Year: 2019
Type: article
Abstract: We report the discovery of superconductivity (SC) in the ternary aluminide Nb 5 Sn 2 Al, which crystallizes in the W 5 Si 3 -type structure with one-dimensional Nb chains along the c -axis. It is found that the compound has a multiband nature and becomes a weakly coupled, type-II superconductor below 2.0 K. The bulk nature of SC is confirmed by the specific heat jump, whose temperature dependence shows apparent deviation from a single isotropic gap behavior. The lower and upper critical fields are estimated to be 2.0 mT and 0.3 T, respectively. From these values, we derive the penetration depth, coherence length and Ginzburg–Landau parameter to be 516 nm, 32.8 nm and 15.6, respectively. In contrast, the isostructural compound Ti 5 Sn 2 Al does not superconduct above 0.5 K. A comparison of these results with other W 5 Si 3 -type superconductors suggests that T c of these compounds correlates with the average number of valence electrons per atom.
Authors: Jifeng Wu, Bin Liu, Yanwei Cui, Hangdong Wang, Zhicheng Wang, Zhi Ren, Guanghan Cao
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G3219483439, G8611434399
OpenAlex ID: W2905765295