Thermally stimulated depolarisation current in sodium-potassium borosilicate glass

The thermally stimulated depolarisation current (TSDC) has been measured in sodium-potassium borosilicate glass of composition 15% Na₂O, 13.64% K₂O, 19.47%B₂O₃ 51.89% SiO₂. Gold and aluminium electrodes were used for these measurements and TSDC curves of NaK borosilicate glass were obtained by varying the polarising temperature T_p and polarising voltage V_p in a systematic manner. The observed peaks were remarkably reproducible. Partial heating experiments were performed to investigate the activation energy of the thermally released carriers. By an analysis of the current peaks, the relaxation time τ(T) and hence the activation energy of relaxation of the carriers were determined. Results of dc measurements on the same samples are presented for comparison.