Electronic and Volumetric Effects in Ternary Compounds of Ytterbium

We present complete results of self-consistent electronic-structure calculations of Yb-based and Lu-based ternary intermetallic compounds, namely, YbCu4Ag, YbCu4Au, YbCu4Pd, and LuCu4Ag. All these materials show a characteristic peak in the optical conductivity at about 2–2.5 eV. From the analysis of the allowed interband transitions among the calculated bands at the Γ point, we explain the origin of this peak. YbCu4Ag is a Kondo system with a high Kondo temperature. YbCu4-Au and -Pd order magnetically below 1 K. We give an interpretation of the origin of the different degree of f-d hybridization observed experimentally in these Yb-based compounds. © 1996 The American Physical Society.