X-RAY-DIFFRACTION OF SRTIO3 BATIO3 MULTILAYER FILMS/

The structural properties of SrTiO3/BaTiO3 multilayer films on SrTiO3 substrate grown by molecular beam epitaxy were investigated as a funct ion of modulation length. The crystallographic quality was evaluated b y X-ray diffraction measurement and confirmed the epitaxial cube-on-cu be structure, that is BaTiO3[001]//SrTiO3[001]//substrate[001] and BaT iO3(100)//SrTiO3(100)//substrate(100). When the total thickness of the multilayer films was less than 100 Angstrom, they were grown into coh erent structure in spite of apparently lattice mismatch. The lattice p arameters both in the growth plane and along the growth plane and alon g the growth direction depended on the modulation length. The volumes of the multilayer films no longer kept bulk Poisson's ratio. Thus, com pression stress was introduced in the growth plane of BaTiO3 layers an d expansion stress was in the growth plane of SrTiO3 layers.