Experimental Evidence for Anisotropic Interactions in Some Rare-Earth Intermetallic Compounds

Abstract

We have studied the magnetic properties of the rare‐earth alloys RAl, RNi, and R₃Ni, with R = Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, in high magnetic fields up to 70 kOe. For the three series, the magnetic properties differ according to the alloyed rare earth. The compounds RAl of DyAl type and RNi of FeB type are ferromagnetic or antiferromagnetic. The compounds R₃Ni exhibit metamagnetism, except Tm₃Ni which has a ferromagnetic behavior. We have studied the magnetic structure of NdAl, TbAl, HoAl, ErAl, TmAl, NdNi, ErNi, HoNi, and Er₃Ni by neutron diffraction. They have all a noncolinear magnetic structure except NdNi, in which the magnetic moments are parallel. We have studied the stability of the magnetic structures by means of group theory; they are all stabilized by strongly anisotropic magnetic interactions between rare‐earth atoms.