Efficient spin current generation from new, low-loss Mg(Al,Fe)2O4 films into heavy metals

ORAL

Abstract

Low-damping magnetic insulators are essential to the growing field of spintronics since they can generate and transfer spin currents without associated charge currents. We have recently developed a new ferrimagnetic insulator, MgAl0.5Fe1.5O4 (MAFO), which has Gilbert damping as low as 1x10-3. Through resonant excitation of the MAFO layer, we observed significant spin pumping from MAFO films into adjacent Pt and β-W layers by enhanced Gilbert damping and electrical voltage peaks that appear at ferromagnetic resonance (FMR). There is a reversal of the transverse voltage signal in MAFO/Pt and MAFO/β-W, which is consistent with the opposite signs of the spin Hall angle in these two materials and indicates the signal is due to the inverse spin Hall effect and not to proximity-induced anisotropic magnetoresistance (AMR). Further, angular dependent magnetoresistance (ADMR) measurements reveal that the spin Hall magnetoresistance (SHMR) is 7-10 times larger than the AMR contribution, so spin pumping effects dominate the magnetic dynamics of the bilayers. From FMR and ADMR measurements, we deduced a spin-mixing conductance of ~3x1014 Ω-1 m-2 in MAFO/Pt. Together, these measurements indicate that MAFO is an excellent candidate for efficient spin current-based heterostructures and devices.

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Presenters

  • Lauren Riddiford

    Department of Applied Physics, Stanford University, Geballe Laboratory for Advanced Materials, Stanford University, Applied Physics, Stanford University

Authors

  • Lauren Riddiford

    Department of Applied Physics, Stanford University, Geballe Laboratory for Advanced Materials, Stanford University, Applied Physics, Stanford University

  • Jacob Wisser

    Department of Applied Physics, Stanford University, Geballe Laboratory for Advanced Materials, Stanford University, Applied Physics, Stanford University

  • Satoru Emori

    Virginia Tech, Physics, Virginia Tech, Department of Science, Virginia Tech

  • Peng Li

    Geballe Laboratory for Advanced Materials, Stanford University

  • Debangsu Roy

    Department of Physics, New York University, Physics, New York University

  • Egecan Cogulu

    Physics, New York University

  • Olaf M Van T Erve

    US Naval Research Laboratory, Naval Research Laboratory, United States Naval Research Laboratory

  • Yong Deng

    Materials Science, Stanford University

  • Shan X Wang

    Materials Science, Stanford University

  • Berend Jonker

    US Naval Research Laboratory, Naval Research Lab, Naval Research Laboratory, Materials Science and Technology Division, U.S. Naval Research Laboratory, United States Naval Research Laboratory

  • Andrew D Kent

    Department of Physics, New York University, New York Univ NYU, Physics, New York University, New York University

  • Yuri Suzuki

    Stanford University, Department of Applied Physics, Stanford University, Applied Physics, Stanford University, Geballe Laboratory for Advanced Materials, Stanford University