electrical (I-V and optical properties were studied by the two point props system and UV/Vis/NIR spectrophotometer. The results showed the films under 550 ˚ C were crystalline. The thickness and grain size were 350 and 50 nm respectively. The electrical conductivity in the sample with Al / glass substrate under 550 ˚ C was better than the other samples. When temperature increased, the energy gap decreased from 4.05 to 4.03 eV for direct cases.

Thermal stability of SiO{sub 2}–B{sub 2}O{sub 3}–Al{sub 2}O{sub 3}–Na{sub 2}O–CaO glasses with high Nd{sub 2}O{sub 3} and MoO{sub 3} concentrations

Energy Technology Data Exchange (ETDEWEB)

Chouard, Nolwenn [Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie Paris (IRCP), 75005, Paris (France); Laboratoire d' Etude et Développement des Matrices de Conditionnement, CEA/DEN/DTCD/SECM, Marcoule, 30207, Bagnols-sur-Cèze (France); Caurant, Daniel, E-mail: daniel.caurant@chimie-paristech.fr [Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie Paris (IRCP), 75005, Paris (France); Majérus, Odile; Guezi-Hasni, Nadia [Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie Paris (IRCP), 75005, Paris (France); Dussossoy, Jean-Luc [Laboratoire des Matériaux et Procédés Actifs, CEA/DEN/DTCD/SECM/LMPA, Marcoule, 30207, Bagnols-sur-Cèze (France); Baddour-Hadjean, Rita; Pereira-Ramos, Jean-Pierre [Groupe Electrochimie et Spectroscopie des Matériaux (UMR CNRS 7182), Institut de Chimie et des Matériaux Paris-Est, 94320, Thiais (France)

2016-06-25

The incorporation of high MoO{sub 3} amounts in borosilicate glasses developed for the immobilization of radioactive waste may lead to the crystallization of Mo-rich phases that may induce a decrease of the long term performances of glasses. It is thus essential to understand their crystallization mechanisms and the possible effect of other abundant fission products present in the wastes (such as rare earths) in order to control or to avoid their formation during glass preparation. This paper presents a study, performed by X-ray diffraction, scanning electron microscopy, Raman and optical absorption spectroscopies of the stability as a function of the thermal treatment temperature T{sub C} of a simplified Mo-rich nuclear waste glass. The impact of the addition of a high amount of Nd{sub 2}O{sub 3} on the thermal stability of this glass is studied. For comparison, the thermal stability of a Nd{sub 2}O{sub 3}-rich glass without Mo is also presented. The crystallization range of all phases formed in these glasses (CaMoO{sub 4}, Na{sub 2}MoO{sub 4}, Ca{sub 2}Nd{sub 8}(SiO{sub 4}){sub 6}O{sub 2} (apatite)) and the evolution of their structure and microstructure as a function of T{sub C} are presented. The introduction of Nd{sub 2}O{sub 3} in the MoO{sub 3}-rich glass inhibits the crystallization of molybdates (increase of Mo solubility), as long as apatite does not form which suggests that [MoO{sub 4}]{sup 2-} entities and Nd{sup 3+} cations are close to each other in the glass structure. Besides, when a high density of apatite crystals form, for instance from glass surface, small Mo-rich partially crystallized globular heterogeneities are observed between these crystals that exacerbate the nucleation of new apatite crystals (nucleating effect). - Highlights: • Effect of MoO{sub 3} and Nd{sub 2}O{sub 3} separately or together on glass crystallization is studied. • The crystallization range of molybdates and apatite (Ca{sub 2}Nd{sub 8}(SiO{sub 4}){sub 6}O{sub 2}) was

Diffusion barrier performances of thin Mo, Mo-N and Mo/Mo-N films between Cu and Si

International Nuclear Information System (INIS)

Song Shuangxi; Liu Yuzhang; Mao Dali; Ling Huiqin; Li Ming

2005-01-01

In this work, we have studied the diffusion barrier performances of Mo, Mo-N and Mo/Mo-N metallization layers deposited by sputtering Mo in Ar/N 2 atmospheres, respectively. Samples were subsequently annealed at different temperatures ranging from 400 to 800 deg C in vacuum condition. The film properties and their suitability as diffusion barriers and protective coatings in silicon devices were characterized using four-point probe measurement, X-ray diffractometry, scanning electron microscopy, Auger electron spectroscopy and transmission electron microscopy analyses. Experimental results revealed that the Mo (20 nm)/Mo-N (30 nm) layer was able to prevent the diffusion reaction between Cu and Si substrate after being annealed at 600 deg C for 30 min. The adhesion between layers and the content of N atoms are the key parameters to improve the properties of Mo-based barrier materials. The Mo layer interposed between Cu and Mo-N diluted the high nitrogen concentration of the barrier and so enhanced the barrier performances

Semi-transparent photovoltaic glazing based on electrodeposited CIGS solar cells on patterned molybdenum/glass substrates

Directory of Open Access Journals (Sweden)

Sidali Tarik

2018-01-01

Full Text Available In this paper, a new way of preparing semi-transparent solar cells using Cu(In1−xGaxSe2 (CIGS chalcopyrite semiconductors as absorbers for BIPV applications is presented. The key to the elaboration process consists in the co-electrodeposition of Cu-In-Ga mixed oxides on submillimetric hole-patterned molybdenum substrate, followed by thermal reduction to metallic alloys and selenisation. This method has the advantage of being a selective deposition technique where the thin film growth is carried out only on Mo covered areas. Thus, after annealing, the transparency of the sample is always preserved, allowing light to pass through the device. A complete device (5 × 5 cm2 with 535 μm diameter holes and total glass aperture of around 35% shows an open circuit voltage (VOC of 400 mV. Locally, the I-V curves reveal a maximum efficiency of 7.7%, VOC of 460 mV, JSC of 24 mA.cm−2 in an area of 0.1 cm2 with 35% aperture. This efficiency on the semi-transparent area is equivalent to a record efficiency of 11.9% by taking into account only the effective area.

Preparation and characterization of nanocrystalline ITO thin films on glass and clay substrates by ion-beam sputter deposition method

International Nuclear Information System (INIS)

Venkatachalam, S.; Nanjo, H.; Kawasaki, K.; Wakui, Y.; Hayashi, H.; Ebina, T.

2011-01-01

Nanocrystalline indium tin oxide (ITO) thin films were prepared on clay-1 (Clay-TPP-LP-SA), clay-2 (Clay-TPP-SA) and glass substrates using ion-beam sputter deposition method. X-ray diffraction (XRD) patterns showed that the as-deposited ITO films on both clay-1 and clay-2 substrates were a mixture of amorphous and polycrystalline. But the as-deposited ITO films on glass substrates were polycrystalline. The surface morphologies of as-deposited ITO/glass has smooth surface; in contrast, ITO/clay-1 has rough surface. The surface roughnesses of ITO thin films on glass and clay-1 substrate were calculated as 4.3 and 83 nm, respectively. From the AFM and SEM analyses, the particle sizes of nanocrystalline ITO for a film thickness of 712 nm were calculated as 19.5 and 20 nm, respectively. Optical study showed that the optical transmittance of ITO/clay-2 was higher than that of ITO/clay-1. The sheet resistances of as-deposited ITO/clay-1 and ITO/clay-2 were calculated as 76.0 and 63.0 Ω/□, respectively. The figure of merit value for as-deposited ITO/clay-2 (12.70 x 10 -3 /Ω) was also higher than that of ITO/clay-1 (9.6 x 10 -3 /Ω), respectively. The flexibilities of ITO/clay-1 and ITO/clay-2 were evaluated as 13 and 12 mm, respectively. However, the ITO-coated clay-2 substrate showed much better optical and electrical properties as well as flexibility as compared to clay-1.

Structural role of molybdenum in nuclear glasses: an EXAFS study

International Nuclear Information System (INIS)

Calas, G.; Le Grand, M.; Galoisy, L.; Ghaleb, D.

2003-01-01

The Mo environment has been investigated in inactive nuclear glasses using extended X-ray absorption spectroscopy (XAS). Mo is present in a tetrahedron coordinated to oxygen in the form of molybdate groups [MoO 4 ] 2- (d(Mo-O)=1.78 A). This surrounding is not affected by the presence of noble metal phases in the nuclear glass. Relying on the XAS results, on the bond-valence model and on molecular dynamics simulations of a simplified borosilicate model glass, we show that these groups are not directly linked to the borosilicate network but rather located within alkali and alkaline-earth rich domains in the glass. This specific location in the glass network is a way to understand the low solubility of Mo in glasses melted under oxidizing conditions. It also explains the possible phase separation of a yellow phase enriched in alkali molybdates in molten nuclear glasses or the nucleation of calcium molybdates during thermal aging of these glasses. Boron coordination changes in the molten and the glassy states may explain the difference in the composition of the crystalline molybdates, as they exert a direct influence on the activity of alkalis in borosilicate glasses and melts

Wet chemical etching of Al-doped ZnO film deposited by RF magnetron sputtering method on textured glass substrate for energy application

Energy Technology Data Exchange (ETDEWEB)

Hwang, Ki Hwan; Nam, Sang Hun; Jung, Won Suk; Lee, Yong Min; Yang, Hee Su; Boo, Jin Hyo [Dept. of Chemistry, Sungkyunkwan University, Suwon (Korea, Republic of)

2015-03-15

The etching of glasses in aqueous hydrofluoric acid (HF) solutions is applied in many technological fields. Particularly, the textured transparent conductive oxide materials on the glass substrate etched by HF were used to improve the current density of solar cells. In this study, the textured glass substrate has been etched by solution and the Al-doped ZnO (AZO) thin films have been prepared on this textured glass substrates by RF magnetron sputtering method. After the AZO film deposition, the surface of AZO has been etched by hydrochloric acid with different concentration and etching time. Etched AZO thin films had higher haze ratio and sheet resistance than bare AZO glass. Increases in the root-mean-square surface roughness of AZO films enhanced from 53.78 to 84.46 nm the haze ratio in above 700 nm wavelength. Our process could be applicable in texturing glass and etching AZO surface to fabricate solar cell in industrial scale. We also carried out fabricating an organic solar-cell device. Energy conversion efficiency improvement of 123% was obtained with textured AZO-based solar-cell device compared with that of nontextured solar-cell device.

Crystal Nucleation Using Surface-Energy-Modified Glass Substrates.

Science.gov (United States)

Nordquist, Kyle A; Schaab, Kevin M; Sha, Jierui; Bond, Andrew H

2017-08-02

Systematic surface energy modifications to glass substrates can induce nucleation and improve crystallization outcomes for small molecule active pharmaceutical ingredients (APIs) and proteins. A comparatively broad probe for function is presented in which various APIs, proteins, organic solvents, aqueous media, surface energy motifs, crystallization methods, form factors, and flat and convex surface energy modifications were examined. Replicate studies ( n ≥ 6) have demonstrated an average reduction in crystallization onset times of 52(4)% (alternatively 52 ± 4%) for acetylsalicylic acid from 91% isopropyl alcohol using two very different techniques: bulk cooling to 0 °C using flat surface energy modifications or microdomain cooling to 4 °C from the interior of a glass capillary having convex surface energy modifications that were immersed in the solution. For thaumatin and bovine pancreatic trypsin, a 32(2)% reduction in crystallization onset times was demonstrated in vapor diffusion experiments ( n ≥ 15). Nucleation site arrays have been engineered onto form factors frequently used in crystallization screening, including microscope slides, vials, and 96- and 384-well high-throughput screening plates. Nucleation using surface energy modifications on the vessels that contain the solutes to be crystallized adds a layer of useful variables to crystallization studies without requiring significant changes to workflows or instrumentation.

Synthesis and Analysis of MnTiO3 Thin Films on ITO Coated Glass Substrates

Science.gov (United States)

Martin, Emerick; Sahiner, Mehmet-Alper

Perovskites like Manganese Titanium Oxide have interesting chemical properties that may be advantageous to the development of p-n junction photovoltaic cells. Due to the limited understanding behind the compound, it is essential to know the characteristics of it when it is deposited in thin film form. The cells were created using pulsed laser deposition method for two separate mediums (first layers after ITO). ZnO was deposited onto ITO glass for the first sample. For the second sample, a layer of pure Molybdenum was deposited onto the ITO glass. The MnTiO3 was then deposited onto both samples. There was a target thickness of 1000 Angstroms, but ellipsometry shows that, for the Mo based sample, that film thickness was around 1500 Angstroms. There were inconclusive results for the ZnO based sample. The concentration of active carriers was measured using a Hall Effect apparatus for the Mo based sample. The XRD analyses were used to confirm the perovskite structure of the films. Measurements for photoelectric conversion efficiency were taken using a Keathley 2602 ScourceMeter indicated low values for efficiency. The structural information that is correlated with the low electrical performance of this sample will be discussed. SHU-NJSGC Summer 2015 Fellowship.

Room temperature deposition of perpendicular magnetic anisotropic Co{sub 3}Pt thin films on glass substrate

Energy Technology Data Exchange (ETDEWEB)

Chen, Yu-Shen; Dai, Hong-Yu; Hsu, Yi-Wei [Department of Chemical Engineering and Materials Science, Yuan-Ze University, Chung-Li 32003, Taiwan (China); Ou, Sin-Liang, E-mail: slo@mail.dyu.edu.tw [Department of Materials Science and Engineering, Da-Yeh University, Changhua 51591, Taiwan (China); Chen, Shi-Wei [National Synchrotron Radiation Research Center (NSRRC), Hsinchu 300, Taiwan (China); Lu, Hsi-Chuan; Wang, Sea-Fue [Department of Materials and Mineral Resources Engineering, National Taipei University of Technology, Taipei 106, Taiwan (China); Sun, An-Cheng, E-mail: acsun@saturn.yzu.edu.tw [Department of Chemical Engineering and Materials Science, Yuan-Ze University, Chung-Li 32003, Taiwan (China)

2017-03-01

Co{sub 3}Pt alloy thin films were deposited on the glass substrate at room temperature (RT) and 300 °C, which showed high perpendicular magnetic anisotropy (PMA) and isotropy magnetic behaviors, respectively. Co{sub 3}Pt HCP (0002) planes grew along the substrate plane for the films deposited at RT. The easy axis [0001] was consequently vertical to the substrate surface and obtained the predominant PMA. Large magnetic domains and sharp boundary also supported high PMA in RT-deposited samples. On the other hand, the PMA was significantly decreased with increasing the deposition temperature from RT to 300 °C. Hard HCP(0002) and soft A1(111) co-existed in the film and the magnetic exchanged coupling between these two phases induced isotropy magnetic behavior. In addition, the various thicknesses (t) of the RT-deposited Co{sub 3}Pt films were deposited with different base pressures prior to sputtering. The Kerr rotation loops showed high PMA and out-of-plane squareness (S{sub ⊥}) of ~0.9 were found in low base pressure chamber. Within high base pressure chamber, Co{sub 3}Pt films just show magnetic isotropy behaviors. This study provides a fabrication method for the preparation of high PMA HCP-type Co{sub 3}Pt films on the glass substrate without any underlayer at RT. The results could be the base for future development of RT-deposited magnetic alloy thin film with high PMA. - Highlights: • Fabricated high perpendicular magnetic anisotropy Co{sub 3}Pt thin film on glass substrate. • Prepared HCP Co{sub 3}Pt thin film at room temperature. • The key to enhance the PMA of the Co{sub 3}Pt films. • Thinner film is good to fabricate PMA Co{sub 3}Pt thin films.

Molybdenum modified phosphate glasses studied by 31P MAS NMR and Raman spectroscopy.

Science.gov (United States)

Szumera, Magdalena

2015-02-25

Glasses have been synthesized in the system P2O5-SiO2-K2O-MgO-CaO modified by addition of MoO3. Glasses were prepared by conventional fusion method from 40 g batches. The influence of Mo-cations on the analysed glass structure was investigated by means of Raman and (31)P MAS-NMR techniques. It has been found that molybdate units can form Mo[MoO4/MoO6]-O-P and/or Mo[MoO4/MoO6]-O-Si bonds with non-bridging oxygens atoms of Q2 methaphosphate units, resulting in the transformation of chain methaphosphate structure into pyrophosphate and finally into orthophosphate structure. It has been also found that increasing amount of MoO3 in the structure of investigated glasses causes their gradual depolymerization and molybdenum ions in the analysed glass matrix act as modifying cations. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of GaN/AlGaN/GaN (0001) and Si (100) substrates on structural properties of extremely thin MoS{sub 2} films grown by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Chromik, Š. [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Sojková, M., E-mail: michaela.sojkova@savba.sk [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Vretenár, V. [STU Centre for Nanodiagnostics, Vazovova 5, 812 43 Bratislava (Slovakia); Rosová, A.; Dobročka, E.; Hulman, M. [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia)

2017-02-15

Highlights: • Observation of the epitaxial growth of the MoS{sub 2} film on the GaN/AlGaN/GaN (0001) substrate and c-axis oriented nanocrystalline MoS{sub 2} film on the Si (100) substrate. • Dependence of the Raman peak position on the crystal structure of MoS{sub 2} film. • Non-linear thickness dependence on the number of laser pulses using PLD from the stoichiometric target. - Abstract: Very thin MoS{sub 2} films were prepared on hexagonal GaN/AlGaN/GaN (0001) and Si (100) substrates from a stoichiometric target by a pulsed laser deposition. Combined results from Raman and X-ray reflectivity measurements have shown that the thinnest samples are 2–2.5 nm thick. The thickness increases with the number of laser pulses applied albeit no simple direct proportion between the two quantities has been observed. Concerning the stoichiometry, the distribution of Mo and S elements within as-deposited films is rather complex. The stoichiometric MoS{sub 2} is making-up only a part of the film. In spite of this, selected area electron diffraction studies have clearly confirmed that the films deposited on Si (100) are nanocrystalline and oriented perpendicularly to the substrate surface while an epitaxial growth of MoS{sub 2} films was observed on GaN/AlGaN/GaN (0001) substrates.

Study of the water-gas shift reaction on Mo2C/Mo catalytic coatings for application in microstructured fuel processors

NARCIS (Netherlands)

Rebrov, E.V.; Kuznetsov, S.A.; Croon, de M.H.J.M.; Schouten, J.C.

2007-01-01

The activity and stability of two types of molybdenum carbide coatings deposited on molybdenum substrates (Mo2C/Mo) were compared in the water-gas shift reaction at 513–631 K. The activity of the Mo2C/Mo coatings obtained by carburization of preoxidized molybdenum substrates in a CH4/H2 mixture at

Room temperature growth of biaxially aligned yttria-stabilized zirconia films on glass substrates by pulsed-laser deposition

CERN Document Server

Li Peng; Mazumder, J

2003-01-01

Room temperature deposition of biaxially textured yttria-stabilized zirconia (YSZ) films on amorphous glass substrates was successfully achieved by conventional pulsed-laser deposition. The influence of the surrounding gases, their pressure and the deposition time on the structure of the films was studied. A columnar growth process was revealed based on the experimental results. The grown biaxial texture appears as a kind of substrate independence, which makes it possible to fabricate in-plane aligned YSZ films on various substrates.

Electrical transport properties of MoO3 thin films prepared by laser assisted evaporation

International Nuclear Information System (INIS)

Lopez-Carreno, L.D.; Pardo, A.; Zuluaga, M.; Torres, J.; Alfonso, J.E.; Cortes-Bracho, O.L.

2007-01-01

In the present paper the growth of MoO 3 thin films on common glass substrates are described. The films were prepared by evaporation of a MoO 3 target with a CO 2 laser (10.6 μm), operating in the continuous wave mode. The effect of substrate temperature on the crystallographic structure and electrical properties of MoO 3 thin films was studied. The chemical composition of the different species formed on the films surface was obtained by X-ray photoelectron spectroscopy (XPS) and the crystalline structure was studied with X-ray diffraction (XRD). The electrical conductivity of the films was determined using the standard four-points method. Conductivity of the films varied from de 10 -9 to 10 -5 (Ωcm) -1 in the 300-600 K temperature range. Arrhenius-type plots for the electrical conductivity indicate the presence of at least two different conduction mechanisms. The I-V characteristic curve shows an ohmic behavior only in the 4.5-60 V range. Outside this interval the I-V curve has a behavior described by a power law. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Development of textured ZnO-coated low-cost glass substrate with very high haze ratio for silicon-based thin film solar cells

Energy Technology Data Exchange (ETDEWEB)

Hongsingthong, Aswin, E-mail: aswin.hongsingthong@nectec.or.th [Solar Energy Technology Laboratory, National Electronics and Computer Technology Center, 112 Thailand Science Park, Phahonyothin Road, Khlong 1, Khlong Luang, Pathumthani 12120 (Thailand); Krajangsang, Taweewat; Limmanee, Amornrat; Sriprapha, Kobsak; Sritharathikhun, Jaran [Solar Energy Technology Laboratory, National Electronics and Computer Technology Center, 112 Thailand Science Park, Phahonyothin Road, Khlong 1, Khlong Luang, Pathumthani 12120 (Thailand); Konagai, Makoto [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1, NE-15, O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

2013-06-30

Zinc oxide (ZnO) films with a very high haze ratio and low resistivity were developed on soda–lime glass substrate by using reactive ion etching (RIE) treatment with carbon tetrafluoride (CF{sub 4}) to modify the substrate surface morphology before the deposition of ZnO films. We found that the surface morphology of the ZnO films deposited by metal organic chemical vapor deposition (MOCVD) technique could be modified by varying the glass treatment conditions and the gas pressure was a key parameter. With increasing glass-etching pressure, the surface morphology of the ZnO films changed from conventional pyramid-like single texture to greater cauliflower-like double texture, leading to significant increases in root mean square roughness and haze ratio of the films. By employing the developed high-haze ZnO films as a front transparent conductive oxide (TCO) layer in microcrystalline silicon solar cells, an enhancement in the quantum efficiency in the long-wavelength region has been achieved. Experimental results have verified that our unique and original glass etching treatment is a simple and effective technique to improve the light-scattering properties of the ZnO films while preserving their good transparency and electrical properties. Thus, the ZnO films deposited on etched soda–lime glass have a high potential for the use as a front TCO layer in thin-film Si solar cells. - Highlights: • High-haze zinc oxide (ZnO) grown on low cost soda–lime glass has been developed. • Surface of the ZnO can be modified by varying glass-substrate etching conditions. • Glass-etching pressure is a key to increase haze ratio of the ZnO films. • Higher cell efficiency has been achieved from cell using etched glass. • High-haze ZnO coated glass is a promising transparent conductive oxide coated glass.

Development of textured ZnO-coated low-cost glass substrate with very high haze ratio for silicon-based thin film solar cells

International Nuclear Information System (INIS)

Hongsingthong, Aswin; Krajangsang, Taweewat; Limmanee, Amornrat; Sriprapha, Kobsak; Sritharathikhun, Jaran; Konagai, Makoto

2013-01-01

Zinc oxide (ZnO) films with a very high haze ratio and low resistivity were developed on soda–lime glass substrate by using reactive ion etching (RIE) treatment with carbon tetrafluoride (CF 4 ) to modify the substrate surface morphology before the deposition of ZnO films. We found that the surface morphology of the ZnO films deposited by metal organic chemical vapor deposition (MOCVD) technique could be modified by varying the glass treatment conditions and the gas pressure was a key parameter. With increasing glass-etching pressure, the surface morphology of the ZnO films changed from conventional pyramid-like single texture to greater cauliflower-like double texture, leading to significant increases in root mean square roughness and haze ratio of the films. By employing the developed high-haze ZnO films as a front transparent conductive oxide (TCO) layer in microcrystalline silicon solar cells, an enhancement in the quantum efficiency in the long-wavelength region has been achieved. Experimental results have verified that our unique and original glass etching treatment is a simple and effective technique to improve the light-scattering properties of the ZnO films while preserving their good transparency and electrical properties. Thus, the ZnO films deposited on etched soda–lime glass have a high potential for the use as a front TCO layer in thin-film Si solar cells. - Highlights: • High-haze zinc oxide (ZnO) grown on low cost soda–lime glass has been developed. • Surface of the ZnO can be modified by varying glass-substrate etching conditions. • Glass-etching pressure is a key to increase haze ratio of the ZnO films. • Higher cell efficiency has been achieved from cell using etched glass. • High-haze ZnO coated glass is a promising transparent conductive oxide coated glass

Sputter deposition of PZT piezoelectric films on thin glass substrates for adjustable x-ray optics.

Science.gov (United States)

Wilke, Rudeger H T; Johnson-Wilke, Raegan L; Cotroneo, Vincenzo; Davis, William N; Reid, Paul B; Schwartz, Daniel A; Trolier-McKinstry, Susan

2013-05-10

Piezoelectric PbZr(0.52)Ti(0.48)O(3) (PZT) thin films deposited on thin glass substrates have been proposed for adjustable optics in future x-ray telescopes. The light weight of these x-ray optics enables large collecting areas, while the capability to correct mirror figure errors with the PZT thin film will allow much higher imaging resolution than possible with conventional lightweight optics. However, the low strain temperature and flexible nature of the thin glass complicate the use of chemical-solution deposition due to warping of the substrate at typical crystallization temperatures for the PZT. RF magnetron sputtering enabled preparation of PZT films with thicknesses up to 3 μm on Schott D263 glass substrates with much less deformation. X-ray diffraction analysis indicated that the films crystallized with the perovskite phase and showed no indication of secondary phases. Films with 1 cm(2) electrodes exhibited relative permittivity values near 1100 and loss tangents below 0.05. In addition, the remanent polarization was 26 μC/cm(2) with coercive fields of 33 kV/cm. The transverse piezoelectric coefficient was as high as -6.1±0.6 C/m(2). To assess influence functions for the x-ray optics application, the piezoelectrically induced deflection of individual cells was measured and compared with finite-element-analysis calculations. The good agreement between the results suggests that actuation of PZT thin films can control mirror figure errors to a precision of about 5 nm, allowing sub-arcsecond imaging.

Electrical performance of multilayer MoS2 transistors on high-κ Al2O3 coated Si substrates

Directory of Open Access Journals (Sweden)

Tao Li

2015-05-01

Full Text Available The electrical performance of MoS2 can be engineered by introducing high-κ dielectrics, while the interactions between high-κ dielectrics and MoS2 need to be studied. In this study, multilayer MoS2 field-effect transistors (FETs with a back-gated configuration were fabricated on high-κ Al2O3 coated Si substrates. Compared with MoS2 FETs on SiO2, the field-effect mobility (μFE and subthreshold swing (SS were remarkably improved in MoS2/Al2O3/Si. The improved μFE was thought to result from the dielectric screening effect from high-κ Al2O3. When a HfO2 passivation layer was introduced on the top of MoS2/Al2O3/Si, the field-effect mobility was further enhanced, which was thought to be concerned with the decreased contact resistance between the metal and MoS2. Meanwhile, the interface trap density increased from 2.4×1012 eV−1cm−2 to 6.3×1012 eV−1cm−2. The increase of the off-state current and the negative shift of the threshold voltage may be related to the increase of interface traps.

Optical properties of the Na{sub 2}O-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3}-MoO{sub 3} glasses

Energy Technology Data Exchange (ETDEWEB)

Saddeek, Yasser B. [Physics Department, Faculty of Science, Al-Azhar University, P.O. 71452, Assiut (Egypt); Aly, K.A., E-mail: kamalaly2001@gmail.co [Physics Department, Faculty of Science, Al-Azhar University, P.O. 71452, Assiut (Egypt); Dahshan, A., E-mail: adahshan73@gmail.co [Department of Physics, Faculty of Science, Suez Canal University, Port Said (Egypt); Kashef, I.M.El. [Department of Physics, Faculty of Education, Suez Canal University, Al Arish (Egypt)

2010-04-02

Glasses with compositions (100 - x)Na{sub 2}B{sub 4}O{sub 7}-0.5Bi{sub 2}O{sub 3}-0.5MoO{sub 3}, with 0 {<=} x {<=} 40 mol% have been prepared using the melt quenching technique. The optical transmittance and reflectance spectrum of the glasses have been recorded in the wavelength range 300-1100 nm. The values of the optical band gap E{sub g}{sup opt} for indirect transition and refractive index have been determined for 0 {<=} x {<=} 40 mol%. The average electronic polarizability of the oxide ion {alpha}{sub O{sup 2-}} and the optical basicity have been estimated from the calculated values of the refractive indices. The variations in the different physical parameters such as the optical band gap, the refractive index, the average electronic polarizability of the oxide ion and the optical basicity with Bi{sub 2}O{sub 3} and MoO{sub 3} content have been analyzed and discussed in terms of the changes in the glass structure. The results are interpreted in terms of the increase in the number of non-bridging oxygen atoms, substitution of longer bond-lengths of Bi-O, and Mo-O in place of shorter B-O bond and the change in Na{sup +} ion concentration.

Effect of oxygen partial pressure on oxidation of Mo-metal

Science.gov (United States)

Sharma, Rabindar Kumar; Kumar, Prabhat; Singh, Megha; Gopal, Pawar; Reddy, G. B.

2018-05-01

This report explains the effect of oxygen partial pressure (PO2 ) on oxidation of Mo-metal in oxygen plasma. XRD results indulge that oxide layers formed on Mo-surfaces at different oxygen partial pressures have two different oxide phases (i.e. orthorhombic MoO3 and monoclinic Mo8O23). Intense XRD peaks at high pressure (i.e. 2.0×10-1 Torr) points out the formation of thick oxide layer on Mo-surface due to presence of large oxygen species in chamber and less oxide volatilization. Whereas, at low PO2 (6.5×10-2 and 7.5×10-2 Torr.) the reduced peak strength is owing to high oxide volatilization rate. SEM micrographs and thickness measurements also support XRD results and confirm that the optimum -2value of PO2 to deposited thicker and uniform oxide film on glass substrate is 7.5×10-2 Torr through plasma assistedoxidation process. Further to study the compositional properties, EDX of the sample M2 (the best sample) is carried out, which confirms that the stoichiometric ratio is less than 3 (i.e. 2.88). Less stoichiometric ratio again confirms the presence of sub oxides in oxide layers on Mo metal as evidenced by XRD results. All the observed results are well in consonance with each other.

Structural and magnetic properties of Ba2LuMoO6: a valence bond glass.

Science.gov (United States)

Coomer, Fiona C; Cussen, Edmund J

2013-02-27

We report here the synthesis of the site ordered double perovskite Ba(2)LuMoO(6). Rietveld refinement of room temperature powder x-ray diffraction measurements indicates that it crystallizes in the cubic space group Fm3m, with a = 8.3265(1) Å. Powder neutron diffraction data indicate that, unusually, this cubic symmetry is maintained down to 2 K, with [Formula: see text], Mo(5+) ions situated on the frustrated face-centred cubic lattice. Despite dc-susceptibility measurements showing Curie-Weiss behaviour with strong antiferromagnetic interactions at T ≥ 200 K, there is no evidence of long range magnetic ordering at 2 K. At T ≤ 50 K, susceptibility measurements indicate a loss in moment to ∼18% of the expected value, and there is a corresponding loss in the magnitude of the magnetic exchange. The structural and magnetic properties of this compound are compared with the related compound Ba(2)YMoO(6), which is a valence bond glass.

The micro-optic photovoltaic behavior of solar cell along with microlens curved glass substrate

International Nuclear Information System (INIS)

Xie, Jin; Wu, Keke; Cheng, Jian; Li, Ping; Zheng, Jiahua

2015-01-01

Highlights: • A microlens array may be micro-ground on curved photovoltaic glass substrate. • Its micro-optical structure absorbs and scatters the inclined light to solar cell. • It increases conversion efficiency and fill factor in weak and inclined lights. • It improves electricity generation by about 4 times in scattered cloudy daylight. • It produces stronger electricity generation in cloudy day than in sunny day. - Abstract: A hybrid of microlens structure and curved surface may produce high value-added micro-optic performance. Hence, the microlens array is proposed on macro curved glass substrate of thin film solar cell. The objective is to understand how the micro-optic behavior of microlens curved array influences indoor power conversion efficiency and outdoor electricity generation. First, the absorptivities of visible light and infrared light were analyzed in connection with the curved microlens sizes; then the microlens curved glass substrate was fabricated by a Computer Numerical Control (CNC) micro-grinding with micro diamond wheel V-tip; finally, its photovoltaic properties and electricity generation were measured, respectively. It is shown that the microlens curved surface may strongly absorb and scatter light to solar cell. It increases the absorptivity of visible light against plane surface, but it decreases the one of infrared light against microlens surface. When it is applied to solar cell, it enhances the power conversion efficiency by 3.4–10.6% under oblique illumination. When it is applied to solar device, it increases the electricity generation of daylight by 119–106% against microlens surface and by 260–419% against traditional plane surface, respectively. The surprising finding is that it produces much larger electricity generation during cloudy day than during sunny day, but traditional plane surface does not so

Optical and morphological characterizations of pyronin dye-poly (vinyl alcohol) thin films formed on glass substrates

International Nuclear Information System (INIS)

Meral, Kadem; Arik, Mustafa; Onganer, Yavuz

2016-01-01

Thin films of pyronin dye mixed with poly(vinyl alcohol) (PVA) on glass substrate were prepared by using spin-coating technique. The optical and morphological properties of the thin films were studied by UV-Vis., steady-state fluorescence spectroscopies and atomic force microscopy (AFM). The thin films on glass substrate were fabricated at various [PVA]/[dye] (P/D) ratios. Hence, the monomeric and H-aggregates thin films of pyronin dye mixed with PVA were formed as a function of the dye and PVA concentration. It was determined that while the monomeric thin films showed strong fluorescence, the formation of H-aggregates in the thin film caused to decreasing the fluorescence intensity. AFM studies demonstrated that the morphology of the thin film was drastically varied with changing the optical property of the thin film such as monomeric and H-aggregates thin films.

Optical and morphological characterizations of pyronin dye-poly (vinyl alcohol) thin films formed on glass substrates

Energy Technology Data Exchange (ETDEWEB)

Meral, Kadem, E-mail: kademm@atauni.edu.tr; Arik, Mustafa, E-mail: marik@tatauni.edu.tr; Onganer, Yavuz, E-mail: yonganer@atauni.edu.tr [Department of Chemistry, Faculty of Sciences, Atatürk University, 25240 Erzurum (Turkey)

2016-04-18

Thin films of pyronin dye mixed with poly(vinyl alcohol) (PVA) on glass substrate were prepared by using spin-coating technique. The optical and morphological properties of the thin films were studied by UV-Vis., steady-state fluorescence spectroscopies and atomic force microscopy (AFM). The thin films on glass substrate were fabricated at various [PVA]/[dye] (P/D) ratios. Hence, the monomeric and H-aggregates thin films of pyronin dye mixed with PVA were formed as a function of the dye and PVA concentration. It was determined that while the monomeric thin films showed strong fluorescence, the formation of H-aggregates in the thin film caused to decreasing the fluorescence intensity. AFM studies demonstrated that the morphology of the thin film was drastically varied with changing the optical property of the thin film such as monomeric and H-aggregates thin films.

Influence of Mo/MoSe{sub 2} microstructure on the damp heat stability of the Cu(In,Ga)Se{sub 2} back contact molybdenum

Energy Technology Data Exchange (ETDEWEB)

Theelen, Mirjam, E-mail: mirjam.theelen@tno.nl [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Delft University of Technology, Photovoltaic Materials and Devices, Mekelweg 4, 2628 CD Delft (Netherlands); Harel, Sylvie [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Verschuren, Melvin [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Tomassini, Mathieu [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Hovestad, Arjan [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Barreau, Nicolas [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Berkum, Jurgen van [Philips Innovation Services, High Tech Campus 11, 5656 AE Eindhoven (Netherlands); Vroon, Zeger [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Zeman, Miro [Delft University of Technology, Photovoltaic Materials and Devices, Mekelweg 4, 2628 CD Delft (Netherlands)

2016-08-01

The degradation behavior of Mo/MoSe{sub 2} layers have been investigated using damp heat exposure. The two studied molybdenum based films with different densities and microstructures were obtained by lifting off Cu(In,Ga)Se{sub 2} layers from a bilayer molybdenum stack on soda lime glass. Hereby, a glass/Mo/MoSe{sub 2} was obtained, which resembles the back contact as present in Cu(In,Ga)Se{sub 2} solar cells. The samples were degraded for 150 h under standard damp heat conditions and analyzed before, during and after degradation. It was observed that the degradation resulted in the formation of needles and molybdenum oxide layers near the glass/Mo and the Mo/Cu(In,Ga)Se{sub 2} interfaces. X-ray Photoelectron Spectroscopy measurements have shown that the sodium was also present at the surface of the degraded material and it is proposed that the degraded material consists mostly of MoO{sub 3} with intercalated Na{sup +}. This element has likely migrated from the soda lime glass. This intercalation process could have led to the formation of Na{sub x}MoO{sub 3} ‘molybdenum bronze’ following this redox reaction: xNa{sup +} + MoO{sub 3} + xe{sup −} ↔ Na{sub x}MoO{sub 3} It is proposed that the formed oxide layer contains Na{sub x}MoO{sub 3} with different Na{sup +} contents and different grades of conductivity. This intercalation process can also explain the high mobility of Na{sup +} via the grain boundaries in molybdenum. It was also observed that the molybdenum film with a top layer deposited at a high pressure is more susceptible for damp heat degradation. - Highlights: • SLG/high pressure Mo/low pressure Mo/MoSe{sub 2} stacks were exposed to damp heat. • Molybdenum deposited at low pressure retained the best reflectivity and conductivity. • Damp heat exposure leads to a Na{sub x}MoO{sub 3}/Mo multilayer structure. • The Na{sub x}MoO{sub 3} probably consists of Na{sup +} intercalated in a (reduced) MoO{sub 3} matrix. • Intercalation can explain the

Study of powellite-rich glass-ceramics for nuclear waste immobilization

International Nuclear Information System (INIS)

Taurines, T.

2012-01-01

MoO 3 is poorly soluble in borosilicate glasses which can lead to the crystallization of undesired phases when its concentration or the charge load (minor actinides and fission products concentration) is too high. Crystallization control is needed to guarantee good immobilization properties. We studied powellite-rich glass-ceramics obtained from a simplified nuclear glass in the system SiO 2 - B 2 O 3 - Na 2 O - CaO - Al 2 O 3 - MoO 3 - RE 2 O 3 (RE = Gd, Eu, Nd) by various heat treatments. Rare earth elements (REE) were added as minor actinides surrogates and as spectroscopic probes. The influence of MoO 3 and RE 2 O 3 content on powellite (CaMoO 4 ) crystallization was investigated. Various glass-ceramics (similar residual glass + powellite) were obtained with large crystal size distributions. Phase separation due to molybdenum occurs during quenching when [MoO 3 ] ≥ 2.5 mol%. We showed that increasing the rare earth content can suppress the phase separation due to molybdenum but it leads to spinodal decomposition of the residual glass. Furthermore, we studied the effects of parent glass complexifying and the insertion of Gd 3+ ions into the powellite structure. In order to understand the influence of microstructure on evolutions under β-irradiation, we studied point defects creation and structural changes. We showed that the damage induced by electronic excitations in the glass-ceramics is driven by the damage in the residual glass. (author) [fr

Microstructural and Wear Behavior Characterization of Porous Layers Produced by Pulsed Laser Irradiation in Glass-Ceramics Substrates.

Science.gov (United States)

Sola, Daniel; Conde, Ana; García, Iñaki; Gracia-Escosa, Elena; de Damborenea, Juan J; Peña, Jose I

2013-09-09

In this work, wear behavior and microstructural characterization of porous layers produced in glass-ceramic substrates by pulsed laser irradiation in the nanosecond range are studied under unidirectional sliding conditions against AISI316 and corundum counterbodies. Depending on the optical configuration of the laser beam and on the working parameters, the local temperature and pressure applied over the interaction zone can generate a porous glass-ceramic layer. Material transference from the ball to the porous glass-ceramic layer was observed in the wear tests carried out against the AISI316 ball counterface whereas, in the case of the corundum ball, the wear volume loss was concentrated in the porous layer. Wear rate and friction coefficient presented higher values than expected for dense glass-ceramics.

Microstructural and Wear Behavior Characterization of Porous Layers Produced by Pulsed Laser Irradiation in Glass-Ceramics Substrates

Directory of Open Access Journals (Sweden)

Jose I. Peña

2013-09-01

Full Text Available In this work, wear behavior and microstructural characterization of porous layers produced in glass-ceramic substrates by pulsed laser irradiation in the nanosecond range are studied under unidirectional sliding conditions against AISI316 and corundum counterbodies. Depending on the optical configuration of the laser beam and on the working parameters, the local temperature and pressure applied over the interaction zone can generate a porous glass-ceramic layer. Material transference from the ball to the porous glass-ceramic layer was observed in the wear tests carried out against the AISI316 ball counterface whereas, in the case of the corundum ball, the wear volume loss was concentrated in the porous layer. Wear rate and friction coefficient presented higher values than expected for dense glass-ceramics.

