Electronic structure and anomalous properties of UAl2, NpAl2, and PuAl2.

Abstract

The electronic ground states of UAl/sub 2/, NpAl/sub 2/, and PuAl/sub 2/ in the C15 crystal structure were determined by performing self-consistent, semirelativistic, warped muffin-tin linear augmented-plane-wave electronic band-structure calculations. Then the densities of states and band states were determined by obtaining solutions including spin-orbit interactions with the self-consistent semirelativistic potential. The partial density of states functions obtained for these systems indicate strong d-f hybridization. A consistent procedure for determining the spin fluctuation parameters from the experimental data was obtained. This procedure was used to obtain the spin-fluctuation parameters from UAl/sub 2/. It is found that this procedure yields parameters that are different from previous estimates and indicates that the calculated parameters such as the bare density of states at the Fermi energy N(0), and the occupied f-band width are consistent with the band-structure values. It is found that although the actinide-actinide separation is about the same, the electronic structure near E/sub F/ is different. These calculations indicate that both d-f hybridization and spin-orbit coupling are important in the electronic structure of these systems.