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