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

doi:10.1140/epjb/e2002-00388-1

2023 Impact factor 1.6

Condensed Matter and Complex Systems

Eur. Phys. J. B 30, 343-349 (2002)
https://doi.org/10.1140/epjb/e2002-00388-1

Study of Ce(Rh_1-xPd_x)₂Si₂: pronounced differences between the CeRh₂Si₂ and CePd₂Si₂ ground states

M. Gómez Berisso¹^a, P. Pedrazzini¹, J. G. Sereni¹, O. Trovarelli², C. Geibel² and F. Steglich²

¹ Lab. Bajas Temperaturas, Centro Atómico Bariloche - IB (CNEA) and CONICET, 8400 S.C. de Bariloche, Argentina
² Max-Planck Institut for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany

Corresponding author: ^a berisso@cab.cnea.gov.ar

Received: 31 December 2001
Revised: 6 July 2002
Published online: 19 December 2002

Abstract

We present electrical resistivity and specific heat measurements of alloys on the Rh rich side of the phase diagram of the Ce(Rh_1-xPd_x)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 $C_{el}(T)$ and $\rho(T)$ clearly confirm a separation of the magnetic phase diagram into two regions: the region $x\le0.3$ , showing a concentration independent characteristic temperature for the 4f-electrons with $T_0\approx45~{\rm K}$ , while for x>0.3, T₀ decreases to $T_0(x=1)\approx15~{\rm K}$ . At low Pd-content, T_N decreases very rapidly from $T_N = 36~{\rm K}$ in pure CeRh₂Si₂ to $T_N=18~{\rm K}$ at x=0.1. With higher Pd concentration T_N stabilizes at $T_N\approx15~{\rm K}$ whereas the magnitude of the anomalies in $C_{el}(T)$ and in the susceptibility around T_N are further reduced and disappear at $x\approx0.3$ . This differs from the behavior found on the Pd-rich side, where T_N 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 CeRh₂ Si₂, in contrast with the localized character of CePd₂Si₂. Further evidence for the itinerant character of CeRh₂Si₂ is given by the $\rho(T)$ dependence observed for $x\le0.3$ , which scales with $\rho(T)$ of the prototype itinerant compound YCo₂.

PACS: 71.10.Hf – Non-Fermi-liquid ground states, electron phase diagrams and phase transition in model systems / 71.27.+a – Strongly correlated electron systems; heavy fermions

© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002