UC Irvine

We have measured specific heat, magnetic susceptibility, and resistivity on the cerium-intermetallic compound CePt2Sn2. The heat capacity shows a strong increase below a few kelvin, typical of a large many-body enhancement of the density of states or equivalently of the effective electronic mass. Just before the material orders antiferromagnetically at TN=0.88 K, the linear temperature coefficient of the specific heat γ is approximately 3.5 J/mol K2, making this material one of the heaviest electron systems known. The low Néel temperature and huge specific heat imply similarly low-energy scales for competing RKKY and Kondo-like interactions.