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Glass System (glass + system)
Selected AbstractsOptical Properties of Co3O4 -Doped ZnO,B2O3,SiO2,Al2O3 Glass System for a Transparent Dielectric LayerJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2009Byung-Hwa Seo There has been a need to improve color temperature without using asymmetric cell structures using transparent dielectric layers with variation of Co3O4 contents in plasma display panel (PDP). In this study, ZnO,B2O3,SiO2,Al2O3 glasses with variations of the Co3O4 content (0, 0.5, 1.0, 1.5, and 2.0 wt%) were fabricated and the optical properties of these glasses were characterized. As the content of Co3O4 increased, the transmittance of the red region (from 580 to 780 nm) decreased more than of the blue region (from 380 to 500 nm). This change of transmittance induced the transition of the coordination of the color temperature toward the blue region. Therefore, the addition of 2 wt% Co3O4 can improve the color temperature from 6087 to 7378 K and the result was confirmed using simulation. [source] Spectroscopic and Thermal Properties of Ga2S3,Na2S,CsCl GlassesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2006Luiz C. Barbosa The synthesis and properties of the vitreous system (0.75,x)Ga2S3,0.25Na2S,xCsCl, with x varying from 0.1 to 0.2, are presented. Thermal, optical, and structural properties such as density, viscosity, thermal expansion coefficient, glass transition temperature, softening point temperature, refractive index, and absorption coefficient were measured using several techniques: X-ray diffraction, Raman scattering, differential thermal analysis, thermal mechanical analysis, and absorption spectroscopy. This glass system presents a high third-order non-linear optical susceptibility that can be significantly increased by increasing the CsCl content without affecting the low phonon frequency. [source] Physical Properties of Chalcogenide and Chalcohalide GlassesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2000Vinh Q. Nguyen The physical properties of glasses in the Ge30As10Se(60,x)Tex system with x= 25, 28, 30, and 35 at.% Te, the Ge30As10Se30Te(30,y)Iy system with y= 5, 10, 20, and 30 at.% I, the Ge30As10Se35Te(25,z)Iz system with z= 2, 6, 10, and 20 at.% I, and the [Ge30As10Se30Te30](100,w)Iw system with w= 0, 5, 10, and 20 at.% I have been investigated. The changes in the glass transition temperature, density, coefficient of thermal expansion, hardness, and viscosity are attributed to the delocalized metallic bonding character of Te in the substitution of Te for Se in the Ge-As-Se-Te glass system and the network-terminating role of iodine in the substitution of I for Te in the Ge-As-Se-Te-I glass system, respectively. [source] NiO-induced crystallization and optical characteristics of Li2O,CaF2,P2O5 glass systemPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2008G. Murali Krishna Abstract Li2O,CaF2,P2O5 glasses mixed with different concentrations of NiO (ranging from 0 mol% to 2.0 mol%) were crystallized. The samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy and differential thermal analysis. Studies were extended to optical absorption and magnetic susceptibility of these glass ceramic samples. The XRD and SEM studies reveal the presence of lithium phosphate, calcium phosphate and nickel phosphate crystal phases. The optical absorption studies together with magnetic susceptibility measurements indicate a gradual transformation of nickel ions from tetrahedral sites to octahedral sites (lasing sites) as the concentration of NiO is increased beyond 0.8 mol%. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] 1/f noise and slow relaxations in glassesANNALEN DER PHYSIK, Issue 12 2009A. Amir Abstract Recently we have shown that slow relaxations in the electron glass system can be understood in terms of the spectrum of a matrix describing the relaxation of the system close to a metastable state. The model focused on the electron glass system, but its generality was demonstrated on various other examples. Here, we study the noise spectrum in the same framework. We obtain a remarkable relation between the spectrum of relaxation rates , described by the distribution function P (,) , 1/, and the 1/f noise in the fluctuating