We report the synthesis and electronic properties of polycrystalline samples of Zr6MBi2 (M = Ru and Fe) crystallizing in the hexagonal Zr6CoAl2-type structure. Based on their electrical resistivity, magnetization, and heat capacity data, Zr6RuBi2 and Zr6FeBi2 are found to exhibit bulk superconductivity below Tc = 4.9 and 1.4 K, respectively. Although Zr6RuBi2 is most likely a conventional superconductor, the considerably higher Tc for M = Ru than that for M = Fe differs from the trend in Tc for Zr6CoAl2-type superconductors reported thus far. The superconductivity of an amorphous solid-solution phase, which may hinder elucidation of the superconducting properties of Zr6MBi2, is also discussed.
@article{arxiv.2410.16684,
title = {Superconductivity in Hexagonal Zr6CoAl2-Type Zr6RuBi2 and Zr6FeBi2},
author = {Kosuke Yuchi and Daisuke Nishio-Hamane and Keita Kojima and Kodai Moriyama and Ryutaro Okuma and Yoshihiko Okamoto},
journal= {arXiv preprint arXiv:2410.16684},
year = {2024}
}