Short-range magnetic correlation with Kondo-lattice behavior in Ce3Ir2Ge2 and superconductivity in La3Ir2Ge2 -: art. no. 073903

We present the results of the magnetic susceptibility, magnetization, specific-heat, and electrical resistivity measurements on rare-earth iridium germanides Ce3Ir2Ge2 and La3Ir2Ge2, crystallizing in the La3Ni2Ga2-type orthorhombic crystal structure. The results reveal that Ce3Ir2Ge2 is a Kondo-lattice system showing characteristic -ln T dependence of magnetic resistivity at high temperatures, while there does not exist evident sign of long-range magnetic ordering at least down to 1.8 K. Instead, a short-range magnetic correlation occurs at about 3.5 K. The La-based compound was found to be a type-II superconducting material with a relatively high critical temperature T-C=4.7 K. A number of the relevant parameters, such as lower critical field, upper critical field, coherence length, penetration depth, and Ginzburg-Landau parameter, were estimated for the La3Ir2Ge2 sample. (C) 2005 American Institute of Physics.