Crstal
Pirkko Wassell
A comparison of the Knight shift and susceptibility of dilute Co impurities in a wide variety of nonmagnetic metal hosts demonstrates that crstal field and orbital splitting of the Co ionic levels cannot be neglected, as is done in most theoretical treatments of the subject. The crystal field level splitting of the 4F Hund's rule ground state is at least a few tenths of an eV in low temperature noble metal hosts for which the characteristic coupling energy kTK to conduction electrons is 0.1 eV or smaller. In liquid metal hosts, crystal field effects appear to be small. Data on polyvalent liquid metals indicate that one or more ionic orbitals lie about 0.3 eV above the 4F level and are populated when kTK is large. The level could be either a 4P or 5D ionic level, corresponding respectively to intra- to interconfiguration mixing in the polyvalent host metals.