Magnetic field and pressure-tuned Fermi liquid in heavy-fermion alloy Eu2ZnSb2

Abstract

Quantum phase transitions are explored in many materials, among which heavy-fermion compounds are the most prominent. Previous studies have shown that different types of transitions in a heavy-fermion compound can be tuned by an external variable, such as (chemical or physical) pressure and magnetic fields. Here we identify a new heavy-fermion alloy Eu₂Zn_0.98Sb₂ as exhibiting a pressure and magnetic field-induced quantum phase transition. An antiferromagnetic order, an extreme large electronic specific heat coefficient, and a Kondo behavior are evident in magnetic susceptibility, specific heat, and resistivity measurements. The Fermi liquid behavior appears after the antiferromagnetic order and Kondo effect gradually suppressed by external magnetic field and pressure, revealing two possible quantum critical phenomenon in Eu₂Zn_0.98Sb₂. A grend-KW ratio $\tilde{A}$/$\tilde{\gamma }$ was then obtained, which is close to that of heavy-fermions. Our findings provide a unique observation of the heavy-fermion behavior in a Eu-based compound.