Crossover between Fermi liquid and non-Fermi liquid behavior in the non-centrosymmetric compound Yb${}_2$Ni${}_{12}$P${}_7$

Abstract

A crossover from a non-Fermi liquid to a Fermi liquid phase in Yb${}_2$Ni${}_{12}$P${}_7$ is observed by analyzing electrical resistivity $\rho (T)$, magnetic susceptibility $\chi (T)$, specific heat $C(T)$, and thermoelectric power $S(T)$ measurements. The electronic contribution to specific heat, $C_e(T)$, behaves as $C_e(T)/T\sim -\ln (T)$ for 5 K $<T<$ 15 K, which is consistent with non-Fermi liquid behavior. Below $T\sim$ 4 K, the upturn in $C_e(T)/T$ begins to saturate, suggesting that the system crosses over into a Fermi-liquid ground state. This is consistent with robust $\rho (T)-{\rho }_0=A{T}^2$ behavior below $T\sim$ 4 K, with the power-law exponent becoming sub-quadratic for $T>$ 4 K. A crossover between Fermi-liquid and non-Fermi liquid behavior suggests that Yb${}_2$Ni${}_{12}$P${}_7$ is in close proximity to a quantum critical point, in agreement with results from recent measurements of this compound under applied pressure.

17 pages, 6 figures, accepted in J. Phys.: Condens. Matter

References in corpus (3)

• On the thermoelectricity of correlated electrons in the zero-temperature limit
• Quantum Valence Criticality as Origin of Unconventional Critical Phenomena
• Thermoelectric response near a quantum critical point: the case of CeCoIn5