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Strain-tuned metamagnetic transition in EuFe<sub>2</sub>As<sub>2</sub>

ORAL

Abstract

Of all the parent compounds of iron-based high-temperature superconductors, EuFe2As2 exhibits by far the largest magnetostructural coupling due to the strong interaction between localized Eu 4f moments and the Fe spin density wave order. However, the formation of structural/antiferromagnetic domains couples the Eu antiferromagnetic order to a series of complex field detwinning processes, which impedes a simple magnetometry measurement from extracting the critical fields of the metamagnetic transition. Here we make a measurement of these critical fields by combining x-ray magnetic circular dichroism with in-situ tunable uniaxial stress and applied magnetic field. The combination of two tuning knobs allows us to separate the stress-detwinning of structural domains from the field reorientation of Eu moments. Intriguingly, the spin flip and saturation field values reveal that in addition to the effective single ion anisotropy from a Eu-Fe biquadratic interaction, the Eu interplanar exchange is also strongly anisotropic. This anisotropic exchange term is likely a consequence of the strong anisotropy in the magnetically ordered Fe layer, revealing the non-trivial interplay between Eu-Fe magnetism in this system.

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Presenters

  • Joshua J Sanchez

    University of Washington

Authors

  • Joshua J Sanchez

    University of Washington

  • Gilberto F L Fabbris

    Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory

  • Yongseong Choi

    Advanced Photon Source, Argonne National Laboratory, Argonne National Laboratory

  • Yue Shi

    University of Washington

  • Paul Malinowski

    University of Washington

  • Jian Liu

    University of Tennessee, University of Tennessee, Knoxville

  • Igor Mazin

    Physics & Astronomy, George Mason University, Department of Physics and Astronomy, George Mason University, George Mason University, Physics and Astronomy, George Mason University, Physics, George Mason University, Department of Physics and Astronomy,, George Mason University, Department of Physics and Astronomy and Quantum Science and Engineering Center, George Mason University – Fairfax, VA, USA

  • Jong-Woo Kim

    Argonne National Laboratory, APS, Argonne National Laboratory

  • Philip James Ryan

    X-ray Science Division, Argonne National Laboratory, Argonne National Laboratory

  • Jiun-Haw Chu

    University of Washington, Department of Physics, University of Washington, Seattle, Department of Physics, University of Washington, Physics, University of Washington