Modification of perpendicular magnetic anisotropy and domain wall velocity in Pt/Co/Pt by voltage-induced strain

TL;DR

This study demonstrates that applying voltage-induced strain to Pt/Co/Pt thin films significantly alters their magnetic anisotropy, coercive field, and domain wall velocity, revealing strain as a powerful tool for magnetic property control.

Contribution

It provides experimental evidence of how voltage-induced strain modifies magnetic anisotropy and domain wall dynamics in thin films, highlighting the role of volume magnetostriction.

Findings

Perpendicular magnetic anisotropy reduced by 10 kJ/m³ with tensile strain

Coercive field decreased by 2-4 Oe due to strain

Domain wall velocity increased by 30-100% under strain

Abstract

The perpendicular magnetic anisotropy K$_e$$_f$$_f$, magnetization reversal, and field-driven domain wall velocity in the creep regime are modified in Pt/Co(0.85-1.0 nm)/Pt thin films by strain applied via piezoelectric transducers. K$_e$$_f$$_f$, measured by the extraordinary Hall effect, is reduced by 10 kJ/m$^3$ by tensile strain out-of-plane {\epsilon}$_z$ = 9 x 10-4, independently of the film thickness, indicating a dominant volume contribution to the magnetostriction. The same strain reduces the coercive field by 2-4 Oe, and increases the domain wall velocity measured by wide-field Kerr microscopy by 30-100 %, with larger changes observed for thicker Co layers. We consider how strain-induced changes in the perpendicular magnetic anisotropy can modify the coercive field and domain wall velocity.