EFFECTS OF SUBSTRATE MATERIALS AND ANNEALING TEMPERATURE ON CRYSTAL-STRUCTURE AND EPITAXY OF LA0.7SR0.3MNO3 FILMS VIA DIPPING-PYROLYSIS PROCESS

Epitaxially grown La0.7Sr0.3MnO3 (LSMO) films were prepared on SrTiO3( 001), LaAlO3(001) and MgO(001) single-crystal substrates by dipping-py rolysis process. The fluctuation of alignments (mosaicity) of the film s was evaluated based on X-ray diffraction 2 theta/theta scans, beta s cans (pole figures) and asymmetric 2 theta/omega scans (reciprocal-spa ce maps). Lattice types and epitaxy were examined in the films after h eat treatment at 1473-1873 K; the lattice type of the films on SrTiO3 was pseudocubic, whereas those on LaAlO3 and MgO were pseudocubic or r hombohedral, depending on the heat-treatment temperature. A mosaic spr ead (Delta omega) of the LSMO film varied with the lattice-mismatch va lue between film and substrate. The LSMO films on SrTiO3 (lattice misf it approximate to 1%) showed high epitaxy with a low Delta omega (appr oximate to 0.50 degrees), whereas the films on MgO (misfit approximate to 8%) exhibited a larger Delta omega (approximate to 2.8 degrees). A lso, surface morphology of the film was found to markedly depend on th e kind of substrate materials and annealing temperature. (C) 1998 Else vier Science S.A. All rights reserved.