Submitted to University Collage of Women for Arts, Science, and Education- Ain Shams University

Abstract

The thesis aimstoprepareand studythe physical, optical and electrical propertiesof sodium phosphate glassesdopedwith different concentrations oflithium oxide(Li2O)with concentrationranging from0- 35 mol%. Also, the thesis includes the transformation of the prepared glasses to their corresponding glass-ceramic derivatives by adding copper oxide (CuO) in small proportions ranging from 0 – 1 mol% and study the effect of annealing on as prepared glass samples. Transparent glasses of 55 P2O5 - (45-x) Na2O –(x) Li2O (0 ≤ x ≤ 35) were prepared using the melt quenching technique. All the prepared glass samples are amorphous as confirmed by XRD. The experimental and theoretical densities are found to decrease with increasing Li2O content, and following the same trend, while the molar volume (Vm) has an opposite trend with the concentration of Li2O. The glass transition temperature (Tg) and crystallization temperature (Tc) were found to decrease with increasing of Li2O content except for glass sample with x = 15 mol%, this glass sample exhibit the highest thermal stability. The FTIR of the prepared glasses were investigated all the vibrational modes of prepared glasses. The variation of optical absorption edge, optical band gap (Eg) and Urbach energy (Eu) depend on Li2O content. It is observed that the increase of Li2O content increases the energy gap values and decrease the Urbach energy which is an indication of the increase in structural disorder of glass.The dc and ac conductivity and their related conduction mechanisms of the investigated glasses were analyzed. Activation energies ΔEdc1, ΔEac1, ΔEdc2 and ΔEac2 at low and high temperatures are calculated. It was found the behavior of both ΔEdc and ΔEac are approximatelythe same.