The diffusion of Zn into this material was investigated by diffusing 70nm-thick ZnO films, deposited onto y-cut LiTaO3 substrates at 700 to 900C, under various atmospheres. It was observed that the surface quality was very sensitive to pressure, but was weakly affected by temperature and atmosphere. Although the surface degraded and became covered with residuals after heat treatment at atmospheric pressure, it was very smooth and clear when the pressure was lowered to below about 10Torr. The Zn-diffused stoichiometric crystals maintained their transparency; even after diffusion at pressures as low as 0.1Torr, without a post-annealing step. The diffusion coefficient varied from 1.1 x 10-2 to 5.5 x 10−1μm2/h in the given temperature range; with an activation energy of 1.95eV.

Diffusion of Zn in Stoichiometric LiTaO3. I.Song, H.Shin, M.Cheong, J.Myoung, M.Lee: Journal of Crystal Growth, 2004, 270[3-4], 568-72