Postdeposition Annealing Effect on Cu2ZnSnS4 Thin Films Grown at Different Substrate Temperature

Directory of Open Access Journals (Sweden)

Samia Ahmed Nadi

2014-01-01

Full Text Available Cu2ZnSnS4 (CZTS thin films were deposited on top of Molybdenum (Mo coated soda lime glass (SLG substrates using a single target rf magnetron sputtering technique. The sputtering parameters such as base pressure, working pressure, rf power, argon (Ar gas flow rate, and deposition time were kept consistent throughout the experiment. The effect of different substrate temperatures, for example, room temperature (RT, 300°C, 350°C, 370°C, 400°C, and 450°C, was analyzed by studying their structural, electrical, and optical properties. As-sputtered films were then annealed at 460°C. X-ray diffraction (XRD measurement revealed the structure to be kesterite with peak of (112 plane in both annealed and as-sputtered CZTS thin films. The crystallinity of the films improved with the increasing substrate temperature until 370°C. Secondary phases of MoS2, CuxMoSx, CuxSnSx, CuxS, and Cu6MoSnS8 (hemusite were also observed in the annealed CZTS films. Scanning electron microscopy (SEM shows crystallite size of deposited CZTS thin film to be proportionally related to deposition temperature. The highest surface roughness of 67.318 nm is observed by atomic force microscopy (AFM. The conductivity type of the films was found to be p-type by Hall effect measurement system.

Magnetic properties of Pr-Fe-B thick-film magnets deposited on Si substrates with glass buffer layer

Science.gov (United States)

Nakano, M.; Kurosaki, A.; Kondo, H.; Shimizu, D.; Yamaguchi, Y.; Yamashita, A.; Yanai, T.; Fukunaga, H.

2018-05-01

In order to improve the magnetic properties of PLD-made Pr-Fe-B thick-film magnets deposited on Si substrates, an adoption of a glass buffer layer was carried out. The glass layer could be fabricated under the deposition rate of approximately 70 μm/h on a Si substrate using a Nd-YAG pulse laser in the vacuum atmosphere. The use of the layer enabled us to reduce the Pr content without a mechanical destruction and enhance (BH)max value by approximately 20 kJ/m3 compared with the average value of non-buffer layered Pr-Fe-B films with almost the same thickness. It is also considered that the layer is also effective to apply a micro magnetization to the films deposited on Si ones.

Extremely improved InP template and GaInAsP system growth on directly-bonded InP/SiO2-Si and InP/glass substrate

International Nuclear Information System (INIS)

Matsumoto, Keiichi; Makino, Tatsunori; Kimura, Katsuya; Shimomura, Kazuhiko

2013-01-01

We have developed an ultrathin InP template with low defect density on SiO 2 -Si and glass substrate by employing wet etching and wafer direct bonding technique. We have demonstrated epitaxial growth on these substrates and GaInAs/InP multiple quantum well layers were grown by low pressure metal-organic vapor-phase epitaxy. Photoluminescence measurements of the layers show that they are optically active and we have obtained almost the same intensity from these substrates compared to the InP substrate. These results may be attributed to improvement of InP template quality and should provide further improvements in device performance realized on SiO 2 -Si and glass substrate. And, these are promising results in terms of integration of InP-based several functional optical devices on SiO 2 -Si and glass substrate. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Realizing near stoichiometric and highly transparent CdS:Mo thin films by a low-cost improved SILAR technique

Energy Technology Data Exchange (ETDEWEB)

Ravichandran, K. [P.G. and Research Department of Physics, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur 613503, Tamil Nadu (India); Nisha Banu, N. [P.G. and Research Department of Physics, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur 613503, Tamil Nadu (India); Research Department of Physics, Kunthavai Naachiyaar Government Arts College for Women (Autonomous), Thanjavur 613007, Tamil Nadu (India); Baneto, M. [CUER-UL, Universite de Lome, BP 1515, Lome (Togo); Senthamil Selvi, V. [Research Department of Physics, Kunthavai Naachiyaar Government Arts College for Women (Autonomous), Thanjavur 613007, Tamil Nadu (India)

2016-02-15

Undoped and molybdenum doped CdS thin films were deposited on glass substrates using Improved Successive Ionic Layer Adsorption and Reaction (ISILAR) technique. The Mo doping level was varied from 0 to 15 at.% in steps of 5 at.%. The XRD analysis shows that all the films are polycrystalline with cubic structure and grow preferentially along the (111) plane. The crystallite size increases gradually with the increase in Mo doping level up to 10 at.% and decreases with further doping. The morphological studies reveal that Mo doping significantly affects the grains size. Qualitative and quantitative compositional analysis show that near stoichiometric undoped and Mo doped CdS thin films can be achieved using this ISILAR technique. All the films exhibit high transparency in the visible region with an average transmittance in the range of 85-95%. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Sol-gel processing of glasses and glass-ceramics for microelectronic packaging

International Nuclear Information System (INIS)

Sriram, M.A.; Kumta, P.N.

1992-01-01

In recent years considerable progress has been made in electronic packaging substrate technology. The future need of miniaturization of devices to increase the signal processing speeds calls for an increase in the device density requiring the substrates to be designed for better thermal, mechanical and electrical efficiency. Fast signal propagation with minimum delay requires the substrate to possess very low dielectric constant. Several glasses and glass-ceramic materials have been identified over the years which show good promise as candidate substrate materials. among these borophosphate and borophosphosilicate glass-ceramics have been recently identified to have the lowest dielectric constant. This paper reports that sol-gel processing has been used to synthesize borosilicate, borophosphosilicate and borophosphate glasses and glass-ceramics using inexpensive boron oxide and phosphorus pentoxide precursors. Preliminary results of the processing of these gels and the effect of volatility of boron alkoxide and its modification on the gel structure are described. X-ray diffraction, Differential thermal analyses and FTIR have been used to characterize the as-prepared and heat treated gels

A simple technique for direct growth of Au into a nanoporous alumina layer on conductive glass as a reusable SERS substrate

Energy Technology Data Exchange (ETDEWEB)

Yu, Jiajie [Chemicobiology and Functional Materials Institute, Nanjing University of Science and Technology, Nanjing 210094 (China); Shen, Muzhong [School of Engineering, AnHui Agricultural University, Hefei 230036 (China); Liu, Siyu; Li, Feng [Chemicobiology and Functional Materials Institute, Nanjing University of Science and Technology, Nanjing 210094 (China); Sun, Dongping, E-mail: sundpe301@163.com [School of Engineering, AnHui Agricultural University, Hefei 230036 (China); Wang, Tianhe, E-mail: thwang56@126.com [Chemicobiology and Functional Materials Institute, Nanjing University of Science and Technology, Nanjing 210094 (China)

2017-06-01

Graphical abstract: A simple technique for direct growth of gold nanoparticles (GNPs) into a nanostructured porous alumina layer on conductive glass slide (PAOCG). Gold was uniformly distributed in porous alumina layer. Au/PAOCG can serve as a portable, durable and reusable SERS substrate. - Highlights: • A simple method of producing nanoporous alumina layer on conductive glasses. • A facile technique for direct growth of gold nanoparticles (GNPs) into PAOCG. • It presents a general protocol for preparation of (MNPs) on conductive glasses. • Au/PAOCG exhibits high SERS sensitivity and excellent reusability. - Abstract: In this paper, we describe a simple technique for direct growth of gold nanoparticles (GNPs) into a nanostructured porous alumina layer on conductive glass slide (PAOCG). PAOCG was attached firmly with a small piece of steel and was then immersed in a HAuCl{sub 4} solution. Electro-induced electrons from steel were employed to reduce AuCl{sub 4}{sup −} on PAOCG. The galvanic replacement reaction (GRR) was adopted as the fundamental mechanism for reducing metal precursors. This mechanism was further studied by open circuit potential-time (OCP-t) experiment and the result demonstrated that steel induced the continuous proceeding of this reaction. This strategy presents a simple and general protocol for preparation of metal nanoparticles (MNPs) on conductive glass substrates. The SERS properties of Au/PAOCG were investigated using aqueous crystal violet (CV) and 4-mercaptopyridine (4-Mpy) as probe molecules. Au/PAOCG allowed as low as 10{sup −9} M CV and 10{sup −8} M 4-Mpy to be detected. The reusability of this substrate was achieved by measuring the SERS spectrum of the probe molecules followed with a 400 °C heat treatment for 10 min to remove the residuals. This substrate could be reused for at least ten cycles without any significantly reduced SERS performance. Therefore, this surface can serve as a portable, durable and reusable SERS

Analysis of diamond-like carbon and Ti/MoS2 coatings on Ti-6Al-4V substrates for applicability to turbine engine applications

International Nuclear Information System (INIS)

Wu, L.; Holloway, B.C.; Kalil, C.; Manos, D.M.

2000-01-01

Ti-6Al-4V substrates have been coated by diamond-like carbon (DLC) films, with no surface pretreatment, and have been coated by Ti/MoS 2 films, with a simple surface pre-cleaning. The DLC films were deposited by planar coil r.f. inductively-coupled plasma-enhanced chemical vapor deposition (r.f. ICPECVD); the Ti/MoS 2 films were deposited by magnetron sputtering. Both the DLC and Ti/MoS 2 films were characterized by pull tests, hardness tests, scanning electron microscopy (SEM), and wear tests (pin-on-disk and block-on-ring) to compare their adhesion, hardness, surface topology, and wear properties to plasma-sprayed Cu-Ni-In coating currently used for turbine engine applications. The DLC films were easily characterized by their optical properties because they were highly transparent. We used variable-angle spectroscopic ellipsometry (VASE) to characterize thickness and to unequivocally extract real and complex index of refraction, providing a rapid assessment of film quality. Thicker coatings yielded the largest hardness values. The DLC coatings did not require abrasive pretreatment or the formation of bond-layers to ensure good adhesion to the substrate. Simple surface pre-cleaning was also adequate to form well-adhered Ti/MoS 2 on Ti-6Al-4V. The results show that the DLC and Ti/MoS 2 coatings are both much better fretting- and wear-resistant coatings than plasma-sprayed Cu-Ni-In. Both show excellent adhesion to the substrates, less surface roughness, harder surfaces, and more wear resistance than the Cu-Ni-In films. (orig.)

Enhanced photocatalytic activity and synthesis of ZnO nanorods/MoS2 composites

Science.gov (United States)

Li, Hui; Shen, Hao; Duan, Libing; Liu, Ruidi; Li, Qiang; Zhang, Qian; Zhao, Xiaoru

2018-05-01

A stable and recyclable organic degradation catalyst based on MoS2 functionalized ZnO nanorods was introduced. ZnO nanorods were synthesized on the glass substrates (2 cm*2 cm) by sol-gel method and hydrothermal method and functionalized with MoS2 via an argon flow annealing method. The structure and morphology of the as-prepared samples were characterized by XRD, SEM and TEM. Results showed that a small amount of MoS2 was successfully wrapped on the surfaces of ZnO nanorods. XPS analyses showed the existence of Zn-S between ZnO and MoS2, indicating that the MoS2 was combined with ZnO through chemical bonds and formed the ZnO/MoS2 heterostructure. PL results revealed that ZnO/MoS2 had lower fluorescence spectra indicating an electron transport channel between ZnO and MoS2 which separated electrons and holes. Photocatalytic experiment showed that ZnO/MoS2 composites showed a better photodegradation performance of Rhodamine B (RhB) after functionalized with MoS2 under the UV light irradiation which could be attributed to the separation and transfer of photogenerated electrons and holes between ZnO and MoS2. Meanwhile, the high active adsorption sites on the edges of MoS2 also accelerated the degradation process. Furthermore, the scavengers were used to investigate the major active species and results indicated that h+ was the major reactive species for the degradation.

MoSx-coated NbS2 nanoflakes growth on glass carbon: an advanced electrocatalyst for the hydrogen evolution reaction

KAUST Repository

Zhou, Xiaofeng; Lin, Shi-Hsin; Yang, Xiulin; Li, Henan; Hedhili, Mohamed N.; Li, Lain-Jong; Zhang, Wenjing; Shi, Yumeng

2018-01-01

Recent experimental and theoretical studies have demonstrated that two-dimensional (2D) transition metal dichalcogenide (TMDC) nanoflakes are one of the most promising candidates for non-noblemetal electrocatalysts for hydrogen evolution reaction (HER). However, it is still demanding to optimize their conductivity and enrich active sites for the high efficient electrochemical performance. Herein, we report a chemical vapor deposition (CVD) and thermal annealing two-step strategy to controllably synthesize hybrid electrocatalysts consisting of metallic NbS2 nanoflake backbones and highly catalytic active MoSx nanocrystalline shell on polished commercial glass carbon (GC). In addition, the amounts of MoSx in the hybrids can be easily adjusted, we first demonstrate that small amount of MoSx obviously promotes the HER activity of 2D NbS2 nanoflakes, which is in good consistence with the density functional theory (DFT) calculation results. Meanwhile, the optimized MoSx@NbS2/GC electrocatalyst displays a superior HER activity with an overpotential of -164 mV at -10 mA/cm2, a small Tafel slope of 43.2 mV/dec, and prominent electrochemical stability. This study provides a new path for enhancing the HER performance of 2D TMDC nanoflakes.

MoSx-coated NbS2 nanoflakes growth on glass carbon: an advanced electrocatalyst for the hydrogen evolution reaction

KAUST Repository

Zhou, Xiaofeng

2018-01-19

Recent experimental and theoretical studies have demonstrated that two-dimensional (2D) transition metal dichalcogenide (TMDC) nanoflakes are one of the most promising candidates for non-noblemetal electrocatalysts for hydrogen evolution reaction (HER). However, it is still demanding to optimize their conductivity and enrich active sites for the high efficient electrochemical performance. Herein, we report a chemical vapor deposition (CVD) and thermal annealing two-step strategy to controllably synthesize hybrid electrocatalysts consisting of metallic NbS2 nanoflake backbones and highly catalytic active MoSx nanocrystalline shell on polished commercial glass carbon (GC). In addition, the amounts of MoSx in the hybrids can be easily adjusted, we first demonstrate that small amount of MoSx obviously promotes the HER activity of 2D NbS2 nanoflakes, which is in good consistence with the density functional theory (DFT) calculation results. Meanwhile, the optimized MoSx@NbS2/GC electrocatalyst displays a superior HER activity with an overpotential of -164 mV at -10 mA/cm2, a small Tafel slope of 43.2 mV/dec, and prominent electrochemical stability. This study provides a new path for enhancing the HER performance of 2D TMDC nanoflakes.

The peculiarity of the formation of zinc films on a glass substrate

Energy Technology Data Exchange (ETDEWEB)

Tomaev, V. V., E-mail: tvaza@mail.ru [Saint Petersburg State University, 198504, Russia, Saint-Petersburg, Petrodvorets, Universitetskii pr. 26 (Russian Federation); Saint Petersburg Mining University, Russia, 199106, St. Petersburg, V.O., 21-st line, 2 (Russian Federation); Polishchuk, V. A., E-mail: vpvova2010@yandex.ru [St. Petersburg University of Information Technologies, Mechanics, and Optics, 197101, Russia, St. Petersburg, Kronverksky Pr., 49 (Russian Federation); Borisov, E. N., E-mail: enbor@bk.ru [Saint Petersburg State University, 198504, Russia, Saint-Petersburg, Petrodvorets, Universitetskii pr. 26 (Russian Federation)

2016-06-17

Thin Nanocrystalline films of the zinc have been fabricated by thermal spraying on the glass substrate. Morphologies and structure of the films had been investigated by the methods X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). It is found that the surface of the films has a different types of the nanocrystals zinc. Were detected intergrowths of two or more the nanocrystals, hexagonal shape. Using the theory of homogeneous and heterogeneous nucleation of a new phase, had been evaluated the geometrical and thermodynamic parameters nanocrystals zinc.

Optical properties of alkaline earth borate glasses

African Journals Online (AJOL)

user

... devices; radiation shields, surgical lasers and their glass ceramic counter ... Alkaline earth oxides improve glass forming capability while heavy metal ... reports on optical properties of MO-B2O3 glasses containing alkaline earth oxides.

Investigation of radiation shielding properties for MeO-PbCl2-TeO2 (MeO = Bi2O3, MoO3, Sb2O3, WO3, ZnO) glasses

Science.gov (United States)

Sayyed, M. I.; Çelikbilek Ersundu, M.; Ersundu, A. E.; Lakshminarayana, G.; Kostka, P.

2018-03-01

In this work, glasses in the MeO-PbCl2-TeO2 (MeO = Bi2O3, MoO3, Sb2O3, WO3, ZnO) system, which show a great potential for optoelectronic applications, were used to evaluate their resistance under high energy ionizing radiations. The basic shielding quantities for determining the penetration of radiation in glass, such as mass attenuation coefficient (μ/ρ), half value layer (HVL), mean free path (MFP) and exposure buildup factor (EBF) values were investigated within the energy range 0.015 MeV ‒ 15 MeV using XCOM program and variation of shielding parameters were compared with different glass systems and ordinary concrete. From the derived results, it was determined that MeO-PbCl2-TeO2 (MeO = Bi2O3, MoO3, Sb2O3, WO3, ZnO) glasses show great potentiality to be used under high energy radiations. Among the studied glass compositions, Bi2O3 and WO3 containing glasses were found to possess superior gamma-ray shielding effectiveness.

Electrical resistivity of CuAlMo thin films grown at room temperature by dc magnetron sputtering

OpenAIRE

Birkett, Martin; Penlington, Roger

2016-01-01

We report on the thickness dependence of electrical resistivity of CuAlMo films grown by dc magnetron sputtering on glass substrates at room temperature. The electrical resistance of the films was monitored in situ during their growth in the thickness range 10–1000 nm. By theoretically modelling the evolution of resistivity during growth we were able to gain an insight into the dominant electrical conduction mechanisms with increasing film thickness. For thicknesses in the range 10–25 nm the ...

Development of a novel non-contact inspection technique to detect micro cracks under the surface of a glass substrate by thermal stress-induced light scattering method

Science.gov (United States)

Sakata, Yoshitaro; Terasaki, Nao; Nonaka, Kazuhiro

2017-05-01

Fine polishing techniques, such as a chemical mechanical polishing treatment, are important techniques in glass substrate manufacturing. However, these techniques may cause micro cracks under the surface of glass substrates because they used mechanical friction. A stress-induced light scattering method (SILSM), which was combined with light scattering method and mechanical stress effects, was proposed for inspecting surfaces to detect polishing-induced micro cracks. However, in the conventional SILSM, samples need to be loaded with physical contact, and the loading point is invisible in transparent materials. Here, we introduced a novel non-contact SILSM using a heating device. A glass substrate was heated first, and then the light scattering intensity of micro cracks was detected by a cooled charge-couple device camera during the natural cooling process. Results clearly showed during the decreasing surface temperature of a glass substrate, appropriate thermal stress is generated for detecting micro cracks by using the SILSM and light scattering intensity from micro cracks changes. We confirmed that non-contact thermal SILSM (T-SILSM) can detect micro cracks under the surface of transparent materials.

X-ray absorption and Raman spectroscopy studies of molybdenum environments in borosilicate waste glasses

Energy Technology Data Exchange (ETDEWEB)

McKeown, David A., E-mail: davidm@vsl.cua.edu; Gan, Hao; Pegg, Ian L.

2017-05-15

Mo-containing high-level nuclear waste borosilicate glasses were investigated as part of an effort to improve Mo loading while avoiding yellow phase crystallization. Previous work showed that additions of vanadium decrease yellow phase formation and increases Mo solubility. X-ray absorption spectroscopy (XAS) and Raman spectroscopy were used to characterize Mo environments in HLW borosilicate glasses and to investigate possible structural relationships between Mo and V. Mo XAS spectra for the glasses indicate isolated tetrahedral Mo{sup 6+}O{sub 4} with Mo-O distances near 1.75 Å. V XANES indicate tetrahedral V{sup 5+}O{sub 4} as the dominant species. Raman spectra show composition dependent trends, where Mo-O symmetrical stretch mode frequencies (ν{sub 1}) are sensitive to the mix of alkali and alkaline earth cations, decreasing by up to 10 cm{sup −1} for glasses that change from Li{sup +} to Na{sup +} as the dominant network-modifying species. This indicates that MoO{sub 4} tetrahedra are isolated from the borosilicate network and are surrounded, at least partly, by Na{sup +} and Li{sup +}. Secondary ν{sub 1} frequency effects, with changes up to 7 cm{sup −1}, were also observed with increasing V{sub 2}O{sub 5} and MoO{sub 3} content. These secondary trends may indicate MoO{sub 4}-MoO{sub 4} and MoO{sub 4}-VO{sub 4} clustering, suggesting that V additions may stabilize Mo in the matrix with respect to yellow phase formation. - Highlights: •Raman and XAS data indicate isolated MoO{sub 4} tetrahedra from the borosilicate network. •Mo-O stretch frequency is sensitive to network-modifying Li and Na concentrations. •Mo-O stretch frequency shifts were also seen with increasing V{sub 2}O{sub 5} and MoO{sub 3} content. •The Raman trends may indicate MoO{sub 4}-MoO{sub 4} and MoO{sub 4}-VO{sub 4} clustering in the glass. •V may stabilize Mo in the glass matrix avoiding yellow phase formation.

Bioactive glass 13-93 as a subchondral substrate for tissue-engineered osteochondral constructs: a pilot study.

Science.gov (United States)

Jayabalan, Prakash; Tan, Andrea R; Rahaman, Mohammed N; Bal, B Sonny; Hung, Clark T; Cook, James L

2011-10-01

Replacement of diseased areas of the joint with tissue-engineered osteochondral grafts has shown potential in the treatment of osteoarthritis. Bioactive glasses are candidates for the osseous analog of these grafts. (1) Does Bioactive Glass 13-93 (BG 13-93) as a subchondral substrate improve collagen and glycosaminoglycan production in a tissue-engineered cartilage layer? (2) Does BG 13-93 as a culture medium supplement increase the collagen and glycosaminoglycan production and improve the mechanical properties in a tissue-engineered cartilage layer? In Study 1, bioactive glass samples (n = 4) were attached to a chondrocyte-seeded agarose layer to form an osteochondral construct, cultured for 6 weeks, and compared to controls. In Study 2, bioactive glass samples (n = 5) were cocultured with cell-seeded agarose for 6 weeks. The cell-seeded agarose layer was exposed to BG 13-93 either continuously or for the first or last 2 weeks in culture or had no exposure. Osteochondral constructs with a BG 13-93 base had improved glycosaminoglycan deposition but less collagen II content. Agarose scaffolds that had a temporal exposure to BG 13-93 within the culture medium had improved mechanical and biochemical properties compared to continuous or no exposure. When used as a subchondral substrate, BG 13-93 did not improve biochemical properties compared to controls. However, as a culture medium supplement, BG 13-93 improved the biochemical and mechanical properties of a tissue-engineered cartilage layer. BG 13-93 may not be suitable in osteochondral constructs but could have potential as a medium supplement for neocartilage formation.

Electrical transport properties of MoO{sub 3} thin films prepared by laser assisted evaporation

Energy Technology Data Exchange (ETDEWEB)

Lopez-Carreno, L.D.; Pardo, A.; Zuluaga, M.; Torres, J.; Alfonso, J.E. [Group of Materials with Technological Applications, GMAT, Physics Department, Universidad Nacional de Colombia, Bogota (Colombia); Cortes-Bracho, O.L. [Group of Materials with Technological Applications, GMAT, Physics Department, Universidad Nacional de Colombia, Bogota (Colombia); Electronic Engineering Department, Universidad Nacional de Colombia, Bogota (Colombia)

2007-07-01

In the present paper the growth of MoO{sub 3} thin films on common glass substrates are described. The films were prepared by evaporation of a MoO{sub 3} target with a CO{sub 2} laser (10.6 {mu}m), operating in the continuous wave mode. The effect of substrate temperature on the crystallographic structure and electrical properties of MoO{sub 3} thin films was studied. The chemical composition of the different species formed on the films surface was obtained by X-ray photoelectron spectroscopy (XPS) and the crystalline structure was studied with X-ray diffraction (XRD). The electrical conductivity of the films was determined using the standard four-points method. Conductivity of the films varied from de 10{sup -9} to 10{sup -5} ({omega}cm){sup -1} in the 300-600 K temperature range. Arrhenius-type plots for the electrical conductivity indicate the presence of at least two different conduction mechanisms. The I-V characteristic curve shows an ohmic behavior only in the 4.5-60 V range. Outside this interval the I-V curve has a behavior described by a power law. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Substrate channel in nitrogenase revealed by a molecular dynamics approach.

Science.gov (United States)

Smith, Dayle; Danyal, Karamatullah; Raugei, Simone; Seefeldt, Lance C

2014-04-15

Mo-dependent nitrogenase catalyzes the biological reduction of N2 to two NH3 molecules at FeMo-cofactor buried deep inside the MoFe protein. Access of substrates, such as N2, to the active site is likely restricted by the surrounding protein, requiring substrate channels that lead from the surface to the active site. Earlier studies on crystallographic structures of the MoFe protein have suggested three putative substrate channels. Here, we have utilized submicrosecond atomistic molecular dynamics simulations to allow the nitrogenase MoFe protein to explore its conformational space in an aqueous solution at physiological ionic strength, revealing a putative substrate channel. The viability of this observed channel was tested by examining the free energy of passage of N2 from the surface through the channel to FeMo-cofactor, resulting in the discovery of a very low energy barrier. These studies point to a viable substrate channel in nitrogenase that appears during thermal motions of the protein in an aqueous environment and that approaches a face of FeMo-cofactor earlier implicated in substrate binding.

X-ray absorption and Raman spectroscopy studies of molybdenum environments in borosilicate waste glasses

Science.gov (United States)

McKeown, David A.; Gan, Hao; Pegg, Ian L.

2017-05-01

Mo-containing high-level nuclear waste borosilicate glasses were investigated as part of an effort to improve Mo loading while avoiding yellow phase crystallization. Previous work showed that additions of vanadium decrease yellow phase formation and increases Mo solubility. X-ray absorption spectroscopy (XAS) and Raman spectroscopy were used to characterize Mo environments in HLW borosilicate glasses and to investigate possible structural relationships between Mo and V. Mo XAS spectra for the glasses indicate isolated tetrahedral Mo6+O4 with Mo-O distances near 1.75 Å. V XANES indicate tetrahedral V5+O4 as the dominant species. Raman spectra show composition dependent trends, where Mo-O symmetrical stretch mode frequencies (ν1) are sensitive to the mix of alkali and alkaline earth cations, decreasing by up to 10 cm-1 for glasses that change from Li+ to Na+ as the dominant network-modifying species. This indicates that MoO4 tetrahedra are isolated from the borosilicate network and are surrounded, at least partly, by Na+ and Li+. Secondary ν1 frequency effects, with changes up to 7 cm-1, were also observed with increasing V2O5 and MoO3 content. These secondary trends may indicate MoO4-MoO4 and MoO4-VO4 clustering, suggesting that V additions may stabilize Mo in the matrix with respect to yellow phase formation.

Wear Resistance of Nano Alumina Containing SiO2-B2O3-Na2O Glass-Ceramic on Steel Substrate

OpenAIRE

A. Faeghinia; A. Zamanian

2016-01-01

The experimental study has been carried out to investigate the tribological properties of nano Alumina reinforced glass-ceramic enamel. The mixtures of (5, 10, 15 wt.%) nano alumina and glass powders have been air sprayed on stainless steel substrate.. The thixotropy, wetting angle and surface tension of used slurry were increased inherently by 15-wt.% nano alumina. By heat treating at 870-640-525 ºC, the homogeneous crystalline sodium silicate phase beside nano alumina was obtained in glass ...

Field emission characteristics of vertically aligned carbon nanotubes with honeycomb configuration grown onto glass substrate with titanium coating

Energy Technology Data Exchange (ETDEWEB)

Huang, Yung-Jui [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Chang, Hsin-Yueh; Chang, Hsuan-Chen [Department of Electronic and computer Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Shih, Yi-Ting; Su, Wei-Jhih [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Ciou, Chen-Hong [Department of Electronic and computer Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Chen, Yi-Ling [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Honda, Shin-ichi [Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280 (Japan); Huang, Ying-Sheng [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Department of Electronic and computer Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Lee, Kuei-Yi, E-mail: kylee@mail.ntust.edu.tw [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Department of Electronic and computer Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

2014-03-15

Highlights: • We have successfully designed the honeycomb patterns on glass substrate by photolithography technique. • Honeycomb-VACNTs were synthesized successfully onto glass substrate by using thermal CVD and covered different Ti films on VACNTs by e-beam evaporation. • After coating the Ti films, the current density reached 7 mA/cm{sup 2} when the electric field was 2.5 V/μm. • The fluorescence of VACNTs with Ti 15 nm films exhibits the high brightness screen and emission uniformity. -- Abstract: Carbon nanotubes (CNTs) were grown successfully onto a glass substrate using thermal chemical vapor deposition (TCVD) with C{sub 2}H{sub 2} gas at 700 °C. The synthesized CNTs exhibited good crystallinity and a vertically aligned morphology. The vertically aligned CNTs (VACNTs) were patterned with a honeycomb configuration using photolithography and characterized using field emission (FE) applications. Owing to the electric field concentration, the FE current density of VACNTs with honeycomb configuration was higher than that of the un-patterned VACNTs. Ti was coated onto the VACNT surface utilizing the relatively lower work function property to enhance the FE current density. The FE current density reached up to 7.0 mA/cm{sup 2} at an applied electric field of 2.5 V/μm. A fluorescent screen was monitored to demonstrate uniform FE VACNTs with a honeycomb configuration. The designed field emitter provided an admirable example for FE applications.

Influences of Indium Tin Oxide Layer on the Properties of RF Magnetron-Sputtered (BaSr)TiO3 Thin Films on Indium Tin Oxide-Coated Glass Substrate

Science.gov (United States)

Kim, Tae Song; Oh, Myung Hwan; Kim, Chong Hee

1993-06-01

Nearly stoichiometric ((Ba+Sr)/Ti=1.08-1.09) and optically transparent (BaSr)TiO3 thin films were deposited on an indium tin oxide (ITO)-coated glass substrate by means of rf magnetron sputtering for their application to the insulating layer of an electroluminescent flat panel display. The influence of the ITO layer on the properties of (BaSr)TiO3 thin films deposited on the ITO-coated substrate was investigated. The ITO layer did not affect the crystallographic orientation of (BaSr)TiO3 thin film, but enhanced the grain growth. Another effect of the ITO layer on (BaSr)TiO3 thin films was the interdiffusion phenomenon, which was studied by means of secondary ion mass spectrometry (SIMS). As the substrate temperature increased, interdiffusion intensified at the interface not only between the grown film and ITO layer but also between the ITO layer and base glass substrate. The refractive index (nf) of (BaSr)TiO3 thin film deposited on a bare glass substrate was 2.138-2.286, as a function of substrate temperature.

Normal and grazing incidence pulsed laser deposition of nanostructured MoSx hydrogen evolution catalysts from a MoS2 target

Science.gov (United States)

Fominski, V. Yu.; Romanov, R. I.; Fominski, D. V.; Dzhumaev, P. S.; Troyan, I. A.

2018-06-01

Pulsed laser ablation of a MoS2 target causes enhanced splashing of the material. So, for MoSx films obtained by pulsed laser deposition (PLD) in the conventional normal incidence (NI) configuration, their typical morphology is characterized by an underlying granular structure with an overlayer of widely dispersed spherical Mo and MoSx particles possessing micro-, sub-micro- and nanometer sizes. We investigated the possibility of using high surface roughness, which occurs due to particle deposition, as a support with a large exposed surface area for thin MoSx catalytic layers for the hydrogen evolution reaction (HER). For comparison, the HER performance of MoSx layers formed by grazing incidence (GI) PLD was studied. During GI-PLD, a substrate was placed along the direction of laser plume transport and few large particles loaded the substrate. The local structure and composition of thin MoSx layers formed by the deposition of the vapor component of the laser plume were varied by changing the pressure of the buffer gas (argon, Ar). In the case of NI-PLD, an increase in Ar pressure caused the formation of quasi-amorphous MoSx (x ≥ 2) films that possessed highly active catalytic sites on the edges of the layered MoS2 nanophase. At the same time, a decrease in the deposition rate of the MoSx film appeared due to the scattering of the vapor flux by Ar molecules during flux transport from the target to the substrate. This effect prevented uniform deposition of the MoSx catalytic film on the surface of most particles, whose deposition rate was independent of Ar pressure. The scattered vapor flux containing Mo and S atoms was a dominant source for MoSx film growth during GI-PLD. The thickness and composition distribution of the MoSx film on the substrate depended on both the pressure of the buffer gas and the distance from the target. For 1.0-2.5 cm from the target, the deposition rate was quite sufficient to form S-enriched quasi-amorphous MoSx (2.5 < x < 6) catalytic

Growth of tin oxide thin films composed of nanoparticles on hydrophilic and hydrophobic glass substrates by spray pyrolysis technique

Energy Technology Data Exchange (ETDEWEB)

Paloly, Abdul Rasheed; Satheesh, M. [Nano Functional Materials Lab, Department of Physics, Cochin University of Science and Technology, Kochi 682022, Kerala (India); Martínez-Tomás, M. Carmen; Muñoz-Sanjosé, Vicente [Departamento de Física Aplicada y Electromagnetismo, Universitat de Valencia, c/Dr Moliner 50, Burjassot, Valencia 46100 (Spain); Rajappan Achary, Sreekumar [Nano Functional Materials Lab, Department of Physics, Cochin University of Science and Technology, Kochi 682022, Kerala (India); Bushiri, M. Junaid, E-mail: junaidbushiri@gmail.com [Nano Functional Materials Lab, Department of Physics, Cochin University of Science and Technology, Kochi 682022, Kerala (India)

2015-12-01

Highlights: • SnO{sub 2} thin films were grown on hydrophilic and hydrophobic glass substrates. • Samples on hydrophobic substrates are having comparatively larger lattice volume. • Films on hydrophobic substrates have larger particles and low density distribution. • Substrate dependent photoluminescence emission is observed and studied. • SnO{sub 2} thin films grown over hydrophobic substrates may find potential applications. - Abstract: In this paper, we have demonstrated the growth of tin oxide (SnO{sub 2}) thin films composed of nanoparticles on hydrophobic (siliconized) and hydrophilic (non-siliconized) glass substrates by using the spray pyrolysis technique. X-ray diffraction (XRD) analysis confirmed the formation of SnO{sub 2} thin films with tetragonal rutile-phase structure. Average particle size of nanoparticles was determined to be in the range of 3–4 nm measured from the front view images obtained by a field emission gun scanning electron microscope (FESEM), while the size of nanoparticle clusters, when present, were in the range of 11–20 nm. Surface morphology of SnO{sub 2} films grown over hydrophobic substrates revealed larger isolated particles which are less crowded compared to the highly crowded and agglomerated smaller particles in films on hydrophilic substrates. Blue shift in the band gap is observed in samples in which the average particle size is slightly larger than the exciton Bohr radius. Photoluminescence (PL) analysis of samples grown over hydrophobic substrates exhibited an intense defect level emission and a weak near band edge emission. The enhanced visible emission from these SnO{sub 2} thin films is attributed to lattice defects formed during the film growth due to the mismatch between the film and the hydrophobic substrate surface.

Influences of oxygen gas flow rate on electrical properties of Ga-doped ZnO thin films deposited on glass and sapphire substrates

International Nuclear Information System (INIS)

Makino, Hisao; Song, Huaping; Yamamoto, Tetsuya

2014-01-01

The Ga-doped ZnO (GZO) films deposited on glass and c-plane sapphire substrates have been comparatively studied in order to explore the role of grain boundaries in electrical properties. The influences of oxygen gas flow rates (OFRs) during the deposition by ion-plating were examined. The dependences of carrier concentration, lattice parameters, and characteristic of thermal desorption of Zn on the OFR showed common features between glass and sapphire substrates, however, the Hall mobility showed different behavior. The Hall mobility of GZO films on glass increased with increasing OFR of up to 15 sccm, and decreased with further increasing OFR. On the other hand, the Hall mobility of GZO films on c-sapphire increased for up to 25 sccm. The role of grain boundary in polycrystalline GZO films has been discussed. - Highlights: • Ga-doped ZnO films were deposited on glass and c-sapphire by ion-plating. • The epitaxial growth on c-sapphire was confirmed by X-ray diffraction. • Dependence of Hall mobility showed different tendency between glass and sapphire. • Grain boundaries influence transport properties at high O 2 gas flow rate

α-MoO3 thin films prepared by spray pyrolysis Películas delgadas de α-MoO3 preparadas por atomización pirolítica

Directory of Open Access Journals (Sweden)

L D López-Carreño

2011-12-01

Full Text Available MoO3 thin films have been deposited on clean glass slides using the spray pyrolysis technique. The samples were grown with different thicknesses by spraying on common glass substrates a solution of(ammoniummolybdatetetrahydrate ((NH36Mo7O244H2O. The samples were characterized by X-ray diffraction (XRD, infrared spectroscopy, scanning electron microscopy (SEM and electrically through electrical resistivity measurements as a function of temperature. It was found that samples present crystalline structure associated with the alpha phase of MoO3 grown with preferential direction of growth along the planes (0k0. As result of increasing the volume of precursor solution sample surface becomes porous. The change in electrical resistance of MoO3 films by exposure to carbon monoxide (CO at room temperature, makes the films obtained by this technique could be promising in its use in gas sensing devices at room temperature.En este trabajo se prepararon películas delgadas de trióxido de molibdeno (MoO3 por la técnica de atomización pirolítica. Las películas fueron depositadas sobre sustratos de vidrio y obtenidas a partir de una solución precursora de Heptamolibdato de Amonio Tetrahidratado ((NH36Mo7O24.4H2O 0.1 M. La temperatura del sustrato se mantuvo constante en 400 oC y se varío el volumen de la solución precursora. Las muestras se caracterizaron por difracción de Rayos X (XRD, espectroscopía infrarroja, Microscopía Electrónica de Barrido (SEM y eléctricamente a través de medidas de resistividad eléctrica en función de la temperatura. Las muestras crecen con estructura cristalina correspondiente a la fase alfa del MoO3 con dirección preferencial de crecimiento a lo largo de los planos (0k0. Al aumentar el volumen de la solución precursora la superficie de las muestras se vuelve porosa. La resistividad en estas muestras cambia en un orden de magnitud cuando son expuestas a la atmosfera de CO.

Activation behavior of boron implanted poly-Si on glass substrate

International Nuclear Information System (INIS)

Furuta, M.; Shimamura, K.; Tsubokawa, H.; Tokushige, K.; Furuta, H.; Hirao, T.

2010-01-01

The activation behavior of boron (B) implanted poly-Si films on glass substrates has been investigated. The effect of B dose and annealing temperature on crystal defects and electrical properties of the films were evaluated by Raman spectroscopy and Hall measurement. It was found that the maximum activation ratio of the film with B dose of 1 x 10 15 cm -2 was obtained when Raman peak associated with disordered amorphous silicon disappeared. However, reverse anneal was observed in the film when the annealing temperature further increased. The results from secondary ion mass spectrometry and Hall measurement revealed that B segregation at the top and bottom interface and deactivation of B substitutional occurred simultaneously in the high-dose specimens when the annealing temperature increased from 600 to 750 o C.

Novel low-temperature sintering ceramic substrate based on indialite/cordierite glass ceramics

Science.gov (United States)

Varghese, Jobin; Vahera, Timo; Ohsato, Hitoshi; Iwata, Makoto; Jantunen, Heli

2017-10-01

In this paper, a novel low-temperature sintering substrate for low temperature co-fired ceramic applications based on indialite/cordierite glass ceramics with Bi2O3 as a sintering aid showing low permittivity (εr) and ultralow dielectric loss (tan δ) is described. The fine powder of indialite was prepared by the crystallization of cordierite glass at 1000 °C/1 h. The optimized sintering temperature was 900 °C with 10 wt % Bi2O3 addition. The relative density achieved was 97%, and εr and tan δ were 6.10 and 0.0001 at 1 MHz, respectively. The composition also showed a moderately low temperature coefficient of relative permittivity of 118 ppm/°C at 1 MHz. The obtained linear coefficient of thermal expansion was 3.5 ppm/°C in the measured temperature range of 100 to 600 °C. The decreasing trend in dielectric loss, the low relative permittivity at 1 MHz, and the low thermal expansion of the newly developed composition make it an ideal choice for radio frequency applications.

