Electron-Hole Competition and Structural Response in the Two-Band Superconductor Nb<sub>2</sub>Pd<sub>x</sub>Se<sub>5</sub>

ORAL

Abstract

The superconducting properties of Nb2PdxSe5 are highly dependent on the Pd stoichiometry. We have synthesized single crystals of Nb2PdxSe5 with x in the range of 0.68 to 0.96 and have carried out detailed single crystal x-ray structural studies. We observe a pivotal shift in the atomic positions that depend on palladium occupancy at the threshold for superconductivity. We will discuss the crystal growth process, our recent findings of the subtle but profound structural changes, and present the rich spectrum of electronic behavior observed for different Pd occupancy regions. At the threshold Pd stoichiometry for superconductivity, a miscibility gap is apparent, with commensurate change in the electronic transport properties. Electron-hole competition in this two-band system is thought to be responsible for this behavior.

*Work at the Univ. of Missouri was supported by the U.S. DOE, Ofc. of Sci., Ofc. of Basic Energy Sci., DE-SC0019114. KW acknowledges support from the NHMFL through the Jack Crow Postdoctoral Fellowship. AG and TEAS acknowledge support from the U.S. DOE, Heavy Elements Chem. Program, DE-FG02-13ER16414. Part of the work was carried out at the NHMFL, supported by the NSF, NSF/DMR-1644779 and the State of FL. JN and TS acknowledge support from the NSF, NSF/DMR-1606952.

Presenters

  • Jennifer Neu

    • National High Magnetic Field Laboratory
    • Florida State Univ
    • Natl High Magnetic Field Lab
    • National High Magnetic Field Laboratory, Florida State University

Authors

  • Jennifer Neu

    • National High Magnetic Field Laboratory
    • Florida State Univ
    • Natl High Magnetic Field Lab
    • National High Magnetic Field Laboratory, Florida State University
  • David E Graf

    • Florida State University
    • National High Magnetic Field Laboratory, Florida State University
    • Department of Physics, National High Magnetic Field Laboratory, Florida State University, Florida, USA
    • National High Magnetic Field Laboratory
    • National High Magnetic Field Lab, Florida State University
    • National High Magnetic Field Laboratory and Department of Physics, Florida State University
    • Florida State Univ
    • Natl High Magnetic Field Lab
    • National High Magnetic Field Lab, Tallahassee, FL 32310, USA
    • National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Tallahassee, FL 32310, USA
    • National High Magnetic Field Laboratory-Florida State University
    • National High Magnetic Field Laboratory, Tallahassee, FL
    • NHMFL, Florida State University
    • NHMFL
  • Kaya Wei

    • Florida State Univ
    • Natl High Magnetic Field Lab
    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA.
  • Alyssa Gaiser

    • Chemistry and Biochemistry, Florida State Univ.
  • Yan Xin

    • National High Magnetic Field Laboratory
    • Natl High Magnetic Field Lab
  • Thomas Albrecht-Schmitt

    • Chemistry and Biochemistry, Florida State Univ.
  • Ryan Baumbach

    • National High Magnetic Field Laboratory/Florida State University
    • MagLab Tallahassee
    • National High Magnetic Field Laboratory
    • National High Magnetic Field Lab, Florida State University
    • Florida State Univ
    • Natl High Magnetic Field Lab
    • National High Magnetic Field Laboratory, Florida State University
    • Physics, NHMFL, Florida State University
  • David J Singh

    • Physics, Univ. of Missouri
  • Theo Siegrist

    • Florida State Univ
    • National High Magnetic Field Laboratory
    • Natl High Magnetic Field Lab
    • Chemical and Biomedical Engineering, FAMU-FSU College of Engineering
    • National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA.; Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering,