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Linear optical properties, optical dielectric constants, and dielectric loss as well as gamma-ray protection capacities of PbO reinforced TeO2–WO3 glasses with chemical composition 20WO3–(80 − x)TeO2–xPbO: x = 10 (WTPb1), 12.5 (WTPb2), 16.25 (WTPb3), 17.5 (WTPb4), and 20 (WTPb5) mol% have been investigated. Density of the investigated glasses gradually enhanced from 5.58 g/cm3 for WTPb1 sample to 5.90 g/cm3 for WTPb5 sample. The indirect optical energy band gap (EOptical) reduced from 2.28 to 2.10 eV. Urbach’s energy (ΔE) improved from 0.225 to 0.255 eV with increasing PbO content mol%. Optical real ( ε 1 ), imaginary ( ε 2) parts of dielectric constant, dielectric loss (tan δ), the refractive index (n), and the extinction coefficient (k) were improved as PbO content enhanced in TWPb glasses. Insertion of PbO in the glass matrix has a direct constructive effect on both the mass (MAC) and linear (LAC) attenuation coefficients for all photon energy among all investigated samples. The highest values of MAC and LAC were possessed for WTPb5 sample, while the lowest values were possessed for WTPb1 sample. In terms of half-value layer (HVL) parameter, the lowest values of HVL were possessed for WTPb5. The effective atomic number (Zeff) of the WTPb glasses has a similar trend of MAC and LAC. Results confirm that WTPb glasses can be considered as a superior for radiation protection compared to some commercial concrete radiation shielding materials. [ABSTRACT FROM AUTHOR]

This study aims to study the radiation shielding features of TeO2–WO3–RO systems (where RO =PbO and Bi2O3). The glasses were theoretically evaluated by using the simulation code Phy–X/PSD. Four TeO2–WO3–Bi2O3 glasses and three TeO2–WO3–PbO glasses were tested in this study. The linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), effective atomic number (Zeff), half value layer (HVL), tenth value layer (TVL), and mean free path (MFP) of the glasses were calculated and analyzed. WTeBi3 and WTeBi4 have the greatest LAC and MAC values at all energies, while WTePb1 had the least LAC and MAC values. At 0.347 MeV, the MAC of the glasses is equal to 0.115 0.117, and 0.107 cm2/g for WTeBi3, WTeBi4, and WTePb1, respectively. The Zeff of the glasses decreased and increased based on the photon interaction phenomena present in low, medium, and high energy ranges. WTeBi2 has the greatest HVL, equal to 2.070 cm and 2.594 cm at 1.333 and 2.506 MeV, respectively, while WTeBi3 has the least, 1.943 cm and 2.532 cm for the same energies, respectively. The TVL values followed the order of WTePb1 < WTePb2 < WTeBi2 < WTePb3 < WTeBi1 < WTeBi3 < WTeBi4 at both the tested energies. The greatest MFPs were observed at the greatest selected energy, 2.506 MeV. The TeO2–WO3–Bi2O3 glasses and TeO2–WO3–PbO glasses were compared against each other and with some other radiation glasses to determine the most effective attenuator. [ABSTRACT FROM AUTHOR]

The authors reported the data found by FT-IR spectroscopy, and ultrasonic velocities investigations of 65TeO2 – 25TiO2 – (10-x) CdO – x La2O3, (0 ≤ x ≤ 10 mol%) of the prepared glass samples. FT-IR spectra of these glass samples have been indicated the cadmium lanthanum tellurite titanate glasses increase the transformation of (TeO4) structural units into (TeO3) structural units with creation of non-bridging oxygen. The mechanical properties have been associated with the results of FT-IR spectra. It was noted that the elastic-moduli, and density of these samples slightly decrease with the increase of lanthanum due to the creation of non-bridging oxygen. UV–visible spectroscopy was recorded at room temperature for these glasses. The increase of Lanthanum shifts the optical spectra to the redshift of the optical bandgap. So, lanthanum is accountable for the increase of non-bridging oxygen due to this shift is obtained. So, the optical bandgap of these glasses has been decreased as well as the refractive index. Polarizability and basicity of the prepared glasses according to the refractive index and optical bandgap have been investigated. [ABSTRACT FROM AUTHOR]

