FABRICATION OF BARIUM-TITANATE STRONTIUM-TITANATE ARTIFICIAL SUPERLATTICE BY ATOMIC LAYER EPITAXY

Epitaxial growth of BaTiO3, SrTiO3 and their superlattices was carried out by the alternating evaporation method using an atomic-layer-epita xy control system for molecular beam epitaxy (MBE). Stable and reprodu cible control of the chemical composition was achieved by layer-by-lay er growth with this system. Both BaTiO3 and SrTiO3 were grown epitaxia lly on SrTiO3 substrates, and clear oscillations of reflection high-en ergy electron diffraction (RHEED) intensity were observed, correspondi ng to the alternating depositions of BaO and TiO2 in BaTiO3 growth. Th e artificial superlattice with the structure of [(BaTiO3)(5)/(SrTiO3)( 5)](7) was fabricated, and the X-ray diffraction (XRD) pattern of the superlattice was simulated by a step model. Diffraction angles of sate llite peaks and the shape of Laue peaks in XRD patterns were consisten t with those calculated, indicating that the designed structure was fa bricated in the superlattice.