No evidence of the crossover in the spin fluctuations of Ca(Fe1-xCox)2As2 and unusual suppression with temperature for x = 0.030.

ORAL

Abstract

In the Ca(Fe1-xCox)2As2 family, the superconductivity appears with Co doping after a first-order suppression of an antiferromagnetic order. Here, we present results of our inelastic neutron scattering measurement on Ca(Fe1-xCox)2As2, x=0.026 (antiferromagnetically ordered below TN=64±7 K) and x=0.030 (superconducting below Tc=14.6±1 K). Our results suggest that, unlike Ba(Fe1-xCox)2As2, smooth evolution of the gapped spin waves to diffusive spin fluctuations is absent in Ca(Fe1-xCox)2As2 and the result is consistent with the first order phase transition from magnetically ordered to superconducting state. Additionally, we observed an unusual suppression of the spin fluctuations with decreasing temperature for x=0.030, possibly arising due to compound’s proximity to the collapsed tetragonal phase.

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Presenters

  • Aashish Sapkota

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Dept. of Physics, Iowa State Univ

Authors

  • Aashish Sapkota

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Dept. of Physics, Iowa State Univ

  • Pinaki Das

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University

  • Anna Boehmer

    Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Iowa state university/Ames Laboratory, Institut fuer Festkoerperphysik, Karlsruhe Institute of Technology, Dept. of Physics, Iowa State Univ

  • Benjamin Ueland

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University

  • Douglas Abernathy

    Oak Ridge National Laboratory, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge National Lab

  • Sergey Budko

    Ames Laboratory and Iowa State University, Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Ames Laboratory and Iowa State Univ, Iowa State University, Ames Laboratory

  • Paul Canfield

    Ames Laboratory and Iowa State University, Ames Laboratory, Iowa State University, Department of Physics and Astronomy, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Iowa state university/Ames Laboratory, Ames Laboratory and Iowa State Univ, Iowa State University and Ames Laboratory, Iowa State University/Ames Laboratory, Iowa State University, Iowa State University / Ames Laboratory, Dept. of Physics, Iowa State Univ, Ames Lab, Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University, Iowa State Univ, Ames Laboratory, Department of Physics and Astronomy, Ames Laboratory and Iowa State University

  • Andreas Kreyssig

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Iowa State University, Ames Laboratory and Iowa State University, Dept. of Physics and Astronomy, Dept. of Physics, Iowa State Univ, Ames Lab

  • Alan Goldman

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Iowa State University, Dept. of Physics, Iowa State Univ

  • Robert McQueeney

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Iowa State University, Ames Laboratory and Iowa State University, Dept. of Physics and Astronomy