J-mixing linear theory for 3d-4f intermetallic compounds

The linear theory for the magnetic anisotropy of 3d-4f intermetallic compounds is generalized in order to account for the J-mixing effects. This is particularly useful for samarium-based alloys, since Sm3+ has a small spin-orbit gap between the fundamental and the first excited multiplets. The analytical formulas obtained from this technique are used to analyze the basal-plane anisotropy of Sm2Co17, for which the J mixing plays a crucial role, and the results are compared with exact numerical calculations. (C) 2003 American Institute of Physics.