STRUCTURAL CHARACTERIZATION OF EPITAXIAL BATIO3 THIN-FILMS GROWN BY SPUTTER-DEPOSITION ON MGO(100)

Epitaxial thin films of BaTiO3 have been prepared using radio-frequenc y magnetron sputter deposition on MgO(100) substrates. Various x-ray-d iffraction techniques were employed to characterize the crystal struct ure of the films. The films were fully tetragonal and consisted of c d omains. Their tetragonality has been shown to be 1.013, which is almos t the same as the bulk value of BaTiO3. However, the cross-sectional t ransmission electron microscopic micrograph showed that a very small a mount of a domains coexists forming 90 degrees domain boundaries in th e matrix of c domains. In spite of the negligible strain caused by the phase transformation, it seems to be inevitable to form a certain sma ll amount of a domains in the BaTiO3 film on MgO system. (C) 1995 Amer ican Institute of Physics.