Bulk conductivity, polarization, and thermally stimulated currents of insulated polar crystals

Abstract

The inevitable space‐charge formation caused by free charge carriers in polar crystals can be described for “insulated” samples as a surface polarization caused by the bulk conductivity. This makes possible a simple quantitative description of the dc and ac isothermal relaxation and of the thermally stimulated currents summarized in this paper and compared with experimental data. It is shown that the bulk conductivity and other parameters may be obtained from the TSC data.

Polarisation of CdF2by blocking electrodes. II. The effect of passing currents

“…For the dopedcrystal, Uwasonly0.34 eV, but the peak is overlapping with the high-temperature tail of the complex peak (cf. § 2.7.2 of [9]). Hence, obviously, a too low value of U was obtained.…”

“…In the case of ideally insulated crystals, the best fit stretched over nearly three orders of magnitude. Next &/SV drops increasingly behind the increase, which should result from decreasing 6 (equation (2.12) of [9]). This is no doubt a consequence of the increasing voltage drop, AV, caused by I , in the bulk and probably also by polarisation connected with the HT peaks.…”

“…According to the SP model, T,,, should shift further towards higher temperatures with decreasing 6 [9], i.e.,…”