Epitaxial Growth of BaTiO3 Thin Film on SrTiO3 Substrate in Ultra High Vacuum without Introducing Oxidant

A high-quality BaTiO3 thin film on SrTiO3 substrate was obtained by shutting off the oxygen supply during growth. Epitaxial growth of BaTiO3 film was carried out with molecular-beam epitaxy (MBE) under extremely low oxygen partial pressure (pO2<1×10-8 Pa). Although only Ba and Ti metals were supplied without introducing oxidant during the growth, a clear reflection high-energy electron diffraction (RHEED) intensity oscillation from layer-by-layer growth of BaTiO3 was observed. Oxygen was automatically fed from the substrate during the growth. The deposited film was found to have an approximately stoichiometric composition and single-phase of BaTiO3 from the analyses of Auger electron spectroscopy (AES) and X-ray diffraction (XRD).