Effects of CoFe Alloy Composition on Non-Electronic Thermal Transport

ORAL

Abstract

CoFe magnetic alloys feature interesting magnetization dynamics that vary as a function of composition. This is, likely, due to their unique electronic band structures that allow for a suppression in electron-magnon scattering at certain CoFe compositions. Recent investigations have shown that Co0.25Fe0.75 has low damping (α ~ 10-4), comparable to ferrimagnetic insulators. In this talk, I investigate the effect of composition on thermal transport. Using time–domain thermo-reflectance (TDTR) analyses, I present a high-resolution thermal conductivity map of a bulk CoFe diffusion multiple. This map allows us to correlate the alloy composition to thermal conductivity. I also report on thermal conductivity and electrical resistivities of sputtered thin-films. To estimate the non-electronic thermal conductivity, we use the Wiedemann-Franz law to subtract the electronic contribution. We observe a correlation between the composition, magnetic damping parameter α, and the non-electronic thermal conductivity. My investigation provides insights into electron-magnon interactions and thermal transport in magnetic metals.

*This work was supported by the U.S. Army Research Laboratory and the U.S. Army Research Office under contract/grant number W911NF-18-1-0364.

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Presenters

  • Ramya Mohan

    • Material Science & Engineering, University of California, Riverside

Authors

  • Ramya Mohan

    • Material Science & Engineering, University of California, Riverside

  • Victor H. Ortiz

    • University of California, Riverside
    • Mechanical Engineering, University of California, Riverside

  • Ji-Cheng Zhao

    • Material Science & Engineering, University of Maryland

  • Sinisa Coh

    • University of California, Riverside
    • Mechanical Engineering, University of California, Riverside

  • Richard Wilson

    • University of California, Riverside
    • Mechanical Engineering, University of California, Riverside