Time-resolved Magneto-optical Kerr Effect Studies on Permalloy/Ru/Permendur Trilayers

ORAL

Abstract

We investigate a series of magnetic trilayer samples consisting of Ni20Fe80(Py)/Ru [x]/Fe49Co49V2(Pmd), where the Ru spacer thickness [x] is varied from 0.7 nm to 17 nm to change the indirect exchange coupling (IEC) between the two magnetic layers. We study the dynamics of these structures by using time-resolved magneto-optical Kerr effect (TR-MOKE) to observe the initial demagnetization and subsequent precession of the magnetic moments as the system returns to equilibrium. Even though the TR-MOKE signal is generated primarily from the top Pmd layer, we observe an unusual beating pattern in the TR-MOKE signal indicative of two coupled oscillators with different precession frequencies. The coupling between the two oscillators depends on the thickness of the Ru spacer layer and hence the strength of the IEC. The results point to the usefulness of TR-MOKE in investigating dynamic coupling effects, including spin pumping, in layered magnetic films.

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Presenters

  • Hengzhou Liu

    • Department of Physics, University of South Florida

Authors

  • Hengzhou Liu

    • Department of Physics, University of South Florida

  • Christopher E Stevens

    • Dept. of Physics, University of South Florida
    • Department of Physics, University of South Florida

  • Mojtaba Ranjbar

    • Department of Physics and Astronomy, Uppsala University

  • Johan Akerman

    • Department of Physics, University of Gothenburg
    • Physics Dept., University of Gothenburg

  • Yevgen Pogoryelov

    • Department of Physics and Astronomy, Uppsala University

  • Olof Karis

    • Department of Physics and Astronomy, Uppsala University

  • Dario A Arena

    • Department of Physics, University of South Florida

  • Denis Karaiskaj

    • Dept. of Physics, University of South Florida
    • Department of Physics, University of South Florida