OPTICAL AND DSC STUDIES OF THE NA2B4O7-PB3O4 GLASS SYSTEM

A series of glass samples were prepared from admixtures of Na//2B//4O//7 and Pb//3O//4 results are reported for optical absorption, infrared absorption spectra and differential scanning calorimetry (DSC) as a function of lead content up to 40 mol%. It is found that the addition of lead oxide decreases the optical energy gap and shifts the optical absorption edges towards lower energies in the range from 4. 96 to 3. 29 ev. The addition of lead oxide does not seem to introduce any new absorption band as compared with the infrared spectrum of pure sodium tetraborate glass.