Alloying effect on auto-oscillation properties of W<sub>100-x</sub>Ta<sub>x</sub>/CoFeB/MgO spin Hall nano-oscillators

ORAL

Abstract

Spin current based devices have the potential for ultra-fast and energy-efficient operation as in spin Hall nano-oscillators (SHNOs)[1-3], SOT-MRAM, and spin logic [4,5]. However, key challenges remain of how to further reduce their high current densities (Jc) and energy consumption. We demonstrate alloying of W with Ta to substantially reduce the Jc in W100-xTax(5nm)/CoFeB(t=1.4-2 nm)/MgO(2nm) SHNOs. Spin-torque ferromagnetic resonance (ST-FMR) measurements showed a substantial improvement in both spin Hall conductivity and spin-orbit torque efficiency from W-Ta alloying. As a direct outcome, we observed a 45% reduction in auto-oscillation current densities measured for different constriction widths resulting in a 65% reduction in threshold power consumption as compared to pure W based SHNOs. Our work reveals promising aspects of how W-Ta alloys can promote energy-efficient operation of emerging spintronic devices.

 

References:

1. Mazraati et al Appl. Phys. Lett. 109, 242402 (2016).

2. Fulara et al., Sci. Adv. 5, eaax8467 (2019).

3. Zahedinejad et al., Nat. Nanotechnol. 15, 47–52 (2020).

4. Garello et al., Appl. Phys. Lett. 105, 212402 (2014).

5. Cubukcu et al., Appl. Phys. Lett. 104, 042406 (2014).

 

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Presenters

  • Nilamani Behera

    • 1Physics Department, University of Gothenburg, 41296 Gothenburg, Sweden.
    • Physics Department, University of Gothenburg

Authors

  • Nilamani Behera

    • 1Physics Department, University of Gothenburg, 41296 Gothenburg, Sweden.
    • Physics Department, University of Gothenburg

  • Himanshu Fulara

    • Indian Institute of Technology Roorkee
    • 1Physics Department, University of Gothenburg, 41296 Gothenburg, Sweden. 2Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667, India
    • Indian Institute of Technology Roorkee, India
    • Physics Department, University of Gothenburg

  • Mohammad Zahedinejad

    • 1Physics Department, University of Gothenburg, 41296 Gothenburg, Sweden.
    • Physics Department, University of Gothenburg

  • Afshin Houshang

    • University of Gothenburg
    • 1Physics Department, University of Gothenburg, 41296 Gothenburg, Sweden.
    • Physics Department, University of Gothenburg

  • Johan Åkerman

    • Goteborg Univ
    • University of Gothenburg
    • 1Physics Department, University of Gothenburg, 41296 Gothenburg, Sweden.
    • University of Gothenburg, Sweden
    • Physics Department, University of Gothenburg
    • Physics Department, University of Gothenburg, 412 96 Gothenburg, Sweden