Crossover between Fermi liquid and non-Fermi liquid behavior in the non-centrosymmetric compound Yb2Ni12P7

A crossover from a non-Fermi liquid to a Fermi liquid phase in Yb2Ni12P7 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 similar to - ln(T) for 5K < T < 15K, which is consistent with non-Fermi liquid behavior. Below T similar to 4K, 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) = AT(2) behavior below T similar to 4K, with the power-law exponent becoming sub-quadratic for T > 4K. A crossover between Fermi-liquid and non-Fermi liquid behavior suggests that Yb2Ni12P7 is in close proximity to a quantum critical point, in agreement with results from recent measurements of this compound under applied pressure.