Extreme Fermi surface smearing in a maximally disordered concentrated solid solution

ORAL

Abstract

The impact of extreme chemical disorder on the Fermi surface of the equiatomic alloy Ni0.25Fe0.25Co0.25Cr0.25 was probed by high-resolution X-ray Compton scattering. Such experiments probe the Fermi surface via the occupied momentum states, meaning that such measurements are ideally suited to revealing the electronic structure of such disordered alloys. The smearing of the Fermi surface is rather strong, reaching up to 40% of 2π/a, but nevertheless a Fermi surface can be clearly identified in the experimental data and the extent of the smearing and its variation on and across different sheets has been investigated. By connecting this smearing with the coherence length of the quasiparticle states, estimates of the electronic mean-free-path and residual resistivity have been made. It is found that the mean-free paths are in the range 0.7 - 0.9 nm.

*The Compton scattering experiment was performed with the approval of the Japan Synchrotron Radiation Research Institute (JASRI, proposal no. 2016A1323). H.R. and D.A.L. gratefully acknowledge the financial support of the UK EPSRC (EP/L015544/1), and the National Secretariat of Higher Education, Science, Technology and Innovation of Ecuador (SENESCYT), respectively.

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Presenters

  • Stephen Dugdale

    • HH Wills Physics Laboratory, University of Bristol, United Kingdom
    • University of Bristol

Authors

  • Stephen Dugdale

    • HH Wills Physics Laboratory, University of Bristol, United Kingdom
    • University of Bristol

  • Hannah Robarts

    • HH Wills Physics Laboratory, University of Bristol, United Kingdom
    • University of Bristol

  • Thomas E Millichamp

    • HH Wills Physics Laboratory, University of Bristol, United Kingdom

  • Daniel A Lagos

    • HH Wills Physics Laboratory, University of Bristol, United Kingdom

  • Jude Laverock

    • HH Wills Physics Laboratory, University of Bristol, United Kingdom

  • David Billington

    • SPring-8, Japan Synchrotron Radiation Institute, Japan

  • Jonathan Duffy

    • Department of Physics, University of Warwick, United Kingdom
    • University of Warwick

  • Daniel O'Neill

    • Department of Physics, University of Warwick, United Kingdom

  • Sean Giblin

    • School of Physics and Astronomy, Cardiff University
    • Cardiff University
    • School of Physics and Astronomy, Cardiff University, United Kingdom
    • University of Cardiff

  • Jonathan Taylor

    • DMSC, European Spallation Source, Denmark
    • European Spallation Source

  • Grazyna Kontrym-Sznajd

    • Institute of Low Temperature and Structure Research, Polish Academy of Science, Poland

  • Malgorzata Samsel-Czekala

    • Institute of Low Temperature and Structure Research, Polish Academy of Science, Poland

  • Hongbin Bei

    • Materials Science and Technology Division, Oak Ridge National Laboratory

  • Sai Mu

    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Department of Condensed Matter Physics and Materials Science, Oak Ridge National Laboratory

  • German Samolyuk

    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory

  • George Malcolm Stocks

    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Oak Ridge Natioinal Laboratory