Magnetic properties of rare earth atoms in palladium: crystal field effects, EPR, and magnetic moment

Recent studies of the magnetic properties of rare earth (RE) atoms dissolved in metals and particularly in Pd are reviewed. The effects of the crystalline electric field on the RE and the corresponding magnetic behavior and electron paramagnetic resonance (EPR) are discussed. Selected examples are chosen from an extensive series of magnetic measurements on dilute alloys of Pd1−xRx where R = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu in order to illustrate the behavior of the RE in Pd. The magnetic properties of the RE in Pd are well described by a semiempirical formula which yields the RE moment and hence the valence state, and host susceptibility. The temperature and field dependence of the magnetic moment also are compared with calculations based on crystal field parameters derived from a reanalysis of recent EPR measurements of RE ions in single crystal Pd by the University of Geneva group. This analysis shows that for Dy an effective spin Hamiltonian is not appropriate for describing the EPR data, but it is adequate for Er in Pd.