The correlation of MgO-doped near-stoichiometric LiNbO3 composition to thedefect structure

Undoped and MgO-doped LiNbO3 single crystals with near-stoichiometric compo sitions were grown from K2O-doped melts and Li-rich melts by two different growth techniques. Near-stoichiometric LiNbO3 single crystals. having large [Li]/[Nb] ratios of 0.988-0.993. showed smaller threshold concentrations o f MgO than congruent crystals for the behavior of Curie temperature. OH abs orption band and optical damage properties. We discuss the ideal defect str ucture models, and find that the Li-site vacancy model is consistent with t he experimental results for MgO-doped near-stoichiometric LiNbO3 single cry stals. (C) 2000 Published by Elsevier Science B.V. All rights reserved.