CHARACTERIZATION OF Pr6O11 DOPED ZINC FLUOROBORATE GLASS

Pr3+ doped zinc fluoroborate glasses with the chemical composition [(mol %) 30ZnF2 – 20 TeO2 – (50-x) B2O3 – xPr6O11] (where x = 0.0, 0.1, 0.5, 1.0 and 1.5 mol %) of different concentration of rare earth element praseodymium (Pr3+) have been prepared by conventional melt quench technique. The physical parameters like density, refractive index, number density, molar refraction, molar electronic polarizability, electronic polarizability, dielectric constant, polaron radius, inter–ionic separation, molar volume and oscillator strength of these glasses were calculated as a function of dopant concentration. The densities and refractive indices of these glasses were found to be in the range 2.0 g/cm3 - 2.67 g/cm3 and 1.644 – 1.73 respectively. Stability of the glass doped with 1.0 mol % Pr3+ was found to be 120

The Study of Electron Beam Irradiation on Eu2O3 Doped Pbf2 - Teo2 - B2O3 Glasses

We report here the combined structural, optical andthermal studies carried out for the prepared Eu2O3 doped PbF2-TeO2-B2O3 glass [built using melting molding technique] samplesbefore and after being subjected to electron beam of energy 7.5MeV [Dose: 150 kGy], containing 0-2.5 mol% of Eu2O3. Theincrease in densities of the samples both before and afterirradiation has been understood, mainly due to the UV-VIS-NIRdata, energy band gap (Eg) values and the characteristictemperatures obtained from Differential Scanning Calorimetry(DSC) study. The decrement in the values of energy band gapand the shifting of the absorption cut-off wavelength of UV-VISNIRspectra towards red edge, proved the formation of colorcenters in the glass network after irradiation. The changes in thephysical appearance of the glasses from light yellow to deepyellowish color after irradiation were studied through colormeasurement. The change in Hunter L values after irradiation,through color measurement was a proof for the color centers orabsorption centers created in the glass sites. Glass transformationtemperatures [glass transition (Tg), onset of crystallization (Tx),crystallization (Tc) and melting temperature (Tm)] throughDifferential Scanning Calorimetry (DSC), were analyzed to studythe thermal effects on amorphized borate glasses and check itsreaction on stability and vitreous network of the glass samplesboth before and after electron beam irradiation

Influence of 1.25 MeV gamma rays on optical and luminescent features of Er3+ doped zinc bismuth borate glasses

Glasses based on 10ZnO-5Na2CO3-10Bi2O3-(75-x)B2O3-xEr2O3 with x = (0, 0.1, 0.3, 0.5, 0.7, 1.0) mol%, were synthesized by melt quenching technique and characterized through optical and luminescent features, before and after irradiating them with high energy (1.25 MeV) gamma rays. The amorphous nature of the glasses and the presence of various structural groups like BiO6, BO3 and BO4 were confirmed through XRD and FTIR measurements. Optical properties were studied through UV–VIS–NIR absorption spectra. Decrease in band gap values after gamma irradiation confirmed the creation of color centers in the glass matrix. Thermally stimulated Luminescence (TL) and Optically Stimulated Luminescence (OSL) spectroscopy techniques were used to study the trap centers induced after irradiation. The number of peaks and their trapping parameters were assessed using the Computerized Glow Curve Deconvolution (CGCD). The linearity in dose response proves their suitability in usage for dosimeter and shields in radiation zones within the dose. Keywords: Absorption, Erbium, Optically Stimulated Luminescence, Thermoluminescence, Scanning Electron Micrograph, Trap parameter

Physical, structural and optical properties of Sm3+ doped lithium zinc alumino borate glasses

WOS:000469890100015Sm3+ doped lithium zinc alumino borate glasses with composition 15ZnF(2)-12Li(2)CO(3)-10BaO-8Al(2)O(3) (55-x) B2O3-xSm(2)O(3) where x = 0.1, 0.3, 0.5, 0.7 and 1.1 mol% were prepared by conventional melt quenching technique Their optical, physical, structural, mechanical and luminescence properties are investigated. UV-Vis-NIR absorption spectra showed all possible transitions of samarium ion in this glass matrix. Band gap values for all the glass samples were above 3 eV confirming the insulating nature for the glass. Densities, assessed using the Archimedes rule, were observed to be increasing with increasing samarium concentration. Increase in molar volume with addition of samarium content indicated that the extension of glass network is on account of the increase of number of Non-Bridging Oxygens created by network modifier samarium ions. Scanning Electron Microscopy (SEM) image showed a smooth surface for the synthezied glass. X-Ray Diffraction (XRD) technique was employed to verify the amorphous nature of the glasses. A Makishima and Mackenzie theoretical model gave acceptable approximation of elasticity constants viz. Young's modulus, shear modulus, bulk modulus and Poisson's ratio. The high Vickers hardness values evaluated with mechanical loads of 50, 100, 300, 500, 1000 g force, proved the stability of the glasses. Emission spectra showed a prominent transition (4)G(5/2) -> H-6(7/2) at 598 nm excited with H-6(5/2) -> P-4(3/2) transition at 401 nm. Luminescence quenching effect was observed beyond 0.3 mol% Sm2O3 addition. The chromaticity coordinates (x, y) clustered in the orange-red region, making these Sm3+ doped lithium zinc alumino borate glasses suitable candidate for applications in LEDs and solid-state lasers