Structural and Physical Properties of ZnO Modified Bismuth Silicate Glasses

Zinc bismuth silicate glasses with compositions ( , and 40) have been prepared by conventional melt-quench technique and the solubility limit of zinc in bismuth silicate glass system has been estimated using X-ray diffraction technique. Density has been measured using Archimedes' principle; with increase in ZnO in the samples, the molar volume and density are found to decrease. The glass transition temperature ( ) has been determined by using differential scanning calorimetry (DSC) and is observed to increase with increase in ZnO content. Raman and FTIR spectra have been recorded at room temperature and the analysis of Raman and FTIR shows that in all the glass compositions, asymmetric and symmetric stretched vibrations of Si–O bonds in SiO4 tetrahedral units exist and with decrease in Bi2O3, the contribution of symmetric vibrations begins to dominate which results in increased compactness of the glass structure. 1. Introduction Glasses based on heavy metal oxide have attracted attention of researcher’s community for their excellent IR transmission compared with conventional glasses [1, 2]. The bismuth oxide glasses have wide range of applications for optical and electronic devices, mechanical sensors, and reflecting windows [3, 4]. Bi2O3 is not a classical glass former but due to high polarisibility and small field strength of Bi3+ ions, in the presence of conventional glass formers like SiO2, PbO and B2O3, a glass network of BiO3 and BiO6 may be built [5]. However, the structural role played by Bi2O3 in glasses is complicated. Bi2O3 is suitable for forming glass with high refractive index, nontoxicity, wide transmission range, and so forth [6]. SiO2 in its various amorphous forms has an extremely wide spectrum of industrial applications [7]. Several reports on ZnO-Bi2O3 with B2O3 and TeO2, CdO-ZnO-V2O5, V2O5-Bi2O3-B2O3, and V2O5-ZnO-Bi2O3 systems exist in literature [8–14], but physical and structural studies of SiO2-ZnO-Bi2O3 are rare. The aim of present paper is to investigate the effect of ZnO on physical and structural properties of bismuth silicate glass samples using the techniques of XRD, DSC, FTIR, and Raman spectroscopy. 2. Experimental The glass samples in the system with composition , and 40 were prepared using analar grade SiO2, Bi2O3, and ZnO chemicals, by conventional melt-quench method. However, the samples with (ZnO content) higher than 40 had also been tried to synthesize but we could not succeed. For the synthesis of samples, the weighed quantities of SiO2, ZnO and Bi2O3 in appropriate proportions were well-mixed using pestle mortar