Use of an arc plasma rotating in a magnetic field for metal coating glass substrates

International Nuclear Information System (INIS)

Vukanovic, V.; Butler, S.; Kapur, S.; Krakower, E.; Allston, T.; Belfield, K.; Gibson, G.

1983-01-01

First results are reported about deposition of metals on glass substrate using a low current arc plasma source at atmospheric pressure. The arc source consists of a graphite cathode rod placed on the axis of a graphite anode cylinder aligned in a magnetic field. The carrier gas is argon. The deposition material, zinc or gold, is evaporated from a reservoir in the cathode. Depositions on flat substrates positioned on the periphery of the rotating plasma within the anode tube and in a jet outside the anode have been investigated. The investigations are planned to lead towards laser fusion target pusher layer fabrication. This fabrication would be facilitated by a high pressure deposition process where target levitation is readily performed

Impact of deposition temperature on the properties of SnS thin films grown over silicon substrate—comparative study of structural and optical properties with films grown on glass substrates

Science.gov (United States)

Assili, Kawther; Alouani, Khaled; Vilanova, Xavier

2017-11-01

Tin sulfide (SnS) thin films were chemically deposited over silicon substrate in a temperature range of 250 °C-400 °C. The effects of deposition temperature on the structural, morphological and optical properties of the films were evaluated. All films present an orthorhombic SnS structure with a preferred orientation along (040). High absorption coefficients (in the range of 105 cm-1) were found for all obtained films with an increase in α value when deposition temperature decreases. Furthermore, the effects of substrate type were investigated based on comparison between the present results and those obtained for SnS films grown under the same deposition conditions but over glass substrate. The results suggest that the formation of SnS films onto glass substrate is faster than onto silicon substrate. It is found that the substrate nature affects the orientation growth of the films and that SnS films deposited onto Si present more defects than those deposited onto glass substrate. The optical transmittance is also restricted by the substrate type, mostly below 1000 nm. The obtained results for SnS films onto silicon suggest their promising integration within optoelectronic devices.

Preparation of a gel of zirconium molybdate for use in the generators of 99 Mo - 99m Tc prepared with 99 Mo produced by the 98 Mo(n,γ)99 Mo reaction

International Nuclear Information System (INIS)

Osso Junior, Joao A.; Lima, Ana Lucia V.P.; Silva, Nestor C. da; Nieto, Renata C.; Velosa, Adriana C. de

1998-01-01

IPEN develops a project concerning the preparation of a gel of Zirconium Molybdate for use in the generators of 99 Mo- 99m Tc . 99m Tc is the most used radioisotope in nuclear medicine diagnosis procedures and nowadays the generators are being prepared with imported 99 Mo, produced by 235 U fission. The production of 99 Mo by the 98 Mo(n, γ) 99 Mo reaction is now possible because of the power upgrade of IPEN's IEA-R1 reactor, from 2 to 5 MW. This work describes the preparation method of Zirconium Molybdate gel that will be used in the 99 Mo- 99m Tc generators. The gel is prepared by the chemical reaction between Mo, in Mo O 3 form, and Zr, in Zr O Cl 2 .8H 2 O form. After the reaction, the gel is filtered, dried and cracked with saline solution. The product is then loaded into glass columns for use as 99m Tc generator. The results showed the good quality of the gel prepared at laboratory level and of the generators evaluated. (author)

Surface adhesion study of La2O3 thin film on Si and glass substrate for micro-flexography printing

Science.gov (United States)

Hassan, S.; Yusof, M. S.; Embong, Z.; Maksud, M. I.

2017-01-01

Adhesive property can be described as an interchangeably with some ink and substance which was applied to one surface of two separate items that bonded together. Lanthanum oxide (La2O3) has been used as a rare earth metal candidate as depositing agent or printing ink. This metal deposit was embedded on Silica (Si) wafer and glass substrate using Magnetron Sputtering technique. The choose of Lanthanum oxide as a target is due to its wide application in producing electronic devices such as thin film battery and printed circuit board. The La2O3 deposited on the surface of Si wafer and glass substrate was then analyzed using Angle Resolve X-Ray Photoelectron Spectroscopy (ARXPS). The position for each synthetic component in the narrow scan of Lanthanum (La) 3d and O 1s are referred to the electron binding energy (eV). This research will focus on 3 narrow scan regions which are C 1s, O 1s and La 3d. Further discussion of the spectrum evaluation will be discussed in detail. Here, it is proposed that from the adhesive and surface chemical properties of La is the best on glass substrate which suitable as an alternative medium for micro-flexography printing technique in printing multiple fine solid lines at nano scale. Hence, this paper will describe the capability of this particular metal as rare earth metal in a practice of micro-flexography printing.

Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique

International Nuclear Information System (INIS)

Martínez, H.M.; Torres, J.; López Carreño, L.D.; Rodríguez-García, M.E.

2013-01-01

Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO 3 (H 2 O) 2 was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into α-MoO 3 . The optical gap diminishes as the substrate temperature rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO 3 films' sensitivity was analyzed for CO and H 2 O in the temperature range 160 to 360 K; the results indicate that CO and H 2 O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H 2 O. - Highlights: ► A low cost technique is used which produces good material. ► Thin films are prepared using ammonium molybdate tetra hydrated. ► The control of the physical properties of the samples could be done. ► A calculation method is proposed to determine the material optical properties. ► The MoO 3 thin films prepared by spray pyrolysis could be used as gas sensor.

Manufacturing Process for OLED Integrated Substrate

Energy Technology Data Exchange (ETDEWEB)

Hung, Cheng-Hung [Vitro Flat Glass LLC, Cheswick, PA (United States). Glass Technology Center

2017-03-31

The main objective of this project was to develop a low-cost integrated substrate for rigid OLED solid-state lighting produced at a manufacturing scale. The integrated substrates could include combinations of soda lime glass substrate, light extraction layer, and an anode layer (i.e., Transparent Conductive Oxide, TCO). Over the 3⁺ year course of the project, the scope of work was revised to focus on the development of a glass substrates with an internal light extraction (IEL) layer. A manufacturing-scale float glass on-line particle embedding process capable of producing an IEL glass substrate having a thickness of less than 1.7mm and an area larger than 500mm x 400mm was demonstrated. Substrates measuring 470mm x 370mm were used in the OLED manufacturing process for fabricating OLED lighting panels in single pixel devices as large as 120.5mm x 120.5mm. The measured light extraction efficiency (calculated as external quantum efficiency, EQE) for on-line produced IEL samples (>50%) met the project’s initial goal.

Compositional Dependence of Solubility/Retention of Molybdenum Oxides in Aluminoborosilicate-Based Model Nuclear Waste Glasses.

Science.gov (United States)

Brehault, Antoine; Patil, Deepak; Kamat, Hrishikesh; Youngman, Randall E; Thirion, Lynn M; Mauro, John C; Corkhill, Claire L; McCloy, John S; Goel, Ashutosh

2018-02-08

Molybdenum oxides are an integral component of the high-level waste streams being generated from the nuclear reactors in several countries. Although borosilicate glass has been chosen as the baseline waste form by most of the countries to immobilize these waste streams, molybdate oxyanions (MoO 4 2- ) exhibit very low solubility (∼1 mol %) in these glass matrices. In the past three to four decades, several studies describing the compositional and structural dependence of molybdate anions in borosilicate and aluminoborosilicate glasses have been reported in the literature, providing a basis for our understanding of fundamental science that governs the solubility and retention of these species in the nuclear waste glasses. However, there are still several open questions that need to be answered to gain an in-depth understanding of the mechanisms that control the solubility and retention of these oxyanions in glassy waste forms. This article is focused on finding answers to two such questions: (1) What are the solubility and retention limits of MoO 3 in aluminoborosilicate glasses as a function of chemical composition? (2) Why is there a considerable increase in the solubility of MoO 3 with incorporation of rare-earth oxides (for example, Nd 2 O 3 ) in aluminoborosilicate glasses? Accordingly, three different series of aluminoborosilicate glasses (compositional complexity being added in a tiered approach) with varying MoO 3 concentrations have been synthesized and characterized for their ability to accommodate molybdate ions in their structure (solubility) and as a glass-ceramic (retention). The contradictory viewpoints (between different research groups) pertaining to the impact of rare-earth cations on the structure of aluminoborosilicate glasses are discussed, and their implications on the solubility of MoO 3 in these glasses are evaluated. A novel hypothesis explaining the mechanism governing the solubility of MoO 3 in rare-earth containing aluminoborosilicate

Effect of barrier layers on the properties of indium tin oxide thin films on soda lime glass substrates

International Nuclear Information System (INIS)

Lee, Jung-Min; Choi, Byung-Hyun; Ji, Mi-Jung; An, Yong-Tae; Park, Jung-Ho; Kwon, Jae-Hong; Ju, Byeong-Kwon

2009-01-01

In this paper, the electrical, structural and optical properties of indium tin oxide (ITO) films deposited on soda lime glass (SLG) haven been investigated, along with high strain point glass (HSPG) substrate, through radio frequency magnetron sputtering using a ceramic target (In 2 O 3 :SnO 2 , 90:10 wt.%). The ITO films deposited on the SLG show a high electrical resistivity and structural defects compared with those deposited on HSPG due to the Na ions from the SLG diffusing to the ITO film by annealing. However, these properties can be improved by intercalating a barrier layer of SiO 2 or Al 2 O 3 between the ITO film and the SLG substrate. SIMS analysis has confirmed that the barrier layer inhibits the Na ion's diffusion from the SLG. In particular, the ITO films deposited on the Al 2 O 3 barrier layer, show better properties than those deposited on the SiO 2 barrier layer.

Mo-containing tetrahedral amorphous carbon deposited by dual filtered cathodic vacuum arc with selective pulsed bias voltage

International Nuclear Information System (INIS)

Pasaja, Nitisak; Sansongsiri, Sakon; Intarasiri, Saweat; Vilaithong, Thiraphat; Anders, Andre

2007-01-01

Metal-containing tetrahedral amorphous carbon films were produced by dual filtered cathodic vacuum arc plasma sources operated in sequentially pulsed mode. Negatively pulsed bias was applied to the substrate when carbon plasma was generated, whereas it was absent when the molybdenum plasma was presented. Film thickness was measured after deposition by profilometry. Glass slides with silver pads were used as substrates for the measurement of the sheet resistance. The microstructure and composition of the films were characterized by Raman spectroscopy and Rutherford backscattering, respectively. It was found that the electrical resistivity decreases with an increase of the Mo content, which can be ascribed to an increase of the sp 2 content and an increase of the sp 2 cluster size

Glass Formation, Chemical Properties and Surface Analysis of Cu-Based Bulk Metallic Glasses

Directory of Open Access Journals (Sweden)

Akihisa Inoue

2011-04-01

Full Text Available This paper reviews the influence of alloying elements Mo, Nb, Ta and Ni on glass formation and corrosion resistance of Cu-based bulk metallic glasses (BMGs. In order to obtain basic knowledge for application to the industry, corrosion resistance of the Cu–Hf–Ti–(Mo, Nb, Ta, Ni and Cu–Zr–Ag–Al–(Nb bulk glassy alloy systems in various solutions are reported in this work. Moreover, X-ray photoelectron spectroscopy (XPS analysis is performed to clarify the surface-related chemical characteristics of the alloy before and after immersion in the solutions; this has lead to a better understanding of the correlation between the surface composition and the corrosion resistance.

Platinoids and molybdenum in nuclear waste containment glasses: a structural study

International Nuclear Information System (INIS)

Le Grand, M.

2000-01-01

This work deals with the structure of borosilicate nuclear glasses and with some relationships between structure and macroscopic properties. Two types of elements which may disturb the industrial process - platinoids (Ru and Pd) and molybdenum - are central to this work. Platinoids induce weak modifications on the structure of the glass, causing a depolymerization of the glassy network, an increase of the [3] B/ [4] B ratio and a modification of the medium range order around Si between 3.3 and 4.5 angstrom. The modifications of viscosity and density induced by platinoids in the glass are not due to the structural effect of the platinoids. The increase of viscosity is attributed to needle shaped RuO 2 . It can be moderated by imposing reducing conditions during the elaboration of the glass. The slight difference between experimental and calculated densities is due to the increase of the volume percentage of bubbles in the glass with increasing platinoid content. Mo is either present in the glass as molybdic groupings, or mobilized in chemically complex molybdic crystalline phases. The chemical composition and mineralogy of these phases has been obtained using electronic microprobe data and XRD with Rietveld analysis. The distribution of the different elements between the crystalline phases and the glass is strongly influenced by the structural role of the various cations in the glass. The Mo present in the glass appears as MoO 4 tetrahedra, independent of the borosilicate network. The formation of the crystalline phases can be explained by the existence of a precursor in which the MoO 4 tetrahedra are concentrated in rich alkali and earth-alkali bearing areas of the glass. (author)

Effects of temperature and Mo2C layer on stress and structural properties in CVD diamond film grown on Mo foil

International Nuclear Information System (INIS)

Long, Fen; Wei, Qiuping; Yu, Z.M.; Luo, Jiaqi; Zhang, Xiongwei; Long, Hangyu; Wu, Xianzhe

2013-01-01

Highlights: •Polycrystalline diamond films were grown on Mo foil substrates by HF-CVD. •We investigated the temperature dependence of the film stress for each sample. •We show that how the thermal stress and intrinsic stress affects the total stress. •The stress of Mo foil substrate obtained by XRD was investigated in this study. •The effect of Mo 2 C interface layer for stress of multilayer system was considered. -- Abstract: Polycrystalline diamond films have been prepared by hot-filament-assisted chemical vapor deposition (HFCVD) on Mo foils. The morphology, growth rate, phase composition, element distribution and residual stress of the films at different temperature were investigated by field-emission scanning electron microscopy, Raman spectrum, field emission electron probe microanalysis and X-ray diffraction. Results show that the residual stress of the diamond films is compressive. The thermal stress plays a decisive role in the total stress, while the intrinsic stress can change the trend of the total stress. The residual stress of substrate gradually changes from tensile stress to compressive stress with the increase of the deposited temperature. A Mo 2 C interlayer is formed during deposition process, and this layer has an important influence on the stresses of films and substrates

Crystallization of 21.25Gd2O3-63.75MoO3-15B2O3 glass induced by femtosecond laser at the repetition rate of 250 kHz

International Nuclear Information System (INIS)

Zhong, M.J.; Han, Y.M.; Liu, L.P.; Zhou, P.; Du, Y.Y.; Guo, Q.T.; Ma, H.L.; Dai, Y.

2010-01-01

We report the formation of β'-Gd 2 (MoO 4 ) 3 (GMO) crystal on the surface of the 21.25Gd 2 O 3 -63.75MoO 3 -15B 2 O 3 glass, induced by 250 kHz, 800 nm femtosecond laser irradiation. The morphology of the modified region in the glass was clearly examined by scanning electron microscopy (SEM). By micro-Raman spectra, the laser-induced crystals were confirmed to be GMO phases and it is found that these crystals have a strong dependence on the number and power of the femtosecond laser pulses. When the irradiation laser power was 900 mW, not only the Raman peaks of GMO crystals but also some new peaks at 214 cm -1 , 240 cm -1 , 466 cm -1 , 664 cm -1 and 994 cm -1 which belong to the MoO 3 crystals were observed. The possible mechanisms are proposed to explain these phenomena.

Investigation of metastable immiscibility in nuclear-waste-glasses. I-III

International Nuclear Information System (INIS)

Egnell, J.; Larsen, J.G.; Moeller, L.; Roed, G.

1981-12-01

Metastable liquid-liquid separation in glasses can often cause significant changes in physical and chemical properties of the original homogeneous glass. In some technical borosilicate glasses this phenomenon is used to change the chemical durability of the glass. For potential nuclear-waste-glasses the slow cooling through the temperature range 550 0 C - 700 0 C may lead to such a liquid-liquid phase separation. In order to investigate the susceptibility of phase separation of nuclear-waste-glasses, two KBS model glasses, ABS-39 and ABS-41, were investigated. Two of the subsequent reports are concerned with this problem. The third report also takes into consideration the effects of MoO 3 on the immiscibility gap. The maximum amount of MoO 3 that can be dissolved in ABS-39 and ABS 41 is also determined. (Auth.)

Spectroscopic properties of triangular silver nanoplates immobilized on polyelectrolyte multilayer-modified glass substrates

Science.gov (United States)

Rabor, Janice B.; Kawamura, Koki; Muko, Daiki; Kurawaki, Junichi; Niidome, Yasuro

2017-07-01

Fabrication of surface-immobilized silver nanostructures with reproducible plasmonic properties by dip-coating technique is difficult due to shape alteration. To address this challenge, we used a polyelectrolyte multilayer to promote immobilization of as-received triangular silver nanoplates (TSNP) on a glass substrate through electrostatic interaction. The substrate-immobilized TSNP were characterized by absorption spectrophotometry and scanning electron microscopy. The bandwidth and peak position of localized surface plasmon resonance (LSPR) bands can be tuned by simply varying the concentration of the colloidal solution and immersion time. TSNP immobilized from a higher concentration of colloidal solution with longer immersion time produced broadened LSPR bands in the near-IR region, while a lower concentration with shorter immersion time produced narrower bands in the visible region. The shape of the nanoplates was retained even at long immersion time. Analysis of peak positions and bandwidths also revealed the point at which the main species of the immobilization had been changed from isolates to aggregates.

Synthesis and characterization of α-MoO3 microspheres packed with nanoflakes

International Nuclear Information System (INIS)

Sharma, Rabindar K; Reddy, G B

2014-01-01

In this paper, we report the fabrication of three-dimensional molybdenum oxide (α-MoO 3 ) microspheres (MSs) packed with nanoflakes by facile and eco-friendly physical vapour deposition processes. Synthesis processes include sequences of plasma-assisted sublimation and thermal evaporation routes on a nickel-coated glass substrate in three individual stages. It is observed that nanostructured films deposited in the first and second stages function as seed layers for the growth of MoO 3 MSs. The structural study divulged that the MoO 3 MSs are polycrystalline in nature with pure orthorhombic phase. The morphological study endorses the uniform growth of MSs on a large area scale having diameters in the range of 0.7–2 µm with the finely packed single crystalline nanoflakes with mean thicknesses of nearly 60 nm. These single crystalline flakes are not individual but in the form of randomly distributed bunches embedded on the surface of MSs. Vibrational study of molybdenum and oxygen atoms in the MSs is carried out by Raman and Fourier transform infrared analysis, which further assured the existence of a pure orthorhombic crystal phase of MoO 3 MSs and also justified the x-ray diffractogram findings. The MoO 3 MSs show intense photoluminescence emission at room temperature with the five prominent peaks located at 424, 457, 486, 521 and 536 nm in accordance with the improvement in the degree of crystallinity. The possible growth strategy of α-MoO 3 MSs packed with nanoflakes is proposed in this paper briefly. (paper)

Phase equilibria in the MgMoO4-Ln2(MoO4)3 (Ln=La,Gd) systems

International Nuclear Information System (INIS)

Fedorov, N.F.; Ipatov, V.V.; Kvyatkovskij, O.V.

1980-01-01

Phase equilibria in the MgMoO 4 -Ln 2 (MoO 4 ) 3 systems (Ln=La, Gd) have been studied by static and dynamic methods of the physico-chemical analysis, using differential thermal, visual-polythermal, crystal-optical, X-ray phase, and infrared spectroscopic methods, and their phase diagrams have been constructed. Phase equilibria in the systems studied are characterized by limited solubility of components in the liquid state, formation of solid solutions on the base of α- and β-forms of Gd 2 (MoO 4 ) 3 . Eutectics in the MgMoO 4 -Ln 2 (MoO 4 ) 3 (Ln=La, Gd) systems corresponds to the composition of 71 mode % La 2 (MoO 4 ) 3 -29 mole % MgMoO 4 , tsub(melt)--935+-5 deg C and 57 mole % Gd 2 (MoO 4 ) 3 -43 mole % MgMoO 4 , tsub(melt)=1020+-5 deg C. The region of glass formation has been established [ru

Deformation behavior of Re alloyed Mo thin films on flexible substrates: In situ fragmentation analysis supported by first-principles calculations.

Science.gov (United States)

Jörg, Tanja; Music, Denis; Hauser, Filipe; Cordill, Megan J; Franz, Robert; Köstenbauer, Harald; Winkler, Jörg; Schneider, Jochen M; Mitterer, Christian

2017-08-07

A major obstacle in the utilization of Mo thin films in flexible electronics is their brittle fracture behavior. Within this study, alloying with Re is explored as a potential strategy to improve the resistance to fracture. The sputter-deposited Mo 1-x Re x films (with 0 ≤ x ≤ 0.31) were characterized in terms of structural and mechanical properties, residual stresses as well as electrical resistivity. Their deformation behavior was assessed by straining 50 nm thin films on polyimide substrates in uniaxial tension, while monitoring crack initiation and propagation in situ by optical microscopy and electrical resistance measurements. A significant toughness enhancement occurs with increasing Re content for all body-centered cubic solid solution films (x ≤ 0.23). However, at higher Re concentrations (x > 0.23) the positive effect of Re is inhibited due to the formation of dual-phase films with the additional close packed A15 Mo 3 Re phase. The mechanisms responsible for the observed toughness behavior are discussed based on experimental observations and electronic structure calculations. Re gives rise to both increased plasticity and bond strengthening in these Mo-Re solid solutions.

Crystalline ordered states of CuIn1−xGaxSe2 (x = 0, 0.3, and 1.0) thin-films on different substrates investigated by Raman scattering spectroscopy

International Nuclear Information System (INIS)

Jeong, A.R.; Jo, W.; Song, M.; Yoon, S.

2012-01-01

Structural properties of Cu(In,Ga)Se 2 absorber layers have been examined for photovoltaic applications. Thin-films with three different chemical compositions, CuInSe 2 (CIS), Cu(In,Ga)Se 2 (CIGS) and CuGaSe 2 (CGS), were grown by co-evaporation on two kinds of substrates: Mo-coated soda-lime glass and bare soda-lime glass. Intriguing morphology and grain-growth behaviors were found in the surface of the films. X-ray diffraction of the films exhibited phase formation of the stoichiometric chalcopyrite phase of the materials while signs of secondary phases like Cu 2 Se and Cu–Se 2 were also observed. The optical transmittance of the films was measured to obtain their optical bandgaps, which were well matched with the bulk values of CIS, CIGS, and CGS, which are 1.1, 1.4, and 1.7 eV, respectively. Using Raman scattering spectroscopy, the A 1 mode was observed to shift from 177 cm −1 for CIS to 189 cm −1 for CGS as the Ga content increased. The films on Mo substrates are likely to have secondary phases, which is not the case for soda-lime glass. An indication of the formation of the CuAu structure is obtained from the CIS thin-films. - Highlights: ► We report structural and optical properties of CIGS films on different substrates. ► Various optical tools were used to characterize the CIGS films. ► Crystalline ordered states were examined by A1 mode of Raman spectra.

Determination of work of adhesion of gelatin hydrogels on a glass substrate

Science.gov (United States)

Thakre, Avinash A.; Singh, Arun K.

2018-04-01

In this article, work of adhesion (w adh ) of soft gelatin hydrogels on a smooth glass substrate is determined experimentally using the wedge adhesion test. The results showed that w adh decreases with the increase in gelatin concentration in the hydrogels but the same is found to be independent of thickness of hydrogel specimen. These results are used further for establishing a scaling law between w adh and mesh size (ξ) of the three dimensional structure present in the hydrogel as w adh ∼ ξ 8.6. Finite element analysis is also carried out for validating the fracture stability of wedge test in view of analytical prediction. At the end, practical significance of the present study is also discussed.

Polymer brushes: a controllable system with adjustable glass transition temperature of fragile glass formers.

Science.gov (United States)

Xie, Shi-Jie; Qian, Hu-Jun; Lu, Zhong-Yuan

2014-01-28

We present results of molecular dynamics simulations for coarse-grained polymer brushes in a wide temperature range to investigate the factors that affect the glass transition in these systems. We focus on the influences of free surface, polymer-substrate interaction strength, grafting density, and chain length not only on the change of glass transition temperature Tg, but also the fragility D of the glass former. It is found that the confinement can enhance the dependence of the Tg on the cooling rate as compared to the bulk melt. Our layer-resolved analysis demonstrates that it is possible to control the glass transition temperature Tg of polymer brushes by tuning the polymer-substrate interaction strength, the grafting density, and the chain length. Moreover, we find quantitative differences in the influence range of the substrate and the free surface on the density and dynamics. This stresses the importance of long range cooperative motion in glass formers near the glass transition temperature. Furthermore, the string-like cooperative motion analysis demonstrates that there exists a close relation among glass transition temperature Tg, fragility D, and string length ⟨S⟩. The polymer brushes that possess larger string length ⟨S⟩ tend to have relatively higher Tg and smaller D. Our results suggest that confining a fragile glass former through forming polymer brushes changes not only the glass transition temperature Tg, but also the very nature of relaxation process.

Transparent conducting properties of anatase Ti0.94Nb0.06O2 polycrystalline films on glass substrate

International Nuclear Information System (INIS)

Hitosugi, T.; Ueda, A.; Nakao, S.; Yamada, N.; Furubayashi, Y.; Hirose, Y.; Konuma, S.; Shimada, T.; Hasegawa, T.

2008-01-01

We report on transparent conducting properties of anatase Ti 0.94 Nb 0.06 O 2 (TNO) polycrystalline films on glass substrate, and discuss the role of grain crystallinity and grain boundary on resistivity. Thin films of TNO were deposited using pulsed laser deposition at substrate temperature ranging from room temperature to 350 deg. C, with subsequent H 2 -annealing at 500 deg. C. Polycrystalline TNO films showed resistivity of 4.5 x 10 -4 Ω cm and 1.5 x 10 -3 Ω cm for films prepared at substrate temperature of room temperature and 250 deg. C, respectively. X-ray diffraction measurements and transmission electron microscopy reveal that grain crystallinity and grain boundary play key roles in conductive films

Study of rigidity of semiconducting vanadate glasses and its ...

Indian Academy of Sciences (India)

These parameters along with the coordination number of the glasses affect the glass transition temperature. The correlation between the elastic moduli and thermal properties of these samples showed that 0.25MoO3–0.25PbO–0.5V2O5 glass is the most rigid and has an applicable glass transition temperature for coating.

Interfacial analysis and properties of regioregular Poly (3-Hexyl thiophene) spin-coated on an Indium tin oxide coated glass substrate

CSIR Research Space (South Africa)

Malgas, GF

2008-08-01

Full Text Available Interfacial analysis of the rrP3HT samples spincoated on a glass substrate was studied in detail using transmission electron microscopy (TEM) and SEM measurements. Very homogeneous and smooth polymer (P3HT and PEDOT:PSS) layers are observed...

Fabrication and Enhanced Photoelectrochemical Performance of MoS₂/S-Doped g-C₃N₄ Heterojunction Film.

Science.gov (United States)

Ye, Lijuan; Wang, Dan; Chen, Shijian

2016-03-02

We report on a novel MoS2/S-doped g-C3N4 heterojunction film with high visible-light photoelectrochemical (PEC) performance. The heterojunction films are prepared by CVD growth of S-doped g-C3N4 film on indium-tin oxide (ITO) glass substrates, with subsequent deposition of a low bandgap, 1.69 eV, visible-light response MoS2 layer by hydrothermal synthesis. Adding thiourea into melamine as the coprecursor not only facilitates the growth of g-C3N4 films but also introduces S dopants into the films, which significantly improves the PEC performance. The fabricated MoS2/S-doped g-C3N4 heterojunction film offers an enhanced anodic photocurrent of as high as ∼1.2 × 10(-4) A/cm(2) at an applied potential of +0.5 V vs Ag/AgCl under the visible light irradiation. The enhanced PEC performance of MoS2/S-doped g-C3N4 film is believed due to the improved light absorption and the efficient charge separation of the photogenerated charge at the MoS2/S-doped g-C3N4 interface. The convenient preparation of carbon nitride based heterojunction films in this work can be widely used to design new heterojunction photoelectrodes or photocatalysts with high performance for H2 evolution.

Correlation between hardness and stress in Al-(Nb, Mo, Ta) thin films

Energy Technology Data Exchange (ETDEWEB)

Car, T., E-mail: car@irb.h [Rudjer Boskovic Institute, Division of Materials Science, Bijenicka cesta 54, 10000 Zagreb, P.O.B. 1016 (Croatia); Radic, N. [Rudjer Boskovic Institute, Division of Materials Science, Bijenicka cesta 54, 10000 Zagreb, P.O.B. 1016 (Croatia); Panjan, P.; Cekada, M. [Jozef Stefan Institute, Ljubljana (Slovenia); Tonejc, A. [Department of Physics, Bijenicka cesta 32, 10000 Zagreb, P.O.B. 331 (Croatia)

2009-06-30

The thin films of Al{sub x}Nb{sub 1-x} (95 {>=} x {>=} 20), Al{sub x}Mo{sub x} (90 {>=} x {>=} 20) and Al{sub x}Ta{sub 1-x} (95 {>=} x {>=} 20) were prepared by magnetron codeposition at room temperature. The average film thickness was from 325 to 400 nm, depending on the film composition. The structure of the as-deposited films was examined by the X-ray diffraction. The stress of the films was determined from the substrate deformation by the profilometer, and the microhardness (load 2 mN) was examined by the micro- and nano-hardness device. For the purpose of the examination of the hardness, the samples were deposited onto the sapphire wafers, while the examination of the film stress, was performed by using thin glass substrates. For all the Al-(Nb, Mo, Ta) alloy compositions, the microhardness is predominantly under the influence of the harder element, and monotonically decreases with the increase of the aluminum content. However, the microhardness of the amorphous AlTa films was higher than the bulk value of a harder element (Ta) in the alloy. A simple empirical linear relationship between the Vickers hardness, the bulk value hardness of the transition metal (harder element) and the elastic energy fraction of the identation deformation, was established. The elastic energy fraction in the microhardness is also linearly correlated with the stress in films.

Substrate-induced instability in gas microstrip detectors

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.

1992-12-01

The results of a programme of research into substrate-induced gain instability in gas microstrip detectors are reported. Information has been collected on a wide range of substrates including many commonly available glasses and ceramics. A theoretical model of the gain instability is proposed. While we have not yet found an acceptable substrate for the construction of high flux detectors our experience points to electronically conductive glasses as the most promising source of a stable substrate. (Author)

Morphology-dependent electrocatalytic performance of Fe2(MoO43 for electro-oxidation of methanol in alkaline medium

Directory of Open Access Journals (Sweden)

Daoming Zhang

2017-06-01

Full Text Available Electrochemically synthesized nanosphere, nanorod and nanotube Fe2(MoO43 at optimized temperature and current density are characterized with XRD, SEM, TEM, XPS. Crystal lattices of the three types Fe2(MoO43 detected by HRTEM are well matched with the simulation analysis results from Materials Studio 6.0 based on the inorganic crystal structure database (ICSD data and the modified XRD lattice parameters. The ratios of Fe/Mo on the surface resulted from XPS analysis are 1.47, 1.63 and 2.22 respectively for nanosphere, nanorod and nanotube. The mixture of Fe2(MoO43 with polytetrafluoroethylene dispersion are coated on glass carbon substrate as electrode for electrocatalytic performance test by cyclic voltammetries in 0.1 mol/L KOH and 1 mol/L methanol electrolyte. Methanol oxidation peak current density of the Nanotube- Fe2(MoO43/GCEs electrode is 3.27 mA/cm2 higher than 2.8 mA/cm2 of platinum foil electrode, which shows enhanced catalytic activity of Nanotube-Fe2(MoO43/GCEs. The cyclic stability in terms of peak current retention are 91%, 92% and 88% respectively for Nanosphere-Fe2(MoO43/GCE, Nanorod-Fe2(MoO43/GCE and Nanotube-Fe2(MoO43/GCE electrode after 220 cycles. It is concluded that nanosized Fe2(MoO43 could be promising alternative non-noble electro-catalysts for electro-oxidation of methanol in alkaline medium.

Deposition of gold nanoparticles on glass substrate by ultrasonic spray pyrolysis

International Nuclear Information System (INIS)

Garza, Maria de la; Hernandez, Tomas; Colas, Rafael; Gomez, Idalia

2010-01-01

Ultrasonic spray pyrolysis was used to deposit gold nanoparticles on a glass substrate using ZrO 2 as a surrounding medium. The deposition was made using three flow rates of caring gas. The characterization was made by UV-Vis spectroscopy, X-ray diffraction, scanning electronic microscopy and atomic force microscopy. The UV-Vis spectra showed that the surface plasmon resonance peak, indicative of the presence of gold nanoparticles, was shown to shift towards the red spectrum as the flow rate increased; this shift can be associated to the change in size of the particles, which are assumed to grow on a {1 1 1} planes, as was detected by X-ray diffraction. Gold nanoparticles of spheroidal morphology with a relation of around 2:1 were detected by scanning electron microscopy, these observations were confirmed by atomic force microscopy.

Deposition of gold nanoparticles on glass substrate by ultrasonic spray pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Garza, Maria de la; Hernandez, Tomas [Laboratorio de Materiales I, Centro de Laboratorios Especializados, Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Colas, Rafael [Programa Doctoral en Ingenieria de Materiales, Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Gomez, Idalia, E-mail: mgomez@fcq.uanl.mx [Laboratorio de Materiales I, Centro de Laboratorios Especializados, Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico)

2010-10-25

Ultrasonic spray pyrolysis was used to deposit gold nanoparticles on a glass substrate using ZrO{sub 2} as a surrounding medium. The deposition was made using three flow rates of caring gas. The characterization was made by UV-Vis spectroscopy, X-ray diffraction, scanning electronic microscopy and atomic force microscopy. The UV-Vis spectra showed that the surface plasmon resonance peak, indicative of the presence of gold nanoparticles, was shown to shift towards the red spectrum as the flow rate increased; this shift can be associated to the change in size of the particles, which are assumed to grow on a {l_brace}1 1 1{r_brace} planes, as was detected by X-ray diffraction. Gold nanoparticles of spheroidal morphology with a relation of around 2:1 were detected by scanning electron microscopy, these observations were confirmed by atomic force microscopy.

High-temperature laser annealing for thin film polycrystalline silicon solar cell on glass substrate

Science.gov (United States)

Chowdhury, A.; Schneider, J.; Dore, J.; Mermet, F.; Slaoui, A.

2012-06-01

Thin film polycrystalline silicon films grown on glass substrate were irradiated with an infrared continuous wave laser for defects annealing and/or dopants activation. The samples were uniformly scanned using an attachment with the laser system. Substrate temperature, scan speed and laser power were varied to find suitable laser annealing conditions. The Raman spectroscopy and Suns- V oc analysis were carried out to qualify the films quality after laser annealing. A maximum enhancement of the open circuit voltage V oc of about 100 mV is obtained after laser annealing of as-grown polysilicon structures. A strong correlation was found between the full width half maximum of the Si crystalline peak and V oc. It is interpreted as due to defects annealing as well as to dopants activation in the absorbing silicon layer. The maximum V oc reached is 485 mV after laser treatment and plasma hydrogenation, thanks to defects passivation.

Nanosheet controlled epitaxial growth of PbZr0.52Ti0.48O3 thin films on glass substrates

NARCIS (Netherlands)

Bayraktar, Muharrem; Chopra, A.; Bijkerk, Frederik; Rijnders, Augustinus J.H.M.

2014-01-01

Integration of PbZr0.52Ti0.48O3 (PZT) films on glass substrates is of high importance for device applications. However, to make use of the superior ferro- and piezoelectric properties of PZT, well-oriented crystalline or epitaxial growth with control of the crystal orientation is a prerequisite. In

Modelling the local atomic structure of molybdenum in nuclear waste glasses with ab initio molecular dynamics simulations.

Science.gov (United States)

Konstantinou, Konstantinos; Sushko, Peter V; Duffy, Dorothy M

2016-09-21

The nature of chemical bonding of molybdenum in high level nuclear waste glasses has been elucidated by ab initio molecular dynamics simulations. Two compositions, (SiO 2 ) 57.5 -(B 2 O 3 ) 10 -(Na 2 O) 15 -(CaO) 15 -(MoO 3 ) 2.5 and (SiO 2 ) 57.3 -(B 2 O 3 ) 20 -(Na 2 O) 6.8 -(Li 2 O) 13.4 -(MoO 3 ) 2.5 , were considered in order to investigate the effect of ionic and covalent components on the glass structure and the formation of the crystallisation precursors (Na 2 MoO 4 and CaMoO 4 ). The coordination environments of Mo cations and the corresponding bond lengths calculated from our model are in excellent agreement with experimental observations. The analysis of the first coordination shell reveals two different types of molybdenum host matrix bonds in the lithium sodium borosilicate glass. Based on the structural data and the bond valence model, we demonstrate that the Mo cation can be found in a redox state and the molybdate tetrahedron can be connected with the borosilicate network in a way that inhibits the formation of crystalline molybdates. These results significantly extend our understanding of bonding in Mo-containing nuclear waste glasses and demonstrate that tailoring the glass composition to specific heavy metal constituents can facilitate incorporation of heavy metals at high concentrations.

The effect on phase separation of the oxidation state of molybdenum in a Na2O-B2O3-SiO2 glass

International Nuclear Information System (INIS)

Kawamoto, Y.; Clemens, K.; Tomozawa, M.; Warden, J.T.

1981-01-01

The effect of oxidation state on phase separation was studied for 13Na 2 O, 49B 2 O 3 , 38SiO 2 (mol%) glasses containing 1 mol% Mo oxide. The glasses were melted under various conditions to vary the oxidation states of Mo ions. The oxidation states of Mo ions were determined by chemical analysis and ESR. The crystallisation tendency, the immiscibility temperature, and the phase separation morphology of the glasses were examined by DTA, x-ray diffraction, opalescence method, and replica electron microscopy. Glasses containing Mo 4+ ions have a great tendency to precipitate MoO 2 crystals. The immiscibility temperature of glass goes through a minimum when the oxidation states of Mo ions are changed. It was suggested that there is an optimum oxidation state to prevent crystallisation and to suppress the phase separation tendency of this system. (author)

High-performance flexible inverted organic light-emitting diodes by exploiting MoS2 nanopillar arrays as electron-injecting and light-coupling layers.

Science.gov (United States)

Guo, Kunping; Si, Changfeng; Han, Ceng; Pan, Saihu; Chen, Guo; Zheng, Yanqiong; Zhu, Wenqing; Zhang, Jianhua; Sun, Chang; Wei, Bin

2017-10-05

Inverted organic light-emitting diodes (IOLEDs) on plastic substrates have great potential application in flexible active-matrix displays. High energy consumption, instability and poor electron injection are key issues limiting the commercialization of flexible IOLEDs. Here, we have systematically investigated the electrooptical properties of molybdenum disulfide (MoS 2 ) and applied it in developing highly efficient and stable blue fluorescent IOLEDs. We have demonstrated that MoS 2 -based IOLEDs can significantly improve electron-injecting capacity. For the MoS 2 -based device on plastic substrates, we have achieved a very high external quantum efficiency of 7.3% at the luminance of 9141 cd m -2 , which is the highest among the flexible blue fluorescent IOLEDs reported. Also, an approximately 1.8-fold improvement in power efficiency was obtained compared to glass-based IOLEDs. We attributed the enhanced performance of flexible IOLEDs to MoS 2 nanopillar arrays due to their light extraction effect. The van der Waals force played an important role in the formation of MoS 2 nanopillar arrays by thermal evaporation. Notably, MoS 2 -based flexible IOLEDs exhibit an intriguing efficiency roll-up, that is, the current efficiency increases slightly from 14.0 to 14.6 cd A -1 with the luminance increasing from 100 to 5000 cd m -2 . In addition, we observed that the initial brightness of 500 cd m -2 can be maintained at 97% after bending for 500 cycles, demonstrating the excellent mechanical stability of flexible IOLEDs. Furthermore, we have successfully fabricated a transparent, flexible IOLED with low efficiency roll-off at high current density.

