Radiation Defects in LiBaF_3 Perovskites

摘要

We investigated the electron paramagnetic resonance (EPR), recombination afterglow, thermostimulated luminescence (TSL) and absorption of LiBaF_3 perovskites crystals X-irradiated at 80 K. The self-trapped hole centre V_K(F_2) oriented along the [110] axis and electron F type (F_A) centres are identified. X-irradiation at temepratures below 200 K results in creation of a long-term temperature-independent afterglow-tunnelling luminescence (TL), with main emission bands at 300, 370 nm and 430 nm. The short wavelength TL bands are associated with the tunnelling recombination of the F type centre with the V_k centre. The thermal stability of V_K centre is estimated to be about 130 K.