Quantum critical behavior in the heavy Fermion single crystal Ce(Ni 0.935Pd0.065)2Ge2

Abstract

We have performed magnetic susceptibility, specific heat, resistivity, and inelastic neutron scattering measurements on a single crystal of the heavy Fermion compound Ce(Ni0.93BPd0.06B)2Ge 2, which is believed to be close to a quantum critical point (QCP) at T = 0. At lowest temperature(1.8-3.5 K), the magnetic susceptibility behaves as χ(T) - χ(0) T-1/6 with χ(0) = 0.032 × 10-6 m3/mole (0.0025 emu/mole). For T < 1 K, the specific heat can be fit to the formula ΔC/T = γ0 - T1/2 with γ0 of order 700 mJ/mole-K2. The resistivity behaves as ρ = ρ0 + AT3/2 for temperatures below 2 K. This low temperature behavior for γ(T) and ρ(T) is in accord with the SCR theory of Moriya and Takimoto[1]. The inelastic neutron scattering spectra show a broad peak near 1.5 meV that appears to be independent of Q; we interpret this as Kondo scattering with T K = 17 K. In addition, the scattering is enhanced near Q=(1/2, 1/2, 0) with maximum scattering at ΔE = 0.45 meV; we interpret this as scattering from antiferromagnetic fluctuations near the antiferromagnetic QCP. © Published under licence by IOP Publishing Ltd.