Quantum critical behavior in a CePt ferromagnetic Kondo lattice

Abstract

Most of the studies of heavy fermions near a quantum critical point (QCP) have been carried out on antiferromagnetic systems. In this paper we report on the disappearance of ferromagnetic (FM) order in CePt as seen by the ac magnetic susceptibility and the electrical resistance measurements under pressures $P$ up to 15 GPa. The pressure dependence of the Curie temperature ${T}_{C}(P)$ follows a typical Doniach's phase diagram for Kondo lattice systems and it is consistent with a QCP at the critical pressure ${P}_{C}\ensuremath{\approx}12.1\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. The resistance in the vicinity of the QCP shows clearly a non-Fermi liquid (NFL) and beyond that a Fermi liquid (FL) state is recovered. A semiquantitative discussion on the nature of the vanishing of ${T}_{C}$ in a FM Ce Kondo lattice is given for the first time.