Competing magnetic anisotropies in the mixed rare-earth Laves hydrides - art. no. 094419

We have studied the temperature evolution of magnetic structure in mixed La ves hydrides (R-1, R-2) Mn2H4, where R is a rare-earth ion, by powder neutr on diffraction. The spin orientation results from a compromise between the competing anisotropies of R-1, R-2, and Mn ions. The spin orientation at lo w temperature was analyzed using a single-ion cubic crystal-field model. We found quite an original behavior in the hydrides: the spin orientations di ffer from nonhydrogenated compounds, and cannot be explained by a unique se t of crystal-field parameters. This suggests that the hydrogen superstructu re strongly influences the anisotropy.