Superconducting SrSnP with Strong Sn-P Antibonding Interaction: Is the Sn Atom Single or Mixed Valent?

ORAL

Abstract

The large single crystals of SrSnP were prepared using Sn self-flux method. SrSnP crystallizes in the CaGaN structure type with space group P4/nmm (S.G.129, Pearson symbol tP6). A combination of magnetic susceptibility, resistivity, and heat capacity measurements confirms the bulk superconductivity with Tc = 2.3(1) K in SrSnP. According to the X-ray photoelectron spectroscopy (XPS) measurement, the assignments of Sr2+ and P3- are consistent with the chemical valence electron balance principles. Moreover, it is highly likely that Sn atom has only one unusual oxidation state. First-principles calculations indicate the bands around Fermi level are hybridized among Sr-d, Sn-p, and P-p orbitals. The strong Sn-P and Sr-P interactions pose as keys to stabilize the crystallographic structure and induce the superconductivity, respectively. The physics-based electronic and phononic calculations are consistent with the molecular viewpoint. After including the spin-orbit coupling (SOC) into the calculation, the band degeneracies at G-point in the first Brillouin zone (BZ) split into two bands, which yield to the van Hove singularities around Fermi level.

–

Presenters

  • Xin Gui

    • Chemistry, Louisiana State University
    • Louisiana State University
    • Department of Chemistry, Louisiana State University
    • Chemistry, Louisiana State Univeristy

Authors

  • Xin Gui

    • Chemistry, Louisiana State University
    • Louisiana State University
    • Department of Chemistry, Louisiana State University
    • Chemistry, Louisiana State Univeristy

  • Zuzanna Sobczak

    • Department of Solid State Physics, Gdansk University of Technology

  • Tay-Rong Chang

    • National Cheng Kung University
    • Physics, National Cheng Chung University
    • Physics, National Cheng Kung University, Tainan, 701, Taiwan
    • Department of Physics, National Cheng Kung University
    • Physics, National Tsing Hua University
    • Physics, National Cheng Kung University

  • Xitong Xu

    • International Center for Quantum Materials, Peking University

  • Shuang Jia

    • International Center for Quantum Materials, Peking University
    • Peking University, China
    • Physics, Peking University
    • Peking University
    • International Center for Quantum Materials, School of Physics, Peking University

  • Tomasz Klimczuk

    • Department of Solid State Physics, Gdansk University of Technology

  • Weiwei Xie

    • Chemistry, Louisiana State University
    • Louisiana State University
    • Department of Chemistry, Louisiana State University
    • Chemistry, Louisiana State Univeristy