Electrical, dielectric, and optical properties of Sb2O3–Li2O–MoO3 glasses

International audienceTemperature and frequency dependencies of DC and AC conductivities, dielectric response, static permittivity, optical absorption edge, infrared absorption spectrum, density, and temperatures of glass transition and crystallization for lithium molybdenum–antimonite glasses, (80 − x)Sb2O3–20Li2O–xMoO3, where x = 0–40, are measured and discussed. The DC conductivity increases with increasing concentration of MoO3. At 150 °C, it ranges from 5 × 10− 11 S/m up to 3 × 10− 8 S/m. Polaron hopping between Mo5 + and Mo6 + ions contributes, probably, to the DC conductivity. Ionic conductivity by Li+ ions is also present. The conduction activation energy monotonously decreases from 1.15 eV, at x = 5, down to 0.91 eV, at x = 40. In all glasses with x > 0, the conduction activation energy is close to a half of the indirect allowed optical gap. The pre-exponential factor, σ0, goes through a sharp maximum close to the composition (x = 20) with both the highest glass transition temperature and the largest thermal stability range. The frequency dependence of the AC conductivity is composed of three components — the DC conductivity and two AC components. For x = 35 and 40, the activation energy of electrical relaxation is equal to 0.954 ± 0.008 eV and the pre-exponential factor of relaxation times is equal to (4 ± 1) 10− 14 s. The static relative permittivity ranges from 17.4 to 23.0. Strong extrinsic absorption bands in infrared region originate from hydroxyl ions, CO2 impurities, and silicon–oxygen vibrations. The UV–visible indirect allowed absorption edge shifts from 2.6 eV to 2.1 eV with increasing MoO3 content. With increasing MoO3 content the glasses darken, from a light yellow color, at x = 0, to a deep brown color, at x = 40

Etude de la dévitrification des verres Sb2O3-PbI2

International audienc

Mechanical, thermal and optical properties of new chloroantimonite glasses in the Sb₂O₃–PbCl₂–AgCl system

New chloroantimonite glasses were obtained in the Sb₂O₃–PbCl₂–AgCl ternary system. Thermal, optical and mechanical properties were studied. The silver chloride concentration was increased at the expense of antimony oxide according to the following composition rules: (80–x)Sb₂O₃–20PbCl₂–xAgCl; (70–x)Sb₂O₃–30PbCl₂–xAgCl. Depending on AgCl content, Vickers micro-hardness varied between 110 MPa and 140 MPa. Elastic moduli were measured by ultrasonic velocity. The optical transmission range extended from 400 nm in the visible spectrum to 7 mm in the infrared spectrum. The refractive index was close to 2. Glass transition temperature measured by DSC ranged from 250 to 290°C. It was noticed that the glass transition temperature decreased as AgCl substitute for Sb₂O₃ and the more stable system was with 20% PbCl₂ in the (80–x)Sb₂O₃–20PbCl₂–xAgCl.Описано нові хлорантімонітові скла, отримані в потрійній системі Sb₂O₃–PbCl₂–AgCl. Подано результати дослідження їх теплових, оптичних і механічних властивостей. Вміст хлориду у складі цих матеріалів збільшено, що вплинуло на їх мікротвердість. Залежно від вмісту AgCl мікротвердість скла змінювалася в межах від 110 до 140 МРа. Оптичний діапазон пропускання збільшений з 400 nm у видимій області спектра до 7 mm в інфрачервоному спектрі. Показник заломлення ~2. Температура склування, виміряна методом диференційної сканівної калориметрії, коливалася в межах 250...290°С. Відмічено, що вона зменшується за заміни Sb₂O₃ AgCl і найстабільніша система з 20% PbCl₂ у склі (80–x)Sb₂O₃–20PbCl₂–xAgCl.Описаны новые хлорантимонитовые стекла, полученные в тройной системе Sb₂O₃–PbCl₂–AgCl. Представлены результаты исследований их тепловых, оптических и механических свойств. Содержание хлорида в составе этих материалов увеличено, что повлияло на их микротвердость. В зависимости от содержания AgCl микротвердость стекла изменялась в пределах от 110 до 140 МРа. Оптический диапазон пропускания увеличен от 400 nm в видимой области спектра до 7 mm в инфракрасном спектре. Показатель преломления ~2. Температура стеклования, измеренная методом дифференциальной сканирующей калориметрии, колебалась в пределах 250...290°С. Отмечено, что она уменьшается в меру замены Sb₂O₃ AgCl и наиболее стабильная система с 20% PbCl₂ в стекле (80–x)Sb₂O₃–20PbCl₂–xAgCl

