Electronic structure and magnetism of rare-earth intermetallic compounds

Abstract

The electronic structure of R 2PdSi 3 (R=Ce, Nd, Tb, Dy, Ho, Er) and HoTX (T=Co, Ni, Rh, Pd, Ag; X=Si, Ge, Sn, Ga) compounds was studied by X-ray and ultraviolet photoemission spectroscopy. For the R 2PdSi 3 (R=Nd, Tb–Er) compounds, the valence band is dominated by the multiplet structure of the rare-earth atoms and by the Pd 4d band at E=4 eV. In these compounds, the density of states at the Fermi level is low and the Ruderman–Kittel–Kasuya–Yosida interaction seems to play a minor role in the magnetic interactions. The valence bands of the HoTX compound are also dominated by the Ho 4f and the transition metal nd ( n=3,4) states. The multiplet structure of the Ho 4f states corresponds to that of the Ho 3+ ion for all these compounds. The states at the Fermi level contain contributions from Ho (5d6 s) for T=Ag and from additional nd states of the T element for compounds with T=Co, Ni, Pd and Rh.