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

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.