APS Logo

Very high spin Hall conductivities and spin Hall ratios in epitaxial Iridium di-oxide films

ORAL

Abstract

New metallic materials with exceptionally high spin Hall conductivities and accompanying high spin Hall ratios are desirable both to produce more efficient systems for spin-orbit torque applications and to further test the fundamental understanding of intrinsic spin-orbit interactions. A particularly interesting candidate for such research is the metallic rutile oxide Iridium di-oxide which angle resolved photoemission spectroscopy studies have shown exhibits Dirac nodal lines in the band structure, a feature that could enable a very high . Here we report spin-torque ferromagnetic resonance studies of the damping-like and field-like torques exerted on an adjacent ferromagnetic layer as the result of current flowing in epitaxial (110) and (001) IrO2 films. The (110) films exhibit a damping-like torque efficiency ≈ 0.18 at 293 K, which sets a lower bound for the spin Hall conductivity . The higher resistivity (~ 300 µΩ-cm) (001) films exhibit even stronger spin-orbit torques, with ranging from ~0.45 at 293K to 0.8 at 30 K as decreases, behavior indicative of the dirty metal regime. The very high value for (001) IrO2, ≥ , is both a challenge for current theoretical understanding and an exciting prospect for more efficient SOT applications.

–

Presenters

  • ARNAB BOSE

    School of Applied and Engineering Physics, Cornell University, Cornell University

Authors

  • ARNAB BOSE

    School of Applied and Engineering Physics, Cornell University, Cornell University

  • Jocienne Nelson

    Department of Physics, Cornell University, Cornell University, Cornell University

  • Xiyue Zhang

    School of Applied and Engineering Physics, Cornell University

  • Raksit Jain

    School of Applied and Engineering Physics, Cornell University

  • Shengjie Shi

    School of Applied and Engineering Physics, Cornell University, Cornell University

  • Darrell Schlom

    Cornell University, Department of Materials Science and Engineering, Cornell University, Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University, Materials Science and Engineering, Cornell University, Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA, Platform for the Accelerated Realization, Analysis, & Discovery of Interface Materials (PARADIM), Cornell University

  • Daniel C. Ralph

    Department of Physics, Cornell University, Cornell University, Cornell University, Physics, Cornell

  • David Muller

    Cornell University, School of Applied and Engineering Physics, Cornell University, Applied and Engineering Physics, Cornell University

  • Kyle M Shen

    Cornell University, Department of Physics, Cornell University, Cornell University, Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Laboratory of Atomic and Solid State Physics, Department of Physics, Kavli Institute at Cornell for Nanoscale Science, Cornell University

  • Robert Buhrman

    School of Applied and Engineering Physics, Cornell University, Cornell University, Physics, Cornell University