Magnetization behavior of RFe3-hydrides (R = Tb, Er and Tm)

Abstract

The RFe/sub 3/ compounds (R = heavy rare earth), crystallizing in rhombohedral PuNi/sub 3/ type structure, absorb typically three hydrogens per formula unit at room temperature. The hydrogen absorption does not change the structure of these compounds but merely causes an expansion of the lattice. Magnetization studies have been carried out on the hydrides in the temperature range 4.2 to 300 K and in applied fields up to 21 kOe. The parent compounds are known to be ferrimagnetically ordered with reasonably high Curie temperatures. The magnetization of the hydrides at 4.2 K is observed to be smaller than that of the corresponding parent compounds. The compensation temperature also decrease on hydrogen absorption. These results may be taken to imply either an increase in moment on iron and/or a decrease in rare earth moment. In ErFe/sub 3/-hydride, a sharp increase in magnetization is observed close to room temperature. This is attributed to the change in easy direction of magnetization.