occupancies of the localized electronic sites. This noise can be observed using local capacitance measurements. We confirm our analytic results using numerics, and also show how the Onsager symmetry is fulfilled in the system. [source] Antimicrobial Gallium-Doped Phosphate-Based Glasses,ADVANCED FUNCTIONAL MATERIALS, Issue 5 2008Sabeel P. Valappil Abstract Novel quaternary gallium-doped phosphate-based glasses (1, 3, and 5 mol % Ga2O3) were synthesized using a conventional melt quenching technique. The bactericidal activities of the glasses were tested against both Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Clostridium difficile) bacteria. Results of the solubility and ion release studies showed that these glass systems are unique for controlled delivery of Ga3+. 71Ga NMR measurements showed that the gallium is mostly octahedrally coordinated by oxygen atoms, whilst FTIR spectroscopy provided evidence for the presence of a small proportion of tetrahedral gallium in the samples with the highest gallium content. FTIR and Raman spectra also afford an insight into the correlation between the structure and the observed dissolution behavior via an understanding of the atomic-scale network bonding characteristics. The results confirmed that the net bactericidal effect was due to Ga3+, and a concentration as low as 1 mol % Ga2O3 was sufficient to mount a potent antibacterial effect. The dearth of new antibiotics in development makes Ga3+ a potentially promising new therapeutic agent for pathogenic bacteria including MRSA and C. difficile. [source] Enhanced Blue Emission from Transparent Oxyfluoride Glass,Ceramics Containing Pr3+:BaF2 NanocrystalsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2010Kaushik Biswas Transparent glass,ceramics containing Pr3+:BaF2 nanocrystals in the chemical composition of SiO2,BaF2,K2CO3,La2O3,Sb2O3 oxyfluoride glass systems have been prepared from melt quenching and with a subsequent heat-treatment method. The luminescence and structural properties of these materials have been evaluated and the results are reported. Rietveld analysis of X-ray diffraction patterns and investigation of transmission electron microscopy confirmed the presence of BaF2 nanocrystals dispersed in the heat-treated glass matrices. Measured UV-Vis-NIR absorption spectra exhibited nine bands of the transitions 3H4,3P2, (1I6, 3P1), 3P0, 1D2, 1G4, 3F3, 3F2, 3H6, and 3H5 from all the samples with nondegenerated 1I6 and 3P1 levels in the glass,ceramics. The photoluminescence spectra show an enhancement in the intensities upon ceramization, indicating the incorporation of Pr3+ ions into BaF2 nanocrystals that possess a low phonon energy (346 cm,1). This has further been corroborated from the observation of a significant threefold increase in the relative intensity ratio of blue (3P0,3H4) to red (1D2,3H4, 3P0,3H6) emissions from glass,ceramics compared with the glass. This is due to a significant decrease of multiphonon nonradiative relaxation from the 3P0 to the 1D2 level of Pr3+ in glass,ceramics. Time-resolved spectra exhibit 3P0 -level decays faster than the 1D2 level. [source] Use of CsCl to Enhance the Glass Stability Range of Tellurite Glasses for Er3+ -Doped Optical Fiber DrawingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2007Carmen Rosa Eyzaguirre Tellurite glasses are important as a host of Er3+ ions because of their good solubility and because they present broadband optical gain compared with Er3+ -doped silica, with the potential to increase the bandwidth of communication systems. However, the small glass stability range (GSR) of tellurite glasses compromises the quality of the optical fibers. We show that the addition of CsCl to tellurite glasses can increase their GSR, making it easier to draw good-quality optical fibers. CsCl acts like a network modifier in glass systems, weakening the network by forming Te,Cl bonds. We show that the thermal expansion coefficient mismatch is in the right direction for optical fiber fabrication purposes and that the Bi2O3 content can be used to control the refractive index of clad and core glasses. Single-mode and multi-mode Er3+ -doped optical fibers were produced by the rod-in-tube method using highly homogeneous TeO2,ZnO,Li2O,Bi2O3,CsCl glasses. [source] | |||||||||||||