Electric-field-driven domain wall dynamics in perpendicularly magnetized multilayers

Diego López González,Yasuhiro Shirahata,Ben Van De Wiele,Sebastiaan Van Dijken,Arianna Casiraghi,Kévin J A Franke,Tomoyasu Taniyama

doi:10.1063/1.4979267

Diego López González, Yasuhiro Shirahata + Show 5 more

Open Access

https://doi.org/10.1063/1.4979267

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Abstract

We report on reversible electric-field-driven magnetic domain wall motion in a Cu/Ni multilayer on a ferroelectric BaTiO3 substrate. In our heterostructure, strain-coupling to ferroelastic domains with in-plane and perpendicular polarization in the BaTiO3 substrate causes the formation of domains with perpendicular and in-plane magnetic anisotropy, respectively, in the Cu/Ni multilayer. Walls that separate magnetic domains are elastically pinned onto ferroelectric domain walls. Using magneto-optical Kerr effect microscopy, we demonstrate that out-of-plane electric field pulses across the BaTiO3 substrate move the magnetic and ferroelectric domain walls in unison. Our experiments indicate an exponential increase of domain wall velocity with electric field strength and opposite domain wall motion for positive and negative field pulses. The application of a magnetic field does not affect the velocity of magnetic domain walls, but independently tailors their internal spin structure, causing a change in domain wall dynamics at high velocities.

Highlights

Controlled motion of domain walls in perpendicularly magnetized layers forms the basis of spintronic memory and logic device concepts.[1,2] The technological relevance of materials with perpendicular magnetic anisotropy (PMA) stems from the stability and small width of their domain walls
The velocity or pinning of magnetic domain walls that are driven by a magnetic field or electrical current is deliberately tuned
Since the underlying physics relies on the variation of PMA, electric field control is most pronounced for thermally activated creep motion

Summary

Introduction

Controlled motion of domain walls in perpendicularly magnetized layers forms the basis of spintronic memory and logic device concepts.[1,2] The technological relevance of materials with perpendicular magnetic anisotropy (PMA) stems from the stability and small width of their domain walls. Electric-field-driven domain wall dynamics in perpendicularly magnetized multilayers The velocity or pinning of magnetic domain walls that are driven by a magnetic field or electrical current is deliberately tuned.

Results

Conclusion