Preparation and characterization of nanocrystalline composites Mo-C-N hard films

Energy Technology Data Exchange (ETDEWEB)

Liu, Q. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, POB 1129, 230031 Hefei (China); Liu, T. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, POB 1129, 230031 Hefei (China); Fang, Q.F. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, POB 1129, 230031 Hefei (China)]. E-mail: qffang@issp.ac.cn; Liang, F.J. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, POB 1129, 230031 Hefei (China); Wang, J.X. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, POB 1129, 230031 Hefei (China)

2006-05-01

Molybdenum carbonitride (MoCN) films were deposited on Si (001) and stainless steel substrates by reactive direct-current magnetron sputtering with a molybdenum and graphite composite target. By changing the substrate temperature and the N{sub 2} / Ar ratio in the sputtering gas, it is found that good quality MoCN films can be deposited at substrate temperature of 300-400 deg. C under N{sub 2} partial pressure of 0.25-0.5 Pa with a total working pressure of 1 Pa. The structures of the films deposited at such conditions were determined by X-ray diffraction and X-ray photoelectron spectroscopy analysis as nanocrystalline molybdenum carbonitride with a grain size of several ten nanometers was embedded in the amorphous matrix of C and CN {sub x}. The hardness of the MoCN films can reach 28 GPa, much higher than the value of MoC and MoN films alone.

Spectral and optical performance of electrochromic poly(3,4-ethylenedioxythiophene) (PEDOT) deposited on transparent conducting oxide coated glass and polymer substrates

International Nuclear Information System (INIS)

Sindhu, S.; Narasimha Rao, K.; Ahuja, Sharath; Kumar, Anil; Gopal, E.S.R.

2006-01-01

Electrochromic devices utilizing conjugated polymers as electrochromic layers have gained increasing attention owing to their optical properties, fast switching times and contrast ratios. Polyethylenedioxythiophene (PEDOT) is an excellent material from its electrochromic properties, high conductivity and high stability in the doped form. Aqueous dispersions of PEDOT were either spin coated or electro-polymerized on transparent conducting oxide coated glass and polyethylene tetraphthalate (PET) film substrates. The spectro- and opto-electrochemical studies of the films on transparent conducting oxide coated glass/PET substrates were performed. These films have application in the fabrication of electrochromic windows (smart windows). Smart window devices having excellent switching characteristics over wide range of temperature are used for glazing applications. The aerospace industry is interested in the development of visors and windows that can control glare for pilots and passengers, especially if the coatings can be made on curved surfaces and electrically conducting

Investigation of the Structural, Electrical, and Optical Properties of the Nano-Scale GZO Thin Films on Glass and Flexible Polyimide Substrates

Directory of Open Access Journals (Sweden)

Fang-Hsing Wang

2016-05-01

Full Text Available In this study, Ga2O3-doped ZnO (GZO thin films were deposited on glass and flexible polyimide (PI substrates at room temperature (300 K, 373 K, and 473 K by the radio frequency (RF magnetron sputtering method. After finding the deposition rate, all the GZO thin films with a nano-scale thickness of about 150 ± 10 nm were controlled by the deposition time. X-ray diffraction patterns indicated that the GZO thin films were not amorphous and all exhibited the (002 peak, and field emission scanning electron microscopy showed that only nano-scale particles were observed. The dependences of the structural, electrical, and optical properties of the GZO thin films on different deposition temperatures and substrates were investigated. X-ray photoemission spectroscopy (XPS was used to measure the elemental composition at the chemical and electronic states of the GZO thin films deposited on different substrates, which could be used to clarify the mechanism of difference in electrical properties of the GZO thin films. In this study, the XPS binding energy spectra of Ga2p3/2 and Ga2p1/2 peaks, Zn2p3/2 and Zn2p1/2 peaks, the Ga3d peak, and O1s peaks for GZO thin films on glass and PI substrates were well compared.

Glass matrix armor

International Nuclear Information System (INIS)

Calkins, N.C.

1991-01-01

This patent describes an armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the insides surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material

Highly (001) oriented L1{sub 0}-CoPt/TiN multilayer films on glass substrates with perpendicular magnetic anisotropy

Energy Technology Data Exchange (ETDEWEB)

An, Hongyu; Sannomiya, Takumi; Muraishi, Shinji; Nakamura, Yoshio; Shi, Ji, E-mail: shi.j.aa@m.titech.ac.jp [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Xie, Qian; Zhang, Zhengjun [Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Wang, Jian [National Institute for Materials Science (NIMS), Sengen 1-2-1, Tsukuba, Ibaraki 305-0047 (Japan)

2015-03-15

To obtain strong perpendicular magnetic anisotropy (PMA) based on L1{sub 0} structure for magnetic storage devices, costly single crystalline substrates are generally required to achieve (001) texture. Recently, various studies also have focused on depositing different kinds of seed layers on glass or other amorphous substrates to promote (001) preferred orientation of L1{sub 0} CoPt and FePt. TiN is a very promising seed layer material because of its cubic crystalline structure (similar to MgO) and excellent diffusion barring property even at high temperatures. In the present work, highly (001) oriented L1{sub 0}-CoPt/TiN multilayer films have been successfully deposited on glass substrates. After annealing at 700 °C, the film exhibits PMA, and a strong (001) peak is detected from the x-ray diffraction profiles, indicating the ordering transformation of CoPt layers from fcc (A1) to L1{sub 0} structure. It also is found that alternate deposition of cubic TiN and CoPt effectively improves the crystallinity and (001) preferred orientation of CoPt layers. This effect is verified by the substantial enhancement of (001) reflection and PMA with increasing the period number of the multilayer films.

Infrared-transmittance tunable metal-insulator conversion device with thin-film-transistor-type structure on a glass substrate

Directory of Open Access Journals (Sweden)

Takayoshi Katase

2017-05-01

Full Text Available Infrared (IR transmittance tunable metal-insulator conversion was demonstrated on a glass substrate by using thermochromic vanadium dioxide (VO2 as the active layer in a three-terminal thin-film-transistor-type device with water-infiltrated glass as the gate insulator. Alternative positive/negative gate-voltage applications induce the reversible protonation/deprotonation of a VO2 channel, and two-orders of magnitude modulation of sheet-resistance and 49% modulation of IR-transmittance were simultaneously demonstrated at room temperature by the metal-insulator phase conversion of VO2 in a non-volatile manner. The present device is operable by the room-temperature protonation in an all-solid-state structure, and thus it will provide a new gateway to future energy-saving technology as an advanced smart window.

Shielding of electromagnetic fields by metallic glasses with Fe and Co matrix

International Nuclear Information System (INIS)

Nowosielski, R.; Griner, S.

1997-01-01

The influence of chemical composition and magnetic and electric properties for shielding of electromagnetic fields with frequency 10-1000 kHz, by metallic glasses has been analysed. For investigation were selected two groups of metallic glasses with matrix of Fe and Co. Particularly, in there were selected metallic glasses as follows; Fe 78 Si 9 B 13 , Co 68 Fe 4 Mo 1.5 Si 13.5 B 13 , Co 69 Mo 2 Fe 4 Si 14 B 11 , Co 70.5 Fe 2.5 Mn 4 Mo 1 Si 9 B 15 . The experiments were realised for casting metallic glasses by the CMBS method in the form of strips with width 10 mm. Obtained results of shielding indicate clear for very good shielding effectiveness of one layer shields both electric and magnetic components of electromagnetic fields, although shielding of magnetic component is smaller than electric. (author). 17 refs, 5 figs, 9 tabs

Effect of Ag film thickness on the optical and the electrical properties in CuAlO2/Ag/CuAlO2 multilayer films grown on glass substrates

International Nuclear Information System (INIS)

Oh, Dohyun; No, Young Soo; Kim, Su Youn; Cho, Woon Jo; Kwack, Kae Dal; Kim, Tae Whan

2011-01-01

Research highlights: The CuAlO 2 /Ag/CuAlO 2 multilayer films were grown on glass substrates using radio-frequency magnetron sputtering at room temperature. Effects of Ag film thickness on the optical and the electrical properties in CuAlO 2 /Ag/CuAlO 2 multilayer films grown on glass substrates were investigated. X-ray diffraction patterns showed that the phase of the CuAlO 2 layer was amorphous. Atomic force microscopy images showed that Ag films with a thickness of a few nanometers had island structures. The morphology Ag films with a thickness of 8 nm was uniform. The morphology of the Ag films inserted in the CuAlO 2 films significantly affected the optical transmittance and the resistivity of the CuAlO 2 films deposited on glass substrates. The maximum transmittance of the CuAlO 2 /Ag/CuAlO 2 multilayer films with a thickness of 8 nm was 89.16%. The resistivity of the CuAlO 2 /Ag/CuAlO 2 multilayer films with an Ag film thickness of 18 nm was as small as about 2.8 x 10 -5 Ω cm. The resistivity of the CuAlO 2 /Ag/CuAlO 2 multilayer films was decreased as a result of the thermal annealing treatment. These results indicate that CuAlO 2 /Ag/CuAlO 2 multilayer films grown on glass substrates hold promise for potential applications as TCO films in solar cells. - Abstract: Effects of Ag film thickness on the optical and the electrical properties in CuAlO 2 /Ag/CuAlO 2 multilayer films grown on glass substrates were investigated. Atomic force microscopy images showed that Ag films with a thickness of a few nanometers had island structures. X-ray diffraction patterns showed that the phase of the CuAlO 2 layer was amorphous. The resistivity of the 40 nm-CuAlO 2 /18 nm-Ag/40 nm-CuAlO 2 multilayer films was 2.8 x 10 -5 Ω cm, and the transmittance of the multilayer films with an Ag film thickness of 8 nm was approximately 89.16%. These results indicate that CuAlO 2 /Ag/CuAlO 2 multilayer films grown on glass substrates hold promise for potential applications as

Radiation damages on superionic conducting glasses

International Nuclear Information System (INIS)

Awano, T.; Handa, K.; Matsuyama, T.

2000-01-01

We measured ESR spectra of color centers on AgI-AgPO 3 , AgI-Ag 2 O-B 2 O 3 , AgI-Ag 2 MoO 4 , AgI-Ag 2 WO 4 , (CH 3 ) 4 NI-(C 2 H 5 ) 4 NI-AgI (TMAI-TEAI-AgI) and its derivatives of superionic conducting glasses. In organic-inorganic mixed glasses, organic ion radicals were observed. They were not affected by ionic conductivity. On the contrary, Ag 2+ , Ag 0 and aggregated Ag 0 were observed in inorganic glasses. These color centers in inorganic glasses were affected by ionic conductivity. (author)

Direct electrochemistry of glucose oxidase and a biosensor for glucose based on a glass carbon electrode modified with MoS2 nanosheets decorated with gold nanoparticles

International Nuclear Information System (INIS)

Su, Shao; Sun, Haofan; Xu, Fei; Yuwen, Lihui; Wang, Lianhui; Fan, Chunhai

2014-01-01

An electrochemical glucose biosensor was developed by immobilizing glucose oxidase (GOx) on a glass carbon electrode that was modified with molybdenum disulfide (MoS 2 ) nanosheets that were decorated with gold nanoparticles (AuNPs). The electrochemical performance of the modified electrode was investigated by cyclic voltammetry, and it is found that use of the AuNPs-decorated MoS 2 nanocomposite accelerates the electron transfer from electrode to the immobilized enzyme. This enables the direct electrochemistry of GOx without any electron mediator. The synergistic effect the MoS 2 nanosheets and the AuNPs result in excellent electrocatalytic activity. Glucose can be detected in the concentration range from 10 to 300 μM, and down to levels as low as 2.8 μM. The biosensor also displays good reproducibility and long-term stability, suggesting that it represents a promising tool for biological assays. (author)

Structural study of Mg doped cobalt ferrite thin films on ITO coated glass substrate

Science.gov (United States)

Suthar, Mahesh; Bapna, Komal; Kumar, Kishor; Ahuja, B. L.

2018-05-01

We have synthesized thin films of Co1-xMgxFe2O4 (x = 0, 0.4, 0.6, 0.8, 1) on transparent conducting indium tin oxide (ITO) coated glass substrate by pulsed laser deposition method. The structural properties of the grown films were analyzed by the X-ray diffraction and Raman spectroscopy, which suggest the single phase growth of these films. Raman spectra revealed the incorporation of Mg ions into CoFe2O4 lattice and suggest that the Mg ions initially go both to the octahedral and tetrahedral sites upto a certain concentration. For higher concentration, Mg ions prefer to occupy the tetrahedral sites.

Scalable Patterning of MoS2Nanoribbons by Micromolding in Capillaries

KAUST Repository

Hung, Yu-Han; Lu, Ang-Yu; Chang, Yung-Huang; Huang, Jing-Kai; Chang, Jeng-Kuei; Li, Lain-Jong; Su, Ching-Yuan

2016-01-01

, such as SiO2/Si, sapphire, Au film, FTO/glass, and graphene-coated glass. The degree of crystallinity of the as-prepared MoS2 was discovered to be adjustable by varying the temperature through postannealing. The high-temperature thermolysis (1000 °C) results

Rhenium Alloys as Ductile Substrates for Diamond Thin-Film Electrodes.

Science.gov (United States)

Halpern, Jeffrey M; Martin, Heidi B

2014-02-01

Molybdenum-rhenium (Mo/Re) and tungsten-rhenium (W/Re) alloys were investigated as substrates for thin-film, polycrystalline boron-doped diamond electrodes. Traditional, carbide-forming metal substrates adhere strongly to diamond but lose their ductility during exposure to the high-temperature (1000°C) diamond, chemical vapor deposition environment. Boron-doped semi-metallic diamond was selectively deposited for up to 20 hours on one end of Mo/Re (47.5/52.5 wt.%) and W/Re (75/25 wt.%) alloy wires. Conformal diamond films on the alloys displayed grain sizes and Raman signatures similar to films grown on tungsten; in all cases, the morphology and Raman spectra were consistent with well-faceted, microcrystalline diamond with minimal sp 2 carbon content. Cyclic voltammograms of dopamine in phosphate-buffered saline (PBS) showed the wide window and low baseline current of high-quality diamond electrodes. In addition, the films showed consistently well-defined, dopamine electrochemical redox activity. The Mo/Re substrate regions that were uncoated but still exposed to the diamond-growth environment remained substantially more flexible than tungsten in a bend-to-fracture rotation test, bending to the test maximum of 90° and not fracturing. The W/Re substrates fractured after a 27° bend, and the tungsten fractured after a 21° bend. Brittle, transgranular cleavage fracture surfaces were observed for tungsten and W/Re. A tension-induced fracture of the Mo/Re after the prior bend test showed a dimple fracture with a visible ductile core. Overall, the Mo/Re and W/Re alloys were suitable substrates for diamond growth. The Mo/Re alloy remained significantly more ductile than traditional tungsten substrates after diamond growth, and thus may be an attractive metal substrate for more ductile, thin-film diamond electrodes.

Orthorhombic MoO{sub 3} nanobelts based NO{sub 2} gas sensor

Energy Technology Data Exchange (ETDEWEB)

Mane, A.A. [Thin Film Nanomaterials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India); General Science and Humanities Department, Sant Gajanan Maharaj College of Engineering, Mahagaon, 416 503 (India); Moholkar, A.V., E-mail: avmoholkar@gmail.com [Thin Film Nanomaterials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India)

2017-05-31

Highlights: • The effect of thickness on physicochemical and NO{sub 2} gas sensing properties of sprayed MoO{sub 3} nanobelts has been reported. • The sprayed MoO{sub 3} nanobelts show the NO{sub 2} gas response of 68% for 100 ppm concentration at an operating temperature of 200 °C. • The lower detection limit of MoO{sub 3} nanobelts based NO{sub 2} sensor is found to be half of the IDLH value (20 ppm). - Abstract: Molybdenum trioxide (MoO{sub 3}) nanobelts have been deposited onto the glass substrates using chemical spray pyrolysis (CSP) deposition method. The XRD patterns reveal that films are polycrystalline having an orthorhombic crystal structure. Raman spectra confirm that the films are orthorhombic in phase. The XPS study shows the presence of two well resolved spectral lines of Mo-3d core levels appearing at the binding energy values of 232.82 eV and 235.95 eV corresponding to Mo-3d{sub 5/2} and Mo-3d{sub 3/2}, respectively. These binding energy values are assigned to Mo{sup 6+} oxidation state of fully oxidized MoO{sub 3}. The FE-SEM micrographs show the formation of nanobelts-like morphology. The AFM micrographs reveal that the RMS surface roughness increases from 16.5 nm to 17.5 nm with increase in film thickness from 470 nm to 612 nm and then decreases to 16 nm for 633 nm film thickness. The band gap energy is found to be decreased from 3.40 eV to 3.38 eV. To understand the electronic transport phenomenon in MoO{sub 3} thin films, dielectric properties are studied. For 612 nm film thickness, the highest NO{sub 2} gas response of 68% is obtained at an operating temperature of 200 °C for 100 ppm concentration with response and recovery times of 15 s and 150 s, respectively. The lower detection limit is found to be 10 ppm which is half of the immediately dangerous to life or health (IDLH) value of 20 ppm. Finally, NO{sub 2} gas sensing mechanism in an orthorhombic MoO{sub 3} crystal structure is discussed in detail.

Salt-assisted clean transfer of continuous monolayer MoS2 film for hydrogen evolution reaction

Science.gov (United States)

Cho, Heung-Yeol; Nguyen, Tri Khoa; Ullah, Farman; Yun, Jong-Won; Nguyen, Cao Khang; Kim, Yong Soo

2018-03-01

The transfer of two-dimensional (2D) materials from one substrate to another is challenging but of great importance for technological applications. Here, we propose a facile etching and residue-free method for transferring a large-area monolayer MoS2 film continuously grown on a SiO2/Si by chemical vapor deposition. Prior to synthesis, the substrate is dropped with water- soluble perylene-3, 4, 9, 10-tetracarboxylic acid tetrapotassium salt (PTAS). The as-grown MoS2 on the substrate is simply dipped in water to quickly dissolve PTAS to yield the MoS2 film floating on the water surface, which is subsequently transferred to the desired substrate. The morphological, optical and X-ray photoelectron spectroscopic results show that our method is useful for fast and clean transfer of the MoS2 film. Specially, we demonstrate that monolayer MoS2 film transferred onto a conducting substrate leads to excellent performance for hydrogen evolution reaction with low overpotential (0.29 V vs the reversible hydrogen electrode) and Tafel slope (85.5 mV/decade).

INFLUENCE OF THE SILICON INTERLAYER ON DIAMOND-LIKE CARBON FILMS DEPOSITED ON GLASS SUBSTRATES

Directory of Open Access Journals (Sweden)

Deiler Antonio Lima Oliveira

2012-06-01

Full Text Available Diamond-like carbon (DLC films as a hard protective coating have achieved great success in a diversity of technological applications. However, adhesion of DLC films to substrates can restrict their applications. The influence of a silicon interlayer in order to improve DLC adhesion on glass substrates was investigated. Amorphous silicon interlayer and DLC films were deposited using plasma enhanced chemical vapor deposition from silane and methane, respectively. The bonding structure, transmittance, refraction index, and adherence of the films were also evaluated regarding the thickness of the silicon interlayer. Raman scattering spectroscopy did not show any substantial difference in DLC structure due to the interlayer thickness of the silicon. Optical measurements showed a sharp decrease of transmittance in the ultra-violet region caused by the fundamental absorption of the light. In addition, the absorption edge of transmittance shifted toward longer wavelength side in the ultra-violet region as the thickness of the silicon interlayer increased. The tribological results showed an increase of DLC adherence as the silicon interlayer increased, which was characterized by less cracks around the grooves.

Surface-enhanced Raman spectroscopy based on conical holed enhancing substrates

International Nuclear Information System (INIS)

Chen, Yao; Chen, Zeng-Ping; Zuo, Qi; Shi, Cai-Xia; Yu, Ru-Qin

2015-01-01

In this contribution, surface-enhanced Raman spectroscopy (SERS) based on conical holed glass substrates deposited with silver colloids was reported for the first time. It combines the advantages of both dry SERS assays based on plane films deposited with silver colloids and wet SERS assays utilizing cuvettes or capillary tubes. Compared with plane glass substrates deposited with silver colloids, the conical holed glass substrates deposited with silver colloids exhibited five-to ten-folds of increase in the rate of signal enhancement, due to the internal multiple reflections of both the excitation laser beam and the Raman scattering photons within conical holes. The application of conical holed glass substrates could also yield significantly stronger and more reproducible SERS signals than SERS assays utilizing capillary tubes to sample the mixture of silver colloids and the solution of the analyte of interest. The conical holed glass substrates in combination with the multiplicative effects model for surface-enhanced Raman spectroscopy (MEM SERS ) achieved quite sensitive and precise quantification of 6-mercaptopurine in complex plasma samples with an average relative prediction error of about 4% and a limit of detection of about 0.02 μM using a portable i-Raman 785H spectrometer. It is reasonable to expect that SERS technique based on conical holed enhancing substrates in combination with MEM SERS model can be developed and extended to other application areas such as drug detection, environmental monitoring, and clinic analysis, etc. - Highlights: • A novel conical holed SERS enhancing substrate was designed and manufactured. • The optimal conical holed glass substrates can produce stronger SERS signal. • The novel substrates can overcome the shortcomings of both dry and wet methods. • The novel substrates coupled with MEM SERS can realize quantitative SERS assays

Mechanical behavior of Fe{sub 75}Mo{sub 5}P{sub 10}C{sub 7.5}B{sub 2.5} bulk-metallic glass under torsional loading

Energy Technology Data Exchange (ETDEWEB)

Zhang Xinjian [School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072 (China); Huang Lu [Department of Materials Science and Engineering, University of Tennessee, TN 37996 (United States); Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Chen Xu, E-mail: xchen@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072 (China); Liaw, Peter K. [Department of Materials Science and Engineering, University of Tennessee, TN 37996 (United States); An Ke [Neutron Scattering Sciences Division, Oak Ridge National Laboratory, TN 37831 (United States); Zhang Tao [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Wang Gongyao [Department of Materials Science and Engineering, University of Tennessee, TN 37996 (United States)

2010-11-15

Research highlights: {yields} Fe{sub 75}Mo{sub 5}P{sub 10}C{sub 7.5}B{sub 2.5} bulk-metallic glass exhibits a brittle characteristic under torsional loading. {yields} The BMG occurs in a tensile mode failure under torsional loading. {yields} A slight cyclic-hardening behavior was observed in the initial loading cycles during torsional-fatigue tests. {yields} The torsional fatigue-fracture surface consists of three main regions. - Abstract: Pure- and cyclic-torsional studies were conducted on a Fe{sub 75}Mo{sub 5}P{sub 10}C{sub 7.5}B{sub 2.5} (atomic percent, at.%) bulk-metallic glass at room temperature for an understanding of its damage and fracture mechanisms. Under pure-torsional loading, the metallic glass exhibited very little plastic strain before fracture. The fracture initiated along the maximum tensile-stress plane, which is about 45{sup o} to the axial direction. The shear-fracture strength ({approx}510 MPa) is much lower than the compressive-fracture strength ({approx}3280 MPa), which suggests that different deformation mechanisms be present under various loading modes. Instead of an apparent vein-type structure, the fracture morphologies revealed a crack-initiation site, a mirror region, a mist region, and a hackle region. Under cyclic-torsional loading, fatigue cracks initiated from casting defects, and propagate generally along the maximum tensile-stress plane. A slight cyclic-hardening behavior was observed in initial loading steps. The fatigue-fracture surface consists of three main regions: the fatigue crack-initiation, crack-propagation, and final-fast-fracture areas. The striations resulting from the blunting and re-sharpening of the fatigue crack tip were observed in the crack-propagation region. Based on these results, the damage and fracture mechanisms of the metallic glass induced by torsional loadings are elucidated.

Molecular Orientation in Two Component Vapor-Deposited Glasses: Effect of Substrate Temperature and Molecular Shape

Science.gov (United States)

Powell, Charles; Jiang, Jing; Walters, Diane; Ediger, Mark

Vapor-deposited glasses are widely investigated for use in organic electronics including the emitting layers of OLED devices. These materials, while macroscopically homogenous, have anisotropic packing and molecular orientation. By controlling this orientation, outcoupling efficiency can be increased by aligning the transition dipole moment of the light-emitting molecules parallel to the substrate. Light-emitting molecules are typically dispersed in a host matrix, as such, it is imperative to understand molecular orientation in two-component systems. In this study we examine two-component vapor-deposited films and the orientations of the constituent molecules using spectroscopic ellipsometry, UV-vis and IR spectroscopy. The role of temperature, composition and molecular shape as it effects molecular orientation is examined for mixtures of DSA-Ph in Alq3 and in TPD. Deposition temperature relative to the glass transition temperature of the two-component mixture is the primary controlling factor for molecular orientation. In mixtures of DSA-Ph in Alq3, the linear DSA-Ph has a horizontal orientation at low temperatures and slight vertical orientation maximized at 0.96Tg,mixture, analogous to one-component films.

Synthesis and characterization of MoO3 films by acid hydrolysis of K2Mo4O13

International Nuclear Information System (INIS)

Hernan, L.; Morales, J.

1989-01-01

The behaviour of K 2 Mo 4 O 13 heated under reflux in an acid medium has been studied. A metastable polymorphic MoO 3 phase crystallizing in the hexagonal system was obtained. Lengthy treatment led to the formation of orthorhombic MoO 3 with the (010) planes perfectly oriented parallel to the substrate. SEM images do not support a topotactic mechanism for the successive transformations. The reactions involved probably take place through the polymerization of discrete units formed in the bulk solution

Influence of the film thickness on the structure, optical and electrical properties of ITO coatings deposited by sputtering at room temperature on glass and plastic substrates

International Nuclear Information System (INIS)

Guillén, C; Herrero, J

2008-01-01

Transparent and conductive indium tin oxide (ITO) films with thickness between 0.2 and 0.7 µm were deposited by sputtering at room temperature on glass and polyethylene terephthalate (PET) substrates. All films were polycrystalline, with crystallite size increasing and lattice distortion decreasing when the film thickness was increased. Besides, transmission in the near-infrared region is found to be decreasing and carrier concentration increasing when the film thickness was increased. For the same thickness, the lattice distortion is slightly lower and the carrier concentration higher for the layers grown on PET substrates. A direct relationship between the lattice distortion and the free carrier concentration has been established, applying to the films grown on glass and plastic substrates. By adjusting ITO coating thickness, sheet resistance below 15 Ω sq −1 and average visible transmittance about 90% have been achieved by sputtering at room temperature

Turnover-dependent inactivation of the nitrogenase MoFe-protein at high pH.

Science.gov (United States)

Yang, Kun-Yun; Haynes, Chad A; Spatzal, Thomas; Rees, Douglas C; Howard, James B

2014-01-21

Proton uptake accompanies the reduction of all known substrates by nitrogenase. As a consequence, a higher pH should limit the availability of protons as a substrate essential for turnover, thereby increasing the proportion of more highly reduced forms of the enzyme for further study. The utility of the high-pH approach would appear to be problematic in view of the observation reported by Pham and Burgess [(1993) Biochemistry 32, 13725-13731] that the MoFe-protein undergoes irreversible protein denaturation above pH 8.65. In contrast, we found by both enzyme activity and crystallographic analyses that the MoFe-protein is stable when incubated at pH 9.5. We did observe, however, that at higher pHs and under turnover conditions, the MoFe-protein is slowly inactivated. While a normal, albeit low, level of substrate reduction occurs under these conditions, the MoFe-protein undergoes a complex transformation; initially, the enzyme is reversibly inhibited for substrate reduction at pH 9.5, yet in a second, slower process, the MoFe-protein becomes irreversibly inactivated as measured by substrate reduction activity at the optimal pH of 7.8. The final inactivated MoFe-protein has an increased hydrodynamic radius compared to that of the native MoFe-protein, yet it has a full complement of iron and molybdenum. Significantly, the modified MoFe-protein retains the ability to specifically interact with its nitrogenase partner, the Fe-protein, as judged by the support of ATP hydrolysis and by formation of a tight complex with the Fe-protein in the presence of ATP and aluminum fluoride. The turnover-dependent inactivation coupled to conformational change suggests a mechanism-based transformation that may provide a new probe of nitrogenase catalysis.

X-ray luminescent glasses

International Nuclear Information System (INIS)

Takahashi, T.; Yamada, O.

1981-01-01

X-ray luminescent glasses comprising a divalent cation such as an alkaline earth metal or other divalent cations such as pb, cd, or zn, and certain rare earth metaphosphates are suitable as vitreous, x-ray phosphors or x-ray luminescent glass fibers in an x-ray intensifying screen. The glasses have the composition n(Mo X p2o5)((1-y)tb2o3 X yce2o3 X 3p2o5) wherein N is greater than zero but less than or equal to 16, M is an alkaline earth metal or other divalent cation such as pb, cd, or zn, and Y is greater than or equal to zero but less than one

Femtosecond laser texturing of glass substrates for improved light in-coupling in thin-film photovoltaics

Science.gov (United States)

Imgrunt, J.; Chakanga, K.; von Maydell, K.; Teubner, U.

2017-12-01

Due to their low thickness, thin-film solar cells usually suffer from poor light absorption. To improve this situation, light-management is necessary. Within the present work, in order to enhance light coupling, an ultra-short-pulse laser is used for texturing substrates. Here commercially available multi component soda lime glass substrates are patterned with a dot grid at ambient air pressure with 150 fs pulses, centered at a wavelength of 775 nm. The structures consist of small depressions with approximately 3 μ m diameter. Varying depths of around 300 nm could be well reproduced. Reducing the pitch (distance between structure-to-structure centers), from ten to approximately one times the crater diameter, influences the structure quality and increases the deformation of the surface in the vicinity of the depressions. Consequently, the diffuse light scattering is improved from 0 to 30% haze. Overall, the presented approach is quite simple. This single-step texturing technique which can be easily used on different substrates is applicable in a wide range of thin-film solar cells. It has the advantage that ultra-thin electrodes can be used as the front contact as well as the potential to be integrated into a PV production line. Thus, complicated layer stacks for absorption enhancement can be avoided.

High efficiency bifacial Cu2ZnSnSe4 thin-film solar cells on transparent conducting oxide glass substrates

Directory of Open Access Journals (Sweden)

Jung-Sik Kim

2016-09-01

Full Text Available In this work, transparent conducting oxides (TCOs have been employed as a back contact instead of Mo on Cu2ZnSnSe4 (CZTSe thin-film solar cells in order to examine the feasibility of bifacial Cu2ZnSn(S,Se4 (CZTSSe solar cells based on a vacuum process. It is found that the interfacial reaction between flourine doped tin oxide (FTO or indium tin oxide (ITO and the CZTSe precursor is at odds with the conventional CZTSe/Mo reaction. While there is no interfacial reaction on CZTSe/FTO, indium in CZTSe/ITO was significantly diffused into the CZTSe layers; consequently, a SnO2 layer was formed on the ITO substrate. Under bifacial illumination, we achieved a power efficiency of 6.05% and 4.31% for CZTSe/FTO and CZTSe/ITO, respectively.

Substrate bias effects on composition and coercivity of CoCrTa/Cr thin films on canasite and glass

Science.gov (United States)

Deng, Y.; Lambeth, D. N.; Sui, X.; Lee, L.-L.; Laughlin, D. E.

1993-05-01

CoCrTa/Cr thin films were prepared by rf diode sputtering onto canasite and glass substrates at various bias voltages from two targets of different compositions (Co82.8Cr14.6Ta2.6 and Co86Cr12Ta2). While Auger depth profile analysis indicates that there is some broadening at the CoCrTa-Cr interface, x-ray fluorescence spectroscopy reveals that changes in alloy composition due to the resputtering processes are even more prominent. For both targets, as the substrate bias increases the Co content in the films declines, and the magnetization decreases. The maximum film coercivity appears to correlate to the final film composition. By investigating the results from both targets, it is concluded that the coercivity reaches a maximum when the film composition is in the neighborhood of Co84Cr13Ta3. Thus, to optimize the coercivity different bias voltages are required for each target. Excessive substrate bias, however, leads to films with low magnetization and coercivity.

Atomic layer deposition of alternative glass microchannel plates

Energy Technology Data Exchange (ETDEWEB)

O' Mahony, Aileen, E-mail: aom@incomusa.com; Craven, Christopher A.; Minot, Michael J.; Popecki, Mark A.; Renaud, Joseph M.; Bennis, Daniel C.; Bond, Justin L.; Stochaj, Michael E.; Foley, Michael R.; Adams, Bernhard W. [Incom, Inc., 294 Southbridge Road, Charlton, Massachusetts 01507 (United States); Mane, Anil U.; Elam, Jeffrey W. [Argonne National Laboratory, 9700 S. Cass Ave., Argonne, Illinois 60439 (United States); Ertley, Camden; Siegmund, Oswald H. W. [Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, California 94720 (United States)

2016-01-15

The technique of atomic layer deposition (ALD) has enabled the development of alternative glass microchannel plates (MCPs) with independently tunable resistive and emissive layers, resulting in excellent thickness uniformity across the large area (20 × 20 cm), high aspect ratio (60:1 L/d) glass substrates. Furthermore, the use of ALD to deposit functional layers allows the optimal substrate material to be selected, such as borosilicate glass, which has many benefits compared to the lead-oxide glass used in conventional MCPs, including increased stability and lifetime, low background noise, mechanical robustness, and larger area (at present up to 400 cm{sup 2}). Resistively stable, high gain MCPs are demonstrated due to the deposition of uniform ALD resistive and emissive layers on alternative glass microcapillary substrates. The MCP performance characteristics reported include increased stability and lifetime, low background noise (0.04 events cm{sup −2} s{sup −1}), and low gain variation (±5%)

A new paramagnetic center of copper ion γ-irradiated phosphate glasses

International Nuclear Information System (INIS)

Bogomolova, L.D.; Fedorov, A.G.; Jachkin, V.A.; Lazukin, V.N.; Pavlushkina, T.K.

1981-01-01

In the present paper are shown the results of EPR and optical absorption investigations of copper ions in γ-irradiated sodium-phosphate glasses and in MO-P 2 O 5 glasses (M = MG,Ca, Sr, Zn, Ba) containing copper and comparisons are made with the data for sodium-silicate glasses. (orig./HOF)

Optical study of gamma irradiated sodium metaphosphate glasses containing divalent metal oxide MO (ZnO or CdO

Directory of Open Access Journals (Sweden)

E. Nabhan

Full Text Available Sodium metaphosphate glasses containing divalent metal oxide, ZnO or CdO with composition 50 P2O5 – (50 − x Na2O – x MO (ZnO, or CdO where x = 0, 10, 20 (mol% were prepared by conventional melt method. UV/visible spectroscopy and FTIR spectroscopy are measured before and after exposing to successive gamma irradiation doses (5–80 kGy. The optical absorption spectra results of the samples before irradiation reveal a strong UV absorption band at (∼230 nm which is related to unavoided iron impurities. The effects of gamma irradiation on the optical spectral properties of the various glasses have been compared. From the optical absorption spectral data, the optical band gap is evaluated. The main structural groups and the influence of both divalent metal oxide and gamma irradiation effect on the structural vibrational groups are realized through IR spectroscopy. The FTIR spectra of γ-irradiated samples are characterized by the stability of the number and position for the main characteristic band of phosphate groups. To better understood the structural changes during γ-irradiation, a deconvolution of FTIR spectra in the range 650–1450 cm−1 is made. The FTIR deconvolution results found evidence that, the changes occurring after gamma irradiation have been related to irradiation induced structural defects and compositional changes. Keywords: Sodium metaphosphate glass, UV–visible spectra, IR spectra, Deconvolution, Optical band gap, Gamma ray

Transparent conducting properties of anatase Ti{sub 0.94}Nb{sub 0.06}O{sub 2} polycrystalline films on glass substrate

Energy Technology Data Exchange (ETDEWEB)

Hitosugi, T. [Department of Chemistry, University of Tokyo, Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan)], E-mail: hitosugi@chem.s.u-tokyo.ac.jp; Ueda, A. [Department of Chemistry, University of Tokyo, Tokyo 113-0033 (Japan); Nakao, S.; Yamada, N.; Furubayashi, Y.; Hirose, Y.; Konuma, S. [Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan); Shimada, T.; Hasegawa, T. [Department of Chemistry, University of Tokyo, Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan)

2008-07-01

We report on transparent conducting properties of anatase Ti{sub 0.94}Nb{sub 0.06}O{sub 2} (TNO) polycrystalline films on glass substrate, and discuss the role of grain crystallinity and grain boundary on resistivity. Thin films of TNO were deposited using pulsed laser deposition at substrate temperature ranging from room temperature to 350 deg. C, with subsequent H{sub 2}-annealing at 500 deg. C. Polycrystalline TNO films showed resistivity of 4.5 x 10{sup -4} {omega} cm and 1.5 x 10{sup -3} {omega} cm for films prepared at substrate temperature of room temperature and 250 deg. C, respectively. X-ray diffraction measurements and transmission electron microscopy reveal that grain crystallinity and grain boundary play key roles in conductive films.

Synthesis and analysis of Mo-Si-B based coatings for high temperature oxidation protection of ceramic materials

Science.gov (United States)

Ritt, Patrick J.

The use of Ni-based superalloys in turbine engines has all but been exhausted, with operating temperatures nearing the melting point of these materials. The use of ceramics in turbine engines, particularly ceramic matrix composites such as SiC/C and SiC/SiC, is of interest due to their low density and attractive mechanical properties at elevated temperatures. The same materials are also in consideration for leading edges on hypersonic vehicles. However, SiC-based composites degrade in high temperature environments with low partial pressures of oxygen due to active oxidation, as well as high temperature environments containing water or sand. The need for a protective external coating for SiC-based composites in service is obvious. To date, no coating investigated for SiC/C or SiC/SiC has been proven to be resistant to oxidation and corrosion at intermediate and high temperatures, as well as in environments deficient in oxygen. The Mo-Si-B coating shows great promise in this area, having been proven resistant to attack from oxidation at extreme temperatures, from water vapor and from calcia-magnesia-aluminosilicate (CMAS). The adaptation of the Mo-Si-B coating for ceramic materials is presented in detail here. Evaluation of the coating under a range of oxidation conditions as well as simulated re-entry conditions confirms the efficacy of the Mo-Si-B based coating as protection from catastrophic failure. The key to the oxidation and corrosion resistance is a robust external aluminoborosilica glass layer that forms and flows quickly to cover the substrate, even under the extreme simulated re-entry conditions. Suppression of active oxidation of SiC, which may occur during atmospheric re-entry and hypersonic flight trajectories, has also been examined. In order to adapt the Mo-Si-B based coating to low partial pressures of oxygen and elevated temperatures, controlled amounts of Al were added to the Mo-Si-B based coating. The resulting coating decreased the inward

Hydrogenated amorphous silicon solar cells fabricated at low substrate temperature 110°C on flexible PET substrate

Science.gov (United States)

Ramakrishna, M.; Kumari, Juhi; Venkanna, K.; Agarwal, Pratima

2018-05-01

In this paper, we report a-Si:H solar cells fabricated on flexible Polyethylene terephthalate (PET) and corning glass. The a-Si:H thin films were prepared at low substrate temperature (110oC) on corning 1737 glass with different rf powers. The influence of rf power on structural and optoelectronic properties of i-a-Si:H were studied. The films deposited at rf power 50W show less broadening of peak. This indicates these films are more ordered. With this optimized parameter for i-layer, solar cells fabricated on flexible PET substrate show best efficiency of 3.3% whereas on corning glass 3.82%.

Direct determination of monolayer MoS2 and WSe2 exciton binding energies on insulating and metallic substrates

KAUST Repository

Park, Soohyung; Mutz, Niklas; Schultz, Thorsten; Blumstengel, Sylke; Han, Ali; Aljarb, Areej; Li, Lain-Jong; List-Kratochvil, Emil J W; Amsalem, Patrick; Koch, Norbert

2018-01-01

Understanding the excitonic nature of excited states in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is of key importance to make use of their optical and charge transport properties in optoelectronic applications. We contribute to this by the direct experimental determination of the exciton binding energy (E b,exc) of monolayer MoS2 and WSe2 on two fundamentally different substrates, i.e. the insulator sapphire and the metal gold. By combining angle-resolved direct and inverse photoelectron spectroscopy we measure the electronic band gap (E g), and by reflectance measurements the optical excitonic band gap (E exc). The difference of these two energies is E b,exc. The values of E g and E b,exc are 2.11 eV and 240 meV for MoS2 on sapphire, and 1.89 eV and 240 meV for WSe2 on sapphire. On Au E b,exc is decreased to 90 meV and 140 meV for MoS2 and WSe2, respectively. The significant E b,exc reduction is primarily due to a reduction of E g resulting from enhanced screening by the metal, while E exc is barely decreased for the metal support. Energy level diagrams determined at the K-point of the 2D TMDCs Brillouin zone show that MoS2 has more p-type character on Au as compared to sapphire, while WSe2 appears close to intrinsic on both. These results demonstrate that the impact of the dielectric environment of 2D TMDCs is more pronounced for individual charge carriers than for a correlated electron–hole pair, i.e. the exciton. A proper dielectric surrounding design for such 2D semiconductors can therefore be used to facilitate superior optoelectronic device function.

