Role of B diffusion in the interfacial Dzyaloshinskii-Moriya interaction in Ta/Co20Fe60B20/MgO nanowires

DOI: 10.1103/PhysRevB.91.014433

Authors: R. Lo Conte (Johannes Gutenberg Universität-Mainz, Institut für Physik) , E. Martinez (Departamento Fisica Aplicada, Universidad de Salamanca) , A. Hrabec (School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom) , A. Lamperti (Laboratorio MDM, IMM-CNR) , T. Schulz (Johannes Gutenberg Universität-Mainz, Institut für Physik) , L. Nasi (IMEM-CNR) , L. Lazzarini (IMEM-CNR) , R. Mantovan (Laboratorio MDM, IMM-CNR) , F. Maccherozzi (Diamond Light Source) , S. Dhesi (Diamond Light Source) , B. Ocker (Singulus Technologies) , Christopher Marrows (School of Physics and Astronomy, University of Leeds) , Thomas Moore (School of Physics and Astronomy, University of Leeds) , Mathias Klaui (Johannes Gutenberg Universität-Mainz, Institut für Physik)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 91 (1)

State: Published (Approved)
Published: January 2015

Abstract: We report on current-induced domain wall motion in Ta/Co20Fe60B20/MgO nanowires. Domain walls are observed to move against the electron flow when no magnetic field is applied, while a field along the nanowires strongly affects the domain wall motion velocity. A symmetric effect is observed for up-down and down-up domain walls. This indicates the presence of right-handed domain walls, due to a Dzyaloshinskii-Moriya interaction (DMI) with a DMI coefficient D=+0.06mJ/m2. The positive DMI coefficient is interpreted to be a consequence of B diffusion into the Ta buffer layer during annealing, which was observed by chemical depth profiling measurements. The experimental results are compared to one-dimensional model simulations including the effects of pinning. This modeling allows us to reproduce the experimental outcomes and reliably extract a spin-Hall angle θSH=–0.11 for Ta in the nanowires, showing the importance of an analysis that goes beyond the model for perfect nanowires.

Diamond Keywords: Data Storage

Subject Areas: Physics, Materials, Information and Communication Technology


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Added On: 02/02/2015 12:38

Discipline Tags:

Physics Components & Micro-systems Information & Communication Technologies Magnetism Materials Science Nanoscience/Nanotechnology

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