A model for the structure of intrinsic defects in this material was presented which was based upon the coexistence of both Li and Nb vacancies. The contents of the various types of intrinsic defect were then determined as a function of the composition in off-congruent crystals. A comparison with the phonon characteristics obtained from Raman data demonstrated the validity of the present description of a defect structure having a predominance of Li vacancies. Anomalies in the dependencies of the electro-optical properties upon the crystal composition could be explained by the model; thus confirming the reliability of the present model and the calculations.

Coexistence of Li and Nb Vacancies in the Defect Structure of Pure LiNbO3 and its Relationship to Optical Properties. F.Abdi, M.D.Fontana, M.Aillerie, P.Bourson: Applied Physics A, 2006, 83[3], 427-34