Preparation of epitaxial and olycrystalline La_0.8Sr_0.2MnO_3 films by dipping-pyrolysis process

摘要

The films of La_0.8Sr_0.2MnO_3 (LSMO) were prepared on single-crystal SrTiO_3(100) and polycrystalline yttria-stabilized zirconia (YSZ) substrates by dipping-pyrolysis process using metal naphthenates as starting materials. The crystallinity, grain alignment, morphology and electric properties of the films were compared. Epitaxial films were found to grow on SrTiO_3, heat-treated at 1200 deg C, by x-ray diffraction, and to exhibit very smooth surfaces by SEM and AFM observations. on the other hand, the surfaces of ther polycrystalline films grown on YSZ consisted of round-shaped LSMO grains. The resistivity of the epitaxial films was about two orders of magnitude lower than that of the polycrystalline films prepared under the same conditions. Preparation of epitaxial LSMO films on SrTiO_3(110) is also presented.