Ferromagnetism and transport properties of the Kondo system Ce4Sb1.5Ge1.5

Ferromagnetic ordering with a small magnetic moment is found below 14 K from SQUID measurements for the compound Ce4Sb1.5Ge1.5. The transport characteristics of a number of Ce4Sb3−xTx (T=Ge, Si, Sn, Pb, Al) systems were measured at room temperature, Ce4Sb1.5Ge1.5 demonstrating the highest Seebeck coefficient. Its transport properties (resistivity, thermal conductivity, and thermoelectric power) are experimentally investigated in detail up to low temperatures. The Kondo-lattice behavior of resistivity and its anomaly at the ordering point are found. A comparison with the Wiedemann-Franz law is performed.