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arXiv · 0707.3029

Collapse of antiferromagnetism in CeRh2Si2 : volume versus entropy

A. Villaume·D. Aoki·Y. Haga·G. Knebel·R. Boursier·J. Flouquet
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Abstract

The thermal expansion of the heavy fermion compound CeRh2Si2 has been measured under pressure as a function of temperature using strain gages. A large anomaly associated to the Neel temperature has been detected even above the suspected critical pressure Pc = 1.05 GPa where no indication of antiferromagnetism has been observed in calorimetry experiments sensitive to the entropy change. An unexpected feature is the pressure slowdown of the antiferromagnetic-paramagnetic transition by comparison to the fast pressure collapse predicted for homogeneous first order quantum phase transition with one unique pressure singularity at Pc. A large pressure dependance is observed in the anisotropy of the thermal expansion measured parallel or perpendicular to the c axis of this tetragonal crystal. The Fermi surface reconstruction associated to the first order transition produces quite different pressure response in the transport scattering measured along different crystallographic directions. A brief discussion is made on other examples of first order quantum transitions in strongly correlated electronic systems : MnSi and CeCoIn5.

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A. Villaume, D. Aoki, Y. Haga, G. Knebel, R. Boursier, J. Flouquet. 2007-07-20. Collapse of antiferromagnetism in CeRh2Si2 : volume versus entropy. https://doi.org/10.1088/0953-8984%2F20%2F01%2F015203

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