Unidirectional motion of magnetic domain walls: the experiment and numerical simulation

L A Pamyatnykh,S E Pamyatnykh,L Yu Agafonov,D S Mekhonoshin,M S Lysov,G A Shmatov

doi:10.1088/1742-6596/1389/1/012001

Abstract

The results of study of unidirectional motion of topologically different domain structures under the influence of periodic bipolar and unipolar magnetic field pulses applied perpendicular to the sample plane of (111) iron garnet single crystal plate are presented. The response of the domain structure to the field pulses was studied by direct observations utilizing the stroboscopic technique. Experimentally obtained dependences of the speed of unidirectional motion of stripe domains on the parameters of external bipolar pulsed magnetic field are compared with the results of numerical simulations.

Highlights

The unidirectional motion of various magnetic structures (domain walls (DWs), bubble magnetic domains (BMDs), skyrmions) is a key phenomenon necessary for creating new types of magnetic memory devices [1,2,3,4]
The sample was subjected to demagnetization in an alternating magnetic field with an amplitude decreasing to zero, as a result a stripe domain structure with DWs oriented along the axis [2 11] was formed in the sample (figure 1(a))
In this case the following forces are acting on the DW: external pulsed magnetic field force that shifts the DW from equilibrium, “restoring” force associated with magnetostatic energy of stripe domain structure and dynamic friction force associated with attenuation of magnetization precession in magnetic field

Summary

Introduction

The unidirectional motion of various magnetic structures (domain walls (DWs), bubble magnetic domains (BMDs), skyrmions) is a key phenomenon necessary for creating new types of magnetic memory devices [1,2,3,4]. The motion of an array of domain walls as a whole under the influence of an alternating magnetic field is known as the drift of DWs. Up until now in most of the works the DW drift was studied in harmonic magnetic fields [5,6,7,8,9]. This paper is devoted to determination of patterns and revealing of the necessary conditions for the ordered unidirectional motion of various domain structures (DSs) in single crystals of iron garnets under the influence of pulsed magnetic fields. The results of experimental studies are compared with the results of numerical simulations performed using the model of coupled harmonic oscillators [5,7,11] with the parameters of the real sample

Methods

Results

Conclusion