Heavy-electron antiferromagnetism in CePt2Sn2.

Abstract

We have measured specific heat, magnetic susceptibility, and resistivity on the cerium-intermetallic compound ${\mathrm{CePt}}_{2}$${\mathrm{Sn}}_{2}$. 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 ${\mathit{T}}_{\mathit{N}}$=0.88 K, the linear temperature coefficient of the specific heat \ensuremath{\gamma} is approximately 3.5 J/mol ${\mathrm{K}}^{2}$, making this material one of the heaviest electron systems known. The low N\'eel temperature and huge specific heat imply similarly low-energy scales for competing RKKY and Kondo-like interactions.