No abstract

No abstract

No abstract

Using standard melt-quench technique, transition metal oxide (2 mol% of V 2 O 5) doped glasses having composition xZnO•(30 − x)Li 2 O•70B 2 O 3 (x = 0, 2, 5, 7 and 10) are prepared. The density (D) is measured using buoyancy and found to be lying between 2.21 and 2.45 g/cm 3 with an increasing trend on substituting ZnO contents in place of Li 2 O. The theoretical optical basicity (th) is calculated and found to increase with increasing inclusion of ZnO indicating an increase in the ionic character. The molar refraction (R m), refractive index (n r) and molar polarizability (˛m) are calculated and explained on the basis of structural changes. The optical absorption spectra have been used to evaluate the values of optical band gap (E opt) and band tailing parameter (B). It is observed that E opt decreases with the increasing contents of ZnO in base glass matrix. The decrease in E opt is an evidence of enhancement in the number of non-bridging oxygen atoms (NBOs) thereby increasing the four-coordinated boron atoms. The as-quenched samples in bulk form are subjected to differential thermal analysis (DTA) to assess the glass transition temperature (T g), which is 476 • C for pure lithium borate glass. The variations suggest that the structure is being modified by the substitution of ZnO.