Study of Ce(Rh1-xPdx)2Si2: pronounced differences between the CeRh2Si2 and CePd2Si2 ground states

M. GÓMEZ BERISSO; P. PEDRAZZINI; J.G. SERENI; O. TROVARELLI; C. GEIBEL; F. STEGLICH

EUROPEAN PHYSICAL JOURNAL B - CONDENSED MATTER

EDP Sciences

Lugar: Ulis; Año: 2002 vol. 30 p. 343 - 349

1434-6028

We present electrical resistivity and specific heat measurements of alloys on the Rh rich side of the phase diagram of the Ce(Rh1-xPdx)2Si2 system. We compare these results with those obtained at intermediate and low Rh concentrations. The analysis of the concentration and temperature dependence of the entropy and of the scaling behaviour of Cel(T) and ρ(T) clearly confirm a separation of the magnetic phase diagram into two regions: the region x≤0.3, showing a concentration independent characteristic temperature for the 4f-electrons with T0≈45K, while for x>0.3, T0 decreases to T0(x=1)≈15K. At low Pd-content, TN decreases very rapidly from TN=36K in pure CeRh2Si2 to TN=18K  at x=0.1. With higher Pd concentration TN stabilizes at TN≈15K whereas the magnitude of the anomalies in Cel(T) and in the susceptibility around TN are further reduced and disappear at x≈0.3. This differs from the behavior found on the Pd-rich side, where TN decreases continuously to zero with increasing Rh content. The pronounced differences observed between both phase boundaries and the drastic effect of doping on the Rh rich side suggest an itinerant character in CeRh2Si2, in contrast with the localized character of CePd2Si2. Further evidence for the itinerant character of CeRh2Si2 is given by the ρ(T) dependence observed for x≤0.3, which scales with ρ(T) of the prototype itinerant compound YCo2.