Physical properties of Ce 2CoSn 2

Abstract

A complete physical characterisation, through specific heat, electrical resistivity and magnetization measurements was performed, in a wide temperature range, on the new phase Ce 2CoSn 2, which crystallizes in a very large fcc cell with a structure type similar to the Tb 117Fe 52Ge 112 one. From the real part of the AC susceptibility data a broad maximum can be observed at 7 K with an inflexion point, in agreement with the maximum observed in the imaginary part of the AC susceptibility, at a lower temperature (around 6 K). We hypothesize that the lower maximum can be attributed to an antiferromagnetic transition while the upper one could be related to the onset of a Kondo regime. The antiferromagnetic order is confirmed by magnetization measurements performed at 2 K in magnetic fields up to 9 Tesla: a metamagnetic transition could be observed around 0.4 Tesla. In the paramagnetic range the inverse of susceptibility follows a modified Curie–Weiss law, with an effective paramagnetic moment μ=2.89 μ B and a paramagnetic Curie temperature slightly positive. The heat capacity results suggest that this phase might be a heavy fermion system, with an electronic specific heat coefficient γ=1.3 J/K 2 mol. The electrical resistivity measurements exhibit a pronounced minimum at about 13 K and below this temperature a logarithmic Kondo-like behaviour is observed.