The effect of d electrons on crystal field potentials in rare earth metals and dilute alloys

The effect of 5d character on the crystalline electric field in noble metal rare earth alloys and in pure rare earths has been investigated. The change in sign of the fourth order CEF coefficient in the noble metal alloys can be interpreted in terms of this d character. From symmetry this d like component has no effect on the sixth order coefficients whose varying magnitude in these alloys can be explained using the f like contribution. In the pure rare earth metals it is likely that d character will predominate.