Electronic Structure of the fcc Transition Metals Ir, Rh, Pt, and Pd

Abstract

We give a complete description of a relativistic augmented-plane-wave calculation of the band structures of the paramagnetic fcc transition metals Ir, Rh, Pt, and Pd. The width and position of the $d$ band decrease in the sequence Ir, Pt, Rh, Pd; and $N({E}_{F})=13.8,23.2,18.7, \mathrm{and} 32.7$ (states/atom)/Ry, respectively. Spin-orbit coupling is important for all four metals and the coupling parameter varies by 30% over the $d$ bandwidth. Detailed comparisons with de Haas---van Alphen Fermi-surface dimensions have previously been presented and the agreement was very good. Comparison with measured electronic specific-heat coefficients $\ensuremath{\gamma}$ and cyclotron masses indicate that the average mass enhancements are 1.37, 1.44, 1.63, and 1.66 for Ir, Rh, Pt, and Pd, respectively; and that for both Pt and Pd the partial enhancements on the closed electron surface and on the open hole surface are 1.51 and 1.68, respectively. Saddle points in the fifth band are important for the large peak in $N(E)$ near the top of the $d$ band. The experimental $\ensuremath{\gamma}(x)$ for ${\mathrm{Rh}}_{x}{\mathrm{Pd}}_{1\ensuremath{-}x}$ is not uniformly enhanced over the calculated rigid-band $\ensuremath{\gamma}(x)$. The experimentally observed field and temperature dependences of the magnetic susceptibility for Pd are consistent with the calculated $N(E)$.