The absorption and diffusion of H in these intermetallic compounds, and the resultant changes in their magnetic properties, were investigated. Intermediate H concentrations indicated the solid-solution nature of the hydrides. On the basis of equilibrium and non-equilibrium absorption experiments, the net reaction energies, bulk diffusion constants, and surface barrier energies for Fe17Sm2 were determined. Low-temperature quantum diffusion was proposed for the hydride and the corresponding nitride.

S.Wirth, R.Skomski, J.M.D.Coey: Physical Review B, 1997, 55[9], 5700-7