Electronic Structure of Heavy-Fermion Systems YbT2Zn20(T= Fe, Co, Ru, Rh, Os, Ir)

Abstract

Electronic band structure calculations were carried out for dilute rare earth bearing family of R T 2 Zn 20 ( R = Y, Yb, Lu, T = Fe, Co, Ru, Rh, Os, Ir) adopting the linear muffin-tin-orbital method in the atomic sphere approximation within the framework of the local spin-density approximation (LSDA). The Fermi energies in the 4f-itinerant band structures are found to be located in the immediate vicinity of the 4f-band of the j = 7/2 state with extremely narrow band width. In the Yb A 2 Zn 20 ( A = Fe, Ru, and Os) compounds, the j = 7/2 bands are situated just below the Fermi level. In the Yb B 2 Zn 20 ( B = Co, Rh, and Ir) compounds, the j = 7/2 bands touch the Fermi level. These trends of the 4f-bands are consistent with thermodynamic and transport properties. The calculated de Haas–van Alphen (dHvA) frequencies fairly well reproduce the data detected in pulsed fields directed along [110] and [111] directions for Yb X 2 Zn 20 ( X = Fe, Co, and Rh), Lu X 2 Zn 20 ( X = Fe and Co), and YCo 2 Zn 20 , althou...