取代对过渡金属二硫属化物Nb(SeₓS₁₋ₓ)₂范德华层状结构超导相的影响。

Effect of substitution on the superconducting phase of transition metal dichalcogenide Nb(Se[Formula: see text]S[Formula: see text])[Formula: see text] van der Waals layered structure.

作者信息

Tsuppayakorn-Aek Prutthipong, Pluengphon Prayoonsak, Phansuke Piya, Inceesungvorn Burapat, Busayaporn Wutthikrai, Kaewtubtim Pungtip, Bovornratanaraks Thiti

机构信息

Extreme Conditions Physics Research Laboratory (ECPRL) and Physics of Energy Materials Research Unit, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, 10330 Thailand.

Thailand Centre of Excellence in Physics, Ministry of Higher Education, Science, Research and Innovation, 328 Si Ayutthaya Road, Bangkok, 10400 Thailand.

出版信息

Sci Rep. 2021 Jul 26;11(1):15215. doi: 10.1038/s41598-021-94000-2.

DOI:10.1038/s41598-021-94000-2

PMID:34312409

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8313716/

Abstract

By means of first-principles cluster expansion, anisotropic superconductivity in the transition metal dichalcogenide Nb(Se[Formula: see text]S[Formula: see text])[Formula: see text] forming a van der Waals (vdW) layered structure is observed theoretically. We show that the Nb(Se[Formula: see text]S[Formula: see text])[Formula: see text] vdW-layered structure exhibits minimum ground-state energy. The Pnnm structure is more thermodynamically stable when compared to the 2H-NbSe[Formula: see text] and 2H-NbS[Formula: see text] structures. The characteristics of its phonon dispersions confirm its dynamical stability. According to electronic properties, i.e., electronic band structure, density of states, and Fermi surface indicate metallicity of Nb(Se[Formula: see text]S[Formula: see text])[Formula: see text]. The corresponding superconductivity is then investigated through the Eliashberg spectral function, which gives rise to a superconducting transition temperature of 14.5 K. This proposes a remarkable improvement of superconductivity in this transition metal dichalcogenide.

摘要

通过第一性原理团簇展开，从理论上观察到形成范德华（vdW）层状结构的过渡金属二硫属化物Nb(SeₓS₁₋ₓ)₂中的各向异性超导性。我们表明，Nb(SeₓS₁₋ₓ)₂的vdW层状结构具有最低的基态能量。与2H-NbSe₂和2H-NbS₂结构相比，Pnnm结构在热力学上更稳定。其声子色散特性证实了它的动力学稳定性。根据电子性质，即电子能带结构、态密度和费米面表明Nb(SeₓS₁₋ₓ)₂具有金属性。然后通过Eliashberg谱函数研究相应的超导性，得出超导转变温度为14.5 K。这表明这种过渡金属二硫属化物的超导性有显著改善。