Neutron, synchrotron X-ray diffraction and X-ray absorption studies of CaLaFeMnO6 double perovskite

High-resolution neutron and synchrotron X-ray powder diffraction data of CaLaFeMnO6 double perovskite have been used in a joint Rietveld refinement method to obtain accurate room temperature structure which includes a precise set of atomic positions and thermal motion parameters. The valence states of Mn and Fe in the octahedra were also determined by X-ray absorption spectroscopy by measuring Mn and Fe K edges at room temperature. The simultaneous refinement of both synchrotron X-ray and neutron diffraction data reaffirmed that the system indeed possesses orthorhombic structure with space group Pbnm. X-ray absorption spectroscopic measurements reveal that both Mn and Fe occupy the octahedral sites with valence state of +4 and +3, respectively. No cationic ordering arrangement was found and Fe/Mn was found to be randomly distributed over the octahedral sites. The results agree well with the earlier published neutron diffraction data.

Polyhedral view along (001) of the LaCaMnFeO6 double perovskite system determined by the joint refinement of high-resolution neutron and synchrotron X-ray diffraction data using Rietveld refinement method.Figure optionsDownload as PowerPoint slide