Ultralow Damping in Epitaxial Spinel Ferrite Thin Films

ORAL

Abstract

Magnetic insulator thin films are expected to be excellent media for spin-based information without charge flow. This expectation relies on the premise that magnetic insulators exhibit lower magnetic damping compared to their metallic counterparts. However, insulating behavior is not a sufficient requirement for low damping, as evidenced by the very limited options for low-damping magnetic insulators. In this presentation, we demonstrate a new class of ultralow-damping insulator based on design criteria minimizing orbital angular momentum as well as crystalline and cation valence disorder. Specifically, we show ultralow damping in spinel structure magnesium aluminum ferrite (MAFO), in which magnetization arises solely from Fe3+ ions with zero orbital angular momentum. Epitaxial MAFO films with thicknesses <20 nm exhibit ferromagnetic resonance linewidths of ≈0.6 mT around 10 GHz and Gilbert damping parameters of ≈0.0015. Our findings demonstrate that minimal spin-orbit coupling and coherent epitaxy allow for ultralow damping in ferrite thin films, expanding the materials choices for energy-efficient insulator spintronics.

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Presenters

  • Satoru Emori

    Physics, Virginia Polytechnic Institute and State University, Virginia Tech

Authors

  • Satoru Emori

    Physics, Virginia Polytechnic Institute and State University, Virginia Tech

  • Di Yi

    Stanford Univ, Applied Physics, Stanford University, Stanford University

  • Samuel Crossley

    Department of Applied Physics, Stanford University, Applied Physics, Stanford University, Stanford University

  • Jacob Wisser

    Applied Physics, Stanford University, Stanford University

  • Purnima Balakrishnan

    Stanford University

  • Padraic Shafer

    Lawrence Berkeley National Laboratory, Advanced Light Source, Lawrence Berkeley National Laboratory, Advanced Light Source

  • Christoph Klewe

    Advanced Light Source, Lawrence Berkeley National Laboratory

  • Alpha N'Diaye

    Lawrence Berkeley National Laboratory, Lawrence Berkeley Natl Lab, Advanced Light Source, Advanced Light Source, Lawrence Berkeley National Laboratory

  • Brittany Urwin

    Air Force Research Laboratory

  • Krishnamurthy Mahalingam

    Air Force Research Laboratory

  • Brandon Howe

    Air Force Research Laboratory

  • Harold Hwang

    Geballe Laboratory for Advanced Materials, Department of Applied Physics, Stanford University, Stanford, CA, United States, Stanford Institute for Materials and Energy Science, Department of Applied Physics, Stanford University, Department of Applied Physics, Geballe Laboratory for Advanced Materials, Stanford Institute for Materials and Energy Sciences, Stanford University, SLAC National Accelerator, Applied Physics, Stanford University, Stanford Univ, Stanford University, Stanford Univeristy

  • Elke Arenholz

    Lawrence Berkeley National Laboratory, Advanced Light Source, Lawrence Berkeley National Laboratory, Advance Light Source, Lawrence Berkeley National Laboratory, Advanced Light Source

  • Yuri Suzuki

    Applied Physics, Stanford University, Stanford Univ, Stanford University