Imaging small skyrmions at room temperature in Fe-rich Fe<sub>1.2</sub>Ge epitaxial films

ORAL

Abstract

Chiral magnets exhibit a variety of interesting magnetic phases including topological skyrmion spin textures, a candidate for ultrahigh density memory. A widely studied chiral magnet is FeGe which exhibits skyrmions (∼ 70 nm in diameter) up to its Curie temperature of ∼270 K. To raise the Curie temperature of FeGe and achieve skyrmions at room temperature, we adopted a strategy to develop artificial chiral magnets via atomic-layer molecular beam epitaxy (MBE) far from equilibrium. Specifically, by adding excess Fe atoms to epitaxial FeGe films, we engineered a new Fe-rich Fe1.2Ge material which has its Curie temperature above room temperature. Magnetic imaging by Magnetic Force Microscopy (MFM) and Lorentz Transmission Electron Microscopy (LTEM) reveal the presence of small skyrmions (<20 nm diameter) at room temperature, two important characteristics for new magnetic memory. Topological Hall effect measurements confirm the topological nature of the observed spin textures.

*Research supported by DARPA Grant No. D18AP00008

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Presenters

  • Camelia Selcu

    • Ohio State University

Authors

  • Camelia Selcu

    • Ohio State University

  • Tao Liu

    • University of Electronic Science and Technology of China

  • Binbin Wang

    • Ohio State University-Columbus
    • Ohio State University

  • Nuria Bagues Salguero

    • Ohio State Univ - Columbus

  • Po-Kuan Wu

    • Ohio State University
    • Ohio State Univ - Columbus

  • Timothy Q Hartnett

    • University of Virginia
    • Material science and engineering, University of Virginia

  • Shuyu W Cheng

    • Ohio State University
    • The Ohio State University
    • Ohio State University - Columbus

  • Denis Pelekhov

    • Ohio State University
    • Ohio State Univ - Columbus

  • Roland A Bennett

    • Ohio State University

  • Joseph P Corbett

    • Ohio State University

  • Jacob J Repicky

    • Ohio State Univ - Columbus

  • Brendan A McCullian

    • Cornell University

  • P Chris Hammel

    • Ohio State Univ - Columbus

  • Jay Gupta

    • Ohio State University
    • The Ohio State University

  • Mohit Randeria

    • Ohio State University

  • Prasanna V Balachandran

    • University of Virginia

  • Shuyu W Cheng

    • Ohio State University
    • The Ohio State University
    • Ohio State University - Columbus

  • Roland K Kawakami

    • Ohio State University
    • The Ohio State University