Collective Interactions in Pseudoternary Compounds Based on The Heavy Fermion CePtSi

李文新(W. H. Lee) ； 古煥球(H. C. Ku) ； R. N. Shelton

《Chinese Journal of Physics》 26卷1S期 (1988/02) Pp. 46-53

並列摘要

The nature of collective interactions in pseudoternary systems based on the recently discovered heavy-fermion compound CePtSi are investigated using precision electrical resistivity measurements on two distinct series of compounds. For ten polycrystalline samples in the isostructural series Ce(Pt1-xNix)Si(0≦x≦1), we observe a transition from a Kondo-lattice regime for the heavy fermion CePtSi to a regime where mixed-valence effects dominate for CeNiSi. In contrast, vancancies in the series CePt1-xSi have a pronounced effect on the strength of the RKKY interaction, resulting in magnetic order for x≧0.04. This is definite evidence for a transition from a heavy-fermion state to a long-range, magnetically ordered state. The relative strengths of the interactions that give rise to the heavy-fermion state, mixed-valence effects, Korido-lattice behavior and magnetic order are discussed for these materials.