Electronic structure and thermodynamic properties of Ce3Rh4Sn13 and La3Rh4Sn13

Abstract

We report on the electronic structure and basic thermodynamic properties of Ce3Rh4Sn13 and of the reference compound La3Rh4Sn13. XPS core-level spectra revealed a stable trivalent configuration of the Ce atoms in Ce3Rh4Sn13, consistent with magnetic susceptibility data. Band structure calculations within the LSDA+U approximation yield the qualitatively correct description of Ce in a trivalent state. The reliability of the theoretical results has been confirmed by a comparison of the calculated XPS valence band spectra with experimental data. The calculated densities of states as well as the rare-earth (RE) 3d XPS spectra point to a weak hybridization between the RE 4f shell and the conduction band states. The band structure calculations result in a magnetic ground state for Ce3Rh4Sn13. Previous analysis pointed to the partial occupancy of the 2a site by Sn atoms. The charge density analysis reveals the dominant metallic character of the chemical bonding at the 2a atomic position. Simulation of vacancies at the 2a site using the virtual crystal approximation (VCA) indicate that the magnetic properties of Ce3Rh4Sn13 strongly depend on the Sn content, which could explain the discrepancy in magnetic properties between different Ce3Rh4Sn13 samples.