Antiferromagnetism and enhanced specific heat in CeM 2Sn 2 ( M = Ni, Ir, Cu, Rh, Pd and Pt)

W.P Beyermann,M.F Hundley,P.C Canfield,C Godart,M Selsane,Z Fisk,J.L Smith,J.D Thompson

doi:10.1016/0921-4526(91)90553-q

W.P Beyermann, M.F Hundley + Show 6 more

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https://doi.org/10.1016/0921-4526(91)90553-q

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Journal: Physica B Condensed Matter	Publication Date: May 1, 1991
Citations: 24	License type: cc-by

Affiliation: Los Alamos National Laboratory

Abstract

Specific heat, DC susceptibility, and resistivity measurements on annealed, polycrystalline samples of CeM 2Sn 2, where M = Ni, Ir, Cu, Rh, Pd, or Pt, indicate that each of these compounds orders antiferromagnetically with transition temperatures ranging from T N = 4.1 to ≈ 0.5 K. All these materials have significant enhancements of the specific heat just before the transition, which can be as large as ∼ 3.5J/mol K 2 in some cases. Provided the enhanced heat capacities above T N are associated with large effective masses, the anomalously low ordering temperature and the very large C/ T suggest that T N and the Kondo temperature T K are comparable, making these materials particularly attractive for studying the interplay between these competing interactions. The susceptibility for each member of the series except M = Ir follows a Curie-Weiss behavior with a high-temperature effective moment μ eff ∼ 2.5μ B Ce and a small negative paramagnetic Curie temperature.

Highlights

CeIr,Snz shows a low-temperature maximum similar to CeNiSn, followed by a sharp drop associated with the magnetic transition
Determining absolute values for the resistivity was not possible because of geometric irregularities in the samples, but the magnitudes at room temperature are estimated to be of the order of a few 100 FQ cm
The sharp drop at low temperatures in CeIr,Sn, is probably due to a loss of magnetic scattering. This is the only member of the series where a resistive anomaly coincides with the magnetic phase transition found in the specific heat

Summary

Introduction

CeIr,Snz shows a low-temperature maximum similar to CeNiSn, followed by a sharp drop associated with the magnetic transition. Determining absolute values for the resistivity was not possible because of geometric irregularities in the samples, but the magnitudes at room temperature are estimated to be of the order of a few 100 FQ cm. This is the only member of the series where a resistive anomaly coincides with the magnetic phase transition found in the specific heat.

Results

Conclusion