Micromagnetism and topological defects in magnetoelectric media

Abstract

This paper briefly reviews research of the magnetoelectric materials and multiferroics as domain-structured media. The review is focused on magnetoelectric phenomena in epitaxial iron garnet films (electrically induced displacement and tilting of domain boundaries) as a striking example of magnetoelectricity in micromagnetism. The paper also considers the effect of an electric field on other topological defects in magnetically ordered media, including Bloch lines and Bloch points at domain boundaries, magnetic vortices, and skyrmions.

The Mechanisms of Electric Field‐Induced Magnetic Bubble Domain Blowing

“…The physics of multiferroics, the materials with several coexisting types of ordering, and magnetic ferroelectrics in particular, has progressed tremendously from the beginning of this century . Nowadays a new trend has emerged: to consider the magnetoelectricity on the level of a domain and even a domain wall …”

“…The phenomenon of electric field induced bubble domain generation is observed in the presence of magnetic bias field that has two components: the in‐plane magnetic field ( H || ) to enhance magnetoelectric coupling and the field perpendicular to the film sample ( H ⊥ ) bringing the film magnetic structure to single domain state. At the phase boundary of the single domain state where the stripe domain structure is about to arise one can blow magnetic bubbles one after another just by touching the surface of the sample with the electrode and applying the voltage to it (Figure , bottom left inset).…”

Antiferromagnetic spin cantings as a driving force of ferroelectricity in multiferroic Cu2OSeO3

“…In [40,41] an expression for the electric polarization is found, which coincides with term P iso in Eq. (22).…”

Electroinduced magnetic bubble domain nucleation

“…The displacement of the domain wall in an iron garnet film with a crystallographic orientation (210) under the action of an inhomogeneous electric field of the tip electrode was experimentally demonstrated in [4]. This phenomenon is explained by the presence of electrical polarization of the domain wall: the effect is of magnetoelectric nature.…”

“…Later it was experimentally shown [4,5] that the displacement of the domain wall in an inhomogeneous electric field can be increased by applying an in-plane magnetic field.…”