The effect of a Cu3Ba2YO7 buffer layer upon the quality of radio-frequency magnetron sputtered epitaxial (001) titanate thin films on a LaAlO3 substrate was investigated by using high-resolution transmission electron microscopy. The magnetron-sputtered titanate films usually exhibited a columnar sub-grain morphology. By using a 75nm-thick Cu3Ba2YO7 buffer layer, the sub-grain boundary area was considerably reduced as compared with single-layer films. Sub-grain widths of about 130nm were observed; corresponding to an 80% reduction in the sub-grain boundary area. The density of misfit dislocations was also reduced by 80%.

Reduction of Density of Subgrain Boundaries and Misfit Dislocations in Epitaxial (001) SrTiO3 Thin Films. L.Ryen, X.Wang, P.Petrov, E.Carlsson, U.Helmersson, E.Olsson: Journal of Applied Physics, 1999, 85[8], 3976-83