Molecular magnetism and crystal field effects in the Kondo system Ce3Pd20(Si,Ge)6 with two Ce sublattices

The unusual electronic and magnetic properties of the systems Ce3Pd20T6 (T=Ge, Si) with two non-equivalent Ce positions are discussed. The logarithmic growth of resistance for both systems confirms the presence of the Kondo effect in the two respective temperature ranges. The two-scale behavior is explained by consecutive splitting of Ce ion levels in the crystal field. The effects of the frustration caused by the coexistence of the different Ce positions are treated, which may also significantly enhance the observed values of specific heat. A model of “molecular magnetism” with Ce2 cubes is developed.