The hydrothermal growth of hetroepitaxial perovskite films, as reviewed for BaTiO3, Pb(Zr,Ti)O3 and K(Nb,Ta)O3, on single crystal perovskite substrates occurs by the island mode of growth is affected by solution chemistry. Films can be synthesized at temperatures as low as 90°C. Islands, nucleated on the ledges, grow and coalescence. Coalescence of slightly misoriented grains (mosaic blocks) produce threading dislocations at the interface where they meet. As for most epitaxial processes, dislocations are also observed at the interface due the lattice misfit of the substrate and film structures. The aqueous solution chemistry effects interfacial chemistry, e.g., via specific adsorbing ions, confirmed by adsorption measurements, and plays an important role in controlling film faceting. Protons are incorporated during synthesis; cation vacancies occur to charge balance the protons. The point and line defects can be removed by heating; the point defects degrade the dielectric properties.

Keywords: Perovskites, epitaxy, hydrotherwal