Electrical noise in magnetic tunnel junctions due to magneto-structural transitions of CoFeB/MgO interfaces

ORAL

Abstract

Magnetic tunnel junctions (MTJs) play a central role in spintronics research as memory elements, nanoscale microwave oscillators, local magnetic sensors, and neuromorphic network components. Understanding and controlling electric noise in MTJs is a prerequisite for employing them in next-generation applications. Here, we study MTJ nanopillars of 50 nm diameter consisting of CoFeB free layer, MgO tunnel barrier, and CoFe based synthetic antiferromagnet. We observe random telegraph noise which is frequently found in MTJs and yet not fully understood. Varying the temperature in the range of 80-300 K for an MTJ in the parallel state, we encounter anomalous device resistance (steps) attributed [1,2] to magneto-structural phase transitions of iron oxide clusters at the CoFeB/MgO interface. At temperatures of these anomalies, telegraph noise shows a significant increase. This correlation suggests that the oxide clusters have a significant impact on MTJ noise characteristics.

*Supported by DoE EFRC SHINES DE-SC0012670 and NSF ECCS-1810541.

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Presenters

  • Arezoo Etesamirad

    • Physics and Astronomy, University of California, Riverside

Authors

  • Arezoo Etesamirad

    • Physics and Astronomy, University of California, Riverside

  • David Nelson

    • Physics and Astronomy, University of California, Riverside

  • Keanuhea Dailey

    • Physics and Astronomy, University of California, Riverside

  • Jordan A Katine

    • Western Digital, San Jose
    • Hitachi Global Storage Technologies

  • Ilya Krivorotov

    • Physics and Astronomy, University of California, Irvine
    • Department of Physics and Astronomy, University of California, Irvine

  • Igor Barsukov

    • Physics and Astronomy, University of California, Riverside