Transport Spin Polarization of High-Curie Temperature MnBi Films

ORAL

Abstract

We report on the study of the structural, magnetic and transport properties of highly textured MnBi films with the Curie temperature of 628 K. In addition to detailed measurements of resistivity and magnetization, we measure transport spin polarization of MnBi by Andreev reflection spectroscopy and perform first-principles electronic structure calculations. A transport spin polarization of up to 63{\%} is observed, consistent with the calculations and with a recent observation of a large magnetoresistance in MnBi contacts. The band structure calculations indicate that, in spite of almost identical densities of states at the Fermi energy, the large disparity in the Fermi velocities leads to high transport spin polarization of MnBi. The correlation between the values of magnetization and spin polarization observed in MnBi will be discussed.

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Authors

  • Pushkal Thapa

    Dept. of Physics, Wayne State University, Detroit, MI, 48202

  • Parashu Kharel

    Nebraska Center for Materials and Nanoscience (NCMN), Univ. of Nebraska, Lincoln, NE, 68588

  • Pavel Lukashev

    NCMN, Univ. of Nebraska, Lincoln, NE, 68588

  • Renat F. Sabirianov

    University of Nembraska at Omaha, Dept. of Physics, Univ. of Nebraska, Omaha, NE, 68182, Univesity of Nebraska at Omaha, University of Nebraska at Omaha

  • Evgeny Tsymbal

    NCMN, Univ. of Nebraska, Lincoln, NE, 68588, University of Nebraska - Lincoln, Department of Physics and Astronomy, University of Nebraska, Lincoln, NE, USA, University of Nebraska, Department of Physics and Astronomy \& Nebraska Center for Materials and Nanotechnology, University of Nebraska, Lincoln, NE 68588

  • David Sellmyer

    NCMN, Univ. of Nebraska, Lincoln, NE, 68588

  • Boris Nadgorny

    Dept. of Physics, Wayne State University, Detroit, MI, 48202