Domain wall (magnetism)
A domain wall is a term used in physics which can have similar meanings in magnetism, optics, or string theory.
These phenomena can all be generically described as topological solitons which occur whenever a discrete symmetry is spontaneously broken.
The domain wall thickness depends on the anisotropy of the material, but on average spans across around 100–150 atoms.
The anisotropy energy is lowest when the individual magnetic moments are aligned with the crystal lattice axes thus reducing the width of the domain wall.
These include missing or different (foreign) atoms, oxides, insulators and even stresses within the crystal.
[9][10] After their application to any inhomogeneous region, they predict the existence of even parts in functions of the distribution of order parameters.
Identification of the remaining odd parts of these functions was formulated[11] based on symmetry transformations that interrelate domains.
[12] Symmetry-based predictions of the structure of the multiferroic domain walls have been proven using phenomenology coupling via magnetization[13] and/or polarization[14] spatial derivatives (flexomagnetoelectric).
[15] Non-magnetic inclusions in the volume of a ferromagnetic material, or dislocations in crystallographic structure, can cause "pinning" of the domain walls (see animation).
(Presented is a Néel wall, and not a Bloch one, see below)