Direct determination of monolayer MoS2 and WSe2 exciton binding energies on insulating and metallic substrates

Science.gov (United States)

Park, Soohyung; Mutz, Niklas; Schultz, Thorsten; Blumstengel, Sylke; Han, Ali; Aljarb, Areej; Li, Lain-Jong; List-Kratochvil, Emil J. W.; Amsalem, Patrick; Koch, Norbert

2018-04-01

Understanding the excitonic nature of excited states in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is of key importance to make use of their optical and charge transport properties in optoelectronic applications. We contribute to this by the direct experimental determination of the exciton binding energy (E b,exc) of monolayer MoS2 and WSe2 on two fundamentally different substrates, i.e. the insulator sapphire and the metal gold. By combining angle-resolved direct and inverse photoelectron spectroscopy we measure the electronic band gap (E g), and by reflectance measurements the optical excitonic band gap (E exc). The difference of these two energies is E b,exc. The values of E g and E b,exc are 2.11 eV and 240 meV for MoS2 on sapphire, and 1.89 eV and 240 meV for WSe2 on sapphire. On Au E b,exc is decreased to 90 meV and 140 meV for MoS2 and WSe2, respectively. The significant E b,exc reduction is primarily due to a reduction of E g resulting from enhanced screening by the metal, while E exc is barely decreased for the metal support. Energy level diagrams determined at the K-point of the 2D TMDCs Brillouin zone show that MoS2 has more p-type character on Au as compared to sapphire, while WSe2 appears close to intrinsic on both. These results demonstrate that the impact of the dielectric environment of 2D TMDCs is more pronounced for individual charge carriers than for a correlated electron-hole pair, i.e. the exciton. A proper dielectric surrounding design for such 2D semiconductors can therefore be used to facilitate superior optoelectronic device function.

Direct determination of monolayer MoS2 and WSe2 exciton binding energies on insulating and metallic substrates

KAUST Repository

Park, Soohyung

2018-01-03

Understanding the excitonic nature of excited states in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is of key importance to make use of their optical and charge transport properties in optoelectronic applications. We contribute to this by the direct experimental determination of the exciton binding energy (E b,exc) of monolayer MoS2 and WSe2 on two fundamentally different substrates, i.e. the insulator sapphire and the metal gold. By combining angle-resolved direct and inverse photoelectron spectroscopy we measure the electronic band gap (E g), and by reflectance measurements the optical excitonic band gap (E exc). The difference of these two energies is E b,exc. The values of E g and E b,exc are 2.11 eV and 240 meV for MoS2 on sapphire, and 1.89 eV and 240 meV for WSe2 on sapphire. On Au E b,exc is decreased to 90 meV and 140 meV for MoS2 and WSe2, respectively. The significant E b,exc reduction is primarily due to a reduction of E g resulting from enhanced screening by the metal, while E exc is barely decreased for the metal support. Energy level diagrams determined at the K-point of the 2D TMDCs Brillouin zone show that MoS2 has more p-type character on Au as compared to sapphire, while WSe2 appears close to intrinsic on both. These results demonstrate that the impact of the dielectric environment of 2D TMDCs is more pronounced for individual charge carriers than for a correlated electron–hole pair, i.e. the exciton. A proper dielectric surrounding design for such 2D semiconductors can therefore be used to facilitate superior optoelectronic device function.

Temperature dependence of residual stress in TiC coated Mo

International Nuclear Information System (INIS)

Yoshizawa, I.; Fukutomi, M.; Kamada, K.

1984-01-01

The effects of fabrication temperature and heat treatment on the residual stress in TiC coated Mo have been studied by using X-ray diffractometry. TiC coatings on Mo single crystal substrates with (100) and (111) surfaces were carried out with the Activated Reactive Evaporation (ARE) method. It was found that all Mo substrates measured show tensile residual stresses, and their values decrease as the fabrication temperature increases from 300 to 700 0 C. On the other hand, TiC films measured showed compressive residual stresses, for both TiC/Mo(100) and TiC/Mo(111) specimens. These compressive stresses also decreased with increasing the fabrication temperature. The residual stresses measured were higher in TiC/Mo(100) than in TiC/Mo(111). It was found that the compressive stresses in as-grown TiC films change to the tensile stresses after annealing at 1700 0 C for 30 min. The preferred orientations of TiC films were observed to depend on the fabrication temperature. However, no epitaxial growth of TiC films was found as far as the present experiment was concerned. (orig.)

Mechanical Properties of Stable Glasses Using Nanoindentation

Science.gov (United States)

Wolf, Sarah; Liu, Tianyi; Jiang, Yijie; Ablajan, Keyume; Zhang, Yue; Walsh, Patrick; Turner, Kevin; Fakhraai, Zahra

Glasses with enhanced stability over ordinary, liquid quenched glasses have been formed via the process of Physical Vapor Deposition (PVD) by using a sufficiently slow deposition rate and a substrate temperature slightly below the glass transition temperature. These stable glasses have been shown to exhibit higher density, lower enthalpy, and better kinetic stability over ordinary glass, and are typically optically birefringent, due to packing and orientational anisotropy. Given these exceptional properties, it is of interest to further investigate how the properties of stable glasses compare to those of ordinary glass. In particular, the mechanical properties of stable glasses remain relatively under-investigated. While the speed of sound and elastic moduli have been shown to increase with increased stability, little is known about their hardness and fracture toughness compared to ordinary glasses. In this study, glasses of 9-(3,5-di(naphthalen-1-yl)phenyl)anthracene were deposited at varying temperatures relative to their glass transition temperature, and their mechanical properties measured by nanoindentation. Hardness and elastic modulus of the glasses were compared across substrate temperatures. After indentation, the topography of these films were studied using Atomic Force Microscopy (AFM) in order to further compare the relationship between thermodynamic and kinetic stability and mechanical failure. Z.F. and P.W. acknowledge funding from NSF(DMREF-1628407).

Exfoliated MoS2 nanosheets as efficient catalysts for electrochemical hydrogen evolution

International Nuclear Information System (INIS)

Ji, Shanshan; Yang, Zhe; Zhang, Chao; Liu, Zhenyan; Tjiu, Weng Weei; Phang, In Yee; Zhang, Zheng; Pan, Jisheng; Liu, Tianxi

2013-01-01

Graphical abstract: An efficient electrocatalyst for hydrogen evolution has been developed based on exfoliation of bulk MoS 2 crystals via a direct dispersion and ultrasonication method. Drop-casting method is used to fabricate the exfoliated MoS 2 nanosheets modified glass carbon electrode (E-MoS 2 /GCE) with various loadings. The E-MoS 2 /GCE with electrode loading of 48 μg cm −1 exhibits high catalytic activity for hydrogen evolution with a low overpotential (−0.12 V) and a high current density (1.26 mA cm −2 , at η = 150 mV). -- Highlights: • Two-dimensional MoS 2 nanosheets have been obtained by exfoliation of bulk MoS 2 crystals. • Exfoliated MoS 2 nanosheets show high electrocatalytic activity for H 2 production. • This study provides a new approach for renewable and economic H 2 production. -- Abstract: An efficient electrocatalyst for hydrogen evolution has been developed based on liquid exfoliation of bulk MoS 2 via a direct dispersion and ultrasonication method. Transmission electron microscopy and atomic force microscopy measurements show that the exfoliated MoS 2 consists of two-dimensional nanosheets. The exfoliated MoS 2 nanosheets modified glass carbon electrode (E-MoS 2 /GCE) with various loadings is fabricated via a drop-casting method. The electrocatalytic activity of E-MoS 2 /GCE toward hydrogen evolution reaction is examined using linear sweep voltammetry. It is shown that the E-MoS 2 /GCE with an electrode loading of 48 μg cm −2 exhibits a high catalytic activity for hydrogen evolution with a low overpotential (−0.12 V) and a high current density (1.26 mA cm −2 , at η = 150 mV)

Effect of thermal treatment on the CO and H2O sensing properties of MoO3 thin films

International Nuclear Information System (INIS)

Torres-Luengo, M; Martínez, H M; Torres, J; López-Carreño, L D

2014-01-01

MoO 3 thin films were prepared on Corning glass substrates using the chemical spray pyrolysis technique. A 0.1 M solution of ammonium molybdate tetrahydrate was used as precursor one. 5ml and 20 ml of the precursor solution was sprayed with the substrate temperature maintained at 623 K. Thermal treatment involved drying at 393 K for 8 h with continuous N 2 flow, followed by a vacuum annealing at 473 K for 2 h in a residual inert atmosphere. XRD indicates that the crystallographic structure corresponded to the orthorhombic α-MoO 3 phase. Electrical characterization was carried out in a system operating under high vacuum conditions. The samples could be cooled down to LN 2 temperature and heated in a controlled way up to 473 K. To elucidate the electrical response of the films to CO and H 2 O exposure, the I-V characteristic curve was measured over the whole temperature range. The electrical resistance of the films decreased with increasing temperature. In 5 ml films, the sensitivity to both gases increased which thermal treatment, reaching values between 40% and 60% at room temperature. On the contrary, the 20 ml films' sensitivity decreased almost half of their original values after thermal treatment

Crystallization of 21.25Gd{sub 2}O{sub 3}-63.75MoO{sub 3}-15B{sub 2}O{sub 3} glass induced by femtosecond laser at the repetition rate of 250 kHz

Energy Technology Data Exchange (ETDEWEB)

Zhong, M.J.; Han, Y.M. [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China); Liu, L.P. [Hunan Biological and Electromechanical Polytechnic, Changsha 410126 (China); Zhou, P.; Du, Y.Y.; Guo, Q.T. [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China); Ma, H.L., E-mail: mahl@staff.shu.edu.cn [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China); Dai, Y. [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China)

2010-12-01

We report the formation of {beta}'-Gd{sub 2}(MoO{sub 4}){sub 3} (GMO) crystal on the surface of the 21.25Gd{sub 2}O{sub 3}-63.75MoO{sub 3}-15B{sub 2}O{sub 3} glass, induced by 250 kHz, 800 nm femtosecond laser irradiation. The morphology of the modified region in the glass was clearly examined by scanning electron microscopy (SEM). By micro-Raman spectra, the laser-induced crystals were confirmed to be GMO phases and it is found that these crystals have a strong dependence on the number and power of the femtosecond laser pulses. When the irradiation laser power was 900 mW, not only the Raman peaks of GMO crystals but also some new peaks at 214 cm{sup -1}, 240 cm{sup -1}, 466 cm{sup -1}, 664 cm{sup -1} and 994 cm{sup -1}which belong to the MoO{sub 3} crystals were observed. The possible mechanisms are proposed to explain these phenomena.

Glass/ceramic coatings for implants

Science.gov (United States)

Tomsia, Antoni P [Pinole, CA; Saiz, Eduardo [Berkeley, CA; Gomez-Vega, Jose M [Nagoya, JP; Marshall, Sally J [Larkspur, CA; Marshall, Grayson W [Larkspur, CA

2011-09-06

Glass coatings on metals including Ti, Ti6A14V and CrCo were prepared for use as implants. The composition of the glasses was tailored to match the thermal expansion of the substrate metal. By controlling the firing atmosphere, time, and temperature, it was possible to control the reactivity between the glass and the alloy and to fabricate coatings (25-150 .mu.m thick) with excellent adhesion to the substrate. The optimum firing temperatures ranged between 800 and 840.degree. C. at times up to 1 min in air or 15 min in N.sub.2. The same basic technique was used to create multilayered coatings with concentration gradients of hydroxyapatite (HA) particles and SiO.sub.2.

Comparison of a model vapor deposited glass films to equilibrium glass films

Science.gov (United States)

Flenner, Elijah; Berthier, Ludovic; Charbonneau, Patrick; Zamponi, Francesco

Vapor deposition of particles onto a substrate held at around 85% of the glass transition temperature can create glasses with increased density, enthalpy, kinetic stability, and mechanical stability compared to an ordinary glass created by cooling. It is estimated that an ordinary glass would need to age thousands of years to reach the kinetic stability of a vapor deposited glass, and a natural question is how close to the equilibrium is the vapor deposited glass. To understand the process, algorithms akin to vapor deposition are used to create simulated glasses that have a higher kinetic stability than their annealed counterpart, although these glasses may not be well equilibrated either. Here we use novel models optimized for a swap Monte Carlo algorithm in order to create equilibrium glass films and compare their properties with those of glasses obtained from vapor deposition algorithms. This approach allows us to directly assess the non-equilibrium nature of vapor-deposited ultrastable glasses. Simons Collaboration on Cracking the Glass Problem and NSF Grant No. DMR 1608086.

Fabrication of transparent superhydrophobic silica-based film on a glass substrate

Science.gov (United States)

Wang, Shing-Dar; Luo, Shih-Shiang

2012-05-01

Tetraethoxysilane (TEOS) was hydrolyzed in an acidic environment and then reacted with hexamethyldisilazane (HMDS) to obtain a superhydrophobic transparent film on a glass substrate. The molar ratios of water and ethanol to TEOS, the pH value of the acidic (or basic) water that is used to hydrolyze TEOS, the heat treatment conditions and other factors were investigated systematically to optimize the transmission through, and the contact angle of water on the film. HMDS (total amount of HMDS/TEOS = 2) was divided into 20 parts, which were added into the sol successively to prevent the sudden production of a large quantity of NH3 in a small area of the sol. The optical and hydrophobic properties of the sol gel continued to change after it had been prepared. The conditions that TEOS was hydrolyzed with acidic water at pH 1.2 at 70 °C and the sol gel was aged at 20 °C for 48 h realized transmission of 90.9% and a water contact angle of 154.3°. No additional surface chemistry modification was needed.

Microstructure and micromechanical properties of electrodeposited Zn–Mo coatings on steel

Energy Technology Data Exchange (ETDEWEB)

Kazimierczak, Honorata, E-mail: h.kazimierczak@imim.pl [Institute of Metallurgy and Material Science, Polish Academy of Sciences, 30-059 Krakow, Reymonta 25 (Poland); Ozga, Piotr [Institute of Metallurgy and Material Science, Polish Academy of Sciences, 30-059 Krakow, Reymonta 25 (Poland); Berent, Katarzyna [Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, 30-059 Krakow, Mickiewicza Av. 30 (Poland); Kot, Marcin [Faculty of Mechanical Engineering and Robotics, AGH University of Science and Technology, 30-059 Krakow, Mickiewicza Av. 30 (Poland)

2015-07-05

Highlights: • The conditions for electrodeposition of uniform and compact Zn–Mo coatings have been studied. • Zn–Mo coatings microstructure can be controlled by the molybdenum content. • Surface roughness can be controlled by the content of Mo in coatings. • The value of microhardness grows gradually with the increase of Mo content up to 3 wt.%. - Abstract: The aim of the work was to characterise the new coating material based on zinc with the addition of molybdenum, electrodeposited on steel substrate from nontoxic, citrate based electrolytes. The surface composition of deposits was ascertained by chemical analysis (WDXRF). The morphology of coatings was studied by SEM. The surface morphology and roughness of Zn–Mo coatings on steel was investigated by AFM. The microhardness and Young modulus were determined by indentation technique, whereas the coating adhesion to the substrate was examined by means of scratch test. The optimal ranges of electrodeposition parameters, enabling the preparation of good quality coatings (i.e. uniform, compact, with good adhesion to the substrate), was specified. The morphology of deposits depends significantly on the content of molybdenum and on the thickness of electrodeposited layer. The microhardness of Zn–Mo coating increases with the increase of molybdenum content up to 3 wt.% and then reaches about 3.5 GPa, which is almost five times that of the value of the microhardness of the Zn coating studied.

Plasmonic nanoholes as SERS devices for biosensing applications: An easy route for nanostructures fabrication on glass substrates

KAUST Repository

Candeloro, Patrizio

2016-12-26

Surface enhanced Raman spectroscopy (SERS) has been largely exploited in the last decade for biochemical and biomedical research. But some issues still require attention before transferring SERS to bioclinical routinely practices, such as reproducibility, quantitative analysis and signal background interference. In this work we propose an easy and cheap route, based on a template stripping technique, for producing plasmonic nanostructured films with SERS capabilities. We focus our attention to nanoholes in a continuous gold film, conversely to the majority of the literature which is dealing with individual nanostructures. Plasmon resonances occur at the holes edges, thus enabling the possibility of SERS signals from biomolecules and the potential application as biosensors. One advantage of the nanoholes patterned film is the optical-subdiffraction pitch, which prevents any Raman and/or fluorescence signal arising from the bottom slide. This effect paves the way to standard glass slides, much cheaper than CaF2 ones, as suitable substrates for SERS devices, without any interfering signal coming from the glass itself.

Amorphous-crystalline transition studied in hydrated MoO3

International Nuclear Information System (INIS)

Camacho-Lopez, M.A.; Haro-Poniatowski, E.; Lartundo-Rojas, L.; Livage, J.; Julien, C.M.

2006-01-01

In this work we study the thermal behavior of hydrated MoO 3 synthesized via acidification of sodium molybdate. MoO 3 .nH 2 O (n = 1.4) amorphous compound was heated in air at increasing temperatures in order to obtain the crystalline MoO 3 phase. We have studied the structural changes as a function of annealing temperature by Raman spectroscopy. A statistical study to determine the average size of the crystallites at each annealing step has been realized by scanning electron microscopy. Results show that the hydrated MoO 3 .1.4H 2 O glass transforms in an amorphous MoO 3 .0.7H 2 O phase prior to its crystallization, while the sample heated at 500 deg. C crystallizes into the orthorhombic α-MoO 3 phase with micro-crystallites having an average size of 6.8 μm

Biaxially oriented CdTe films on glass substrate through nanostructured Ge/CaF2 buffer layers

Science.gov (United States)

Lord, R. J.; Su, P.-Y.; Bhat, I.; Zhang, S. B.; Lu, T.-M.; Wang, G.-C.

2015-09-01

Heteroepitaxial CdTe films were grown by metal organic chemical vapor deposition on glass substrates through nanostructured Ge/CaF2 buffer layers which were biaxially oriented. It allows us to explore the structural properties of multilayer biaxial semiconductor films which possess small angle grain boundaries and to test the principle of a solar cell made of such low-cost, low-growth-temperature semiconductor films. Through the x-ray diffraction and x-ray pole figure analysis, the heteroepitaxial relationships of the mutilayered films are determined as [111] in the out-of-plane direction and CdTe//Ge//{ }{{{CaF}}2} in the in-plane direction. The I-V curves measured from an ITO/CdS/CdTe/Ge/CaF2/glass solar cell test structure shows a power conversion efficiency of ˜η = 1.26%, illustrating the initial success of such an approach. The observed non-ideal efficiency is believed to be due to a low shunt resistance and high series resistance as well as some residual large-angle grain boundary effects, leaving room for significant further improvement.

Growth of MoO3 nanostructured thin films as a function of O2-partial pressure

Science.gov (United States)

Sharma, Rabindar Kumar; Kumar, Prabhat; Reddy, G. B.

2015-06-01

In this report, we synthesized molybdenum trioxide (α-MoO3) nanostructured thin films (NSTs) with nanoflakes (NFs) on the Ni-coated glass substrates employing plasma assisted sublimation process (PASP) as a function of oxygen partial pressure (PO2). The effect of oxygen partial pressure on structural, morphological, and vibrational properties have been investigated systematically. The structural analysis divulged that all films deposited at different PO2 have pure orthorhombic phase, no impurity phase is detected under the limit of resolution. The morphological studies of samples is carried out by SEM, revealed that features as well as alignment of MoO3 NSTs can be monitored by PO2 and the sample having best features is obtained at 7.5×10-2 Torr. In addition, the more insight information is accomplished by TEM/HRTEM on the best featured sample, which confirmed the single crystalline nature of nanoflakes. The vibrational study of all samples are performed by FTIR, and strongly supports the XRD observations. All the results are in consonance with each other.

Comparison of Cu(In, Ga)Se{sub 2} thin films deposited on different preferred oriented Mo back contact by RF sputtering from a quaternary target

Energy Technology Data Exchange (ETDEWEB)

Tian, Jing [Sichuan University, College of Materials Science and Engineering, Chengdu (China); Solar Energy Research Institute, Yunnan Normal University, Education Ministry Key Laboratory of Renewable Energy Advanced Materials and Manufacturing Technology, Kunming (China); Peng, Lianqin; Chen, Jinwei; Wang, Gang; Wang, Xueqin; Kang, Hong; Wang, Ruilin [Sichuan University, College of Materials Science and Engineering, Chengdu (China)

2014-09-15

The Cu(In, Ga)Se{sub 2} (CIGS) thin films were deposited on bare glass and DC sputtered preferential oriented Mo-coated glass by RF sputtering from a single quaternary target. The structural and morphological properties of the films were characterized by X-ray diffraction (XRD), Raman spectroscope, energy dispersive X-ray spectrometer (EDS) and atomic force microscope (AFM). Preferred orientation of the Mo back contact was tuned between (110) and (211) plane by controlling the thickness. All the deposited CIGS thin films show (112) preferred oriented chalcopyrite structures. The films prepared on Mo-coated glass show higher quality crystallinity, better stoichiometry composition and more smooth surface morphology. Especially, the film on (211) oriented Mo-coated glass with the best integrated performance is expected to be a candidate absorber for high-efficiency CIGS solar cell device. (orig.)

Intercalation of Si between MoS2 layers

Directory of Open Access Journals (Sweden)

Rik van Bremen

2017-09-01

Full Text Available We report a combined experimental and theoretical study of the growth of sub-monolayer amounts of silicon (Si on molybdenum disulfide (MoS2. At room temperature and low deposition rates we have found compelling evidence that the deposited Si atoms intercalate between the MoS2 layers. Our evidence relies on several experimental observations: (1 Upon the deposition of Si on pristine MoS2 the morphology of the surface transforms from a smooth surface to a hill-and-valley surface. The lattice constant of the hill-and-valley structure amounts to 3.16 Å, which is exactly the lattice constant of pristine MoS2. (2 The transitions from hills to valleys are not abrupt, as one would expect for epitaxial islands growing on-top of a substrate, but very gradual. (3 I(V scanning tunneling spectroscopy spectra recorded at the hills and valleys reveal no noteworthy differences. (4 Spatial maps of dI/dz reveal that the surface exhibits a uniform work function and a lattice constant of 3.16 Å. (5 X-ray photo-electron spectroscopy measurements reveal that sputtering of the MoS2/Si substrate does not lead to a decrease, but an increase of the relative Si signal. Based on these experimental observations we have to conclude that deposited Si atoms do not reside on the MoS2 surface, but rather intercalate between the MoS2 layers. Our conclusion that Si intercalates upon the deposition on MoS2 is at variance with the interpretation by Chiappe et al. (Adv. Mater. 2014, 26, 2096–2101 that silicon forms a highly strained epitaxial layer on MoS2. Finally, density functional theory calculations indicate that silicene clusters encapsulated by MoS2 are stable.

Absence of traditional magnetoresistivity mechanisms in Sr2FeMoO6 thin films grown on SrTiO3, MgO and NdGaO3 substrates.

Science.gov (United States)

Saloaro, M; Majumdar, S; Huhtinen, H; Paturi, P

2012-09-12

Magnetoresistive double perovskite Sr(2)FeMoO(6) thin films were grown with two different deposition pressures on SrTiO(3), MgO and NdGaO(3) substrates by pulsed laser deposition and thorough structural, magnetic and magneto-transport characterization was made. According to x-ray diffraction, all the films were phase pure and fully textured. Indication of substrate dependent strain and low angle grain boundaries was found, especially in films on MgO. Both the deposition pressure and the choice of the substrate have a strong influence on the saturation magnetization, M(s), and Curie temperature, T(C). The structural and magnetic data indicate the presence of anti-site disorder (ASD) in the films. The temperature dependence of resistivity showed semiconductive behaviour at temperatures below 100 K and metallic behaviour at higher temperatures. The semiconductive behaviour was found to increase with increasing ASD. In good quality films, up to 12% negative magnetoresistance (MR) was observed and films grown on MgO and NGO substrates also showed low field MR. However, the most significant observation of this study was that the magnetoresistivity of these Sr(2)FeMoO(6) thin films could not be explained with any traditional MR mechanism, but carried the clear signature of superposition of different mechanisms, in particular low angle grain boundary tunnelling and suppression of antiferromagnetically ordered domains under a magnetic field.

Plasma-assisted synthesis of MoS2

Science.gov (United States)

Campbell, Philip M.; Perini, Christopher J.; Chiu, Johannes; Gupta, Atul; Ray, Hunter S.; Chen, Hang; Wenzel, Kevin; Snyder, Eric; Wagner, Brent K.; Ready, Jud; Vogel, Eric M.

2018-03-01

There has been significant interest in transition metal dichalcogenides (TMDs), including MoS2, in recent years due to their potential application in novel electronic and optical devices. While synthesis methods have been developed for large-area films of MoS2, many of these techniques require synthesis temperatures of 800 °C or higher. As a result of the thermal budget, direct synthesis requiring high temperatures is incompatible with many integrated circuit processes as well as flexible substrates. This work explores several methods of plasma-assisted synthesis of MoS2 as a way to lower the synthesis temperature. The first approach used is conversion of a naturally oxidized molybdenum thin film to MoS2 using H2S plasma. Conversion is demonstrated at temperatures as low as 400 °C, and the conversion is enabled by hydrogen radicals which reduce the oxidized molybdenum films. The second method is a vapor phase reaction incorporating thermally evaporated MoO3 exposed to a direct H2S plasma, similar to chemical vapor deposition (CVD) synthesis of MoS2. Synthesis at 400 °C results in formation of super-stoichiometric MoS2 in a beam-interrupted growth process. A final growth method relies on a cyclical process in which a small amount of Mo is sputtered onto the substrate and is subsequently sulfurized in a H2S plasma. Similar results could be realized using an atomic layer deposition (ALD) process to deposit the Mo film. Compared to high temperature synthesis methods, the lower temperature samples are lower quality, potentially due to poor crystallinity or higher defect density in the films. Temperature-dependent conductivity measurements are consistent with hopping conduction in the plasma-assisted synthetic MoS2, suggesting a high degree of disorder in the low-temperature films. Optimization of the plasma-assisted synthesis process for slower growth rate and better stoichiometry is expected to lead to high quality films at low growth temperature.

Top-Emission Organic Light Emitting Diode Fabrication Using High Dissipation Graphite Substrate

Directory of Open Access Journals (Sweden)

Yu-Sheng Tsai

2014-01-01

Full Text Available This study uses a synthetic graphite fiber as the heat dissipation substrate for top-emission organic light emitting diode (TEOLED to reduce the impact from joule heat. UV glue (YCD91 was spin coated onto the substrate as the insulation layer. The TEOLED structure is (glass; copper; graphite substrate/YCD91 glue/Al/Au/EHI608/TAPC/Alq3/LiF/Al/Ag. The proposed graphite fiber substrate presents better luminous performance compared with glass and copper substrate devices with luminance of 3055 cd/m2 and current efficiency of 6.11 cd/A at 50 mA/cm2. When lighting period of different substrates TEOLED, the substrate case back temperature was observed using different lighting periods. A glass substrate element operating from 5 to 25 seconds at 3000 cd/m2 luminance produced a temperature rate of 1.207°C/sec. Under 4000 cd/m2 luminance the copper and graphite substrate temperature rates were 0.125°C/sec and 0.088°C/sec. Graphite component lifetime was determined to be 1.875 times higher than the glass components and 1.125 times higher than that of copper.

Mobility restrictions and glass transition behaviour of an epoxy resin under confinement.

Science.gov (United States)

Djemour, A; Sanctuary, R; Baller, J

2015-04-07

Confinement can have a big influence on the dynamics of glass formers in the vicinity of the glass transition. Already 40 to 50 K above the glass transition temperature, thermal equilibration of glass formers can be strongly influenced by the confining substrate. We investigate the linear thermal expansion and the specific heat capacity cp of an epoxy resin (diglycidyl ether of bisphenol A, DGEBA) in a temperature interval of 120 K around the glass transition temperature. The epoxy resin is filled into controlled pore glasses with pore diameters between 4 and 111 nm. Since DGEBA can form H-bonds with silica surfaces, we also investigate the influence of surface silanization of the porous substrates. In untreated substrates a core/shell structure of the epoxy resin can be identified. The glass transition behaviours of the bulk phase and that of the shell phase are different. In silanized substrates, the shell phase disappears. At a temperature well above the glass transition, a second transition is found for the bulk phase - both in the linear expansion data as well as in the specific heat capacity. The cp data do not allow excluding the glass transition of a third phase as being the cause for this transition, whereas the linear expansion data do so. The additional transition temperature is interpreted as a separation between two regimes: above this temperature, macroscopic flow of the bulk phase inside the porous structure is possible to balance the mismatch of thermal expansion coefficients between DGEBA and the substrate. Below the transition temperature, this degree of freedom is hindered by geometrical constraints of the porous substrates. Moreover, this second transition could also be found in the linear expansion data of the shell phase.

Properties of MoO3 thin film polymorphs

International Nuclear Information System (INIS)

McCarron, E.M.; Carcia, P.F.

1987-01-01

Thin film polymorphs of molybdenum trioxide have been synthesized by RF sputtering. Films deposited on thermally floating substrates are polycrystalline and exhibit preferred orientation. Depending upon the oxygen partial pressure maintained during sputtering, the films can be made to crystallize in either the thermodynamically stable orthorhombic α MoO 3 form (unique 2D-layered structure) or the metastable monoclinic β MoO 3 phase (3D ReO 3 -related structure). Metastable β films can be converted thermally to the α phase and the transformation appears topotactic. Films deposited on the cooled substrates are amorphous. A correlation between the particular phase formed and adatom mobility is noted

MBE growth of few-layer 2H-MoTe2 on 3D substrates

Science.gov (United States)

Vishwanath, Suresh; Sundar, Aditya; Liu, Xinyu; Azcatl, Angelica; Lochocki, Edward; Woll, Arthur R.; Rouvimov, Sergei; Hwang, Wan Sik; Lu, Ning; Peng, Xin; Lien, Huai-Hsun; Weisenberger, John; McDonnell, Stephen; Kim, Moon J.; Dobrowolska, Margaret; Furdyna, Jacek K.; Shen, Kyle; Wallace, Robert M.; Jena, Debdeep; Xing, Huili Grace

2018-01-01

MoTe2 is the least explored material in the Molybdenum-chalcogen family. Molecular beam epitaxy (MBE) provides a unique opportunity to tackle the small electronegativity difference between Mo and Te while growing layer by layer away from thermodynamic equilibrium. We find that for a few-layer MoTe2 grown at a moderate rate of ∼6 min per monolayer, a narrow window in temperature (above Te cell temperature) and Te:Mo ratio exists, where we can obtain pure phase 2H-MoTe2. This is confirmed using reflection high-energy electron diffraction (RHEED), Raman spectroscopy and X-ray photoemission spectroscopy (XPS). For growth on CaF2, Grazing incidence X-ray diffraction (GI-XRD) reveals a grain size of ∼90 Å and presence of twinned grains. In this work, we hypothesis the presence of excess Te incorporation in MBE grown few layer 2H-MoTe2. For film on CaF2, it is based on >2 Te:Mo stoichiometry using XPS as well as 'a' and 'c' lattice spacing greater than bulk 2H-MoTe2. On GaAs, its based on observations of Te crystallite formation on film surface, 2 × 2 superstructure observed in RHEED and low energy electron diffraction, larger than bulk c-lattice spacing as well as the lack of electrical conductivity modulation by field effect. Finally, thermal stability and air sensitivity of MBE 2H-MoTe2 is investigated by temperature dependent XRD and XPS, respectively.

Two-dimensional Si nanosheets with local hexagonal structure on a MoS(2) surface.

Science.gov (United States)

Chiappe, Daniele; Scalise, Emilio; Cinquanta, Eugenio; Grazianetti, Carlo; van den Broek, Bas; Fanciulli, Marco; Houssa, Michel; Molle, Alessandro

2014-04-02

The structural and electronic properties of a Si nanosheet (NS) grown onto a MoS2 substrate by means of molecular beam epitaxy are assessed. Epitaxially grown Si is shown to adapt to the trigonal prismatic surface lattice of MoS2 by forming two-dimensional nanodomains. The Si layer structure is distinguished from the underlying MoS2 surface structure. The local electronic properties of the Si nanosheet are dictated by the atomistic arrangement of the layer and unlike the MoS2 hosting substrate they are qualified by a gap-less density of states. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High performance multilayered nano-crystalline silicon/silicon-oxide light-emitting diodes on glass substrates

Energy Technology Data Exchange (ETDEWEB)

Darbari, S; Shahmohammadi, M; Mortazavi, M; Mohajerzadeh, S [Thin Film and Nano-Electronic Laboratory, School of ECE, University of Tehran, Tehran (Iran, Islamic Republic of); Abdi, Y [Nano-Physics Research Laboratory, Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of); Robertson, M; Morrison, T, E-mail: mohajer@ut.ac.ir [Department of Physics, Acadia University, Wolfville, NS (Canada)

2011-09-16

A low-temperature hydrogenation-assisted sequential deposition and crystallization technique is reported for the preparation of nano-scale silicon quantum dots suitable for light-emitting applications. Radio-frequency plasma-enhanced deposition was used to realize multiple layers of nano-crystalline silicon while reactive ion etching was employed to create nano-scale features. The physical characteristics of the films prepared using different plasma conditions were investigated using scanning electron microscopy, transmission electron microscopy, room temperature photoluminescence and infrared spectroscopy. The formation of multilayered structures improved the photon-emission properties as observed by photoluminescence and a thin layer of silicon oxy-nitride was then used for electrical isolation between adjacent silicon layers. The preparation of light-emitting diodes directly on glass substrates has been demonstrated and the electroluminescence spectrum has been measured.

Development of glass compositions with 9% waste content for the vitrification of high-level waste from LWR nuclear reactors

International Nuclear Information System (INIS)

Lakatos, T.

1979-10-01

Reduction of the contents of waste in glass from 20-25% to 9% causes a decrease of the leaching resistance of the glass. The addition of Zn0 reduces the leaching values by a factor of approximately 10. The crystallized glass ceramics have a lower coefficient of thermal expansion than glassy waste bodies. The separation of the phase which contains Mo occurs during heat treatment. The amount of separated Mo is lower for low alkali sac type (Si0 2 - A1 2 0 3 -Ca0 system) of glasses by a factor of approximately 50. All the glasses were prepared with simulated waste composition. (GBn.)

Liquid-Liquid Phase Separation in Model Nuclear Waste Glasses: A Solid-State Double-Resonance NMR Study

Energy Technology Data Exchange (ETDEWEB)

Martineau, Ch.; Michaelis, V.K.; Kroeker, S. [Univ Manitoba, Dept Chem, Winnipeg, MB R3T 2N2 (Canada); Schuller, S. [CEA Valrho Marcoule, LDMC, SECM, DTCD, DEN, F-30207 Bagnols Sur Ceze (France)

2010-07-01

Double-resonance nuclear magnetic resonance (NMR) techniques are used in addition to single-resonance NMR experiments to probe the degree of mixing between network-forming cations Si and B, along with the modifier cations Cs{sup +} and Na{sup +} in two molybdenum-bearing model nuclear waste glasses. The double-resonance experiments involving {sup 29}Si in natural abundance are made possible by the implementation of a CPMG pulse-train during the acquisition period of the usual REDOR experiments. For the glass with lower Mo content, the NMR results show a high degree of Si-B mixing, as well as an homogeneous distribution of the cations within the borosilicate network, characteristic of a non-phase-separated glass. For the higher-Mo glass, a decrease of B-Si(Q{sup 4}) mixing is observed, indicating phase separation. {sup 23}Na and {sup 133}Cs NMR results show that although the Cs{sup +} cations, which do not seem to be influenced by the molybdenum content, are spread within the borate network, there is a clustering of the Na{sup +} cations, very likely around the molybdate units. The segregation of a Mo-rich region with Na{sup +} cations appears to shift the bulk borosilicate glass composition toward the metastable liquid liquid immiscibility region and induce additional phase separation. Although no crystallization is observed in the present case, this liquid liquid phase separation is likely to be the first stage of crystallization that can occur at higher Mo loadings or be driven by heat treatment. From this study emerges a consistent picture of the nature and extent of such phase separation phenomena in Mo-bearing glasses, and demonstrates the potential of double-resonance NMR methods for the investigation of phase separation in amorphous materials. (authors)

Structure and tribological properties of MoS2 low friction thin films

Directory of Open Access Journals (Sweden)

Paradecka Agnieszka

2017-01-01

Full Text Available The main aim of the studies was the deposition of the AlCrN film, covered by molybdenum disulphide (MoS2 – based lubricant, on the austenitic steel substrate. The AlCrN and MoS2 layers were deposited by PVD lateral rotating ARC-cathodes (LARC and magnetron sputtering technology on the X6CrNiMoTi17-12-2 respectively. Structural characterizations of the MoS2 thin films have been carried out using SEM (scanning electron microscopy and AFM (atomic force microscopy to determine the surface topography as well as HRTEM (high-resolution transmission electron microscopy and Raman spectroscopy for structural investigations. The tribological wear relationships using ball-on-disc test were specified for surface layers, determining the friction co-efficient and mass loss of the investigated surfaces. Tests of the coatings’ adhesion to the substrate material were made using the scratch test. HRTEM investigation shows an amorphous character of the MoS2 layer. In sliding dry friction conditions, the friction co-efficient for the investigated elements is set in the range between 0.4-0.5. The investigated coating reveals high wear resistance. The coating demonstrated a dense cross-sectional morphology as well as good adhesion to the substrate. The good properties of the PVD AlCrN+MoS2 coatings make them suitable in various engineering and industrial applications.

High-quality substrate for fluorescence enhancement using agarose-coated silica opal film.

Science.gov (United States)

Xu, Ming; Li, Juan; Sun, Liguo; Zhao, Yuanjin; Xie, Zhuoying; Lv, Linli; Zhao, Xiangwei; Xiao, Pengfeng; Hu, Jing; Lv, Mei; Gu, Zhongze

2010-08-01

To improve the sensitivity of fluorescence detection in biochip, a new kind of substrates was developed by agarose coating on silica opal film. In this study, silica opal film was fabricated on glass substrate using the vertical deposition technique. It can provide stronger fluorescence signals and thus improve the detection sensitivity. After coating with agarose, the hybrid film could provide a 3D support for immobilizing sample. Comparing with agarose-coated glass substrate, the agarose-coated opal substrates could selectively enhance particular fluorescence signals with high sensitivity when the stop band of the silica opal film in the agarose-coated opal substrate overlapped the fluorescence emission wavelength. A DNA hybridization experiment demonstrated that fluorescence intensity of special type of agarose-coated opal substrates was about four times that of agarose-coated glass substrate. These results indicate that the optimized agarose-coated opal substrate can be used for improving the sensitivity of fluorescence detection with high quality and selectivity.

Investigation of sputtered Mo2BC hard coatings : correlation of nanostructure and mechanical properties

OpenAIRE

Gleich, Stephan

2017-01-01

This thesis is dedicated to the study of Mo2BC coatings on silicon substrates. According to reported ab initio calculations in literature, which predicted a high stiffness and a moderate ductile behavior for the material, Mo2BC is a predestinated candidate to act as hard coating layer. The focus in this thesis is set on the nanostructure of Mo2BC hard coatings explored by transmission electron microscopy as a function of the used substrate temperature, applied during the deposition process us...

An exploratory study of the effects of the dielectric-barrier-discharge surface pre-treatment on the self-assembly processes of a (3-Aminopropyl) trimethoxysilane on glass substrates

International Nuclear Information System (INIS)

Cui Naiyi; Liu Chaozong; Brown, Norman M.D.; Meenan, Brian J.

