Magnetic anisotropies of rare-earth compounds

There are two kinds of magnetic anisotropy in rare-earth compounds: the sin gle-ion anisotropy caused by the crystal field (CF) and the anisotropy of t he two-ion interactions. Both types of anisotropy have to be considered to arrive at a consistent description of the magnetic properties of the orthor hombic intermetallic compound NdCu2. From the analysis of NdCu2 we can deri ve predictions for the type of ordering in other isostructural RCu2 compoun ds, that agree well with experimental results: If the magnetic moments poin t into the crystallographic b-direction, an ordering wave vector of (2/3 00 ) is expected. If the moments are oriented perpendicular to b then the orde ring wave vector is (2/3 10). (C) 2000 Elsevier Science B.V. All rights res erved.