Domain Wall Depinning Process in Bistable Glass-Coated Microwire

Mária Kladivová,Ján Ziman

doi:10.2478/aeei-2013-0012

Abstract

A simple analytically solvable model for description of dynamics of the domain wall depinning process from the closure domain structure in bistable microwires was proposed. In this model closure domain structure is modelled by a single domain wall located in quadratic potential well. Critical parameters of rectangular magnetic field pulse needed to release this wall from the potential well were calculated. Theoretical dependence obtained in this way was fitted to experimental data measured on glass-coated Fe77.5B15Si7.5 microwire. Information about the order of closure domain structure dimension and about the mass of the domain wall, which is depinned from the wire end were obtained in this way.

Highlights

Glass-coated amorphous ferromagnetic microwires are very promising materials for technical application as well as for basic research due to their magnetic properties and simple and cheap fabrication [1,2,3].A large single Barkhausen jump is typical for magnetization reversal process in Fe-based microwires
Axial magnetization reversal starts by depinning of domain wall from the wire end and subsequently the reversal continues by propagation of a single domain wall along the wire
Glass-coated microwire Fe77.5B15Si7.5 prepared by Taylor-Ulitovski method with parameters: length 12 cm, diameter of metallic nucleus about 15 μm, thickness of glass coating about 9 μm was studied in the experiment

Summary

Introduction

A large single Barkhausen jump is typical for magnetization reversal process in Fe-based microwires. It is a result of strong axial anisotropy due to high positive magnetostriction, internal mechanical stresses originating from rapid quenching and presence of glass coating. Axial magnetization reversal starts by depinning of domain wall from the wire end and subsequently the reversal continues by propagation of a single domain wall along the wire. Velocity of this domain wall can be very high and so this phenomenon can be very interesting for technical applications. On the other hand the study of a single domain wall dynamics can give important information for understanding the process of magnetization reversal [4,5,6,7,8] and about dynamic characteristics of a single domain wall [9,10]

Methods

Results

Conclusion