Physical properties of new Sb2O3-V2O5-K2O glasses

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Mechanical, Thermal, and Optical Properties of New Chloroantimonite Glasses in the Sb2O3-PbCl2 -Ag Cl System

International audienceNew chloroantimonite glasses were obtained in the Sb2O3 - PbCl2 -AgCl ternary system. Their thermal, optical, and mechanical properties are studied. The concentration of silver chloride increases at the expense of antimony oxide accordingtothe following composition rules: (80-x)Sb2O3 -20PbCl(2) -xAgCl and (70-x)Sb2O3 -30PbCl(2) -xAgCl. Depending on the AgCl content, Vickers microhardness varied between 110 MPa and 140 MPa. The elastic moduli were measured by ultrasonic velocity. The optical transmission range extended from 400 nm in the visible spectrum to 7 mu m in the infrared spectrum. The refractive index was close to 2. The glass transition temperature measured by the DSC ranged from 250 to 290A degrees C. It is shown that the glass transition temperature decreases as AgCl substitutes for Sb2O3 and a more stable system was with 20% PbCl2 in the (80-x)Sb2O3 -20PbCl(2) -xAgCl

Synthesis and physical properties of glasses in the Sb2O3-PbCl2-MoO3 system

International audienceLead chloroantimonite glasses form stable binary glasses that may accommodate numerous oxides or halides as a third component. Molybdenum trioxide is a glass progenitor leading to molybdate glasses. Ternary glasses have been synthesized and studied in the Sb2O3-PbCl2-MoO3 system. Compositional limits of glass formation are reported and two series of glass samples have been prepared corresponding to the general formulas: (90 − x)Sb2O3-xPbCl2-10MoO3 and (90 − x)Sb2O3-xMoO3-10PbCl2. Glass transition temperature is close to 290 °C at high Sb2O3 content and decreases as antimony oxide is substituted by MoO3 or PbCl2. Position, width and intensity of crystallization peak suggest that devitrification rate is small in some composition ranges. The evolution of density, thermal expansion, refractive index and microhardness has been studied as a function of composition parameter x. Deviations from linearity are observed. They suggest structural changes in the case of the MoO3/Sb2O3 substitution while it appears that molar volume increases linearly versus lead content in the other series of glasses. Refractive index is close to 2.04. Optical transmission ranges from 550 nm in the visible spectrum to 5.5 μm in the infrared. It is limited by extrinsic absorption bands arising from hydroxyls and silicon impurities. Young's, bulk and shear moduli have been measured for the two series of samples

Glass formation in the Sb2O3-CdCl2-SrCl2 ternary system

International audienceVitreous systems based on antimony oxide Sb2O3 have been investigated. The limits for glass formation are reported in the Sb2O3-CdCl2-SrCl2 ternary system, and in the Sb2O3-SrCl2-(0.5CdCl2 + 0.5ZnCl2) pseudo ternary system. Amorphous state is confirmed by XRD patterns. Thermal measurements implemented by differential scanning calorimetry show that Tg is above 300 °C. As a general trend, Tg increases with chloride content. These glasses have an extended transmission in the mid-infrared spectrum with a refractive index larger than 2. The influence of the CdCl2/Sb2O3 substitution on the physical properties has been studied in the (90 − x)Sb2O3-xCdCl2-10SrCl2 system: thermal expansion, Vickers microhardness, Young and bulk modulus decrease as cadmium concentration increases. An inverse dependence is observed for shear modulus. This behaviour is discussed in relation to structural hypothesis

