Electrical and optical properties of some sodium borate glasses

The de-electrical conductivity of sodium borate glasses containing differen t metal oxides namely MgO, CaO, SrO, BaO, CdO and Al2O3 with different perc ents was measured in the temperature range 35-510 degreesC. The activation energies of the electrical conduction and the glass transition temperature were calculated. DTA was carried out for the samples containing 5% MgO and 1% Al2O3 to identify phase transitions. All the results were discussed and correlated according to the molecular structure of the prepared glasses. Al so, the absorption spectra were measured in the 190-900 nm range and interp reted in the terms of structural concepts. A resolution of the observed abs orption spectra showed that four bands were induced with maxima at about 21 0, 270, 420 and 680 nm. Small deviations of these induced bands characteris tic of the glass content were observed and explained in terms of the physic al properties of the contained metal oxides. (C) 2001 Elsevier Science B.V. All rights reserved.