“Crystal fields” for magnetic ions in metals from itinerant electrons

The interaction of conduction electrons with host ions are shown to give rise to “crystal fields”, VC, which act on the magnetic ion in some dilute magnetic alloys. Crystal fields, VN, arising directly from ions neighbouring the magnetic ion have been compared with VC to show that the overall crystal field splitting from all 3d magnetic ions in axial symmetries is enhanced by the p-like character of VC. A04〈r4〉 from VN is also increased by the d-component of VC. The angular properties of itinerant electron states give rise to the above results. For all rare-earth ions in fcc symmetry the radial and angular components of conduction-electron states with mainly d, but also f character, are shown to give rise to a reversal in sign of A04〈r4〉 from VN. A06〈r6〉 is enhanced by the f component of the conduction electrons.