Cubic perovskite films with various compositions were grown onto perovskite substrates, using the chemical solution deposition method, in order to investigate the effect of a large lattice mismatch. The films were pyrolyzed in order to crystallize the perovskite with the required composition, and were then heated to 1000C so as to promote epitaxial grain growth. Pole figures were obtained by X-ray diffraction, and selected area diffraction studies were made of transmission electron microscopy specimens with lattice mismatches of 2.5% (SrTi0.5Zr0.5O3 on SrTiO3), 5% (SrZrO3 on SrTiO3), 7.4% (BaZrO3 on SrTiO3) and 8.2% (SrZrO3 on LaAlO3). This revealed only the orientation, [100](001)film||[100](001)substrate. The X-ray diffraction and transmission electron microscopy results also indicated an increasing polycrystallinity with increasing lattice mismatch. High-resolution electron microscopy of films on SrTiO3 demonstrated that an array of misfit dislocations was present at the interface. The misfit dislocations had line vectors of <100>-type and Burgers vectors of <010>-type. The dislocation separation distances which were obtained by using high-resolution electron microscopy and X-ray diffraction lattice parameter measurements showed that the strain energy within the films, due to lattice mismatch, was almost fully relaxed.

P.A.Langjahr, F.F.Lange, T.Wagner, M.Rühle: Acta Materialia, 1998, 46[3], 773-85