Spectroscopic and Judd-Ofelt Analysis of Nd3+ Ion Doped Lithium Antimony-Borate Glasses for Visible and Near Infrared Laser Application Compared to Standard Emission at 1.06 μm

International audienceThe present work focuses on the spectroscopic luminescence analysis of trivalent neodymium-doped lithium antimony-borate glasses, with the glass composition 70 Sb2O3-(25-x) B2O3-5 li(2)O-x Nd2O3 where x = 0.3; 0.5; 0.7 mol% (SBLN). Around 475 nm excitation used by the transition I-4(9/2 )-> (2)G(9/2) + D-2(3/2) + K-2(15/2) and that induced emission lines of wavelengths lambda emis = 584;673;767;826 nm (red is low intensity). The specific emission follows the transitions (2)G(7/2) + (4)G(5/2b)-> I-4(J) (J = 9/2; 11/2; 13/2; 15/2). Previous work on Nd3+ doped glasses studied near-infrared emission in 4F3/2-> 4IJ mode (J = 9/2; 11/2; 13/2) via near-infrared excitation( 4)I(9/2)-> F-4(5/ 2)+H-2(9/2). The Judd-Ofelt analysis applied to SBLN glasses showed that the S2K parameters are consistent with the values in the literature. SBLN7 glass has the best spectroscopic factor Omega(4)/Omega(6) = 0.974; while the best luminescence branching ratio is that of the green emission and it stands at an average beta = 70%. Similarly, green emission has the best values of stimulated emission cross section and gain bandwidth. Calculated and measured lifetimes are ranged between 15 and 40 microseconds; however, quantum efficiency varies between 50 and 91%. In another side calculated and measured refractive index values are very close. The chromatic coordinates of observed green color showed accurately that lies in the yellowish-green region of the chromaticity diagram edited by CIE 1931. The calculation of its temperature was made by Mc Macy's equation, and it is in the limits of 5100 K; which corresponds to a cool color similar to midday sunlight

Spectroscopic analysis of up conversion luminescence in doped halogeno-antimonite glass

International audienceThe up-conversion emission of Nd3+, Sm3+ and Er3+ has been studied in a new halogeno-antimonite glass with the chemical composition 80 Sb2O3 – 10 ZnBr2 – 10 KCl. Doping concentration was 0.2 mol% of lanthanide (Ln) ions. Rare earths were introduced as fluorides LnF3 that were further converted into oxides. Main physical properties of base glass were measured, including density, thermal expansion, characteristic temperatures, refractive index and optical transmission. The amount of residual hydroxyls was calculated from the OH absorption band around 3000 nm. The recorded up-conversion emission lines are λem = 536 nm for Nd3+ pumped at 805 nm; λem = 563 nm, 600 nm, 631 nm and 645 nm for Sm3+ pumped at 945 nm; λem = 531 nm for Er3+ pumped at 798 nm. Co-doped glass (0.1 Yb3+ + 0.1 Er3+) pumped at 980 nm has three emission lines at 524 nm, 545 nm and 650 nm. Corresponding transitions have been identified and the mechanisms ruling the up-conversion process is discussed. They include excited state absorption (ESA), energy transfer (ET) cooperative energy transfer (CET), emission assisted by phonon (EAP), multiphonon relaxation (MR) and cross- relaxation (CR)

Influence of molybdenum oxide on structural, optical and physical properties of oxychloride glasses for nonlinear optical devices

International audienceThe unconventional Heavy Metal Oxide Glasses (HMOG) are characterized by a low phonon energy, large infrared range transmission, high refractive index and nonlinear optical properties. Ternary glasses have been synthesized and studied in the Sb2O3– MoO3-ZnCl2 system. Further, the glass formation compositional limits are reported and some glass samples with the formula: (90-x)Sb2O3 -xMoO3–10 ZnCl2 (10 ≤ x ≤ 50, mole%) were elaborated. Thermal properties have been measured and indicating that the glass transition temperature decreases with increasing proportions of molybdenum oxide. The evolution of density, microhardness and elastic modulus has been studied as functions of parameter x and Raman spectra measurements have been shown the partial conversion of MoO6 octahedral units into MoO4 tetrahedral