A single ionic thermocurrent band was observed, in crystals which had been doped with Sm3+ impurities, within a temperature range which was higher than the usual ionic thermocurrent bands for the depolarization of electric dipoles. The single ionic thermocurrent band had already been attributed to a depolarization of the space charges which accumulated near to a positive electrode. Combined Fourier analysis and least-squares fitting revealed that the concentration of mobile interstitial F ions at 283K was 3.9 x 1012cm3, and that the Arrhenius parameters were 3.3 x 104cm2/s and 0.805eV for material which was doped with 0.5mol% of SmCl3 impurities.

Fourier Analysis of Ionic Thermocurrents Observed at High Temperature in BaF2:Sm Crystals. Y.Matsumoto, K.Tanaka, K.Kawano, R.Nakata, M.Sumita: Journal of Physics and Chemistry of Solids, 1993, 54[3], 331-41