Surface magnetization reversal and magnetic domain structure in amorphous microwires

Abstract

This paper presents a review on magneto‐optical investigations of the glass‐coated amorphous microwires including magneto‐optical magnetometry and microscopy. We also discuss a Kerr‐effect method of domain‐wall‐motion detection in glass‐coated wires within a classical Sixtus–Tonks experimental scheme. The developed techniques make it possible to observe the surface magnetization reversal and to establish the main mechanisms of domain‐structure formation and transformation.

Magneto-optical study of domain wall dynamics and giant Barkhausen jump in magnetic microwires

“…Two samples have been investigated: Sample 1-metallic nucleus radius 11.2 mm, glass coating thickness 3 mm, and a ratio of metallic nucleus diameter to total microwire diameter r¼0.79 and Sample 2-metallic nucleus radius 10.7 mm, glass coating thickness 2.4 mm and r¼0.82. There were three techniques of the MOKE study: magneto-optical magnetometry (loop tracer), polarizing microscopy and MOKE modified Sixtus-Tonks method to study the surface domain wall dynamics [3]. In order to produce a circular magnetic field H cir , an electric current I flowing through the wire has been used.…”

Magneto-Optical Study of the Surface Reversal Process in Amorphous Glass-Coated Microwires With Positive Magnetostriction

“…4). The light reflected from the cylinder forms a conical surface [16], [17]. As a result, the incidence planes of all rays are not parallel, with opposite rotations on both sides forming the shape of letter "V" relative to main axis of microwire (Fig.…”

Current induced domain wall propagation in Co-rich amorphous microwires

“…Such circular magnetic bistability has been explained considering transformation of the circular multidomain bamboo-like structure observed in the absence of tensile stress into a single domain one. 22 This can explain why we observed the enhancement of the induced voltage in the pick-up coils under tensile stress (see Fig.4b). …”

“…21,22 But for the Fe-rich microwires with spontaneous magnetic bistability presenting radial magnetization direction in the outer domain shell the situation is different: the circumferential magnetic field does not affect the surface magnetization reversal. Instead the circumferential magnetic field affects the switching field of the longitudinal MOKE.…”