الفهرس 
الغلافOnly 14 pages are availabe for public view
 |  | from | 128 |  |  |
| | | from | 128 | | |
Abstract
Glasses system 5Na20-5ZnO-5AhOr65P20s-xMo03¬(20-x)CaO, mol% where 20 >x >0 have been prepared using the conventional melting at temperature 1200 °c and annealing method at 480°c. Density and molar volume were measured by Archimedes principle at room temperature and it was found that density increases with increasing molybdenum content and inversely molar volume decreases. UV -visible optical absorption spectra were measured from 190 to 1100 llffi. The UV -absorption edge, both direct and indirect optical energy gaps, has been studied. the value of Eop,’ lies between 3.2-2.6 e V for the indirect transition and for direct transition the
values vary from 2.7-1.8 eV. Also Urbach energy lies between 0.38- 0.84 eV., the optical transmission and reflection spectra of the glass samples were recorded over the wavelength range of 200-2500 llffi, at normal light incidence. The absorbance (A), and the reflectance (R) optical spectra of the glasses were recorded at room temperature. According to Lambert’s attenuation factor, 11, were determined. The refractive index and the extinction coefficient data were used
to evaluate the absorption coefficient. The molar refraction, electronic polarizability and the optical basicity were obtained.