Determination of the Li/Nb ratio in LiNbO3 crystals prepared by vapor transport equilibration method

Off-congruent lithium niobate (LiNbO 3 ) single crystal was prepared by vapor transport equilibration (VTE). The Li/ Nb ratio was determined by means of indirect methods such as the lattice parameters, the fundamental absorption edge position and the IR vibrational spectrum. Comparison of the results of the VTE LiNbO 3 with those of the congruent crystal and congruent composition melt added 6 wt% K 2 O. In all cases the Li 2 O content was found to be closer to 50% than that of the congruent composition melt added 6 wt% K 2 O. The homogeneity of the composition in the crystal was also investigated. The data presented in this work show that the VTE method can be effectively applied to produce LiNbO 3 stoichiometric crystal.