Magnetic ordering and the electronic properties of the heavy rare-earth metals

The magnetic perturbation of the conduction-electron bands due to the periodic (and ferromagnetic) arrays of 4f moments, occurring in the heavy rare-earth metals, has been estimated from nonrelativistic augmented-plane-wave energy-band results for Tm. The relationship between these perturbations, the ordering period, and other observables, such as the c-axis resistance anomalies, are inspected. Important to these considerations and to an understanding of the ordering of the 4f moments is the magnitude of the perturbation effects which result in sizable gaps relative to the bandwidth in the 5d bands, destroy large segments of Fermi surface (primarily normal to the c axis), and force appreciable redistributions of the populated conduction-electron states.