In this article, the superconducting and normal state properties of TlBi2 with the AlB2-type structure were studied by the resistivity, magnetization and specific heat measurements. It was found that bulk superconductivity with TC = 6.2 K emerges in TlBi2, which is a phonon-mediated s-wave superconductor with a strong electron-phonon coupling (λep = 1.38) and a large superconducting gap (Δ0/kBTC = 2.25). We found that the ρ(T) exhibits an unusual T-linear dependence above 50 K, and can be well described by the Fermi-liquid theory below 20 K. Interestingly, its Kadowaki-Woods ratio A/γ2 [9.2×10−5μΩ cm(mol K2/mJ)2] is unexpectedly one order of magnitude larger than that obtained in many heavy Fermi compounds, although the electron correlation is not so strong.
@article{arxiv.2204.04863,
title = {Superconductivity in TlBi$_2$ with a large Kadowaki-Woods ratio},
author = {Zhihua Yang and Zhen Yang and Qiping Su and Jianhua Du and Enda Fang and Chuxiang Wu and Jinhu Yang and Bin Chen and Hangdong Wang and Minghu Fang},
journal= {arXiv preprint arXiv:2204.04863},
year = {2022}
}