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 hydrogenation-disproportionation-desorption-recombination process, a peculiar microstructure has been observed just after the hydrogenation-disproportionation processing. SmH2 crystals, formed as a result of decomposition of the Sm2Fe17 compound, are present with a fibrous shape, about 7 nm in diameter and 1 mum in length. These SmH2 fibres, all with the same orientation, are arranged at nearly regular intervals of about 11nm and with a definite orientation relationship to the alpha-Fe matrix, <110> Fe// <110> SmH2.