Contrasting Kondo-Lattice Behavior in CeTSi3and CeTGe3(T=Rh and Ir)

Specific-heat, magnetic-susceptibility and electrical-resistivity measurements were carried out on four Ce compounds of tetragonal BaNiSn 3 -type, CeTSi 3 and CeTGe 3 ( T= Rh and Ir). All these compounds show magnetic transitions at low temperatures. CeRhSi 3 and CeIrSi 3 are a Kondo-lattice compound with a relatively high Kondo temperature of the order of 100 K, while CeRhGe 3 and CeIrGe 3 exhibit a very weak Kondo effect, and three magnetic phase transitions below 14.6 K and 8.7 K, respectively. These contrasting behaviors in the silicides and germanides are discussed by comparing with properties of other BaNiSn 3 -type Ce compounds, like CeFeGe 3 and CeCoGe 3 .