The newly discovered CaFe4As3 system displays low-temperature Fermi liquid behavior, with enhanced electron-electron correlations. At high temperatures, the magnetic susceptibility shows Curie-Weiss behavior, with a large temperature-independent contribution. Antiferromagnetic ordering is observed below TN = (88.0 ± 1.0) K, possibly via a spin density wave (SDW) transition. A remarkably sharp drop in resistivity occurs below T2 = (26.4 ± 1.0) K, correlated with a similarly abrupt increase in the susceptibility, but no visible feature in the specific heat. The electronic specific heat coefficient γ at low temperatures is close to 0.02 J molFe−1 K−2, but a higher value for γ (∼0.08 J molFe−1 K−2 can be inferred from a linear C/T \textit{vs.} T2 just above T2. The Kadowaki-Woods ratio A/γ2 = 55∗10−5μΩcm mol2 K2mJ−2 is nearly two orders of magnitude larger than that of heavy fermions.
@article{arxiv.0904.4188,
title = {Fermi liquid state and enhanced electron correlations in the new iron pnictide CaFe$_4$As$_3$},
author = {Liang L. Zhao and Tanghong Yi and James C. Fettinger and Susan M. Kauzlarich and E. Morosan},
journal= {arXiv preprint arXiv:0904.4188},
year = {2009}
}