A regular arrangement of SmH2 fibres in an alpha-Fe matrix, found after the hydrogenation-disproportionation processing of Sm2Fe17

In the course of a study on microstructural changes in Sm2Fe17 during a hyd rogenation-disproportionation-desorption-recombination process, peculiar mi crostructure has been observed just after the hydrogenation-disproportionat ion processing. SmH2 crystals, formed as a result of decomposition of the S m2Fe17 compound, are present with a fibrous shape, about 7 nm in diameter a nd 1 mu m in length. These SmH2 fibres, all with the same orientation, are arranged at nearly regular intervals of about 11 nm and with a definite ori entation relationship to the alpha-Fe matrix, [110]Fe//[110]SmH2.