Superconductivity in layered Zintl phase LiSn2As2

Abstract

We report the superconductivity in the layered Zintl phase LiSn${}_2$As${}_2$, which is isostructural to NaSn${}_2$As${}_2$ and has a transition temperature ($T_{\mathrm{c}}$) of 1.6 K. Despite similar $T_{\mathrm{c}}$ and Debye temperatures, substituting of Na with Li considerably increases the upper critical field. Based on a systematically comparation of Sn${}_4$As${}_3$, NaSnAs, NaSn${}_2$As${}_2$,Na${}_{1-x}$Sn${}_2$P${}_2$, SrSn${}_2$As${}_2$, and LiSn${}_2$As${}_2$, we propose that carrier doping, intimately related to the formation of lone-pair electrons, controls superconductivity in layered SnAs-based compounds rather than chemical pressure. The current findings provide a thorough and comprehensive understanding of Sn-based Zintl phase.

7 pages; 5 figures

References in corpus (3)

• Higher-order Topology of Axion Insulator EuIn${}_2$As${}_2$
• 3D Dirac semimetals: current materials, design principles and predictions of new materials
• SnAs-based layered superconductor NaSn2As2