Solid-state amorphization of SmFe3 by hydrogenation

The structural changes of SmFe3 (PuNi3-type structure) during heating in hydrogen pressures are reported. Hydrogen induced amorphous (HIA) sample is related to the presence of the SmFe2 phase in the starting alloy. α-Fe starts to precipitate from partially amorphous SmFe2Hx already at about 325 °C. The amorphization shows that the amorphous SmFe3Hx phase has a lower Gibb's free energy than the crystalline SmFe3Hx phase. The a-SmFe3Hx phase becomes more stable for increasing hydrogen pressure. The a-SmFe3Hx phase is observed in a relatively small temperature range at high hydrogen pressures. The reported HIA of SmFe3 shows that the application of higher hydrogen pressures has great potential in the search for amorphizing further compounds.