Crystal Structure and Valence Distribution of [(LaMnO3)m(SrMnO3)m]n Artificial Superlattices

The crystal structure of [(LaMnO 3 ) m (SrMnO 3 ) m ] n artificial superlattices and the valence distribution of Mn ions have been studied using the X-ray scattering technique. The stacking structures were determined by the scattering intensities in the out-of-plane direction. The Mn valence distributions were evaluated by the energy dependence of the scattering intensity near the Mn K-edge, which was analyzed on the basis of the obtained crystal structures. The result indicates that the Mn valence becomes 3+ (4+) in the LaMnO 3 (SrMnO 3 ) layers, and the valence has an intermediate value between 3+ and 4+ only at the interface between LaMnO 3 and SrMnO 3 layers. We have also clarified that all the films are insulators independent of the periodicity m .