Dffraction Studies of the P-T Phase Diagram with Single-Crystal Ca122

ORAL

Abstract

Single crystal neutron and high-energy x-ray diffraction have identified the phase lines corresponding to transitions between the ambient-pressure tetragonal (T), the antiferromagnetic orthorhombic (O) and the nonmagnetic collapsed tetragonal (cT) phases of CaFe2As2. We find no evidence of additional structures for pressures up to 2.5 GPa (at 300 K). Both the T-cT and O-cT transitions exhibit significant hysteresis effects and we demonstrate that coexistence of the O and cT phases can occur if a non-hydrostatic component of pressure is present.

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Authors

  • 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

  • Andreas Kreyssig

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

  • K. Prokes

    Helmholtz-Zentrum Berlin f\"ur Materialien und Energie

  • D.K. Pratt

    Ames Laboratory/Department of Physics and Astronomy

  • D.N. Argyriou

    Helmholtz Center-Berlin, Helmholtz-Zentrum Berlin f\"ur Materialien und Energie

  • J.W. Lynn

    NCNR, Gaithersburg, MD 20899

  • S. Nandi

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

  • S.A.J. Kimber

    Helmholtz-Zentrum Berlin f\"ur Materialien und Energie

  • Y. Chen

    NCNR, Gaithersburg, MD 20899

  • Y.B. Lee

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

  • G. Samolyuk

    Ames Laboratory, Ames, IA, 50011, Ames Laboratory and Iowa State University, Ames Laboratory/Department of Physics and Astronomy

  • J.B. Leao

    NCNR, Gaithersburg, MD 20899

  • S.J. Poulton

    NCNR, Gaithersburg, MD 20899

  • S.L. Bud'ko

    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/Iowa State University, Ames Laboratory/Department of Physics and Astronomy, Ames laboratory

  • 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

  • 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

  • B.N. Harmon

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

  • 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