BaTiO3 bilayer films are deposited on SrTiO3 Substrates under different oxygen pressures by pulsed laser deposition. The structural properties of the bilayers are investigated by means of X-ray diffraction, Rutherford backscattering spectrometry, conventional and high-resolution transmission electron microscopy. The BaTiO3 layer with the thickness of 115 nm deposited under higher oxygen pressure (3 x 10(-1) mbar) exhibits a cubic-like structure with lattice parameter a = 0.399 nm. The BaTiO3 layer with the thickness of 220 nm deposited under lower oxygen pressure (2 x 10(-3) mbar) shows a c-axis-oriented domain structure with lattice parameters a = 0.401 nm and c = 0.411 nm. The interface of the BaTiO3 bilayer films is coherent and no interfacial dislocations can be seen over larger regions. The misfit dislocations with Burgers vector of type a < 100 > are observed at the interface between bottom BaTiO3 layer and SrTiO3 substrates. (c) 2005 Elsevier B.V. All rights reserved.