2007-01-01

X-ray photoelectron spectrometry (XPS), Fourier transform infrared spectrometry (FTIR), secondary-ion-mass spectrometry (SIMS) and contact angle measurement have been used in study of the enhancement effect of substrate pre-treatment by dielectric-barrier-discharge (DBD) for the self-assembly of a (3-Aminopropyl) trimethoxysilane (APTS) on glass substrates. In results, the concentration of the APTS molecules self-assembled on the surfaces of both the acetone-washed and the DBD-treated substrates were more than three times of that on the as-supplied substrate. Meanwhile, the self-assembly (SA) layers grown on the DBD-treated substrates have the best quality compared to those grown on the substrates pre-treated in other ways in terms of the silane-substrate bonding and the order of arrangement of the silane molecules

Vertical MoSe2-MoO x p-n heterojunction and its application in optoelectronics

Science.gov (United States)

Chen, Xiaoshuang; Liu, Guangbo; Hu, Yunxia; Cao, Wenwu; Hu, PingAn; Hu, Wenping

2018-01-01

The hybrid n-type 2D transition-metal dichalcogenide (TMD)/p-type oxide van der Waals (vdW) heterojunction nanosheets consist of 2D layered MoSe2 (the n-type 2D material) and MoO x (the p-type oxide) which are grown on SiO2/Si substrates for the first time via chemical vapor deposition technique, displaying the regular hexagon structures with the average length dimension of sides of ˜8 μm. Vertical MoSe2-MoO x p-n heterojunctions demonstrate obviously current-rectifying characteristic, and it can be tuned via gate voltage. What is more, the photodetector based on vertical MoSe2-MoO x heterojunctions displays optimal photoresponse behavior, generating the responsivity, detectivity, and external quantum efficiency to 3.4 A W-1, 0.85 × 108 Jones, and 1665.6%, respectively, at V ds = 5 V with the light wavelength of 254 nm under 0.29 mW cm-2. These results furnish a building block on investigating the flexible and transparent properties of vdW and further optimizing the structure of the devices for better optoelectronic and electronic performance.

Growth of CdS thin films on indium coated glass substrates via chemical bath deposition and subsequent air annealing

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Biswajit; Kumar, Kamlesh; Singh, Balwant Kr; Banerjee, Pushan; Das, Subrata, E-mail: neillohit@yahoo.co.in

2014-11-30

Graphical abstract: - Highlights: • CdS film grown on indium coated glass substrates via CBD and subsequent annealing. • Disappearance of the indium (1 1 2) peak confirms interdiffusion at 300 °C. • SIMS indicates the subsequent interdiffusion at progressively higher temperature. • Composite In–CdS layer showed lower photosensitivity compared to pure CdS. - Abstract: In the present work attempts were made to synthesize indium doped CdS films by fabricating In/CdS bilayers using CBD-CdS on vacuum evaporated In thin films and subsequent air annealing. 135 nm CdS films were grown onto 20 nm and 35 nm indium coated glass substrate employing chemical bath deposition technique. The In/CdS bilayers thus formed were subjected to heat treatment at the temperatures between 200 and 400 °C for 4 min in the muffle furnace to facilitate indium to diffuse into the CdS films. XRD pattern ascertained no noticeable shift in lattice constant implying grain boundary metal segregation, while secondary ion mass spectrometry indicated the diffusion profile of indium into CdS matrices. Mass spectrometry results showed that substantial diffusion of indium had been taken place within CdS at 400 °C. Dark and photocurrent with different illumination time were measured to ascertain the photosensitivity of pure and composite CdS films.

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

Directory of Open Access Journals (Sweden)

Anjaiah J.

2015-03-01

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

Transverse and longitudinal electrooptic properties of highly (100) oriented Pb(Zr,Ti)O{sub 3} films grown on glass substrates

Energy Technology Data Exchange (ETDEWEB)

Choi, Jong-Jin [Department of Future Technology, Korea Institute of Machinery and Materials, 66 Sang-Nam Dong, Chang-Won, Gyeong-Nam, 641-010 (Korea, Republic of) and School of Materials Science and Engineering, Seoul National University, Seoul, 151-742 (Korea, Republic of)]. E-mail: finaljin@kmail.kimm.re.kr; Park, Gun-Tae [School of Materials Science and Engineering, Seoul National University, Seoul, 151-742 (Korea, Republic of); Kim, Hyoun-Ee [School of Materials Science and Engineering, Seoul National University, Seoul, 151-742 (Korea, Republic of); Kim, Dal-Young [Department of Visual Optics, Seoul National University of Technology, 172 Gongreung 2-dong, Nowon-gu, Seoul 139-743 (Korea, Republic of)

2006-12-05

The Pb(Zr,Ti)O{sub 3} [PZT] films with a preferred orientation generally have columnar texture. Because the properties of a PZT film are strongly dependent on its crystallographic direction, the electrooptic properties along the longitudinal and transverse direction are expected to be anisotropic. In this study, highly (100) oriented PZT films were grown on glass and ITO (Indium Tin Oxide) coated glass substrates using the sol-gel multi-coating method with lanthanum nitrate and lanthanum nickel nitrate as buffer layers. The longitudinal and transverse electrooptic properties of the textured films were characterized by transmission-mode measuring equipment with a Senarmont compensator using a sample tilting method. The calculated longitudinal and transverse electrooptic coefficients of the highly (100) oriented PZT films were 147 and 250 pm/V, respectively.

The effects of crystallization and residual glass on the chemical durability of iron phosphate waste forms containing 40 wt% of a high MoO3 Collins-CLT waste

Science.gov (United States)

Hsu, Jen-Hsien; Bai, Jincheng; Kim, Cheol-Woon; Brow, Richard K.; Szabo, Joe; Zervos, Adam

2018-03-01

The effects of cooling rate on the chemical durability of iron phosphate waste forms containing up to 40 wt% of a high MoO3 Collins-CLT waste simulant were determined at 90 °C using the product consistency test (PCT). The waste form, designated 40wt%-5, meets appropriate Department of Energy (DOE) standards when rapidly quenched from the melt (as-cast) and after slow cooling following the CCC (canister centerline cooling)-protocol, although the quenched glass is more durable. The analysis of samples from the vapor hydration test (VHT) and the aqueous corrosion test (differential recession test) reveals that rare earth orthophosphate (monazite) and Zr-pyrophosphate crystals that form on cooling are more durable than the residual glass in the 40wt%-5 waste form. The residual glass in the CCC-treated samples has a greater average phosphate chain length and a lower Fe/P ratio, and those contribute to its faster corrosion kinetics.

Formation of bulk metallic glasses in the Fe-M-Y-B (M = transition metal) system

Energy Technology Data Exchange (ETDEWEB)

Huang, X.M. [International Center for New-Structured Materials (ICNSM) and Laboratory of New-Structured Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Chang, C.T. [Institute for Material Research, Tohoku University, Sendai 980-8577 (Japan); Chang, Z.Y.; Wang, X.D.; Cao, Q.P. [International Center for New-Structured Materials (ICNSM) and Laboratory of New-Structured Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Shen, B.L.; Inoue, A. [Institute for Material Research, Tohoku University, Sendai 980-8577 (Japan); Jiang, J.Z. [International Center for New-Structured Materials (ICNSM) and Laboratory of New-Structured Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)], E-mail: jiangjz@zju.edu.cn

2008-07-28

In this work, quaternary Fe{sub 72-x}M{sub x}Y{sub 6}B{sub 22} (M = Ni, Co and Mo) bulk metallic glasses (BMGs) have been developed. It is found that a fully amorphous Fe{sub 68}Mo{sub 4}Y{sub 6}B{sub 22} cylindrical rod with 6.5 mm in diameter can be prepared by copper mold injection. These alloys have a high glass transition temperature of about 900 K with high fracture strengths up to about 3 GPa although they are still brittle. Magnetic measurements reveal that they are ferromagnetic at ambient temperature with low coercive force of about 2 A/m, saturation magnetization of about 0.7 T and effective permeability of about 7000 at 100 kHz. The newly developed Fe-based quaternary alloys exhibit excellent combination properties: superior glass forming ability (GFA), high glass transition temperature, and soft magnetic properties, which could have potential applications in electronic industries. Furthermore, the effect of Mo addition on GFA in the Fe-Y-B BMG system has been discussed compared with those of Ni and Co additions.

Microstructural and Optical Properties of Porous Alumina Elaborated on Glass Substrate

Science.gov (United States)

Zaghdoudi, W.; Gaidi, M.; Chtourou, R.

2013-03-01

A transparent porous anodized aluminum oxide (AAO) nanostructure was formed on a glass substrate using the anodization of a highly pure evaporated aluminum layer. A parametric study was carried out in order to achieve a fine control of the microstructural and optical properties of the elaborated films. The microstructural and surface morphologies of the porous alumina films were characterized by x-ray diffraction and atomic force microscopy. Pore diameter, inter-pore separation, and the porous structure as a function of anodization conditions were investigated. It was then found that the pores density decreases with increasing the anodization time. Regular cylindrical porous AAO films with a flat bottom structure were formed by chemical etching and anodization. A high transmittance in the 300-900 nm range is reported, indicating a fulfilled growth of the transparent sample (alumina) from the aluminum metal. The data showed typical interference oscillations as a result of the transparent characteristics of the film throughout the visible spectral range. The thickness and the optical constants ( n and k) of the porous anodic alumina films, as a function of anodizing time, were obtained using spectroscopic ellipsometry in the ultraviolet-visible-near infrared (UV-vis-NIR) regions.

Transistors using crystalline silicon devices on glass

Science.gov (United States)

McCarthy, Anthony M.

1995-01-01

A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

Synthesis and properties of ultra-long InP nanowires on glass.

Science.gov (United States)

Dhaka, Veer; Pale, Ville; Khayrudinov, Vladislav; Kakko, Joona-Pekko; Haggren, Tuomas; Jiang, Hua; Kauppinen, Esko; Lipsanen, Harri

2016-12-16

We report on the synthesis of Au-catalyzed InP nanowires (NWs) on low-cost glass substrates. Ultra-dense and ultra-long (up to ∼250 μm) InP NWs, with an exceptionally high growth rate of ∼25 μm min -1 , were grown directly on glass using metal organic vapor phase epitaxy (MOVPE). Structural properties of InP NWs grown on glass were similar to the ones grown typically on Si substrates showing many structural twin faults but the NWs on glass always exhibited a stronger photoluminescence (PL) intensity at room temperature. The PL measurements of NWs grown on glass reveal two additional prominent impurity related emission peaks at low temperature (10 K). In particular, the strongest unusual emission peak with an activation energy of 23.8 ± 2 meV was observed at 928 nm. Different possibilities including the role of native defects (phosphorus and/or indium vacancies) are discussed but most likely the origin of this PL peak is related to the impurity incorporation from the glass substrate. Furthermore, despite the presence of suspected impurities, the NWs on glass show outstanding light absorption in a wide spectral range (60%-95% for λ = 300-1600 nm). The optical properties and the NW growth mechanism on glass is discussed qualitatively. We attribute the exceptionally high growth rate mostly to the atmospheric pressure growth conditions of our MOVPE reactor and stronger PL intensity on glass due to the impurity doping. Overall, the III-V NWs grown on glass are similar to the ones grown on semiconductor substrates but offer additional advantages such as low-cost and light transparency.

Effect of Radiation on Silicon and Borosilicate Glass

National Research Council Canada - National Science Library

Allred, Clark

2003-01-01

.... These two glasses are commonly used as substrates for silicon microelectromechanical (MEMS) devices, and radiation-induced compaction in a substrate can have deleterious effects on device performance...

Gold nano-particles fixed on glass

International Nuclear Information System (INIS)

Worsch, Christian; Wisniewski, Wolfgang; Kracker, Michael; Rüssel, Christian

2012-01-01

Highlights: ► We produced wear resistant gold–ruby coatings on amorphous substrates. ► Thin sputtered gold layers were covered by or embedded in silica coatings. ► Annealing above T g of the substrate glass led to the formation of gold nano particles. ► A 1 1 1-texture of the gold particles is observed via XRD and EBSD. ► EBSD-patterns can be acquired from crystals covered by a thin layer of glass. - Abstract: A simple process for producing wear resistant gold nano-particle coatings on transparent substrates is proposed. Soda-lime-silica glasses were sputtered with gold and subsequently coated with SiO 2 using a combustion chemical vapor deposition technique. Some samples were first coated with silica, sputtered with gold and then coated with a second layer of silica. The samples were annealed for 20 min at either 550 or 600 °C. This resulted in the formation of round, well separated gold nano-particles with sizes from 15 to 200 nm. The color of the coated glass was equivalent to that of gold–ruby glasses. Silica/gold/silica coatings annealed at 600 °C for 20 min were strongly adherent and scratch resistant. X-ray diffraction and electron backscatter diffraction (EBSD) were used to describe the crystal orientations of the embedded particles. The gold particles are preferably oriented with their (1 1 1) planes perpendicular to the surface.

Large-area MoS2 grown using H2S as the sulphur source

International Nuclear Information System (INIS)

Dumcenco, Dumitru; Ovchinnikov, Dmitry; Lopez Sanchez, Oriol; Kis, Andras; Gillet, Philippe; Alexander, Duncan T L; Lazar, Sorin; Radenovic, Aleksandra

2015-01-01

We report on the growth of molybdenum disulphide (MoS 2 ) using H 2 S as a gas-phase sulfur precursor that allows controlling the domain growth direction of domains in both vertical (perpendicular to the substrate plane) and horizontal (within the substrate plane), depending on the H 2 S:H 2 ratio in the reaction gas mixture and temperature at which they are introduced during growth. Optical and atomic force microscopy measurements on horizontal MoS 2 demonstrate the formation of monolayer triangular-shape domains that merge into a continuous film. Scanning transmission electron microscopy of monolayer MoS 2 shows a regular atomic structure with a hexagonal symmetry. Raman and photoluminescence spectra confirm the monolayer thickness of the material. Field-effect transistors fabricated on MoS 2 domains that are transferred onto Si/SiO 2 substrates show a mobility similar to previously reported exfoliated and chemical vapor deposition-grown materials. (paper)

Heterogeneous Nucleation of Colloidal Crystals on a Glass Substrate with Depletion Attraction.

Science.gov (United States)

Guo, Suxia; Nozawa, Jun; Hu, Sumeng; Koizumi, Haruhiko; Okada, Junpei; Uda, Satoshi

2017-10-10

The heterogeneous nucleation of colloidal crystals with attractive interactions has been investigated via in situ observations. We have found two types of nucleation processes: a cluster that overcomes the critical size for nucleation with a monolayer, and a method that occurs with two layers. The Gibbs free energy changes (ΔG) for these two types of nucleation processes are evaluated by taking into account the effect of various interfacial energies. In contrast to homogeneous nucleation, the change in interfacial free energy, Δσ, is generated for colloidal nucleation on a foreign substrate such as a cover glass in the present study. The Δσ and step free energy of the first layer, γ 1 , are obtained experimentally based on the equation deduced from classical nucleation theory (CNT). It is concluded that the ΔG of q-2D nuclei is smaller than of monolayer nuclei, provided that the same number of particles are used, which explains the experimental result that the critical size in q-2D nuclei is smaller than that in monolayer nuclei.

Amorphous-crystalline transition studied in hydrated MoO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Camacho-Lopez, M.A. [Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Paseo Colon y Tollocan, Toluca Edo. de Mexico 50110 (Mexico); Haro-Poniatowski, E. [Departamento de Fisica, Laboratorio de Optica Cuantica, Universidad Autonoma Metropolitana-Iztapalapa, Apdo. Postal 55-534, Mexico, D.F. 09340 (Mexico); Lartundo-Rojas, L. [Laboratorio de Microscopia, Universidad Autonoma Metropolitana-Iztapalapa, Apdo. Postal 55-534, Mexico, D.F. 09340 (Mexico); Livage, J. [Chimie de la Matiere Condensee, Universite Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Julien, C.M. [Institut des Nano-Sciences de Paris, UMR 7588, Universite Pierre et Marie Curie, Campus Boucicaut, 140 rue de Lourmel, 75015 Paris (France)]. E-mail: Christian.Julien@insp.jussieu.fr

2006-11-25

In this work we study the thermal behavior of hydrated MoO{sub 3} synthesized via acidification of sodium molybdate. MoO{sub 3}.nH{sub 2}O (n = 1.4) amorphous compound was heated in air at increasing temperatures in order to obtain the crystalline MoO{sub 3} phase. We have studied the structural changes as a function of annealing temperature by Raman spectroscopy. A statistical study to determine the average size of the crystallites at each annealing step has been realized by scanning electron microscopy. Results show that the hydrated MoO{sub 3}.1.4H{sub 2}O glass transforms in an amorphous MoO{sub 3}.0.7H{sub 2}O phase prior to its crystallization, while the sample heated at 500 deg. C crystallizes into the orthorhombic {alpha}-MoO{sub 3} phase with micro-crystallites having an average size of 6.8 {mu}m.

Isothermal and dynamic oxidation behaviour of Mo-W doped carbon-based coating

Science.gov (United States)

Mandal, Paranjayee; Ehiasarian, Arutiun P.; Hovsepian, Papken Eh.

2015-10-01

The oxidation behaviour of Mo-W doped carbon-based coating (Mo-W-C) is investigated in elevated temperature (400-1000 °C). Strong metallurgical bond between Mo-W-C coating and substrate prevents any sort of delamination during heat-treatment. Isothermal oxidation tests show initial growth of metal oxides at 500 °C, however graphitic nature of the as-deposited coating is preserved. The oxidation progresses with further rise in temperature and the substrate is eventually exposed at 700 °C. The performance of Mo-W-C coating is compared with a state-of-the-art DLC(Cr/Cr-WC/W:C-H/a:C-H) coating, which shows preliminary oxidation at 400 °C and local delamination of the coating at 500 °C leading to substrate exposure. The graphitisation starts at 400 °C and the diamond-like structure is completely converted into the graphite-like structure at 500 °C. Dynamic oxidation behaviour of both the coatings is investigated using Thermo-gravimetric analysis carried out with a slow heating rate of 1 °C/min from ambient temperature to 1000 °C. Mo-W-C coating resists oxidation up to ˜800 °C whereas delamination of DLC(Cr/Cr-WC/W:C-H/a:C-H) coating is observed beyond ˜380 °C. In summary, Mo-W-C coating provides improved oxidation resistance at elevated temperature compared to DLC(Cr/Cr-WC/W:C-H/a:C-H) coating.

Noise origin of Co-Cr-Ta films on ultra-flat glass-ceramic and Si substrates for longitudinal recording disks

International Nuclear Information System (INIS)

Noda, Kohki; Kadokura, Sadao; Naoe, Masahiko

2001-01-01

Co 85 Cr 13 Ta 2 /Cr bilayered films for longitudinal recording disks were deposited by plasma-enhanced facing targets sputtering apparatus on 2.5 in and ultra-flat disk substrates of glass-ceramic and single-crystal silicon. Their noise and read/write characteristics were almost comparable with those of the high-performance disks using Co-Cr-Pt films, with coercivity H c of 2.4 kOe, as a reference disk, even though the Co-Cr-Ta films exhibited macroscopic H c of only 800 Oe. Co 85 Cr 13 Ta 2 films are known as low-noise media. This study addresses the problem of how to obtain low-noise media, using excellent sputtering apparatus and disk substrate materials, to allow practical applications in ultra-high-density recording systems, including 1 in microdrives for mobile applications

Research on Glass Frit Deposition Based on the Electrospray Process

Directory of Open Access Journals (Sweden)

Yifang Liu

2016-04-01

Full Text Available In this paper, the electrospray technology is used to easily deposit the glass frit into patterns at a micro-scale level. First, far-field electrospray process was carried out with a mixture of glass frit in the presence of ethanol. A uniform, smooth, and dense glass frit film was obtained, verifying that the electrospray technology was feasible. Then, the distance between the nozzle and the substrate was reduced to 2 mm to carry out near-field electrospray. The experimental process was improved by setting the range of the feed rate of the substrate to match both the concentration and the flow rate of the solution. Spray diameter could be less at the voltage of 2 kV, in which the glass frit film was expected to reach the minimum line width. A uniform glass frit film with a line width within the range of 400–500 μm was prepared when the speed of the substrate was 25 mm/s. It indicates that electrospray is an efficient technique for the patterned deposition of glass frit in wafer-level hermetic encapsulation.

Epitaxial Single-Layer MoS2 on GaN with Enhanced Valley Helicity

KAUST Repository

Wan, Yi

2017-12-19

Engineering the substrate of 2D transition metal dichalcogenides can couple the quasiparticle interaction between the 2D material and substrate, providing an additional route to realize conceptual quantum phenomena and novel device functionalities, such as realization of a 12-time increased valley spitting in single-layer WSe2 through the interfacial magnetic exchange field from a ferromagnetic EuS substrate, and band-to-band tunnel field-effect transistors with a subthreshold swing below 60 mV dec−1 at room temperature based on bilayer n-MoS2 and heavily doped p-germanium, etc. Here, it is demonstrated that epitaxially grown single-layer MoS2 on a lattice-matched GaN substrate, possessing a type-I band alignment, exhibits strong substrate-induced interactions. The phonons in GaN quickly dissipate the energy of photogenerated carriers through electron–phonon interaction, resulting in a short exciton lifetime in the MoS2/GaN heterostructure. This interaction enables an enhanced valley helicity at room temperature (0.33 ± 0.05) observed in both steady-state and time-resolved circularly polarized photoluminescence measurements. The findings highlight the importance of substrate engineering for modulating the intrinsic valley carriers in ultrathin 2D materials and potentially open new paths for valleytronics and valley-optoelectronic device applications.

Epitaxial Single-Layer MoS2 on GaN with Enhanced Valley Helicity

KAUST Repository

Wan, Yi; Xiao, Jun; Li, Jingzhen; Fang, Xin; Zhang, Kun; Fu, Lei; Li, Pan; Song, Zhigang; Zhang, Hui; Wang, Yilun; Zhao, Mervin; Lu, Jing; Tang, Ning; Ran, Guangzhao; Zhang, Xiang; Ye, Yu; Dai, Lun

2017-01-01

Engineering the substrate of 2D transition metal dichalcogenides can couple the quasiparticle interaction between the 2D material and substrate, providing an additional route to realize conceptual quantum phenomena and novel device functionalities, such as realization of a 12-time increased valley spitting in single-layer WSe2 through the interfacial magnetic exchange field from a ferromagnetic EuS substrate, and band-to-band tunnel field-effect transistors with a subthreshold swing below 60 mV dec−1 at room temperature based on bilayer n-MoS2 and heavily doped p-germanium, etc. Here, it is demonstrated that epitaxially grown single-layer MoS2 on a lattice-matched GaN substrate, possessing a type-I band alignment, exhibits strong substrate-induced interactions. The phonons in GaN quickly dissipate the energy of photogenerated carriers through electron–phonon interaction, resulting in a short exciton lifetime in the MoS2/GaN heterostructure. This interaction enables an enhanced valley helicity at room temperature (0.33 ± 0.05) observed in both steady-state and time-resolved circularly polarized photoluminescence measurements. The findings highlight the importance of substrate engineering for modulating the intrinsic valley carriers in ultrathin 2D materials and potentially open new paths for valleytronics and valley-optoelectronic device applications.

Bioactive Glass Nanoparticles-Loaded Poly(ɛ-caprolactone Nanofiber as Substrate for ARPE-19 Cells

Directory of Open Access Journals (Sweden)

Tadeu Henrique Lima

2016-01-01

Full Text Available Bioactive glass nanoparticles-loaded poly(ɛ-caprolactone nanofibers (BIOG PCL nanofibers were synthesized and evaluated as substrates for ocular cells (ARPE-19. BIOG PCL nanofibers were characterized using SEM, FTIR, and DSC, and the in vitro degradation profile was also investigated. The in vitro ocular biocompatibility of nanofibers was exploited in Müller glial cells (MIO-M1 cells and in chorioallantoic membrane (CAM; and the proliferative capacity, cytotoxicity, and functionality were evaluated. Finally, ARPE-19 cells were seeded onto BIOG PCL nanofibers and they were investigated as supports for in vitro cell adhesion and proliferation. SEM images revealed the incorporation of BIOG nanoparticles into PCL nanofibers. Nanoparticles did not induce modifications in the chemical structure and semicrystalline nature of PCL in the nanofiber, as shown by FTIR and DSC. MIO-M1 cells exposed to BIOG PCL nanofibers showed viability, and they were able to proliferate and to express GFAP, indicating cellular functionality. Moreover, nanofibers were well tolerated by CAM. These findings suggested the in vitro ocular biocompatibility and absence of toxicity of these nanofibers. Finally, the BIOG nanoparticles modulated the protein adsorption, and, subsequently, ARPE-19 cells adhered and proliferated onto the nanostructured supports, establishing cell-substrate interactions. In conclusion, the biodegradable and biocompatible BIOG PCL nanofibers supported the ARPE-19 cells.

Micropatterning of biomolecules on a glass substrate in fused silica microchannels by using photolabile linker-based surface activation

International Nuclear Information System (INIS)

Jang, K.; Mawatari, K.; Kitamori, T.; Xu, Y.; Sato, K.; Tanaka, Y.

2012-01-01

We report on a straightforward method for creating micropatterns of multiple biomolecules. The anti-fouling agent 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer and a photolabile linker (PL) were covalently linked to an amino-terminated silane surface. Patterns were generated by selective removal of the MPC polymer via UV irradiation. Multiple micropatterns of fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (BSA) and rhodamine-labeled goat fragment antigen-binding fragments (FAB) were deposited on a same glass substrate. We also employed micropatterning of multiple biomolecules in that Texas red-labeled BSA and FITC-labeled rabbit anti-mouse IgG were placed inside a microchannel. (author)

Rational growth of semi-polar ZnO texture on a glass substrate for optoelectronic applications

Science.gov (United States)

Lu, B.; Ma, M. J.; Ye, Y. H.; Lu, J. G.; He, H. P.; Ye, Z. Z.

2013-02-01

Semi-polar ZnO films with surface texture were grown on glass substrates via pulsed-laser deposition (PLD) through Co-Ga co-doping. Oxygen pressure (PO2) was found to have significant effects on the structural and optical properties of the Zn(Co, Ga)O (ZCGO) films. A self-textured film with (1\\,0\\,\\bar {1}\\,1) preferred orientation (PO) was achieved by varying the growth conditions including a crucial narrow PO2 window and growth time. A possible mechanism underlying the PO evolution and the final texture of the films was proposed, which can be attributed to the collaboration of the doping effect and the PO2-dependent evolutionary selection process, in which certain grains can have increased vertical growth rate with respect to the substrate surface through interplane diffusion. Moreover, the growth of undoped pure ZnO films proceeded by using the (1\\,0\\,\\bar {1}\\,1) ZCGO film as a buffer layer. The ZnO layers retained a semi-polar characteristic with improved crystallinity and better optical quality. The epitaxy-like orientation of ZnO layers grown on (1\\,0\\,\\bar {1}\\,1) ZCGO films has applications in the development of semi-polar ZnO-based light-emitting diodes.

Crystallization kinetics of BaO-Al2O3-SiO2 glasses

Science.gov (United States)

Bansal, Narottam P.; Hyatt, Mark J.

1989-01-01

Barium aluminosilicate glasses are being investigated as matrix materials in high-temperature ceramic composites for structural applications. Kinetics of crystallization of two refractory glass compositions in the barium aluminosilicate system were studied by differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). From variable heating rate DTA, the crystallization activation energies for glass compositions (wt percent) 10BaO-38Al2O3-51SiO2-1MoO3 (glass A) and 39BaO-25Al2O3-35SiO2-1MoO3 (glass B) were determined to be 553 and 558 kJ/mol, respectively. On thermal treatment, the crystalline phases in glasses A and B were identified as mullite (3Al2O3-2SiO2) and hexacelsian (BaO-Al2O3-2SiO2), respectively. Hexacelsian is a high-temperature polymorph which is metastable below 1590 C. It undergoes structural transformation into the orthorhombic form at approximately 300 C accompanied by a large volume change which is undesirable for structural applications. A process needs to be developed where stable monoclinic celsian, rather than hexacelsian, precipitates out as the crystal phase in glass B.

Oxidation behaviour of metallic glass foams

Energy Technology Data Exchange (ETDEWEB)

Barnard, B.R. [Department of Materials Science and Engineering, 434 Dougherty Hall, University of Tennessee, Knoxville, TN 37996-2200 (United States)], E-mail: bbarnard@utk.edu; Liaw, P.K. [Department of Materials Science and Engineering, 434 Dougherty Hall, University of Tennessee, Knoxville, TN 37996-2200 (United States); Demetriou, M.D.; Johnson, W.L. [Department of Materials Science, Keck Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

2008-08-15

In this study, the effects of porosity on the oxidation behaviour of bulk-metallic glasses were investigated. Porous Pd- and Fe-based bulk-metallic glass (BMG) foams and Metglas ribbons were studied. Oxidizing experiments were conducted at 70 deg. C, and around 80 deg. C below glass-transition temperatures, (T{sub g}s). Scanning-electron microscopy/energy-dispersive spectroscopy (SEM/EDS) studies revealed little evidence of oxidation at 70 deg. C. Specimens exhibited greater oxidation at T{sub g} - 80 deg. C. Oxides were copper-based for Pd-based foams, Fe-, Cr-, and Mo-based for Fe-based foams, and Co-based with borosilicates likely for the Metglas. Pd-based foams demonstrated the best oxidation resistance, followed by Metglas ribbons, followed by Fe-based foams.

Toward the growth of an aligned single-layer MoS2 film.

Science.gov (United States)

Kim, Daeho; Sun, Dezheng; Lu, Wenhao; Cheng, Zhihai; Zhu, Yeming; Le, Duy; Rahman, Talat S; Bartels, Ludwig

2011-09-20

Molybdenum disulfide (molybdenite) monolayer islands and flakes have been grown on a copper surface at comparatively low temperature and mild conditions through sulfur loading of the substrate using thiophenol (benzenethiol) followed by the evaporation of Mo atoms and annealing. The MoS(2) islands show a regular Moiré pattern in scanning tunneling microscopy, attesting to their atomic ordering and high quality. They are all aligned with the substrate high-symmetry directions providing for rotational-domain-free monolayer growth. © 2011 American Chemical Society

Large Area Deposition of MoS2 by Pulsed Laser Deposition with In-Situ Thickness Control

KAUST Repository

Serna, Martha I.

2016-05-24

A scalable and catalyst-free method to deposit stoichiometric Molybdenum Disulfide (MoS2) films over large areas is reported with the maximum area limited by the size of the substrate holder. The method allows deposition of MoS2 layers on a wide range of substrates without any additional surface preparation including single crystals (sapphire and quartz), polycrystalline (HfO2), and amorphous (SiO2). The films are deposited using carefully designed MoS2 targets fabricated with excess of sulfur (S) and variable MoS2 and S particle size. Uniform and layered MoS2 films as thin as two monolayers, with an electrical resistivity of 1.54 × 104 Ω cm-1 were achieved. The MoS2 stoichiometry was as confirmed by High Resolution Rutherford Backscattering Spectrometry (HRRBS). With the method reported here, in situ graded MoS2 films ranging from ~1 to 10 monolayers can also be deposited.

Large Area Deposition of MoS2 by Pulsed Laser Deposition with In-Situ Thickness Control

KAUST Repository

Serna, Martha I.; Yoo, Seong H.; Moreno, Salvador; Xi, Yang; Oviedo, Juan Pablo; Choi, Hyunjoo; Alshareef, Husam N.; Kim, Moon J.; Minary-Jolandan, Majid; Quevedo-Lopez, Manuel A.

2016-01-01

A scalable and catalyst-free method to deposit stoichiometric Molybdenum Disulfide (MoS2) films over large areas is reported with the maximum area limited by the size of the substrate holder. The method allows deposition of MoS2 layers on a wide range of substrates without any additional surface preparation including single crystals (sapphire and quartz), polycrystalline (HfO2), and amorphous (SiO2). The films are deposited using carefully designed MoS2 targets fabricated with excess of sulfur (S) and variable MoS2 and S particle size. Uniform and layered MoS2 films as thin as two monolayers, with an electrical resistivity of 1.54 × 104 Ω cm-1 were achieved. The MoS2 stoichiometry was as confirmed by High Resolution Rutherford Backscattering Spectrometry (HRRBS). With the method reported here, in situ graded MoS2 films ranging from ~1 to 10 monolayers can also be deposited.

DNA origami deposition on native and passivated molybdenum disulfide substrates

Directory of Open Access Journals (Sweden)

Xiaoning Zhang

2014-04-01

Full Text Available Maintaining the structural fidelity of DNA origami structures on substrates is a prerequisite for the successful fabrication of hybrid DNA origami/semiconductor-based biomedical sensor devices. Molybdenum disulfide (MoS2 is an ideal substrate for such future sensors due to its exceptional electrical, mechanical and structural properties. In this work, we performed the first investigations into the interaction of DNA origami with the MoS2 surface. In contrast to the structure-preserving interaction of DNA origami with mica, another atomically flat surface, it was observed that DNA origami structures rapidly lose their structural integrity upon interaction with MoS2. In a further series of studies, pyrene and 1-pyrenemethylamine, were evaluated as surface modifications which might mitigate this effect. While both species were found to form adsorption layers on MoS2 via physisorption, 1-pyrenemethylamine serves as a better protective agent and preserves the structures for significantly longer times. These findings will be beneficial for the fabrication of future DNA origami/MoS2 hybrid electronic structures.

Control of biaxial strain in single-layer molybdenite using local thermal expansion of the substrate

Science.gov (United States)

Plechinger, Gerd; Castellanos-Gomez, Andres; Buscema, Michele; van der Zant, Herre S. J.; Steele, Gary A.; Kuc, Agnieszka; Heine, Thomas; Schüller, Christian; Korn, Tobias

2015-03-01

Single-layer MoS2 is a direct-gap semiconductor whose electronic band structure strongly depends on the strain applied to its crystal lattice. While uniaxial strain can be easily applied in a controlled way, e.g., by bending of a flexible substrate with the atomically thin MoS2 layer on top, experimental realization of biaxial strain is more challenging. Here, we exploit the large mismatch between the thermal expansion coefficients of MoS2 and a silicone-based substrate to apply a controllable biaxial tensile strain by heating the substrate with a focused laser. The effect of this biaxial strain is directly observable in optical spectroscopy as a redshift of the MoS2 photoluminescence. We also demonstrate the potential of this method to engineer more complex strain patterns by employing highly absorptive features on the substrate to achieve non-uniform heat profiles. By comparison of the observed redshift to strain-dependent band structure calculations, we estimate the biaxial strain applied by the silicone-based substrate to be up to 0.2%, corresponding to a band gap modulation of 105 meV per percentage of biaxial tensile strain.

Stability of perovskite solar cells on flexible substrates

Science.gov (United States)

Tam, Ho Won; Chen, Wei; Liu, Fangzhou; He, Yanling; Leung, Tik Lun; Wang, Yushu; Wong, Man Kwong; Djurišić, Aleksandra B.; Ng, Alan Man Ching; He, Zhubing; Chan, Wai Kin; Tang, Jinyao

2018-02-01

Perovskite solar cells are emerging photovoltaic technology with potential for low cost, high efficiency devices. Currently, flexible devices efficiencies over 15% have been achieved. Flexible devices are of significant interest for achieving very low production cost via roll-to-roll processing. However, the stability of perovskite devices remains a significant challenge. Unlike glass substrate which has negligible water vapor transmission rate (WVTR), polymeric flexible film substrates suffer from high moisture permeability. As PET and PEN flexible substrates exhibit higher water permeability then glass, transparent flexible backside encapsulation should be used to maximize light harvesting in perovskite layer while WVTR should be low enough. Wide band gap materials are transparent in the visible spectral range low temperature processable and can be a moisture barrier. For flexible substrates, approaches like atomic layer deposition (ALD) and low temperature solution processing could be used for metal oxide deposition. In this work, ALD SnO2, TiO2, Al2O3 and solution processed spin-on-glass was used as the barrier layer on the polymeric side of indium tin oxide (ITO) coated PEN substrates. The UV-Vis transmission spectra of the prepared substrates were investigated. Perovskite solar cells will be fabricated and stability of the devices were encapsulated with copolymer films on the top side and tested under standard ISOS-L-1 protocol and then compared to the commercial unmodified ITO/PET or ITO/PEN substrates. In addition, devices with copolymer films laminated on both sides successfully surviving more than 300 hours upon continuous AM1.5G illumination were demonstrated.

Structural and electrical properties of iron molybdenum phosphate glasses

International Nuclear Information System (INIS)

De Oliveira, R.S.; Quixada-Ceara, Univ. Estadual do Ceara; De Paiva, J.A.C.; De Araujo, M.A.B.; Sombra, A. S.B.

1998-01-01

iron molybdenum phosphate glasses (xMoO 3 ·(0.6 - x)P 2 O 5 ·0.4Li 2 O) : yFe 2 O 2 with 0≤x≤ 0.6 and y = 0.03 (mol%) prepared in ambient atmosphere using the melt quenching technique were studied by using DC electrical conductivity, 57 Fe Moessbauer and infrared spectroscopies. The Dc conductivity depends on the MoO 3 concentration x. It was observed that, with increasing x, the ratio Fe 2+ /(Fe 3+ + Fe 2+ ) and the Dc conductivity increase. Infrared spectroscopy and X-ray powder diffraction indicate that a Li 2 MoO 4 crystalline phase is present for high MoO 3 content samples (x = 0.5, 0.6)

Growth and hydrogenation of ultra-thin Mg films on Mo(111)

DEFF Research Database (Denmark)

Ostenfeld, Christopher Worsøe; Davies, Jonathan Conrad; Vegge, Tejs

2005-01-01

. Hydrogen cannot be adsorbed on magnesium films under UHV conditions. However, when evaporating Mg in a hydrogen background, a hydrogen overlayer is seen to adsorb at the Mg surface, due to the catalytic interaction with the Mo(1 1 1) substrate and subsequent spill-over. We show that two monolayers of Mg......The growth and hydrogenation of ultra-thin magnesium overlayers have been investigated on a Mo(1 1 1) single crystal substrate. For increasing magnesium coverages we observe intermediate stages in the TPD and LEISS profiles, which illustrate the transition from one monolayer to multilayer growth...

Kinetics of Ni–Mo electrodeposition from Ni-rich citrate baths

International Nuclear Information System (INIS)

Beltowska-Lehman, E.; Indyka, P.

2012-01-01

The kinetics of Ni–Mo alloy electrodeposition on steel substrates from an aqueous citrate–ammonia complex baths has been investigated by means of steady-state polarisation measurements in a system with a rotating disc electrode (RDE). Partial current densities for discharge of Ni(II) and Mo(VI) ions and hydrogen evolution as a function of molybdate concentration in the bath, cathode potentials and the rate of mass transport were determined. It has been shown that – under all investigated conditions – Ni–Mo alloy deposition is more favourable than pure nickel and the cathodic process is strongly influenced by the Mo(VI) content in the solution. The Ni(II) electroreduction rate initially increases, as the cathode potential shifts towards more negative values and the concentration of molybdate grows in the solution. However, for the highest examined MoO 4 2− content, a considerable decrease in the rate of the process is subsequently observed at certain limit potentials, the values of which depend on molybdate concentration and hydrodynamic conditions. This effect, related to the formation of intermediate molybdenum oxides (characterised by very low overvoltage for hydrogen evolution), becomes less pronounced when the RDE rotation speed is increased. Hydrogen evolution is strongly associated with molybdenum deposition. An increase of the molybdate ions concentration in the bath, as well as an increase in the rate of mass transport, leads to an increase in Mo content in deposits and to the reduction of current efficiency. The Ni–Mo coatings electrodeposited from the designed bath (with the current efficiency of about 70%) containing about 30 wt.% Mo, are characterised by a shiny-grey appearance and good adhesion to the steel substrate. They are characterised by column growth and amorphous microstructure with randomly distributed nanocrystallites of the MoNi 4 intermetallic phase.

Laser cladding of bioactive glass coatings.

Science.gov (United States)

Comesaña, R; Quintero, F; Lusquiños, F; Pascual, M J; Boutinguiza, M; Durán, A; Pou, J

2010-03-01

Laser cladding by powder injection has been used to produce bioactive glass coatings on titanium alloy (Ti6Al4V) substrates. Bioactive glass compositions alternative to 45S5 Bioglass were demonstrated to exhibit a gradual wetting angle-temperature evolution and therefore a more homogeneous deposition of the coating over the substrate was achieved. Among the different compositions studied, the S520 bioactive glass showed smoother wetting angle-temperature behavior and was successfully used as precursor material to produce bioactive coatings. Coatings processed using a Nd:YAG laser presented calcium silicate crystallization at the surface, with a uniform composition along the coating cross-section, and no significant dilution of the titanium alloy was observed. These coatings maintain similar bioactivity to that of the precursor material as demonstrated by immersion in simulated body fluid. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Disposable MoS2-Arrayed MALDI MS Chip for High-Throughput and Rapid Quantification of Sulfonamides in Multiple Real Samples.

