Gamma ray interactions with undoped and CuO-doped lithium disilicate glasses

Ultraviolet-visible absorption of undoped lithium disilicate glass reveals strong UV absorption and no visible bands could be identified. Such UV absorption is related to the presence of unavoidable trace iron impurities within raw materials used for the preparation of this glass. Optical absorption of the CuO-doped samples show an extra broad visible band centered at 780 nm and in high CuO contents samples obvious splitting to several component peaks are observed. This characteristic visible absorption of copper-doped samples is correlated with the presence of Cu+2 ions in octahedral coordination with tetragonal distortion. Gamma irradiation of the prepared samples produces radiation-induced defects, which are related to the sharing of host lithium disilicate glass, trace iron impurities and copper iron in their formation. The visible spectrum of the CuO samples shows shielding effect towards successive gamma irradiation.