The interfaces in heterostructured thin films were investigated by means of high-resolution transmission electron microscopy. Depending upon the deposition temperature of the BaTbO3 layers, 2 types of interface were found. At a deposition temperature of 780C, the interfaces between Cu3Ba2YO7 and BaTbO3 were of type-I. In this configuration, a Cu-O chain plane of Cu3Ba2YO7 or Cu3Ba2PrO7 faced a TbO2 plane of BaTbO3. Interface dislocations were found whose line direction was [110] or [¯110]. Residual misfit could be observed in a layer close to the interface. At a deposition temperature of 500C, type-I and type-II interfaces coexisted. In the type-II configuration, a Cu-O plane of Cu3Ba2YO7 or Cu3Ba2PrO7 faced a BaO plane of the BaTbO3 layer. In this case, misfit dislocations were found to lie along the [100] and [010] directions. In addition, the lattice was strongly distorted close to the interface. The differences in dislocation configuration and residual strain level for the 2 types of interface were considered in terms of O-lattice theory and the bonding state of the ions in the interface layer.

The Interfaces in YBa2Cu3O7/BaTbO3 and PrBa2Cu3O7/BaTbO3 Heterostructure Thin Films. C.L.Jia, R.Hojczyk, M.Faley, U.Poppe, K.Urban: Philosophical Magazine A, 1999, 79[4], 873-91