The growth of single crystals of solid solutions of LiNbO3 and LiTaO3 has been studied by using a number of different techniques: Czochralski pulling, Top-Seeded Solution Growth, flux growth from LiBO2 and LiVO3, and by optical floating zone. Crystals with homogenous Li, Ta and Nb compositions were obtained by several techniques. Analysis of local and average compositions of Ta, Nb and Li by Raman spectroscopy, birefringence imaging and X-ray diffraction, in addition to EDAX, is described. The effects of replacing Nb by Ta and of Li non-stoichiometry on the lattice parameters and the compositional disorder over the whole composition range 0 <= x <= 1 are discussed. (c) 2012 Elsevier B.V. All rights reserved.