Electrons and Spin Waves in Heavy Rare Earth Metals

Although the main principles governing the magnetic interactions and magnetic ordering in rare earth metals have been qualitatively understood for some time, it is only relatively recently that a sufficiently detailed study has been made of their electronic and magnetic excitations to place this understanding on a more quantitative basis.

The experimental evidence on the electronic structure of the rare earths is still rather meager but, so far as it goes, is in accord with the detailed description provided by band structure calculations. On the other hand, the experimental study of the magnon dispersion relations by inelastic neutron scattering has provided a wealth of information about the interactions between the local moments, associated with the incompletely filled 4f subshell, and the rest of the crystal.

The main emphasis in these notes will be on the interrelation between the electronic structure of the heavy rare earths, which have been the most extensively studied, and their magnetic properties.