Thermally stimulated conductivity (TSC) and thermally stimulated luminescence (TSL) of spinel single crystals exposed to ionizing radiation have been studied. TSC exhibits peaks at 70, 125, and 340°C whereas TSL peaks occur at 70 and 260°C. The 70°C peak has an activation energy of 0.95 eV and is due to electron release; it has two main spectral components at 260 nm (4.8 eV) and 310 nm (4.0 eV) due to electron capture at trapped holes. The 260°C TSL peak is broad but singly activated (1.5 eV activation) and is dominated by 710 nm (1.75 eV) and 520 nm (2.39 eV) emission due to hole capture at Cr2+ and V2+, respectively. The broad 340°TSC peak appears to contain a substantial contribution due to electron release in the 240-310°C range which makes only a small contribution (260 and 310-nm light) to the TSL peak in this region. Dose dependence and room-temperature decay indicate that initially a substantial portion of the 260-nm afterglow is due to tunneling recombination.
ASJC Scopus subject areas
- Physics and Astronomy(all)