CeAu2In4: A candidate of quasi-one-dimensional antiferromagnetic Kondo lattice*

Abstract

Needle-like single crystals of CeAu2In4 have been grown from In flux and characterized as a new candidate of quasi-one-dimensional Kondo lattice compound by crystallographic, magnetic, transport, and specific-heat measurements down to very low temperatures. We observe an antiferromagnetic transition at T N ≈ 0.9 K, a highly non-mean-field profile of the corresponding peak in specific heat, and a large Sommerfeld coefficient γ = 369 mJ⋅mol−1⋅K−2. The Kondo temperature T K is estimated to be 1.1 K, being low and comparable to T N. While Fermi liquid behavior is observed deep into the magnetically ordered phase, the Kadowaki–Woods ratio is much reduced relative to the expected value for Ce compounds with Kramers doublet ground state. Markedly, this feature shares striking similarities to that of the prototypical quasi-one-dimensional compounds YbNi4P2 and CeRh6Ge4 with tunable ferromagnetic quantum critical point. Given the shortest Ce–Ce distance along the needle direction, CeAu2In4 appears to be an interesting model system for exploring antiferromagnetic quantum critical behaviors in a quasi-one-dimensional Kondo lattice with enhanced quantum fluctuations.