Electronic properties of CeRh1−xGexIn; evolution from an intermediate-valence to a localized 4f-state

We examined how electronic properties of the intermediate-valent CeRhIn are influenced by gradual substitution of rhodium with germanium. Results of specific-heat, magnetic susceptibility, electrical resistivity, thermopower and X-ray photoelectron spectroscopy (XPS) measurements performed in wide range of temperature and magnetic field on polycrystalline samples of CeRh1−xGexIn, for x = 0.1, 0.2 and 0.3, are presented and compared to corresponding data reported earlier for CeRhIn, its hydrides and CePdxRh1−x In solutions. A systematic shift from the intermediate-valence to a localized 4f-state with increasing content of germanium is evident from all obtained results. Non-Fermi liquid state is formed at low temperatures for the solution with the lowest Ge content, but it is destroyed by magnetic field and/or further doping with Ge.