CRYSTAL-STRUCTURE OF LPE-GROWN LINBO3 EPITAXIAL-FILMS

LPE (liquid-phase epitaxial)-grown LiNbO3 films with various thickness es on LiNbO, substrates were characterized using diffraction-space map s and absolute lattice constants. The Li content in the films was esti mated from the absolute lattice constants. The films had strained stru ctures regardless of the film thickness. The Li content increased as t he film thickness increased to about 15-mu m, and it was constant at h im thicknesses thicker than about 15-mu m. It was found that the cryst allinity of the films with thicknesses ranging from about 15-mu m to a bout 25-mu m was better than that of the substrates, because the compo sition was nearly stoichiometric and the films had a small composition gradient, few dislocations and little thermal stress.