Thermally stimulated exoelectron emission observed in mixed Li2B4O7-LiCl ceramics

Previous investigations of thermally stimulated exoelectron emission (TSEE) in Li2B4O7 ceramics showed that microcrystallized samples gave rise to well-isolated and fairly strong TSEE peaks when they were cooled to about -1100C or to lower temperatures before the heating to measure the TSEE, without previous irradiation which is often required to induce TSEE. It was considered that the origin of such TSEE without irradiation might be related to the piezoelectric nature of the Li2B4O7 crystal. In the present investigation the TSEE induced by quenching to liquid nitrogen temperature for sintered samples of Li2B4O7-LiCl mixtures in different ratios was measured. The samples lose their piezoelectricity with the increased contents of LiCl. The results showed a decrease in TSEE with increased LiCl content, supporting the hypothesis. The decrease was not proportional to the LiCl content, however. Additional peaks appearing in samples irradiated with X-rays offer the possibility of an application to radiation dosimetry. (U.K.)