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