The microstructure of (La,Sr)CoO3 which had been grown onto (001)MgO by metalorganic chemical vapor deposition was studied by means of transmission electron microscopy. The (La,Sr)CoO3 film exhibited a predominant ordered anisotropic perovskite-type structure which was denoted by n-La0.5Sr0.5CoO3. This structure resulted from lattice substitution between La and Sr. An atomic model for the structure was determined here for the first time. It was found that the film comprised domains which exhibited an [001], [010] and/or [100] anisotropy. Numerous stacking faults with a displacement vector of ¼[011] were observed. The stacking faults were confined to the (100) and (010) planes, and were produced by [100] and [010] steps, respectively, on the (001) MgO substrate. The (010) and (100) interplanar distances in the film were constrained by lattice mismatch between the film and the substrate, and by the presence of (010) and (100) planar stacking faults.

Z.L.Wang, J.Zhang: Philosophical Magazine A, 1995, 72[6], 1513-29