Non-Fermi-Liquid State in URu_0.68Pd_0.32Ge

Abstract

We report the measurements of dc-magnetization (M), specic heat (Cp) and electrical resistivity (ρ) of an intermetallic URu0.68Pd0.32Ge, that lies at the border between nonmagnetic and magnetic regimes in the magnetic phase diagram of solid solutions URu1−xPdxGe. The studied composition shows enhanced dc-magnetic susceptibility χ(T ) and the Sommerfeld ratio Cp(T )/T at low temperatures. Below 4 K χ(T ), Cp(T )/T and ρ(T ) can be described by χ(T ) ∝ T −0.48 , Cp(T )/T ∝ √ T and ρ(T ) ∝ c ln(T ) + AT 3/2 , respectively. These observations provide an evidence that URu0.68Pd0.32Ge is a moderately heavy-fermion system with an electronic ground state of non-Fermi liquid character. We found non-linear eect of the magnetization and a large value of the Wilson ratio, which are consistent with the interpretation in terms of magnetic instability.

Thermoelectric Power of the URu1-xPdxGe System

“…Measurements of magnetization, M (T ), specic heat, C p (T ), and electrical resistivity, ρ(T ), have revealed a dramatic change in their ground-state magnetic properties; from non-magnetic (x < 0.35), through antiferromagnetic (x = 0.35−0.8) to a complex magnetic state with two successive magnetic phase transitions in x = 0.9 and 1. It is remarkable that compositions located at the nonmagnetic-magnetic border were found to exhibit typical non-Fermi-liquid properties, such as [3,4]. To shed more light on the electron transport properties, we present in this contribution experimental data of thermoelectric power for URu 1−x Pd x Ge and discuss them in the frameworks of the existing theories.…”