CaFe$_{2}$As$_{2}$ Phonons via Inelastic X-ray Scattering and First Principles Calculations

ORAL

Abstract

In the iron pnictides, the sensitivity of the iron magnetic moment to the arsenic position suggests a strong relationship between phonons and magnetism. We measured the phonon dispersion of several branches in the high temperature tetragonal phase of CaFe$_{2}$As$_{2}$ using inelastic x-ray scattering on single-crystal samples. These measurements were compared to ab-initio calculations of the phonons. Spin polarized calculations imposing the antiferromagnetic order present in the low temperature orthorhombic phase dramatically improves agreement between theory and experiment. This is discussed in terms of the strong antiferromagnetic correlations that are known to persist in the tetragonal phase.

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Authors

  • Steven Hahn

    • Ames Laboratory and Iowa State University

  • Ahmet Alatas

    • Advanced Photon Source, Argonne National Laboratory

  • Bogdan Leu

    • Advanced Photon Source, Argonne National Laboratory

  • Y.B. Lee

    • Ames Laboratory and Iowa State University
    • Ames Laboratory/Department of Physics and Astronomy

  • N. Ni

    • Ames Laboratory and Iowa State University
    • Ames Laboratory and Physics Department and Astronomy, Iowa State University, Ames, IA
    • Ames Lab / Iowa State University
    • Ames Laboratory, US DOE and Iowa State University
    • Iowa State University
    • Ames Laboratory/Department of Physics and Astronomy

  • D.Y. Chung

    • Materials Science Division, Argonne National Laboratory
    • Argonne National Laboratory

  • Iliya Todorov

    • Materials Science Division, Argonne National Laboratory

  • Mercouri Kanatzidis

    • Materials Science Division, Argonne National Laboratory and Department of Chemistry, Northwestern University

  • Ercan Alp

    • Advanced Photon Source, Argonne National Laboratory

  • P.C. Canfield

    • Ames Laboratory and Department of Physics and Astronomy, Iowa State Univeristy, Ames, Iowa 50011
    • Ames Laboratory and Iowa State University
    • Ames Laboratory and Physics Department and Astronomy, Iowa State University, Ames, IA
    • Ames Laboratory
    • Ames Laboratory, US DOE and Iowa State University
    • Ames Laboratory/Department of Physics and Astronomy
    • Ames Lab / Iowa State University
    • Ames Laboratory/Iowa State University

  • Alan Goldman

    • Ames Laboratory and Physics Department and Astronomy, Iowa State University, Ames, IA
    • Ames Laboratory and Iowa State University
    • Ames Laboratory, US DOE and Iowa State University
    • Ames Laboratory
    • Ames Loboratory, US DOE and Iowa State University
    • Ames Laboratory/Department of Physics and Astronomy
    • Ames Laboratory, US DOE, Iowa State University, Ames, IA 5001, USA

  • R.J. McQueeney

    • Ames Laboratory and Physics Department and Astronomy, Iowa State University, Ames, IA
    • Ames Laboratory and Iowa State University
    • Ames Laboratory, US DOE and Iowa State University
    • Ames Laboratory
    • Ames Laboratory/Department of Physics and Astronomy

  • B.N. Harmon

    • Ames Laboratory and Iowa State University
    • Ames Laboratory/Department of Physics and Astronomy