Investigation of thermoexoemission and thermoluminescence of KCl: Ag by the fractional glow technique

Abstract

The examined KCl:Ag crystal, X-rayed at ≈︁80K, exhibits two distinct well-correlated thermo-stimulated electron emission (TSEE) and luminescence (TSL) peaks at ≈︁210 and ≈︁380 K. induced by Vk centre delocalization and Ag° centre thermoionization, respectively. The revealed close coincidence of the activation energies (≈︁0.7 eV for the 210 K and ≈︁1.15 eV for the 380 K peak) shows that the observed TSEE and TSL are induced by the thermal decay of identical (bulk type) centres, and the TSEE run is not controlled by the electron affinity, but it is either an emission of “hot” electrons accelerated in the X-ray produced electric field in the sample or/and facilitated by the electron escape spots at the surface. The shifts between temperature and TSEE/TSL runs within individual heating oscillations demonstrate that Vk centre hopping diffusion controls the rate of TSEE/TSL acts in the 210 K peak. The results resemble the ones formerly obtained by the same method for LiF and NaF and encourage the using of fractional heating TSEE for the spectroscopy of traps in the surface layers of solids.