In this paper we study the structural and electrical behavior of glass-ceramic material of general formula: xMgO (1-x) (0.5V2O5.0.5MoO3)2TeO2 (0≤x≤0.9) through measurements of density, molar volume, oxygen packing density (OPD), differential scanning calorimetry (DSC) and Raman spectroscopy: electric behavior was studied by impedance spectroscopy. We found that magnesium cation induces the growth of slightly crystallized areas inside the material. Those nanocrystallizations were detected to a greater extent by atomic force microscopy (AFM) and in lesser extent by X-ray diffraction (XRD). Regarding the electrical measurements, it can be established that magnesium cation does not act as good ionic conductor in this material.En este trabajo estudiamos la estructura de un material vítreo cuya fórmula general es: xMgO(1-x)(0.5V2O5.0.5MoO3)2TeO2 (0≤x≤0.9), mediante medidas de densidad, volumen molar, empaquetamiento denso de oxigeno (OPD), calorimetría diferencial de barrido (DSC) y espectroscopia Raman; el comportamiento eléctrico se estudió por medio de espectroscopia de impedancia. Encontramos que el catión magnesio induce el crecimiento de zonas levemente cristalizadas dentro del material. Dichas nanocristalizaciones pudieron ser detectadas en mayor medida por microscopia de fuerzas atómicas (AFM) y en menor medida se pudo observar en los patrones de difracción de Rayos X (DRX). Con respecto a las propiedades eléctricas, se puede establecer que el catión magnesio no actúa como buen conductor iónico en este material.

Quaternary tellurite glass systems in the form 75TeO2-15ZnO-(10-x) Nb2O5-xGd2O3 (x=0.5, 1.0, 1.5, 2.0 and 2.5 mol%) have been prepared by the melt quenching technique. Density, molar volume and oxygen packing density of every glass composition have been measured and calculated. Differential thermal analyses (DTA) have been carried out on the prepared glass systems in the temperature range 300-800 K at heating rate 5, 10, 15, and 20 °C/min. The glass transition, Tg and crystallization, Tc temperatures values were measured by using DTA. Kinetics parameters like activation energy of relaxation structure Et, activation energy of crystallization, Ec and order of crystallization have been calculated for every glass composition. Structural parameters like number of bonds per unit volume (nb) and average stretching force constant (F ¯) have been calculated to interpret the experimental data. [ABSTRACT FROM AUTHOR]

Abstract: The glasses of the composition (45−x)ZnF2–xWO3–49TeO2:1.0Nd2O3/Sm2O3/Eu2O3 with x varying from 5 to 20mol% were synthesized. Optical absorption, fluorescence spectra (in the spectral range 400–2300nm) and also fluorescence decay were studied at ambient temperature. The Judd–Ofelt theory analysis was applied to characterize the absorption and luminescence spectra of Ln3+ ions in these glasses. Following the luminescence spectra, various radiative properties like transition probability A, branching ratio β and the radiative life time τ for 4F3/2 → 4I11/2, 4G5/2 → 6H7/2, 5D0 → 7F2 emission levels respectively for Nd3+, Sm3+ and Eu3+ doped glasses of these glasses have been evaluated. The variations observed in these parameters were discussed following of varying co-ordinations (tetrahedral and octahedral positions) and the valence states of tungsten ions in the glass network. A significant enhancement in the intensities of 4F3/2 → 4I11/2 (Nd3+), 4G5/2 → 6H7/2 (Sm3+) and 5D0 → 7F2 (Eu3+) emission lines has been observed with increase of WO3 content; this is attributed to the increase in the concentration W5+ ions in the glass network that acts as modifiers. The quantitative analysis of these results (with the aid of the data on ESR, IR and Raman spectral studies) has indicated that the glasses mixed with around 15mol% of WO3 have the optimum concentration for yielding the highest quantum efficiency with low phonon losses for the above-mentioned principal transitions. [Copyright &y& Elsevier]

• 1- Melt quenching technique has been used to prepare Bi 2 O 3 -B 2 O 3 -TeO 2 glasses. • 2- Glass density is increased while molar volume decreases with the addition of Bi 2 O 3. • 3- The glass ceramics have been prepared. A series of glass samples based on the concentration of bismuth oxide with the following compositions (90-x) TeO 2 – 10B 2 O 3 – xBi 2 O 3 were x variety 40 ≤ x ≤ 80 mol % have been designed and assembled using the melt quenching technique. The optical properties of these glasses studied by spectrophotometer. The various physical parameters of the studied glasses will be estimated. The glass ceramic has been prepared of the parent glass produced by controlled heat treatment. The density of the glass ceramic is higher than the of the parent glass. The crystalline phases of prepared glass ceramic confirmed by XRD. The XRD of the corresponding glass ceramic shows all samples in nano size. The transmission electron microscope (TEM) used to determine the crystallinity and the particles size of the heat treated of the prepared glasses. The structural of the glass–ceramic prepared confirmed by FT-IR spectra. [ABSTRACT FROM AUTHOR]