Ceramic Composite
G. Upender; V. Chandra Mouli; V. Sreenivasulu; Praveena Kuruva; M. Prasad
Abstract
The new tellurite glasses with chemical composition 64TeO2-15CdO-(20-x) ZnO-xLi2O-1V2O5 (x= 0, 5, 10, 15 and 20 mol %) were synthesized by traditional melt quench hardening method. The glass samples showed broad humps of typical amorphous phase in the X- ray diffraction patterns. The physical properties ...
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The new tellurite glasses with chemical composition 64TeO2-15CdO-(20-x) ZnO-xLi2O-1V2O5 (x= 0, 5, 10, 15 and 20 mol %) were synthesized by traditional melt quench hardening method. The glass samples showed broad humps of typical amorphous phase in the X- ray diffraction patterns. The physical properties of glass samples such as density (ρ), molar volume (Vm), oxygen packing density (OPD), refractive index (n), molar refractivity (Rm) and metallization parameter (M) were estimated. The Fourier transform infrared spectroscopy (FTIR) studies exhibited that replacement of ZnO by Li2O forms significantly some basic structural units of TeO4, TeO3/TeO3+1 and ZnO4. Differential scanning calorimetry (DSC) was employed to find out the glass transition temperature (Tg) and thermal stability ( ). The optical enthrallment studies exhibited that the cut-off wavelength (λ) decreases while optical energy gap (Eopt) and Urbach energy ( ) values increases with an increase an escalation of Li2O content. This tellurite glasses possess an important use such as sensor devices, storage of data system and industrial applications etc.
Bohdan V. Padlyak; Ihor I. Kindrat; Radoslaw Lisiecki; Volodymyr T. Adamiv; Ihor M. Teslyuk
Abstract
The spectroscopic and radiative properties of the Sm-doped borate glasses with Li2B4O7, LiKB4O7, CaB4O7, and LiCaBO3 basic compositions as new luminescent materials have been investigated and analysed. The borate glasses of high chemical purity and optical quality, doped with Sm2O3 in amounts of 0.5 ...
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The spectroscopic and radiative properties of the Sm-doped borate glasses with Li2B4O7, LiKB4O7, CaB4O7, and LiCaBO3 basic compositions as new luminescent materials have been investigated and analysed. The borate glasses of high chemical purity and optical quality, doped with Sm2O3 in amounts of 0.5 and 1.0 mol. % were obtained from corresponding polycrystalline compounds in the air atmosphere using standard glass synthesis technology. The spectroscopic properties of obtained Sm-doped glasses were studied using electron paramagnetic resonance (EPR), optical absorption, photoluminescence, and decay kinetics techniques. The Judd–Ofelt theory had been used for analysis of the optical absorption spectra and calculation of the phenomenological intensity parameters (Ω2, Ω4, Ω6). Radiative properties such as transition probabilities (Arad), branching ratios (βexp < /sub> and βrad), stimulated emission cross-sections (σe), and radiative lifetimes (τrad) were estimated for 4 G5/2 → 6 HJ (J = 5/2, 7/2, 9/2, and 11/2) emission transitions of the Sm 3+ ions in the Li2B4O7:Sm, CaB4O7:Sm, and LiCaBO3:Sm glasses containing 1.0 mol. % Sm2O3. The luminescence kinetics of Sm 3+ centres in the investigated glasses are characterised by a single exponent decay with typical lifetimes, which depend on the basic glass composition and Sm impurity concentration. Experimental lifetimes (τexp < /sub>) have been compared with those calculated (τrad) and quantum efficiencies (η) of the Sm 3+ emission transitions were estimated. The calculated high quantum efficiencies (~ 80 %) and measured high quantum yields of luminescence (~ 14 – 21 %) clearly show that the investigated glasses belong to very promising materials for luminescent and laser applications.