Enhancement on thermal, elastic and optical properties of new formulation tellurite glasses: Influence of ZnO as a glass modifier

Abstract

New formulation of binary zinc-tellurite glasses with empirical formula (ZnO)y(TeO2)1-y where y = 0, 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30 (mol%) have been synthesized by melting and quenching methods. The homogenous glassy phase of zinc-tellurite glasses is proved by XRD measurement. DSC curves discovered that the tellurite glass former was added with modifier ZnO would decrease the glass transition temperature and increased the glass thermal stability. According to the FTIR and Raman spectra, the addition of ZnO into the tellurite glass networks would break the Te–O–Te bonds of TeO4 to TeO3 units and increase the non-bridging oxygen production, which influences the elastic moduli analyses. The optical absorption edge by UV–vis analysis is observed to shift from lower to higher wavelength value with the increment of ZnO molar fraction where it is associated to the less rigidity in the structure of glasses. The calculation of the optical band gap value is seen to be decreased non-linearly with the increase in the amount of ZnO content.