Abstract
The co-ordination number of some of Ge4+ ions in GeO2 glass changes from four to six when alkali oxide is added. This paper deals with how such a change of the co-ordination number is reflected in thermoluminescence (TL) of X-irradiated sodium germanate glasses. The TL intensity integrated in the measured temperature range of RT to 260°C followed a curve similar to that of the Kβ1 emission of Ge atoms in the same glass system. This as well as the ESR data by Weeks and Purcell suggest that TL centers, which can emit light on heating, are more stable when bounded in GeO6 groups than in GeO4 groups, and thus a direct reflection of the change in the co-ordination number on the TL integrated intensity was observed.