Structural defects in flux-grown stoichiometric LiNbO3 single crystals

The effect of growth conditions on the crystal perfection of stoichiometric lithium niobate LiNbO3 prepared by the high-temperature top-seeded solutio n growth technique (HTTSSG) from potassium containing flux was investigated . Flux compositions between 0.09 and 0.21 K2O/LiNbO3 ratio were tested, and it was found that LiNbO3 forms an eutectic system with the K2O, which is c onsidered as the solvent in the system. The exact composition of the eutect ic is close to the 1:5 molar ratio of K2O and LiNbO3. Stoichiometric crysta ls with homogeneous composition were grown from fluxes in the range of 0.16 -0.195 K2O/LiNbO3 ratio. The formation of the structural defects (faceting and ferroelectric domain reversal) have been examined for growth along the Z = [0 0 0 1], Y = [0 1 (1) over bar 0], X = [2 (1) over bar (1) over bar 0 ], [0 1 (1) over bar 1] and [0 (2) over bar 2 1] directions. The developmen t of facets occurred primarily along the {0 1.2} pyramidal planes. Close co nnection was found between faceted growth and the appearance of domain reve rsal. (C) 2000 Elsevier Science B.V. All rights reserved.