Band Theory of the Intermetallic Compound UGe₃

Abstract

The one-electron energy band structure for UGe₃, which has attracted interest as a typical spin-fluctuation system, is calculated by an APW method with the LSD approximation exchange potential. Relativistic effects are taken into account. The 5f electrons hybridise with the Ge 4p electrons considerably and form bands which spread over about 0.2 Ryd. The Fermi level lies at a sharp peak in the density of states. The Fermi surface, the extremal cross-sectional area and the cyclotron mass are calculated carefully. The Fermi surface consists of two closed hole sheets centred at R in the eighth and ninth bands, and a lens-like electron pocket at M and a hollow-ball-like electron sheet centred at R in the tenth band. There exists no open orbit. These calculated results account well for experimental results for the de Haas-van Alphen effect and the magnetoresistance.