Observation of the non-Fermi-liquid behavior in the evolution from heavy-fermion to valence-fluctuation behavior in Ce(Pt1-xRhx)Si2 series

We report the results of electrical resistivity, magnetic susceptibility, heat-capacity, and Ce-L-HI-edge X-ray absorption spectrum (XAS) measurements for a solid solution series Ce(Pt1-xRhx)Si-2 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0). The results reveal that CePtSi2 is an antiferromagnetic heavy-fermion compound with T-N approximate to 1.5 K. As Rh content increases, the Kondo effect gradually dominates over the magnetic ordering and drives the system towards an intermediate-valence (IV) regime with nearly quenched magnetism. Besides, we also observed non-Fermi-liquid behaviors in (CePt0.4RhSi2)-Si-0.6. These results indicate that at x P, 0.6, the system is located in the vicinity of a quantum critical point of the evolution. (C) 2006 Elsevier B.V. All rights reserved.