Strain effects in epitaxially grown La0.7Sr0.3MnO3 thin films

We report here on an X-ray absorption study of La0.7Sr0.3MnO3 films epitaxially grown on SrTiO3 substrate. The local organization around Mn in oriented films with 600 Angstrom in thickness was investigated by polarized Extended X-ray Absorption Fine Structure. The angle between electric field vector and film surface was set equal to 5degrees and 70degrees to investigate almost independently the contribution of the manganese neighbors situated in and out of the film plane. The first neighboring shell oxygen is found to be the same in both geometries, but small changes in the next neighboring contribution are observed. These changes are associated with variation in the Mn-Mn bond length. A small in-plane elongation (3%) is observed in the constrained films with respect to the unconstrained case. (C) 2002 Elsevier Science B.V. All rights reserved.