Science.gov (United States)

Zhao, Yaju; Tang, Minmin; Liao, Qiaobo; Li, Zhoumin; Li, Hui; Xi, Kai; Tan, Li; Zhang, Mei; Xu, Danke; Chen, Hong-Yuan

2018-04-27

In this work, we demonstrate, for the first time, the development of a disposable MoS 2 -arrayed matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) chip combined with an immunoaffinity enrichment method for high-throughput, rapid, and simultaneous quantitation of multiple sulfonamides (SAs). The disposable MALDI MS chip was designed and fabricated by MoS 2 array formation on a commercial indium tin oxide (ITO) glass slide. A series of SAs were analyzed, and clear deprotonated signals were obtained in negative-ion mode. Compared with MoS 2 -arrayed commercial steel plate, the prepared MALDI MS chip exhibited comparable LDI efficiency, providing a good alternative and disposable substrate for MALDI MS analysis. Furthermore, internal standard (IS) was previously deposited onto the MoS 2 array to simplify the experimental process for MALDI MS quantitation. 96 sample spots could be analyzed within 10 min in one single chip to perform quantitative analysis, recovery studies, and real foodstuff detection. Upon targeted extraction and enrichment by antibody conjugated magnetic beads, five SAs were quantitatively determined by the IS-first method with the linear range of 0.5-10 ng/mL ( R 2 > 0.990). Good recoveries and repeatability were obtained for spiked pork, egg, and milk samples. SAs in several real foodstuffs were successfully identified and quantified. The developed method may provide a promising tool for the routine analysis of antibiotic residues in real samples.

A study on molybdenum sulphoselenide (MoSxSe2−x, 0 ≤ x ≤ 2) thin films: Growth from solution and its properties

International Nuclear Information System (INIS)

Anand, T. Joseph Sahaya; Shariza, S.

2012-01-01

Highlights: ► Effect of deposition time on the properties of molybdenum chalcogenide thin films. ► First time to compare the study of binary and ternary molybdenum chalcogenides. ► No previous report on ternary molybdenum sulphoselenide by electrodeposition. ► Semiconducting parameters by CV analysis promising to be good solar cell material. - Abstract: Thin films of molybdenum sulphoselenide, MoS x Se 2−x , (0 ≤ x ≤ 2) have been electrosynthesized on indium-tin-oxide (ITO)-coated glass and stainless steel substrates. The films were characterized for their structural, morphological and compositional characteristics. Their optical and semiconducting parameters were also analysed in order to determine the suitability of the thin films for photoelectrochemical (PEC)/solar cell applications. Structural analysis via X-ray diffraction (XRD) analysis reveals that the films are polycrystalline in nature. Scanning electron microscope (SEM) studies reveals the films were adherent to the substrate with uniform in nature which also confirmed by Transmission electron microscope (TEM). Compositional analysis via energy dispersive X-ray (EDX) technique confirms the presence of Mo, S and Se elements in the films. The optical studies show that the films are of direct bandgap. Results on the semiconductor parameters analysis of the films showed that the nature of the Mott–Schottky plots indicates that the films obtained are of n-type material. For all films, the semiconductor parameter values come in the better range of other transition metal chalcogenides which has proven that MoSSe thin films are capable as solar/PEC cell materials.

Friction and wear performance of diamond-like carbon, boron carbide, and titanium carbide coatings against glass

International Nuclear Information System (INIS)

Daniels, B.K.; Brown, D.W.; Kimock, F.M.

1997-01-01

Protection of glass substrates by direct ion beam deposited diamond-like carbon (DLC) coatings was observed using a commercial pin-on-disk instrument at ambient conditions without lubrication. Ion beam sputter-deposited titanium carbide and boron carbide coatings reduced sliding friction, and provided tribological protection of silicon substrates, but the improvement factor was less than that found for DLC. Observations of unlubricated sliding of hemispherical glass pins at ambient conditions on uncoated glass and silicon substrates, and ion beam deposited coatings showed decreased wear in the order: uncoated glass>uncoated silicon>boron carbide>titanium carbide>DLC>uncoated sapphire. Failure mechanisms varied widely and are discussed. Generally, the amount of wear decreased as the sliding friction decreased, with the exception of uncoated sapphire substrates, for which the wear was low despite very high friction. There is clear evidence that DLC coatings continue to protect the underlying substrate long after the damage first penetrates through the coating. The test results correlate with field use data on commercial products which have shown that the DLC coatings provide substantial extension of the useful lifetime of glass and other substrates. copyright 1997 Materials Research Society

Recovery Act: Low Cost Integrated Substrate for OLED Lighting Development

Energy Technology Data Exchange (ETDEWEB)

Benton, Scott [PPG Industries, Inc., Pittsburgh, PA (United States); Bhandari, Abhinav [PPG Industries, Inc., Pittsburgh, PA (United States)

2012-12-26

PPG pursued the development of an integrated substrate, including the anode, external, and internal extraction layers. The objective of PPG's program was to achieve cost reductions by displacing the existing expensive borosilicate or double-side polished float glass substrates and developing alternative electrodes and scalable light extraction layer technologies through focused and short-term applied research. One of the key highlights of the project was proving the feasibility of using PPG's high transmission Solarphire® float glass as a substrate to consistently achieve organic lightemitting diode (OLED) devices with good performance and high yields. Under this program, four low-cost alternatives to the Indium Tin Oxide (ITO) anode were investigated using pilot-scale magnetron sputtered vacuum deposition (MSVD) and chemical vapor deposition (CVD) technologies. The anodes were evaluated by fabricating small and large phosphorescent organic lightemitting diode (PHOLED) devices at Universal Display Corporation (UDC). The device performance and life-times comparable to commercially available ITO anodes were demonstrated. A cost-benefit analysis was performed to down-select two anodes for further low-cost process development. Additionally, PPG developed and evaluated a number of scalable and compatible internal and external extraction layer concepts such as scattering layers on the outside of the glass substrate or between the transparent anode and the glass interface. In one external extraction layer (EEL) approach, sol-gel sprayed pyrolytic coatings were deposited using lab scale equipment by hand or automated spraying of sol-gel solutions on hot glass, followed by optimizing of scattering with minimal absorption. In another EEL approach, PPG tested large-area glass texturing by scratching a glass surface with an abrasive roller and acid etching. Efficacy enhancements of 1.27x were demonstrated using white PHOLED devices for 2.0mm substrates which are

Nanosheet controlled epitaxial growth of PbZr0.52Ti0.48O3 thin films on glass substrates

Science.gov (United States)

Bayraktar, M.; Chopra, A.; Bijkerk, F.; Rijnders, G.

2014-09-01

Integration of PbZr0.52Ti0.48O3 (PZT) films on glass substrates is of high importance for device applications. However, to make use of the superior ferro- and piezoelectric properties of PZT, well-oriented crystalline or epitaxial growth with control of the crystal orientation is a prerequisite. In this article, we report on epitaxial growth of PZT films with (100)- and (110)-orientation achieved by utilizing Ca2Nb3O10 (CNO) and Ti0.87O2 (TO) nanosheets as crystalline buffer layers. Fatigue measurements demonstrated stable ferroelectric properties of these films up to 5 × 109 cycles. (100)-oriented PZT films on CNO nanosheets show a large remnant polarization of 21 μC/cm2 that is the highest remnant polarization value compared to (110)-oriented and polycrystalline films reported in this work. A piezoelectric response of 98 pm/V is observed for (100)-oriented PZT film which is higher than the values reported in the literature on Si substrates.

Elaboration and characterization of fluorohydroxyapatite and fluoroapatite sol−gel coatings on CoCrMo alloy

Energy Technology Data Exchange (ETDEWEB)

Romonţi, D. Covaciu [University “Politehnica” of Bucharest, Faculty of Applied Chemistry and Materials Science 1-7, Polizu Str., 011061, Bucharest (Romania); Iskra, J. [Jožef Stefan Institute, Department of Physical and Organic Chemistry, Jamova 39, SI-6280 (Slovenia); Bele, M. [National Institute of Chemistry, Laboratory for Materials Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Demetrescu, I. [University “Politehnica” of Bucharest, Faculty of Applied Chemistry and Materials Science 1-7, Polizu Str., 011061, Bucharest (Romania); Milošev, I., E-mail: ingrid.milosev@ijs.si [Jožef Stefan Institute, Department of Physical and Organic Chemistry, Jamova 39, SI-6280 (Slovenia)

2016-04-25

The surface of CoCrMo alloy used in orthopedic and dental applications was modified in order to improve its osseointegration. Fluorohydroxyapatite and fluoroapatite coatings were prepared by the sol–gel procedure and deposited on CoCrMo substrate by immersion. The steps of sol–gel synthesis were studied using Fourier transform infrared spectroscopy. The surfaces of the coatings were characterized using scanning electron microscopy and X-ray diffraction. The electrochemical properties of coatings were tested in Fusayama artificial saliva using polarization measurements. The most stable coating was fluorohydroxyapatite. It also has the strongest adhesion. - Highlights: • Fluorohydroxyapatite and fluoroapatite coatings were deposited by sol–gel process. • Synthesis was optimized in situ using Fourier transform infrared spectroscopy. • Coatings provide corrosion protection of CoCrMo substrate in artificial saliva. • Coatings are macroscopically dense, homogeneous and adhere well to the substrate.

Elaboration and characterization of fluorohydroxyapatite and fluoroapatite sol−gel coatings on CoCrMo alloy

International Nuclear Information System (INIS)

Romonţi, D. Covaciu; Iskra, J.; Bele, M.; Demetrescu, I.; Milošev, I.

2016-01-01

The surface of CoCrMo alloy used in orthopedic and dental applications was modified in order to improve its osseointegration. Fluorohydroxyapatite and fluoroapatite coatings were prepared by the sol–gel procedure and deposited on CoCrMo substrate by immersion. The steps of sol–gel synthesis were studied using Fourier transform infrared spectroscopy. The surfaces of the coatings were characterized using scanning electron microscopy and X-ray diffraction. The electrochemical properties of coatings were tested in Fusayama artificial saliva using polarization measurements. The most stable coating was fluorohydroxyapatite. It also has the strongest adhesion. - Highlights: • Fluorohydroxyapatite and fluoroapatite coatings were deposited by sol–gel process. • Synthesis was optimized in situ using Fourier transform infrared spectroscopy. • Coatings provide corrosion protection of CoCrMo substrate in artificial saliva. • Coatings are macroscopically dense, homogeneous and adhere well to the substrate.

Structural, morphological, and optical characterizations of Mo, CrN and Mo:CrN sputtered coatings for potential solar selective applications

Science.gov (United States)

Ibrahim, Khalil; Mahbubur Rahman, M.; Taha, Hatem; Mohammadpour, Ehsan; Zhou, Zhifeng; Yin, Chun-Yang; Nikoloski, Aleksandar; Jiang, Zhong-Tao

2018-05-01

Mo, CrN, and Mo:CrN sputtered coatings synthesized onto silicon Si(100) substrates were investigated as solar selective surfaces and their potential applications in optical devices. These coatings were characterized using XRD, SEM, UV-vis, and FTIR techniques. XRD investigation, showed a change in CrN thin film crystallite characteristic due to Mo doping. Compared to the CrN coating, the Mo:CrN film has a higher lattice parameter and lower grain size of 4.19 nm and 106.18 nm, respectively. FESEM morphology confirmed the decrement in Mo:CrN crystal size due to Mo doping. Optical analysis showed that in the visible range of the solar spectrum, the CrN coatings exhibit the highest solar absorptance of 66% while the lowest thermal emittance value of 5.67 was recorded for the CrN coating doped with Mo. Consequently, the highest solar selectivity of 9.6, and the energy band-gap of 2.88 eV were achieved with the Mo-doped CrN coatings. Various optical coefficients such as optical absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constants, and energy loss functions of these coatings were also estimated from the optical reflectance data recorded in the wavelength range of 190-2300 nm.

Substrate matters: Magnetic tuning of the Fe monolayer

Energy Technology Data Exchange (ETDEWEB)

Ramanathan, A.A.; Khalifeh, J.M.

2017-03-15

The effect of substrate on the magnetism of the Fe monolayer (ML) is investigated using the total energy DFT calculations with the local spin density approximation (LSDA). The results show an in plane ferromagnetic coupling (FM) and a magnetic moment of 1.78 µ{sub B} for the relaxed Fe ML in the presence of the vanadium substrate. In comparison, the surface Fe(001) magnetic moment ranges between 2.97–3.01 µ{sub B}. This difference in the Fe surface moment of more than 1 µ{sub B} in the presence or absence of Vanadium allows tuning of the Fe magnetic moment and has great potential as a magnetic switch and in spintronic devices. The surface magnetic quenching of Fe with V is much more pronounced than with other transition metal substrates like Molybdenum or Tungsten. We have a reduction of 40.5% of the Fe (001) surface moment which is more than double the reduction obtained with the Fe/Mo(001) or the Fe/W(001) systems. The magnetic quenching is due to the strong hybridization between the Fe and V d bands. This is supported by the observed charge density redistribution and large inward relaxation of 18.37% for the Fe surface upon structural relaxation. The Fe ML is antiferromagnetically (AF) coupled with the V interfacial layer, which has an appreciable induced magnetic moment of 0.48 µ{sub B}. - Highlights: • We report the magnetic quenching of a Fe ML on V(001) substrate. • Almost double as compared to Mo and W substrates. • The Fe surface ML on V(001) shows FM ordering as opposed to AF ordering for Fe ML on Mo(001) and W(001) substrates.

The effect of substrate on thermodynamic and kinetic anisotropies in atomic thin films

International Nuclear Information System (INIS)

Haji-Akbari, Amir; Debenedetti, Pablo G.

2014-01-01

Glasses have a wide range of technological applications. The recent discovery of ultrastable glasses that are obtained by depositing the vapor of a glass-forming liquid onto the surface of a cold substrate has sparked renewed interest in the effects of confinements on physicochemical properties of liquids and glasses. Here, we use molecular dynamics simulations to study the effect of substrate on thin films of a model glass-forming liquid, the Kob-Andersen binary Lennard-Jones system, and compute profiles of several thermodynamic and kinetic properties across the film. We observe that the substrate can induce large oscillations in profiles of thermodynamic properties such as density, composition, and stress, and we establish a correlation between the oscillations in total density and the oscillations in normal stress. We also demonstrate that the kinetic properties of an atomic film can be readily tuned by changing the strength of interactions between the substrate and the liquid. Most notably, we show that a weakly attractive substrate can induce the emergence of a highly mobile region in its vicinity. In this highly mobile region, structural relaxation is several times faster than in the bulk, and the exploration of the potential energy landscape is also more efficient. In the subsurface region near a strongly attractive substrate, however, the dynamics is decelerated and the sampling of the potential energy landscape becomes less efficient than the bulk. We explain these two distinct behaviors by establishing a correlation between the oscillations in kinetic properties and the oscillations in lateral stress. Our findings offer interesting opportunities for designing better substrates for the vapor deposition process or developing alternative procedures for situations where vapor deposition is not feasible

The effect of substrate on thermodynamic and kinetic anisotropies in atomic thin films.

Science.gov (United States)

Haji-Akbari, Amir; Debenedetti, Pablo G

2014-07-14

Glasses have a wide range of technological applications. The recent discovery of ultrastable glasses that are obtained by depositing the vapor of a glass-forming liquid onto the surface of a cold substrate has sparked renewed interest in the effects of confinements on physicochemical properties of liquids and glasses. Here, we use molecular dynamics simulations to study the effect of substrate on thin films of a model glass-forming liquid, the Kob-Andersen binary Lennard-Jones system, and compute profiles of several thermodynamic and kinetic properties across the film. We observe that the substrate can induce large oscillations in profiles of thermodynamic properties such as density, composition, and stress, and we establish a correlation between the oscillations in total density and the oscillations in normal stress. We also demonstrate that the kinetic properties of an atomic film can be readily tuned by changing the strength of interactions between the substrate and the liquid. Most notably, we show that a weakly attractive substrate can induce the emergence of a highly mobile region in its vicinity. In this highly mobile region, structural relaxation is several times faster than in the bulk, and the exploration of the potential energy landscape is also more efficient. In the subsurface region near a strongly attractive substrate, however, the dynamics is decelerated and the sampling of the potential energy landscape becomes less efficient than the bulk. We explain these two distinct behaviors by establishing a correlation between the oscillations in kinetic properties and the oscillations in lateral stress. Our findings offer interesting opportunities for designing better substrates for the vapor deposition process or developing alternative procedures for situations where vapor deposition is not feasible.

The effect of substrate on thermodynamic and kinetic anisotropies in atomic thin films

Energy Technology Data Exchange (ETDEWEB)

Haji-Akbari, Amir; Debenedetti, Pablo G., E-mail: pdebene@exchange.princeton.edu [Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2014-07-14

Glasses have a wide range of technological applications. The recent discovery of ultrastable glasses that are obtained by depositing the vapor of a glass-forming liquid onto the surface of a cold substrate has sparked renewed interest in the effects of confinements on physicochemical properties of liquids and glasses. Here, we use molecular dynamics simulations to study the effect of substrate on thin films of a model glass-forming liquid, the Kob-Andersen binary Lennard-Jones system, and compute profiles of several thermodynamic and kinetic properties across the film. We observe that the substrate can induce large oscillations in profiles of thermodynamic properties such as density, composition, and stress, and we establish a correlation between the oscillations in total density and the oscillations in normal stress. We also demonstrate that the kinetic properties of an atomic film can be readily tuned by changing the strength of interactions between the substrate and the liquid. Most notably, we show that a weakly attractive substrate can induce the emergence of a highly mobile region in its vicinity. In this highly mobile region, structural relaxation is several times faster than in the bulk, and the exploration of the potential energy landscape is also more efficient. In the subsurface region near a strongly attractive substrate, however, the dynamics is decelerated and the sampling of the potential energy landscape becomes less efficient than the bulk. We explain these two distinct behaviors by establishing a correlation between the oscillations in kinetic properties and the oscillations in lateral stress. Our findings offer interesting opportunities for designing better substrates for the vapor deposition process or developing alternative procedures for situations where vapor deposition is not feasible.

High resistivity ZnSe coated substrates for microstrip gas chambers

International Nuclear Information System (INIS)

Sudharsanan, R.; Greenwald, A.C.; Vakerlis, G.; Yoganathan, M.; Cho, H.S.; Kadyk, J.; Dubeau, J.; Dixit, M.

1998-01-01

Microstrip gas chambers (MSGCs) require substrates with sheet resistance in the range of 10 13 --10 16 ohms/square to eliminate polarization and surface charging effects between the electrodes. Thin films of II-VI semiconductors deposited on glass or plastic substrates are attractive for this application since bulk resistivity of these semiconductors vary in the range 10 9 --10 12 ohm-cm and films with good uniformity can be deposited over large-areas using inexpensive deposition techniques. In this paper, deposition, characterization, and fabrication of MSGCs using ZnSe thin films are reported for the first time. ZnSe thin films were deposited on glass and plastic substrates by thermal evaporation. Sheet resistance of ZnSe varied in the range of 10 15 to 10 16 ohms/square depending on the deposition conditions. A MSGC detector fabricated using a 0.5 microm thick ZnSe layer on glass substrate exhibited best values; gas gain of 25,000 and an energy resolution of about 16.7% FWHM at a gain of 1,080 for a 55 Fe source

Electronic structure description of the cis-MoOS unit in models for molybdenum hydroxylases.

Science.gov (United States)

Doonan, Christian J; Rubie, Nick D; Peariso, Katrina; Harris, Hugh H; Knottenbelt, Sushilla Z; George, Graham N; Young, Charles G; Kirk, Martin L

2008-01-09

The molybdenum hydroxylases catalyze the oxidation of numerous aromatic heterocycles and simple organics and, unlike other hydroxylases, utilize water as the source of oxygen incorporated into the product. The electronic structures of the cis-MoOS units in CoCp2[TpiPrMoVOS(OPh)] and TpiPrMoVIOS(OPh) (TpiPr = hydrotris(3-isopropylpyrazol-1-yl)borate), new models for molybdenum hydroxylases, have been studied in detail using S K-edge X-ray absorption spectroscopy, vibrational spectroscopy, and detailed bonding calculations. The results show a highly delocalized Mo=S pi* LUMO redox orbital that is formally Mo(dxy) with approximately 35% sulfido ligand character. Vibrational spectroscopy has been used to quantitate Mo-Ssulfido bond order changes in the cis-MoOS units as a function of redox state. Results support a redox active molecular orbital that has a profound influence on MoOS bonding through changes to the relative electro/nucleophilicity of the terminal sulfido ligand accompanying oxidation state changes. The bonding description for these model cis-MoOS systems supports enzyme mechanisms that are under orbital control and dominantly influenced by the unique electronic structure of the cis-MoOS site. The electronic structure of the oxidized enzyme site is postulated to play a role in polarizing a substrate carbon center for nucleophilic attack by metal activated water and acting as an electron sink in the two-electron oxidation of substrates.

Ideal glass transitions in thin films: An energy landscape perspective

OpenAIRE

Truskett, Thomas M.; Ganesan, Venkat

2003-01-01

We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently, the film's ideal glass transition temperature depend on bulk pressure, film thickness, and the strength of the fluid-fluid and fluid-substrate interactions. The predictions are in qualitative agreement with the experimental trends for the kinetic glass transition temperatu...

Adhesion mapping of chemically modified and poly(ethylene oxide)-grafted glass surfaces

OpenAIRE

Jogikalmath, G.; Stuart, J.K.; Pungor, A.; Hlady, V.

1999-01-01

Two-dimensional mapping of the adhesion pull-off forces was used to study the origin of surface heterogeneity in the grafted poly(ethylene oxide) (PEO) layer. The variance of the pull-off forces measured over the μm-sized regions after each chemical step of modifying glass surfaces was taken to be a measure of the surface chemical heterogeneity. The attachment of γ-glycidoxypropyltrimethoxy silane (GPS) to glass decreased the pull-off forces relative to the clean glass and made the surface mo...

Platinoids and molybdenum in nuclear waste containment glasses: a structural study; Les platinoides et le molybdene dans des verres d'interet nucleaires: etude structurale

Energy Technology Data Exchange (ETDEWEB)

Le Grand, M [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification (DRRV), 30 - Marcoule (France); [Paris-7 Univ., 75 (France)

2000-07-01

This work deals with the structure of borosilicate nuclear glasses and with some relationships between structure and macroscopic properties. Two types of elements which may disturb the industrial process - platinoids (Ru and Pd) and molybdenum - are central to this work. Platinoids induce weak modifications on the structure of the glass, causing a depolymerization of the glassy network, an increase of the {sup [3]}B/{sup [4]}B ratio and a modification of the medium range order around Si between 3.3 and 4.5 angstrom. The modifications of viscosity and density induced by platinoids in the glass are not due to the structural effect of the platinoids. The increase of viscosity is attributed to needle shaped RuO{sub 2}. It can be moderated by imposing reducing conditions during the elaboration of the glass. The slight difference between experimental and calculated densities is due to the increase of the volume percentage of bubbles in the glass with increasing platinoid content. Mo is either present in the glass as molybdic groupings, or mobilized in chemically complex molybdic crystalline phases. The chemical composition and mineralogy of these phases has been obtained using electronic microprobe data and XRD with Rietveld analysis. The distribution of the different elements between the crystalline phases and the glass is strongly influenced by the structural role of the various cations in the glass. The Mo present in the glass appears as MoO{sub 4} tetrahedra, independent of the borosilicate network. The formation of the crystalline phases can be explained by the existence of a precursor in which the MoO{sub 4} tetrahedra are concentrated in rich alkali and earth-alkali bearing areas of the glass. (author)

Metal nanoparticle-doped coloured films on glass and ...

Indian Academy of Sciences (India)

coloured coatings (yellow to pink) on polycarbonate substrates after curing. ... followed by thermal annealing (in the case of glass substrates) or UV curing (in the ... Two representative samples of compositions SiO2 : TiO2 = 1 : 0 and 2 : 3 ...

Cathodic Electrodeposition of Ni-Mo on Semiconducting NiFe2 O4 for Photoelectrochemical Hydrogen Evolution in Alkaline Media.

Science.gov (United States)

Wijten, Jochem H J; Jong, Ronald P H; Mul, Guido; Weckhuysen, Bert M

2018-04-25

Photocathodes for hydrogen evolution from water were made by electrodeposition of Ni-Mo layers on NiFe 2 O 4 substrates, deposited by spin coating on F:SnO 2 -glass. Analysis confirmed the formation of two separate layers, without significant reduction of NiFe 2 O 4 . Bare NiFe 2 O 4 was found to be unstable under alkaline conditions during (photo)electrochemistry. To improve the stability significantly, the deposition of a bifunctional Ni-Mo layer through a facile electrodeposition process was performed and the composite electrodes showed stable operation for at least 1 h. Moreover, photocurrents up to -2.1 mA cm -2 at -0.3 V vs. RHE were obtained for Ni-Mo/NiFe 2 O 4 under ambient conditions, showing that the new combination functions as both a stabilizing and catalytic layer for the photoelectrochemical evolution of hydrogen. The photoelectrochemical response of these composite electrodes decreased with increasing NiFe 2 O 4 layer thickness. Transient absorption spectroscopy showed that the lifetime of excited states is short and on the ns timescale. An increase in lifetime was observed for NiFe 2 O 4 of large layer thickness, likely explained by decreasing the defect density in the primary layer(s), as a result of repetitive annealing at elevated temperature. The photoelectrochemical and transient absorption spectroscopy results indicated that a short charge carrier lifetime limits the performance of Ni-Mo/NiFe 2 O 4 photocathodes. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study on characteristics of U-Mo/Al-Si interaction layers of dispersion fuel plates

International Nuclear Information System (INIS)

Liu Lijian; Yin Changgeng; Chen Jiangang; Sun Changlong; Liu Yunming

2014-01-01

In this paper, we analyzed the characteristics of U-Mo/Al-Si interaction layers of dispersion fuel plates. The results show that the interaction layers (IL) are with irregular morphology and uneven thickness, and are mainly formed in the internal micro cracks of the dispersion fuel particles or at the interface between the particles and the substrates. The diffusion mechanism of U-Mo/Al-Si is the vacancy diffusion, Al and Si are migrating elements, and the diffusion reaction is that Al and Si diffuse to U-Mo alloy. Inside the interaction layers, the Al content keeps constant basically, but the Si content gradually increases with the substrate-fuel direction, and the maximum content of Si appears interaction layers near the U-Mo side. Adding about 5 wt% Si into Al matrix can restrain the diffusion reaction, and improve the performance of dispersion fuel plates finally. (authors)

Low-temperature atomic layer deposition of MoOx for silicon heterojunction solar cells

NARCIS (Netherlands)

Macco, B.; Vos, M.; Thissen, N.F.W.; Bol, A.A.; Kessels, W.M.M.

2015-01-01

The preparation of high-quality molybdenum oxide (MoOx) is demonstrated by plasma-enhanced atomic layer deposition (ALD) at substrate temperatures down to 50 °C. The films are amorphous, slightly substoichiometric with respect to MoO3, and free of other elements apart from hydrogen (&11 at%). The

A suitable material for the substrate of micro-strip gas chamber

International Nuclear Information System (INIS)

Zhang Minglong; Xia Yiben; Wang Linjun; Zhang Weili

2004-01-01

Micro-strip Gas Chamber (MSGC) used as a position sensitive detector has perfect performances in the detection of nuclear irradiations. However, it encounters a severe problem, that is, positive charge accumulation which can be avoided by reducing the surface resistivity of insulating substrate. So, diamond-like carbon (DLC) film is coated on D263 glass to modify its electrical properties as substrate for MSGC. Raman spectroscopy demonstrates that DLC film is of sp 3 (σ bounding) and sp 2 bonding (π bonding), and therefore it is a type of electronically conducting material. It also reveals that the film deposited on D263 glass possesses very large of sp 3 content and consequently is a high quality DLC film. I-V plots indicate that samples with DLC film enjoy very steady and suitable resistivities in the range of 10 9 -10 12 Ω·cm. C-F characteristics also show that samples coated by DLC film have low and stable capacitance with frequency. These excellent performances of the new material, DLC film/D263 glass, meet the optimum requirements of MSGC. DLC film/D263 glass used as the substrate of MSGC should effectively avoid the charge pile-up effect and substrate instability and then improve its performances

Compatibility studies on Mo-coating systems for nuclear fuel cladding applications

Science.gov (United States)

Koh, Huan Chin; Hosemann, Peter; Glaeser, Andreas M.; Cionea, Cristian

2017-12-01

To improve the safety factor of nuclear power plants in accident scenarios, molybdenum (Mo), with its high-temperature strength, is proposed as a potential fuel-cladding candidate. However, Mo undergoes rapid oxidation and sublimation at elevated temperatures in oxygen-rich environments. Thus, it is necessary to coat Mo with a protective layer. The diffusional interactions in two systems, namely, Zircaloy-2 (Zr2) on a Mo tube, and iron-chromium-aluminum (FeCrAl) on a Mo rod, were studied by aging coated Mo substrates in high vacuum at temperatures ranging from 650 °C to 1000° for 1000 h. The specimens were characterized using scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and nanoindentation. In both systems, pores in the coating increased in size and number with increasing temperature over time, and cracks were also observed; intermetallic phases formed between the Mo and its coatings.

Characterization of ultra-thin TiO2 films grown on Mo(112)

International Nuclear Information System (INIS)

Kumar, D.; Chen, M.S.; Goodman, D.W.

2006-01-01

Ultra-thin TiO 2 films were grown on a Mo(112) substrate by stepwise vapor depositing of Ti onto the sample surface followed by oxidation at 850 K. X-ray photoelectron spectroscopy showed that the Ti 2p peak position shifts from lower to higher binding energy with an increase in the Ti coverage from sub- to multilayer. The Ti 2p peak of a TiO 2 film with more than a monolayer coverage can be resolved into two peaks, one at 458.1 eV corresponding to the first layer, where Ti atoms bind to the substrate Mo atoms through Ti-O-Mo linkages, and a second feature at 458.8 eV corresponding to multilayer TiO 2 where the Ti atoms are connected via Ti-O-Ti linkages. Based on these assignments, the single Ti 2p 3/2 peak at 455.75 eV observed for the Mo(112)-(8 x 2)-TiO x monolayer film can be assigned to Ti 3+ , consistent with our previous results obtained with high-resolution electron energy loss spectroscopy

Effect of the Substrate on Phonon Properties of Graphene Estimated by Raman Spectroscopy

Science.gov (United States)

Tivanov, M. S.; Kolesov, E. A.; Korolik, O. V.; Saad, A. M.; Komissarov, I. V.

2018-01-01

Low-temperature Raman studies of supported graphene are presented. A linear temperature dependence of 2D peak linewidths was observed with the coefficients of 0.036 and 0.033 cm^{-1}/K for graphene on copper and glass substrates, respectively, while G peak linewidths remained unchanged throughout the whole temperature range. The different values observed for graphene on glass and copper substrates were explained in terms of the substrate effect on phonon-phonon and electron-phonon interaction properties of the material. The results of the present study can be used to consider substrate effects on phonon transport in graphene for nanoelectronic device engineering.

Effect of modified ITO substrate on electrochromic properties of polyaniline films

Energy Technology Data Exchange (ETDEWEB)

Leon-Silva, U.; Nicho, M.E.; Cruz-Silva, Rodolfo [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, UAEMor, Av. Universidad 1001, Col. Chamilpa, 62209, Cuernavaca, Morelos (Mexico); Hu, Hailin [Departamento de Materiales Solares, Centro de Investigacion en Energia, UNAM, Av. Xochicalco S/N, Temixco, 62580, Morelos (Mexico)

2007-09-22

In this work, we report the morphological and electrochromic properties of electrochemically synthesized polyaniline (PANI) thin films on bare and modified indium-tin oxide (ITO) glass substrates. In the last case, the surface of ITO glass was covered by a self-assembled monolayer of N-phenyl-{gamma}-aminopropyl-trimethoxysilane (PAPTS). Atomic force microscopy images and perfilometry show that smoother and thinner PANI films were grown on PAPTS-modified ITO substrates. PANI-based electrochromic devices (ECDs) were assembled by using a viscous polymeric electrolyte (PE) of LiClO{sub 4} and polymethyl methacrylate (PMMA) co-dissolved in a mixture of propylene and ethylene carbonate. The architectural design of the devices was glass/ITO/PANI/PE/ITO/glass. A dual ECD was also prepared by collocating a poly(3-methylthiophene) (P3MT) thin film as a complementary electrochromic element. The effect of the PAPTS-modified ITO substrate is reflected in a higher optical transmittance at bleach state and a little less color change at 550 nm of PANI-based ECDs. (author)

Platinoids and molybdenum in nuclear waste containment glasses: a structural study; Les platinoides et le molybdene dans des verres d'interet nucleaires: etude structurale

Energy Technology Data Exchange (ETDEWEB)

Le Grand, M. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification (DRRV), 30 - Marcoule (France)]|[Paris-7 Univ., 75 (France)

2000-07-01

This work deals with the structure of borosilicate nuclear glasses and with some relationships between structure and macroscopic properties. Two types of elements which may disturb the industrial process - platinoids (Ru and Pd) and molybdenum - are central to this work. Platinoids induce weak modifications on the structure of the glass, causing a depolymerization of the glassy network, an increase of the {sup [3]}B/{sup [4]}B ratio and a modification of the medium range order around Si between 3.3 and 4.5 angstrom. The modifications of viscosity and density induced by platinoids in the glass are not due to the structural effect of the platinoids. The increase of viscosity is attributed to needle shaped RuO{sub 2}. It can be moderated by imposing reducing conditions during the elaboration of the glass. The slight difference between experimental and calculated densities is due to the increase of the volume percentage of bubbles in the glass with increasing platinoid content. Mo is either present in the glass as molybdic groupings, or mobilized in chemically complex molybdic crystalline phases. The chemical composition and mineralogy of these phases has been obtained using electronic microprobe data and XRD with Rietveld analysis. The distribution of the different elements between the crystalline phases and the glass is strongly influenced by the structural role of the various cations in the glass. The Mo present in the glass appears as MoO{sub 4} tetrahedra, independent of the borosilicate network. The formation of the crystalline phases can be explained by the existence of a precursor in which the MoO{sub 4} tetrahedra are concentrated in rich alkali and earth-alkali bearing areas of the glass. (author)

Infrared and Raman investigation of rare-earth phosphate glasses for potential use as radioactive waste forms

International Nuclear Information System (INIS)

Morgan, S.H.

1989-01-01

This project was designed to investigate the properties of the rare-earth phosphate glass systems CeO 2 -P 2 O 5 and Pr 2 O 3 -P 2 O 5 for potential use as radioactive waste glasses. The glass-forming region and optimum processing parameters of these glass systems were investigated. The structure of the host glasses and glassed loaded with simulated waste elements was investigated using Raman and infrared spectroscopy. Because of the radical differences in the spectra of the molybdenum-loaded glasses, the structure of the MoO 3 -P 2 O 5 glass system was also investigated. 29 refs., 8 figs., 2 tabs

Moiré-related in-gap states in a twisted MoS2/graphite heterojunction

KAUST Repository

Lu, Chun-I; Butler, Christopher J.; Huang, Jing-Kai; Chu, Yu-Hsun; Yang, Hung-Hsiang; Wei, Ching-Ming; Li, Lain-Jong; Lin, Minn-Tsong

2017-01-01

the band gap range of MoS2, and by comparing the tunneling spectra from MoS2 grains of varying rotation with respect to the substrate, show that these features have small but non-negligible dependence on the moiré superstructure. Furthermore, within a

PZT piezoelectric films on glass for Gen-X imaging

Science.gov (United States)

Wilke, Rudeger H. T.; Trolier-McKinstry, Susan; Reid, Paul B.; Schwartz, Daniel A.

2010-09-01

The proposed adaptive optics system for the Gen-X telescope uses piezoelectric lead zirconate titanate (PZT) films deposited on flexible glass substrates. The low softening transition of the glass substrates imposes several processing challenges that require the development of new approaches to deposit high quality PZT thin films. Synthesis and optimization of chemical solution deposited 1 μm thick films of PbZr0.52Ti0.48O3 on small area (1 in2) and large area (16 in2) Pt/Ti/glass substrates has been performed. In order to avoid warping of the glass at temperatures typically used to crystallize PZT films ({700°C), a lower temperature, two-step crystallization process was employed. An {80 nm thick seed layer of PbZr0.30Ti0.70O3 was deposited to promote the growth of the perovskite phase. After the deposition of the seed layer, the films were annealed in a rapid thermal annealing (RTA) furnace at 550°C for 3 minutes to nucleate the perovskite phase. This was followed by isothermal annealing at 550°C for 1 hour to complete crystallization. For the subsequent PbZr0.52Ti0.48O3 layers, the same RTA protocol was performed, with the isothermal crystallization implemented following the deposition of three PbZr0.52Ti0.48O3 spin-coated layers. Over the frequency range of 1 kHz to 100 kHz, films exhibit relative permittivity values near 800 with loss tangents below 0.07. Hysteresis loops show low levels of imprint with coercive fields of 40-50 kV/cm in the forward direction and 50-70 kV/cm in the reverse direction. The remanent polarization varied from 25-35 μC/cm2 and e31,f values were approximately -5.0 C/m2. In scaling up the growth procedure to large area films, where warping becomes more pronounced due to the increased size of the substrate, the pyrolysis and crystallization conditions were performed in a box furnace to improve the temperature uniformity. By depositing films on both sides of the glass substrate, the tensile stresses are balanced, providing a

Transport and dielectric studies on silver based molybdo-tungstate quaternary superionic conducting glasses

International Nuclear Information System (INIS)

Prasad, P.S.S.; Radhakrishna, S.

1988-01-01

The molybdo-tungstate (MoO 3 -WO 3 ) combination of glass formers with silver oxide (Ag 2 O) as glass modifier and silver iodide (AgI) as ionic conductor were prepared to study the transport and dielectric properties of 60% AgI-40% (x Ag 2 O-y(WO 3 -MoO 3 )) for x/y=0.33 to 3.0 and establish the feasibility of using these glasses as electrolytes in the fabrication and characterisation of solid state batteries and potential memory devices. The details of the preparation of glasses and methods of measurement of their capacitance, dielectric loss factor and ac conductivity in the frequency range 100 Hz - 100 kHz from 30-120 C have been reported. The electronic contribution to the total conductivity, the ionic and electronic transport numbers were determined using Wagners dc polarisation technique. The observed high ionic and low electronic conductivities were attributed to the formation of ionic clusters in the glass and the effect of mixing two glass formers. The observed total ionic conductivity and its temperature dependence was explained using Arrhenius relation σ=σ 0 /T exp(-E/RT) and the measured dielectric constant and dielectric loss were explained on the basis of Jonschers theory. The frequency dependence of dielectric constant obeys the theory based on the polarisation of ions. 25 refs.; 8 figs

Aluminum-doped zinc oxide thin films grown on various substrates using facing target sputtering system

Science.gov (United States)

Kim, Hwa-Min; Lee, Chang Hyun; Shon, Sun Young; Kim, Bong Hwan

2017-11-01

Aluminum-doped zinc oxide (AZO) films were fabricated on various substrates, such as glass, polyethylene naphthalate (PEN), and polyethylene terephthalate (PET), at room temperature using a facing target sputtering (FTS) system with hetero ZnO and Al2O3 targets, and their electrical and optical properties were investigated. The AZO film on glass exhibited compressive stress while the films on the plastic substrates showed tensile stress. These stresses negatively affected the crystalline quality of the AZO films, and it is suggested that the poor crystalline quality of the films may be related to the neutral Al-based defect complexes formed in the films; these complexes act as neutral impurity scattering centers. AZO films with good optoelectronic properties could be formed on the glass and plastic substrates by the FTS technique using the hetero targets. The AZO films deposited on the glass, PEN, and PET substrates showed very low resistivities, of 5.0 × 10-4 Ω cm, 7.0 × 10-4 Ω cm, and 7.4 × 10-4 Ω cm, respectively. Further, the figure merit of the AZO film formed on the PEN substrate in the visible range (400-700 nm) was significantly higher than that of the AZO film on PET and similar to that of the AZO film on glass. Finally, the average transmittances of the films in the visible range (400-700 nm) were 83.16% (on glass), 76.3% (on PEN), and 78.16% (on PET).

