Quantum critical fluctuations in the heavy fermion compound Ce(Ni0.935Pd0.065)(2)Ge-2

Abstract

Electric resistivity, specific heat, magnetic susceptibility, and inelastic neutron scattering experiments were performed on a single crystal of the heavy fermion compound Ce(Ni0.935Pd0.065)(2)Ge-2 in order to study the spin fluctuations near an antiferromagnetic (AF) quantum critical point (QCP). The resistivity and the specific heat coefficient for T <= 1 K exhibit the power law behavior expected for a 3D itinerant AF QCP (rho(T) similar to T-3/2 and gamma(T) similar to gamma 0 - bT(1/2)). However, for 2 <= T <= 10 K, the susceptibility and specific heat vary as logT and the resistivity varies linearly with temperature. Furthermore, despite the fact that the resistivity and specific heat exhibit the non-Fermi liquid behavior expected at a QCP, the correlation length, correlation time, and staggered susceptibility of the spin fluctuations remain finite at low temperature. We suggest that these deviations from the divergent behavior expected for a QCP may result from alloy disorder.