Superconductivity in SnSb with a natural superlattice structure. (2nd November 2018)

• Record Type: Journal Article
• Authors: Liu, Bin; Wu, Jifeng; Cui, Yanwei; Wang, Hangdong; Liu, Yi; Wang, Zhicheng; Ren, Zhi; Cao, Guanghan
• Is Part Of: Superconductor science & technology. Volume 31:Number 12(2018:Dec.)
• Publication Date: 2018-11-02
• Subjects: superconductivity -- binary alloy -- natural superlattice; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/aae6fe
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: We report the results of electrical resistivity, magnetic, and thermodynamic measurements on polycrystalline SnSb, whose structure consists of stacks of Sb bilayers and Sn4 Sb3 septuple layers along the c -axis. The material is found to be a weakly coupled, fully gapped, type-II superconductor with a bulk T c of 1.50 K, while showing a zero resistivity transition at a significantly higher temperature of 2.48 K. The Sommerfeld coefficient and upper critical field, obtained from specific heat measurements, are 2.29 mJ mol −1 K −2 and 520 Oe, respectively. Compositional inhomogeneity and strain effect at the grain boundaries are proposed as possible origins for the difference in resistive and bulk superconducting transitions. In addition, a comparison with the rock-salt structure SnAs superconductor is presented. Our results provide the first clear evidence of bulk superconductivity in a natural superlattice derived from a topological semimetal.