Structural, electronic and magnetic properties of YFeMnH5

Abstract YFeMn alloy exposed to high hydrogen pressure transforms into hydrides with hydrogen concentration higher than 5 H p.f.u. Rietveld’s refinement of XRD data indicates the presence of two hydrides corresponding to YFeMnH 5.46 and YFeMnH 5.02 with the cubic structure of a parent intermetallics. YFeMnH 5.46 was found to be unstable. It desorbs hydrogen yielding YFeMnH 5.02 (referred as YFeMnH 5 ) which was used for further X-ray absorption near edge structure (XANES) and magnetic measurements. Based on XANES studies at the Mn and Fe K-edges, Mn and Fe atoms in YFeMn alloy are in the metallic state, whereas they exhibit partially anionic character in the hydride. Hydrogenation influences the valence state of Mn and Fe in YFeMn, modifies the density of states (DOS) near the Fermi level and induces an increase of the Curie temperature and a decrease of magnetization at 5 K.