Electronic structure of Ce 5Rh 4Sn 10 from XPS and band structure calculations

Abstract

We present a combined experimental and theoretical study of the electronic structure for the heavy-fermion antiferromagnet Ce 5Rh 4Sn 10 based on X-ray photoemission spectroscopy (XPS) data and ab initio band structure calculations. The Ce core-level XPS spectra point to a stable trivalent configuration of Ce atoms in Ce 5Rh 4Sn 10, consistently with both the magnetic susceptibility data and the results of computational structure optimization. The band structure calculations confirm a magnetic ground state with significant magnetic moments only at the Ce atoms. The qualitatively correct description of Ce 3+ in Ce 5Rh 4Sn 10 has been achieved using the LSDA+U approach for the Ce 4f states. The comparison of the theoretical results with experimental XPS valence band spectrum supports their validity. The calculated partial densities of states suggest that there is a variation in binding energy of the occupied 4f states between Ce atoms in nonequivalent crystallographic positions, which is related to the hybridization with Sn states. Finally, the band structure and charge density maps point to the formation of zig-zag chains of the strongly bounded Sn(2), Sn(3) and Rh atoms along the tetragonal axis, whereas Sn(1) shows nearly dispersionless 5s bands. © 2008 EDP Sciences/Società Italiana di Fisica/Springer-Verlag.