BaTiO3 films of various thicknesses were grown on doped and undoped SrTiO3(100) substrates and on (La, Sr)2CuO4 films by a pulse laser deposition method. Both BaTiO3 and (La, Sr)2CuO4 films were smooth and free of particulates. X-ray diffractometry showed that all materials were three-dimensionally aligned with the cube-on-cube epitaxial relationship, and that the films obtained on SrTiO3(100) were of a c-axis-oriented tetragonal phase contrary to previous studies using metal bottom electrodes. As the film thickness decreased, the tetragonality of these films increased and the dielectric constant along the c-axis decreased rapidly, despite reduction of disorder at the interface by use of perovskite electrodes. The 2000-Å-thick BaTiO3 grown on (La, Sr)2CuO4 film had the remnant polarization of about 1.5 µ C/cm2. The results were discussed using a surface layer model.

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