CHARGE SCREENING AND MAGNETIC-ANISOTROPY IN METALLIC RARE-EARTH SYSTEMS

The calculation of magnetic anisotropy constants is performed beyond t he point-charge model for a continuous charge-density distribution of screening conduction electrons. An important role of the nonuniform el ectron density, in particular, of the Friedel oscillations, in the for mation of crystal field is demonstrated. Such effects can modify stron gly the effective ion (impurity) charge and even change its sign. This enables one to justify the anion model, which is often used for discu ssing experimental data on hydrogen-containing systems. Possible appli cations to the pure rare-earth metals and RCo5 (R=rare earth) compound s are discussed. The deformation of magnetic structure near the inters titial positive muon owing to the strong local anisotropy, and the cor responding contribution to the dipole field at the muon are considered .