Templated grain growth of barium titanate single crystals

BaTiO3 single crystals were grown via templated grain growth (TGG), which is a process in which a single-crystal "template" is placed in contact with a sintered polycrystalline matrix and then heated to migrate the single-crystal boundary into the matric. Millimeter-sized, stoichiometric single crystals of BaTiO3 were produced by heating polycrystalline matrix with a relative density of 97% and a Ba/Ti ratio of <1.00, which was bonded to a BaTiO3 single crystal, at temperatures above the eutectic temperature. Growth rates of 590-790, 180-350, and 42-59 <mu>m/h were observed for {111}-, {100}-, and {110}-oriented single-crystal templates, respectively. Lower-surface-energy facets were formed for {111}- and {100}-oriented templates, whereas {110} crystals maintained a {110} growth front, which indicated that this plane orientation was the lowest-energy surface in this system. SrTiO3 also was shown to be a suitable substrate for TGG of BaTiO3.