Preparation and characterization of molybdenum disilicide coating on molybdenum substrate by air plasma spraying

International Nuclear Information System (INIS)

Wang, Yi; Wang, Dezhi; Yan, Jianhui; Sun, Aokui

2013-01-01

MoSi 2 oxidation protective coatings on molybdenum substrate were prepared by air plasma spraying technique (APS). Microstructure, phase composition, porosity, microhardness and bonding strength of the coatings were investigated and determined. Oxidation behavior of the coating at high temperature was also examined. Results show that composition of the coatings is constituted with MoSi 2 and Mo 5 Si 3 , the surface morphology is described as flattened lamellar features, insufficiently flattened protuberance with some degree of surface roughness, a certain quantity of spherical particles, microcracks and pores. Testing results reveal that microhardness and bonding strength of the coatings increase, and porosity decreases with increasing power or decreasing Ar gas flow rate. Moreover, with decreasing the porosity, the microhardness of the coatings increases. The bonding strength of the coatings also increases with increasing spray distance. The MoSi 2 coated Mo substrate exhibited a good oxidation resistance at 1200 °C.

Influence of the Hydrothermal Method Growth Parameters on the Zinc Oxide Nanowires Deposited on Several Substrates

Directory of Open Access Journals (Sweden)

Concepción Mejía-García

2014-01-01

Full Text Available We report the synthesis of ZnO nanowires grown on several substrates (PET, glass, and Si using a two-step process: (a preparation of the seed layer on the substrate by spin coating, from solutions of zinc acetate dihydrate and 1-propanol, and (b growth of the ZnO nanostructures by dipping the substrate in an equimolar solution of zinc nitrate hexahydrate and hexamethylenetetramine. Subsequently, films were thermally treated with a commercial microwave oven (350 and 700 W for 5, 20, and 35 min. The ZnO nanowires obtained were characterized structurally, morphologically, and optically using XRD, SEM, and UV-VIS transmission, respectively. XRD patterns spectra revealed the presence of Zn(OH2 on the films grown on glass and Si substrates. A preferential orientation along c-axis directions for films grown on PET substrate was observed. An analysis by SEM revealed that the growth of the ZnO nanowires on PET and glass is better than the growth on Si when the same growth parameters are used. On glass substrates, ZnO nanowires less than 50 nm in diameter and between 200 nm and 1200 nm in length were obtained. The ZnO nanowires band gap energy for the films grown on PET and glass was obtained from optical transmission spectra.

Controllable Growth of Large-Size Crystalline MoS2 and Resist-Free Transfer Assisted with a Cu Thin Film

Science.gov (United States)

Lin, Ziyuan; Zhao, Yuda; Zhou, Changjian; Zhong, Ren; Wang, Xinsheng; Tsang, Yuen Hong; Chai, Yang

2015-12-01

Two-dimensional MoS2 is a promising material for future nanoelectronics and optoelectronics. It has remained a great challenge to grow large-size crystalline and high surface coverage monolayer MoS2. In this work, we investigate the controllable growth of monolayer MoS2 evolving from triangular flakes to continuous thin films by optimizing the concentration of gaseous MoS2, which has been shown a both thermodynamic and kinetic growth factor. A single-crystal monolayer MoS2 larger than 300 μm was successfully grown by suppressing the nuclei density and supplying sufficient source. Furthermore, we present a facile process of transferring the centimeter scale MoS2 assisted with a copper thin film. Our results show the absence of observable residues or wrinkles after we transfer MoS2 from the growth substrates onto flat substrates using this technique, which can be further extended to transfer other two-dimensional layered materials.

On the use of Plexiglass Substrates for Neutron Mirrors

International Nuclear Information System (INIS)

Maayouf, R.M.A.

2009-01-01

The work deals with neutron reflectivity measurements performed for Ni films coated on different types of the commercially available plexiglass substrates. The Ni coatings were Ni Cr (80% Ni, 20% Cr), 58 Ni and natural nickel. The reflectivity behaviors of 58 Ni and natural nickel are compared with a present measurement performed for a 58 Ni film (150 nm thick) coated on glass substrate. Some of the present mirrors were measured several years before and are included in the presented measurements in order to check the quality of the plexiglass mirrors over years. It has been found, from the presented measurements, that plexiglass, as a substrate, successfully substitutes glass and the quality of the Ni coating can last for several years without deterioration.

Structural and electrical properties of CuAlMo thin films prepared by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Birkett, Martin, E-mail: martin.birkett@northumbria.ac.uk; Penlington, Roger; Wan, Chaoying; Zoppi, Guillaume

2013-07-01

The structural and electrical properties of a low resistivity CuAlMo thin film resistor material were investigated. The thin films were grown on Al{sub 2}O{sub 3} and glass substrates by direct current (dc) magnetron sputtering. The key electrical properties of sheet resistance, temperature coefficient of resistance (TCR) and resistance stability were investigated as a function of sputtering pressure and post-deposition heat treatment time and temperature. A low sputtering pressure range of 0.13 to 0.40 Pa produced CuAlMo films with sheet resistance in the range 0.1 to 0.2 Ω/□ and resistance stability of 0.45 to 0.65% with a TCR of − 90 ppm/°C which could be shifted to zero following annealing in air at 425 °C. Films grown at higher sputtering pressures of 0.53 to 0.80 Pa had increased sheet resistance in the range 0.4 to 0.6 Ω/□ and inferior stability of 0.8 to 1.7% with a more negative TCR of − 110 to − 180 ppm/°C which could not be shifted to zero following annealing. The stability of the films grown at 0.13 and 0.40 Pa could be further improved to < 0.25% with heat treatment, due to the formation of a protective aluminium oxide layer. A minimum dwell time of 3 h at 425 °C was required to stabilise the films and set the electrical properties. - Highlights: • Thin films of copper–aluminium–molybdenum were sputtered on alumina substrates. • Film properties were investigated with variation in process conditions. • Low sputtering pressure gave improved electrical performance. • Post deposition annealing in air further improved electrical performance.

Structural and electrical properties of CuAlMo thin films prepared by magnetron sputtering

International Nuclear Information System (INIS)

Birkett, Martin; Penlington, Roger; Wan, Chaoying; Zoppi, Guillaume

2013-01-01

The structural and electrical properties of a low resistivity CuAlMo thin film resistor material were investigated. The thin films were grown on Al 2 O 3 and glass substrates by direct current (dc) magnetron sputtering. The key electrical properties of sheet resistance, temperature coefficient of resistance (TCR) and resistance stability were investigated as a function of sputtering pressure and post-deposition heat treatment time and temperature. A low sputtering pressure range of 0.13 to 0.40 Pa produced CuAlMo films with sheet resistance in the range 0.1 to 0.2 Ω/□ and resistance stability of 0.45 to 0.65% with a TCR of − 90 ppm/°C which could be shifted to zero following annealing in air at 425 °C. Films grown at higher sputtering pressures of 0.53 to 0.80 Pa had increased sheet resistance in the range 0.4 to 0.6 Ω/□ and inferior stability of 0.8 to 1.7% with a more negative TCR of − 110 to − 180 ppm/°C which could not be shifted to zero following annealing. The stability of the films grown at 0.13 and 0.40 Pa could be further improved to < 0.25% with heat treatment, due to the formation of a protective aluminium oxide layer. A minimum dwell time of 3 h at 425 °C was required to stabilise the films and set the electrical properties. - Highlights: • Thin films of copper–aluminium–molybdenum were sputtered on alumina substrates. • Film properties were investigated with variation in process conditions. • Low sputtering pressure gave improved electrical performance. • Post deposition annealing in air further improved electrical performance

Layer-by-layer thinning of MoSe_2 by soft and reactive plasma etching

International Nuclear Information System (INIS)

Sha, Yunfei; Xiao, Shaoqing; Zhang, Xiumei; Qin, Fang; Gu, Xiaofeng

2017-01-01

Highlights: • Soft plasma etching technique using SF_6 + N_2 as precursors for layer-by-layer thinning of MoSe_2 was adopted in this work. • Optical microscopy, Raman, photoluminescence and atomic force microscopy measurements were used to confirm the thickness change. • Layer-dependent vibrational and photoluminescence spectra of the etched MoSe_2 were also demonstrated. • Equal numbers of MoSe_2 layers can be removed uniformly without affecting the underlying SiO_2 substrate and the remaining MoSe_2 layers. - Abstract: Two-dimensional (2D) transition metal dichalcogenides (TMDs) like molybdenum diselenide (MoSe_2) have recently gained considerable interest since their properties are complementary to those of graphene. Unlike gapless graphene, the band structure of MoSe_2 can be changed from the indirect band gap to the direct band gap when MoSe_2 changed from bulk material to monolayer. This transition from multilayer to monolayer requires atomic-layer-precision thining of thick MoSe_2 layers without damaging the remaining layers. Here, we present atomic-layer-precision thinning of MoSe_2 nanaosheets down to monolayer by using SF_6 + N_2 plasmas, which has been demonstrated to be soft, selective and high-throughput. Optical microscopy, atomic force microscopy, Raman and photoluminescence spectra suggest that equal numbers of MoSe_2 layers can be removed uniformly regardless of their initial thickness, without affecting the underlying SiO_2 substrate and the remaining MoSe_2 layers. By adjusting the etching rates we can achieve complete MoSe_2 removal and any disired number of MoSe_2 layers including monolayer. This soft plasma etching method is highly reliable and compatible with the semiconductor manufacturing processes, thereby holding great promise for various 2D materials and TMD-based devices.

Structure and properties of MoO.sub.3./sub.-containing zinc borophosphate glasses

Czech Academy of Sciences Publication Activity Database

Šubčík, J.; Koudelka, L.; Mošner, P.; Montagne, L.; Revel, B.; Gregora, Ivan

2009-01-01

Roč. 355, 16-17 (2009), 970-975 ISSN 0022-3093 R&D Projects: GA AV ČR KAN301370701 Institutional research plan: CEZ:AV0Z10100520 Keywords : glass formation * glass es * phosphates * structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.252, year: 2009

Reentrant spin glass ordering in an Fe-based bulk metallic glass

Energy Technology Data Exchange (ETDEWEB)

Luo, Qiang; Shen, Jun, E-mail: junshen@tongji.edu.cn [School of Materials Science and Engineering, Tongji University, Shanghai 201804 (China)

2015-02-07

We report the results of the complex susceptibility, temperature, and field dependence of DC magnetization and the nonequilibrium dynamics of a bulk metallic glass Fe{sub 40}Co{sub 8}Cr{sub 15}Mo{sub 14}C{sub 15}B{sub 6}Er{sub 2}. Solid indication of the coexistence of reentrant spin glass (SG) and ferromagnetic orderings is determined from both DC magnetization and AC susceptibility under different DC fields. Dynamics scaling of AC susceptibility indicates critical slowing down to a reentrant SG state with a static transition temperature T{sub s} = ∼17.8 K and a dynamic exponent zv = ∼7.3. The SG nature is further corroborated from chaos and memory effects, magnetic hysteresis, and aging behavior. We discuss the results in terms of the competition among random magnetic anisotropy and exchange interactions and compare them with simulation predictions.

Deposition, characterization, and tribological applications of near-frictionless carbon films on glass and ceramic substrates

International Nuclear Information System (INIS)

Eryilmaz, O L; Johnson, J A; Ajayi, O O; Erdemir, A

2006-01-01

As an element, carbon is rather unique and offers a range of rare opportunities for the design and fabrication of zero-, one-, two-, and three-dimensional nanostructured novel materials and coatings such as fullerenes, nanotubes, thin films, and free-standing nano-to-macroscale structures. Among these, carbon-based two-dimensional thin films (such as diamond and diamond-like carbon (DLC)) have attracted an overwhelming interest in recent years, mainly because of their exceptional physical, chemical, mechanical, electrical, and tribological properties. In particular, certain DLC films were found to provide extremely low friction and wear coefficients to sliding metallic and ceramic surfaces. Since the early 1990s, carbon has been used at Argonne National Laboratory to synthesize a class of novel DLC films that now provide friction and wear coefficients as low as 0.001 and 10 -11 -10 -10 mm 3 N -1 m -1 , respectively, when tested in inert or vacuum test environments. Over the years, we have optimized these films and applied them successfully to all kinds of metallic and ceramic substrates and evaluated their friction and wear properties under a wide range of sliding conditions. In this paper, we will provide details of our recent work on the deposition, characterization, and tribological applications of near-frictionless carbon films on glass and ceramic substrates. We will also provide chemical and structural information about these films and describe the fundamental tribological mechanisms that control their unusual friction and wear behaviour

An experimental study: Role of different ambient on sulfurization of MoO{sub 3} into MoS{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Kumar, Prabhat, E-mail: prabhat89k@gmail.com; Singh, Megha; Sharma, Rabindar K.; Reddy, G.B.

2016-06-25

Molybdenum disulfide (MoS{sub 2}) nanostructured thin films (NTFs) were synthesised by sulfurizing MoO{sub 3} NTFs using three different non-conventional methods (named methods 1–3). Method 1 uses sulfur vapors, second employs H{sub 2}S/Ar gas and third adopts plasma of H{sub 2}S/Ar gas. HRTEM revealed formation of core–shell nanostructures with maximum shell thickness obtained in method 3. The samples showed uniform nanoflakes (NFs) throughout substrate, revealed by SEM, same as their precursor MoO{sub 3.} XRD and Raman analysis disclosed crystalline MoS{sub 2} and degree of crystallinity was greatest in case of sulfurization in plasma ambient. Quantitative analysis of sulfurized films carried out by XPS shows presence of MoS{sub 2} in all three methods with percentage found to be 18%, 87% and ∼100% respectively. The effect of sulfurizing ambient on its efficiency to convert MoO{sub 3} into MoS{sub 2} has been studied and it was found out that plasma ambient has resulted in high quality of MoS{sub 2} NTFs based on parameters as crystallinity, purity, uniformity and stoichiometry control. - Highlights: • Comparison of three non-conventional methods of sulfurization. • Parameters used for comparison are crystallinity, purity, sulfurized thickness, uniformity and stoichiometry. • H{sub 2}S/Ar plasma based method came out to be best among other techniques. • A soft template reactions for sulfurization of MoO{sub 3} nanoflake is proposed.

Ion transport studies in lithium phospho-molybdate glasses containing Cl− ion

International Nuclear Information System (INIS)

Gowda, V.C. Veeranna; Chethana, B.K.; Reddy, C. Narayana

2013-01-01

Highlights: • Addition of LiCl creates more conducting channels for Li + ion movement. • The decrease in E dc with increasing LiCl concentration could be due to Li + ions present in the columbic wells surrounded by Cl − ions are expected to be shallow. • Examined the power law fits using both two term and three term equation with fixed and floated parameters. -- Abstract: Ion conducting glasses in xLiCl–20Li 2 O–(80−x) [0.80P 2 O 5 –0.20MoO 3 ] glass system have been prepared over a wide range of composition (X = 5, 10, 15, 20 and 25 mol%). The electrical conductivity and dielectric relaxation of these glasses were analyzed using impedance spectroscopy in the frequency range of 10 Hz–10 MHz and in the temperature range of 313–353 K. D.c. activation energies extracted from Arrhenius plots using regression analysis, decreases with increasing LiCl mol%. A.c. conductivity data has been fitted to both single and double power law equation with both fixed and variable parameters. The increased conductivity in the present glass system has been correlated with the volume increasing effect and the coordination changes that occur due to structural modification resulting in the creation of non-bridging oxygens (NBO's) of the type O-Mo-O − bonds in the glass network. Dielectric relaxation mechanism in these glasses is analyzed using Kohlrausch–Williams–Watts (KWW) stretched exponential function and stretched exponent (β) is found to be insensitive to temperature

Fabrication and electrical resistivity of Mo-doped VO2 thin films coated on graphite conductive plates by a sol-gel method

Energy Technology Data Exchange (ETDEWEB)

Choi, W.; Jung, H.M.; Um, S. [Hanyang Univ., Seoul (Korea, Republic of). School of Mechanical Engineering

2008-07-01

Vanadium oxides (VO2) can be used in optical devices, thermochromic smart windows and sensors. This paper reported on a study in which vanadium pentoxide (V2O5) powder was prepared and mixed with Molybdenum Oxides (MoO3) to form Mo-doped and -undoped VO2 thin films by a sol-gel method on graphite conductive substrates. The micro-structure and chemical compositions of the Mo-doped and -undoped VO2 thin films was investigated using X-Ray diffraction and scanning electron microscopy. Changes in electrical resistivity were measured as a function of the stoichiometric compositions between vanadium and molybdenum. In this study. Mo-doped and -undoped VO2 thin films showed the typical metal to insulator transition (MIT), where temperature range could be adjusted by modifying the dopant atomic ratio. The through-plane substrate structure of the Mo-doped layer influences the electrical resistivity of the graphite substrate. As the amount of the molybdenum increases, the electrical resistivity of the graphite conductive substrate decreases in the lower temperature range below the freezing point of water. The experimental results showed that if carefully controlled, thermal dissipation of VO2 thin films can be used as a self-heating source to melt frozen water with the electrical current flowing through the graphite substrate. 3 refs., 3 figs.

Surface analysis of Borkron glass for neutron optics applications

International Nuclear Information System (INIS)

Farnoux, B.; Maaza, M.; Maaza, M.; Samuel, F.; Sella, C.

1991-01-01

Grazing Angle Neutron Reflectometry, Optical and Mechanical Roughness Profilometry techniques have been used to study the effects of the polishing operations on the surface of Borkron Schott glass (special borosilicate glass for neutron optics applications) as the polishing tool pressure P and the mean grain size of the polishing powder Φ. The neutron reflectivity investigations have shown that there is formation of a layer at the surface glass substrate. This layer is less dense than the bulk substrate and its thickness is around 60A. The optical and mechanical profilometry measurements have shown that both roughness and waviness decrease with P and Φ. All the experimental results show a good correlation between the neutron refractive index, the thickness and the roughness of the surface layer and the waviness of the glass surface with the two mechanical polishing parameters. The previous techniques have been completed by Secondary Ion Mass Spectroscopy and Atomic Force Microscopy measurements

Microstructure Characterization of WCCo-Mo Based Coatings Produced Using High Velocity Oxygen Fuel

Directory of Open Access Journals (Sweden)

Serkan Islak

2015-12-01

Full Text Available The present study has been carried out in order to investigate the microstructural properties of WCCo-Mo composite coatings deposited onto a SAE 4140 steel substrate by high velocity oxygen fuel (HVOF thermal spray. For this purpose, the Mo quantity added to the WCCo was changed as 10, 20, 30 and 40 wt. % percents. The coatings are compared in terms of their phase composition, microstructure and hardness. Phase compound and microstructure of coating layers were examined using X-ray diffractometer (XRD and scanning electron microscope (SEM. XRD results showed that WCCo-Mo composite coatings were mainly composed of WC, W2C, Co3W3C, Mo2C, MoO2, Mo and Co phases. The average hardness of the coatings increased with increasing Mo content.

Growth parameter enhancement for MoS{sub 2} thin films synthesized by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Serna, Martha I.; Higgins, Marissa; Quevedo-Lopez, Manuel A. [Materials Science and Engineering Department, The University of Texas at Dallas, 800 W Campbell Road RL 10, Richardson TX 75080 (United States); Moreno, Salvador [Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080 (United States); Choi, Hyunjoo [Department of Advanced Materials Engineering, Kookmin University, Jeongneung-dong Seongbuk-gu, Seoul 136-702 (Korea, Republic of); Minary-Jolandan, Majid [Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080 (United States); Alan MacDiarmid Nanotech Institute, The University of Texas at Dallas, 800 W Campbell Road RL 10, Richardson TX 75080 (United States)

2016-12-15

Two-dimensional materials such as graphene and MoS{sub 2} have been the main focus of intense research efforts over the past few years. The most common method of exfoliating these materials, although efficient for lab-scale experiments, is not acceptable for large area and practical applications. Here, we report the deposition of MoS{sub 2} layered films on amorphous (SiO{sub 2}) and crystalline substrates (sapphire) using a pulsed laser deposition (PLD) method. Increased substrate temperature (∝700 C) and laser energy density (>530 mJ /cm{sup 2}) promotes crystalline MoS{sub 2} films < 20 nm, as demonstrated by fast Fourier transform (FFT) and transmission electron microscopy (TEM). The method reported here opens the possibility for large area layered MoS{sub 2} films by using a laser ablation processes. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Structure of MoCN films deposited by cathodic arc evaporation

Energy Technology Data Exchange (ETDEWEB)

Gilewicz, A., E-mail: adam.gilewicz@tu.koszalin.pl [Koszalin University of Technology, Faculty of Technology and Education, Sniadeckich 2, 75-453 Koszalin (Poland); Jedrzejewski, R.; Kochmanska, A.E. [West Pomeranian University of Technology Szczecin, Faculty of Mechanical Engineering and Mechatronics, 19 Piastów Ave., 70-313 Szczecin (Poland); Warcholinski, B. [Koszalin University of Technology, Faculty of Technology and Education, Sniadeckich 2, 75-453 Koszalin (Poland)

2015-02-27

Molybdenum carbonitride (MoCN) coatings were deposited onto HS6-5-2 steel substrate using pure Mo targets in mixed acetylene and nitrogen atmosphere by cathodic arc evaporation. The structural properties of MoCN coatings with different carbon contents (as an effect of the C{sub 2}H{sub 2} flow rate) were investigated systematically. Phase and chemical composition evolution of the coatings were characterized both by the glancing angle of X-ray diffraction (XRD) and wavelength dispersive spectrometry, respectively. These analyses have been supplemented by estimates of grain sizes and stress in the coatings. The XRD results show that the increase in acetylene flow rate causes the formation of molybdenum carbide (MoC) hexagonal phase in the coatings, a reduction of grain size and an increase in internal stress. - Highlights: • MoN and MoCN coatings were deposited by cathodic arc evaporation in nitrogen atmosphere. • MoCN coatings were formed using different acetylene flow rates. • Phase composition evolution was observed. • Crystallite size and stress were calculated.

Molybdenum depletion around P-phases Ni-Cr-Mo-W weld metals

International Nuclear Information System (INIS)

Silva, Cleiton Carvalho; Miranda, Helio Cordeiro de; Farias, Jesualdo Pereira

2010-01-01

This work evaluated the local chemical composition in matrix/precipitate interface in a Ni-Cr-Mo-W alloy weld metals deposited on substrate of C-Mn steel. The microstructural characterization was carried out through optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The results had shown that the presence of secondary phases precipitates in the interdendritic region. Through SEM analysis were observed indications of depletion of Mo around these phases. These precipitates were identified as P-phase by TEM analysis. The Mo depletion indications were confirmed through EDS. The Mo depletion was a result of a reheating due to several welding heat cycles deposited to promote the coating layer. (author)

Preparation of CulnS2 Thin Films on the Glass Substrate by DC Sputtering for Solar Cell Component

International Nuclear Information System (INIS)

Bambang Siswanto; Wirjoadi; Darsono

2007-01-01

The CuInS 2 alloys were deposited on glass substrate using plasma DC sputtering technique. A CuInS 2 alloy target was made from Cu, In, Se powder with impurity of 99.998%. The deposition process was done with the following process parameter variations: deposition time and substrate temperature were the range of 15 to 45 min and 150 to 300 ℃, the gas pressure was kept at 1.4x10 -1 Torr. The purpose of the research is to obtain the solar cell component of CuInS 2 thin films. The electrical and optical properties measurement has been done by four-point probe and UV-Vis. Crystal structure was analyzed using X-ray diffraction (XRD). The result shows that minimum resistance of CuInS 2 thin films is 35.7 kΩ and optical transmittance is 14.7 %. The crystal structure of CuInS 2 is oriented at (112) plane and by Touc-plot method was obtained that the band gap energy of thin films is 1.45 eV. It could be concluded that the CuInS 2 thin film can be used as a solar cell component. (author)

Towards a uniform and large-scale deposition of MoS2 nanosheets via sulfurization of ultra-thin Mo-based solid films.

Science.gov (United States)

Vangelista, Silvia; Cinquanta, Eugenio; Martella, Christian; Alia, Mario; Longo, Massimo; Lamperti, Alessio; Mantovan, Roberto; Basset, Francesco Basso; Pezzoli, Fabio; Molle, Alessandro

2016-04-29

Large-scale integration of MoS2 in electronic devices requires the development of reliable and cost-effective deposition processes, leading to uniform MoS2 layers on a wafer scale. Here we report on the detailed study of the heterogeneous vapor-solid reaction between a pre-deposited molybdenum solid film and sulfur vapor, thus resulting in a controlled growth of MoS2 films onto SiO2/Si substrates with a tunable thickness and cm(2)-scale uniformity. Based on Raman spectroscopy and photoluminescence, we show that the degree of crystallinity in the MoS2 layers is dictated by the deposition temperature and thickness. In particular, the MoS2 structural disorder observed at low temperature (<750 °C) and low thickness (two layers) evolves to a more ordered crystalline structure at high temperature (1000 °C) and high thickness (four layers). From an atomic force microscopy investigation prior to and after sulfurization, this parametrical dependence is associated with the inherent granularity of the MoS2 nanosheet that is inherited by the pristine morphology of the pre-deposited Mo film. This work paves the way to a closer control of the synthesis of wafer-scale and atomically thin MoS2, potentially extendable to other transition metal dichalcogenides and hence targeting massive and high-volume production for electronic device manufacturing.

Preparation and characterization of molybdenum disilicide coating on molybdenum substrate by air plasma spraying

Energy Technology Data Exchange (ETDEWEB)

Wang, Yi [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Wang, Dezhi, E-mail: dzwang68@163.com [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Yan, Jianhui [Advanced Materials Synthesis and Application Technology Laboratory, Hunan University of Science and Technology, Xiangtan 411201 (China); Sun, Aokui [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

2013-11-01

MoSi{sub 2} oxidation protective coatings on molybdenum substrate were prepared by air plasma spraying technique (APS). Microstructure, phase composition, porosity, microhardness and bonding strength of the coatings were investigated and determined. Oxidation behavior of the coating at high temperature was also examined. Results show that composition of the coatings is constituted with MoSi{sub 2} and Mo{sub 5}Si{sub 3}, the surface morphology is described as flattened lamellar features, insufficiently flattened protuberance with some degree of surface roughness, a certain quantity of spherical particles, microcracks and pores. Testing results reveal that microhardness and bonding strength of the coatings increase, and porosity decreases with increasing power or decreasing Ar gas flow rate. Moreover, with decreasing the porosity, the microhardness of the coatings increases. The bonding strength of the coatings also increases with increasing spray distance. The MoSi{sub 2} coated Mo substrate exhibited a good oxidation resistance at 1200 °C.

Effect of sputtering parameters and substrate composition on the structure of tantalum thin films

Energy Technology Data Exchange (ETDEWEB)

Hallmann, Lubica, E-mail: lubica.hallmann@zzm.uzh.c [Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center of Dental Medicine, University of Zürich (Switzerland); Ulmer, Peter [Institute of Geochemistry and Petrology, ETH Zürich (Switzerland)

2013-10-01

The crystallographic properties of tantalum films deposited as a bioactive coating on Co–Cr–Mo and Ti–Al–Nb alloys have been investigated. The desired tough and ductile alpha phase of tantalum has been obtained by DC magnetron sputtering on Co–Cr–Mo and Ti–Al–Nb substrates. The thickness of the tantalum layer was between 20 and 600 nm. The crystallographic structure of tantalum thin film was dependent on the sputtering parameters such as DC power, bias voltage and gas impurities. Oxygen is an important factor for the stabilization of the tantalum alpha phase on Co–Cr–Mo substrate. The crystallographic structure and texture of tantalum thin films was found to be additionally dependent on the substrate composition. For Ti–Al–Nb substrate, oxygen content was not an important factor for the stabilization of the alpha phase. The observed shift of X-ray diffraction peaks to lower 2(θ) is an indication of stress evolving during the sputtering process and was dependent on bias voltage and oxygen content of the carrier gas.

Characterization of a smartphone size haptic rendering system based on thin-film AlN actuators on glass substrates

Science.gov (United States)

Bernard, F.; Casset, F.; Danel, J. S.; Chappaz, C.; Basrour, S.

2016-08-01

This paper presents for the first time the characterization of a smartphone-size haptic rendering system based on the friction modulation effect. According to previous work and finite element modeling, the homogeneous flexural modes are needed to get the haptic feedback effect. The device studied consists of a thin film AlN transducers deposited on an 110  ×  65 mm2 glass substrate. The transducer’s localization on the glass plate allows a transparent central area of 90  ×  49 mm2. Electrical and mechanical parameters of the system are extracted from measurement. From this extraction, the electrical impedance matching reduced the applied voltage to 17.5 V AC and the power consumption to 1.53 W at the resonance frequency of the vibrating system to reach the haptic rendering specification. Transient characterizations of the actuation highlight a delay under the dynamic tactile detection. The characterization of the AlN transducers used as sensors, including the noise rejection, the delay or the output charge amplitude allows detections with high accuracy of any variation due to external influences. Those specifications are the first step to a low-power-consumption feedback-looped system.

Characterization of a smartphone size haptic rendering system based on thin-film AlN actuators on glass substrates

International Nuclear Information System (INIS)

Bernard, F; Basrour, S; Casset, F; Danel, J S; Chappaz, C

2016-01-01

This paper presents for the first time the characterization of a smartphone-size haptic rendering system based on the friction modulation effect. According to previous work and finite element modeling, the homogeneous flexural modes are needed to get the haptic feedback effect. The device studied consists of a thin film AlN transducers deposited on an 110  ×  65 mm 2 glass substrate. The transducer’s localization on the glass plate allows a transparent central area of 90  ×  49 mm 2 . Electrical and mechanical parameters of the system are extracted from measurement. From this extraction, the electrical impedance matching reduced the applied voltage to 17.5 V AC and the power consumption to 1.53 W at the resonance frequency of the vibrating system to reach the haptic rendering specification. Transient characterizations of the actuation highlight a delay under the dynamic tactile detection. The characterization of the AlN transducers used as sensors, including the noise rejection, the delay or the output charge amplitude allows detections with high accuracy of any variation due to external influences. Those specifications are the first step to a low-power-consumption feedback-looped system. (paper)

Magnetic MoS2 on multiwalled carbon nanotubes for sulfide sensing.

Science.gov (United States)

Li, Chunxiang; Zhang, Dan; Wang, Jiankang; Hu, Pingan; Jiang, Zhaohua

2017-07-04

A novel hybrid metallic cobalt insided in multiwalled carbon nanotubles/molybdenum disulfide (Co@CNT/MoS 2 ) modified glass carbon electrode (GCE) was fabricated with a adhesive of Nafion suspension and used as chemical sensors for sulfide detection. Single-layered MoS 2 was coated on CNTs through magnetic traction force between paramagnetic monolayer MoS 2 and Co particles in CNTs. Co particles faciliated the collection of paramagnetic monolayer MoS 2 exfoliated from bulk MoS 2 in solution. Amperometric analysis, cycle voltammetry, cathodic stripping analysis and linear sweep voltammetry results showed the Co@CNT/MoS 2 modified GCE exhibited excellent electrochemical activity to sulfide in buffer solutions, but amperometric analysis was found to be more sensitive than the other methods. The amperometric response result indicated the Co@CNT/MoS 2 -modified GCE electrode was an excellent electrochemical sensor for detecting S 2- with a detection limit of 7.6 nM and sensitivity of 0.23 mA/μM. The proposed electrode was used for the determination of sulfide levels in hydrogen sulfide-pretreated fruits, and the method was also verified with recovery studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Glass fiber reinforced concrete for terrestrial photovoltaic arrays

Science.gov (United States)

Maxwell, H.

1979-01-01

The use of glass-fiber-reinforced concrete (GRC) as a low-cost structural substrate for terrestrial solar cell arrays is discussed. The properties and fabrication of glass-reinforced concrete structures are considered, and a preliminary design for a laminated solar cell assembly built on a GRC substrate is presented. A total cost for such a photovoltaic module, composed of a Korad acrylic plastic film front cover, an aluminum foil back cover, an ethylene/vinyl acetate pottant/adhesive and a cotton fabric electrical isolator in addition to the GRC substrate, of $9.42/sq m is projected, which is less than the $11.00/sq m cost goal set by the Department of Energy. Preliminary evaluations are concluded to have shown the design capabilities and cost effectiveness of GRC; however, its potential for automated mass production has yet to be evaluated.

Transparent Substrates for Plasmonic Sensing by Lithography-Free Fabrication

DEFF Research Database (Denmark)

Thilsted, Anil Haraksingh

This Ph.D. thesis presents fabrication and optimization of transparent plasmonic substrates that can be used for biological and chemical sensing by surface enhanced Raman spectroscopy (SERS) sensing and localized surface plasmon resonance refractive index (LSPR RI) sensing. These substrates are......-free fabrication methods, and resulted in large-area, high throughput and low cost production techniques. The fabrication techniques consisted of using aluminum patterned areas and reactive ion etching (RIE) to achieve nanopillars or nanocylinders in glass; using RIE to achieve nanopillars in silicon as a mould......, respectively. As the substrates were transparent, measurements from the backside were possible, showing a 44%, 1:7% and 71% Raman signal intensity in comparison to the measurements from the front, for the glass nanopillars, the polymer injected nanopillars and the transferred metal nanocaps, respectively...

Highly reflective polymeric substrates functionalized utilizing atomic layer deposition

Science.gov (United States)

Zuzuarregui, Ana; Coto, Borja; Rodríguez, Jorge; Gregorczyk, Keith E.; Ruiz de Gopegui, Unai; Barriga, Javier; Knez, Mato

2015-08-01

Reflective surfaces are one of the key elements of solar plants to concentrate energy in the receivers of solar thermal electricity plants. Polymeric substrates are being considered as an alternative to the widely used glass mirrors due to their intrinsic and processing advantages, but optimizing both the reflectance and the physical stability of polymeric mirrors still poses technological difficulties. In this work, polymeric surfaces have been functionalized with ceramic thin-films by atomic layer deposition. The characterization and optimization of the parameters involved in the process resulted in surfaces with a reflection index of 97%, turning polymers into a real alternative to glass substrates. The solution we present here can be easily applied in further technological areas where seemingly incompatible combinations of polymeric substrates and ceramic coatings occur.

Highly reflective polymeric substrates functionalized utilizing atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Zuzuarregui, Ana, E-mail: a.zuzuarregui@nanogune.eu; Gregorczyk, Keith E. [CIC Nanogune Consolider, de Tolosa Hiribidea 76, 20018 San Sebastián (Spain); Coto, Borja; Ruiz de Gopegui, Unai; Barriga, Javier [IK4-Tekniker, Iñaki Goenaga 5, 20600 Eibar (Spain); Rodríguez, Jorge [Torresol Energy (SENER Group), Avda. de Zugazarte 61, 48930 Las Arenas (Spain); Knez, Mato [CIC Nanogune Consolider, de Tolosa Hiribidea 76, 20018 San Sebastián (Spain); IKERBASQUE Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao (Spain)

2015-08-10

Reflective surfaces are one of the key elements of solar plants to concentrate energy in the receivers of solar thermal electricity plants. Polymeric substrates are being considered as an alternative to the widely used glass mirrors due to their intrinsic and processing advantages, but optimizing both the reflectance and the physical stability of polymeric mirrors still poses technological difficulties. In this work, polymeric surfaces have been functionalized with ceramic thin-films by atomic layer deposition. The characterization and optimization of the parameters involved in the process resulted in surfaces with a reflection index of 97%, turning polymers into a real alternative to glass substrates. The solution we present here can be easily applied in further technological areas where seemingly incompatible combinations of polymeric substrates and ceramic coatings occur.

Highly reflective polymeric substrates functionalized utilizing atomic layer deposition

International Nuclear Information System (INIS)

Zuzuarregui, Ana; Gregorczyk, Keith E.; Coto, Borja; Ruiz de Gopegui, Unai; Barriga, Javier; Rodríguez, Jorge; Knez, Mato

2015-01-01

Reflective surfaces are one of the key elements of solar plants to concentrate energy in the receivers of solar thermal electricity plants. Polymeric substrates are being considered as an alternative to the widely used glass mirrors due to their intrinsic and processing advantages, but optimizing both the reflectance and the physical stability of polymeric mirrors still poses technological difficulties. In this work, polymeric surfaces have been functionalized with ceramic thin-films by atomic layer deposition. The characterization and optimization of the parameters involved in the process resulted in surfaces with a reflection index of 97%, turning polymers into a real alternative to glass substrates. The solution we present here can be easily applied in further technological areas where seemingly incompatible combinations of polymeric substrates and ceramic coatings occur

Structure, thermal stability and resistance under external irradiation of rare earths and molybdenum-rich alumino-borosilicate glasses

International Nuclear Information System (INIS)

Chouard, N.

2011-01-01

In France, the highly radioactive nuclear liquid wastes arising from spent nuclear fuel reprocessing (fission products + minor actinides (FPA)) are currently immobilized in an alumino-borosilicate glass called 'R7T7'. In the future, the opportunity of using new alumino-borosilicate glass compositions (HTC glasses) is considered in order to increase the waste loading in glasses and thus significantly decrease the number of glass canisters. However, the increase of the concentration of FPA could lead to the crystallization of rare-earth-rich phases (Ca 2 RE 8 (SiO 4 ) 6 O 2 ) or molybdenum-rich phases (CaMoO 4 , Na 2 MoO 4 ) during melt cooling, which can modify the confinement properties of the glass (chemical durability, self-irradiation resistance..), particularly if they can incorporate radionuclides α or β in their structure. This thesis can be divided into two parts: The first part deals with studying the relationship that can occur between the composition, the structure and the crystallization tendency of simplified seven oxides glasses, belonging to the SiO 2 -B 2 O 3 -Al 2 O 3 -Na 2 O-CaO-MoO 3 -Nd 2 O 3 system and derived from the composition of the HTC glass at 22,5 wt. % in FPA. The impact of the presence of platinoid elements (RuO 2 in our case) on the crystallization of the different phases is also studied. The second part deals with the effect of actinides α decays and more particularly of nuclear interactions essentially coming from recoil nuclei (simulated here by heavy ions external irradiations) on the behaviour under irradiation of an alumino-borosilicate glass containing apatite Ca 2 Nd 8 (SiO 4 ) 6 O 2 crystals, that can incorporate actinides in their structure. Two samples containing apatite crystals with different size are studied, in order to understand the impact of microstructure on the irradiation resistance of this kind of material. (author) [fr

Structural determination of stable MoOx monolayers on O/Cu3Au(1 0 0): DFT calculations

International Nuclear Information System (INIS)

Valadares, George C.S.; Mendes, F.M.T.; Dionízio Moreira, M.; Leitão, A.A.; Niehus, H.

2012-01-01

Highlights: ► Molybdenum oxide is widely used in catalysis in the chemical industry. ► Recently, ultra-thin (monolayer) films of MoO x have been produced on top of O-Cu 3 Au substrates. ► XPS measurements suggest an unusual +5 charge state of the Mo cation. ► Seeking for a low-energy structure with good match to the experimental STM and XPS. ► Bader charges indicate indeed an intermediate charge state as compared to the more common Mo +4 O 2 and Mo +6 O 3 bulk oxides. -- Abstract: Using ab initio calculations based on density functional theory (DFT), we propose a geometrical structure for MoO x monolayers recently grown on O/Cu 3 Au(1 0 0) substrates. The proposed structure reproduces the p(2 × 2) symmetry found by scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED), as well as the intermediate oxidation state between Mo(IV) and Mo(VI) identified by X-ray photoelectron spectroscopy (XPS). Simulated STM images assign the bright spots in the experimental images to oxygen 2p states.

Characterization of Mo/Si multilayer growth on stepped topographies

NARCIS (Netherlands)

van den Boogaard, Toine; Louis, Eric; Zoethout, E.; Goldberg, K.A.; Bijkerk, Frederik

2011-01-01

Mo/Si multilayer mirrors with nanoscale bilayer thicknesses have been deposited on stepped substrate topographies, using various deposition angles. The multilayer morphology at the step-edge region was studied by cross section transmission electron microscopy. A transition from a continuous- to

Glass-solidification method for high level radioactive liquid waste

International Nuclear Information System (INIS)

Kawamura, Kazuhiro; Kometani, Masayuki; Sasage, Ken-ichi.

1996-01-01

High level liquid wastes are removed with precipitates mainly comprising Mo and Zr, thereafter, the high level liquid wastes are mixed with a glass raw material comprising a composition having a B 2 O 3 /SiO 2 ratio of not less than 0.41, a ZnO/Li 2 O ratio of not less than 1.00, and an Al 2 O 3 /Li 2 O ratio of not less than 2.58, and they are melted and solidified into glass-solidification products. The liquid waste content in the glass-solidification products can be increased up to about 45% by using the glass raw material having such a predetermined composition. In addition, deposition of a yellow phase does not occur, and a leaching rate identical with that in a conventional case can be maintained. (T.M.)