LAYER-BY-LAYER GROWTH OF BATIO3 THIN-FILMS WITH EXTREMELY SMOOTH SURFACES BY LASER MOLECULAR-BEAM EPITAXY

Using pure ozone-assisted laser molecular beam epitaxy, we have grown c-axis-oriented single crystal BaTiO3 thin films on SrTiO3 substrates at temperatures (T-s) of 400-750 degrees C and under ambient gas press ures of 5 x 10(-5) to 1 x 10(-1) Pa, respectively. Stripy reflection h igh-energy electron diffraction (RHEED) patterns and regular RHEED int ensity oscillations reveal the smooth surface and layer-by-layer epita xial growth of the films. Scanning electron microscopy analysis shows that the films are free of pinholes, grain boundaries and outgrowths o n the surface. In addition, we found a strong dependence of the film l attice constant c on T-s, which might be related to the strain in the film.