Optical in situ study of reduction/oxidation processes in YAlO3

The paper presents experimental results on an in situ optical absorption study of reduction/oxidation processes in YAlO3. The increase in the absorption of the bands at 22,000 and 40,000 cm-1 during annealing in an oxidizing atmosphere as well as their bleaching during reduction were studied in YAlO3 and YAlO3:Nd crystals in the temperature range 600-1000 K. The oxidation and reduction kinetics were analyzed by means of exponential decay modeling as well as in the framework of different models, taking into account diffusion and quasi-chemical reactions of the phototropic centers.