Effects of strain relaxation in Pr(0.67)Sr(0.33)MnO(3) films probed by polarization dependent X-ray absorption near edge structure

The Mn K edge X-ray absorption near edge structure (XANES) of Pr(0.67)Sr(0.33)MnO(3) films with different thicknesses on (001) LaAlO(3) substrate was measured, and the effects of strain relaxation on film properties were investigated. The films showed in-plane compressive and out-of-plane tensile strains. Strain relaxation occurred with increasing film thickness, affecting both lattice constant and MnO(6) octahedral rotation. In polarization dependent XANES measurements using in-plane (parallel) and out-of-plane (perpendicular) geometries, the different values of absorption resonance energy E(r) confirmed the film anisotropy. The values of E(r) along these two directions shifted towards each other with increasing film thickness. Correlating with X-ray diffraction (XRD) results it is suggested that the strain relaxation decreased the local anisotropy and corresponding probability of electronic charge transfer between Mn 3d and O 2p orbitals along the in-plane and out-of-plane directions. The XANES results were used to explain the film-thickness dependent magnetic and transport properties.