INFLUENCE OF BORON ON STRUCTURAL FEATURES AND PHOTOREFRACTIVE PROPERTIES OF LiNbO3 SINGLE CRYSTALS

An analysis of studies of single crystals of LiNbO3 stoich, LiNbO3 cong and LiNbO3 : B (0,83 mol.% B2O3 in the charge) was performed. It was established that boron present in the melt is unable to incorporate into the crystal structure of LiNbO3. Boron brings closer in magnitude to each other the effective distribution coefficients of lithium and niobium linking excess niobium in the process of complexation in a melt of a congruent composition. In this case, LiNbO3 : B crystals approach to the stoichiometric crystals in ordering the structural units.