PROTONS AND DEUTERONS IN MAGNESIUM-DOPED SAPPHIRE CRYSTALS

The OH- and OD- stretching frequencies in magnesium-doped aluminum oxi de crystals were determined by infrared absorption measurements, Two v ery broad bands centered at similar to 3005 and 2228 cm(-1) were obser ved for OH and OD-, respectively. Polarization experiment results were compatible with OH- (OD-) ions lying in the basal plane, as is the ca se in undoped crystals, The threshold temperature for the in-diffusion of deuterons was obtained by annealing the samples in flowing D2O vap or; the resulting value was similar to 1050 K. At 1223 K, the diffusio n coefficient was similar to 3 x 10(-7) cm(2)/s, and the activation en ergy was 1.6 eV.