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