Domain wall mobility engineering by a perpendicular magnetic field in microwires with a gradient of perpendicular anisotropy

L Fecova,R Varga,K Richter

doi:10.1063/9.0000120

Abstract

Fast domain wall propagation is a typical feature of amorphous glass-coated microwires with positive magnetostriction. The high domain wall velocity can be effectively tailored either by sample postprocessing or temperature. In this work, we show that the domain wall dynamics can be engineered by a perpendicular magnetic field. We perform the domain wall mobility measurements in microwires with a varying gradient of the perpendicular magnetic anisotropy. It is shown that domain wall mobility is mainly determined by counterplay between the amplitude of perpendicular anisotropy and externally applied perpendicular field. The presence of perpendicular magnetic anisotropy is observed by Scanning electron microscopy. The relation between the maximum applied perpendicular magnetic field, and the wire dimensions are provided based on the measured data.

Highlights

Fast domain wall (DW) motion is a vital factor of modern magnetic sensors and spintronic devices.[1,2,3,4,5]
Rotations of wires in the perpendicular magnetic field lead to a periodic dependence of DW mobilities
Wires with larger d/D ratio are more sensitive to perpendicular fields than wires with lower d/D ratio

Summary

INTRODUCTION

Fast domain wall (DW) motion is a vital factor of modern magnetic sensors and spintronic devices.[1,2,3,4,5] Among other things, current applications require small size, low cost, and multifunctional materials These properties are typical for amorphous magnetically bistable microwires, which appear to be a desirable material for efficient use in practice. Despite the microwires’ cylindrical shape, the DW velocity increases in a perpendicular field applied in one direction and decreases in the opposite direction.[14] a perpendicular field enhances the DW velocity at a particular rotation of microwire.[15] A gradient of a perpendicular magnetic anisotropy can explain such an effect Such a gradient is induced to microwire during the fabrication process because the wire is cooled asymmetrically from one side by a flowing water stream.[17]. The effect of the perpendicular field plays an essential role in DW mobility

EXPERIMENTAL

AND DISCUSSION

CONCLUSION