Quantum critical behavior in the heavy Fermion single crystal Ce(Ni$_{0.935}$Pd$_{0.065}$)$_2$Ge$_2$

C. H. Wang; J. M. Lawrence; A. D. Christianson; S. Chang; K. Gofryk; E. D. Bauer; F. Ronning; J. D. Thompson; K. J. McClellan; J. A. Rodriguez-Rivera; J. W. Lynn

doi:10.1088/1742-6596/273/1/012018

arXiv · 1104.0203

Quantum critical behavior in the heavy Fermion single crystal Ce(Ni$_{0.935}$Pd$_{0.065}$)$_2$Ge$_2$

C. H. Wang·J. M. Lawrence·A. D. Christianson·S. Chang·K. Gofryk·E. D. Bauer·F. Ronning·J. D. Thompson·K. J. McClellan·J. A. Rodriguez-Rivera·J. W. Lynn

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Abstract

We have performed magnetic susceptibility, specific heat, resistivity, and inelastic neutron scattering measurements on a single crystal of the heavy Fermion compound Ce(Ni$_{0.935}$Pd$_{0.065}$)$_2$Ge$_2$, 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 $χ(T)-χ(0)$ $\propto$ $T^{-1/6}$ with $χ(0) = 0.032 \times 10^{-6}$ m$^3$/mole (0.0025 emu/mole). For $T<$ 1 K, the specific heat can be fit to the formula $ΔC/T = γ_0 - T^{1/2}$ with $γ_0$ of order 700 mJ/mole-K$^2$. The resistivity behaves as $ρ= ρ_0 + AT^{3/2}$ 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\cite{Moriya}. 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.

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C. H. Wang, J. M. Lawrence, A. D. Christianson, S. Chang, K. Gofryk, E. D. Bauer, F. Ronning, J. D. Thompson, K. J. McClellan, J. A. Rodriguez-Rivera, J. W. Lynn. 2011-04-01. Quantum critical behavior in the heavy Fermion single crystal Ce(Ni$_{0.935}$Pd$_{0.065}$)$_2$Ge$_2$. https://doi.org/10.1088/1742-6596%2F273%2F1%2F012018

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