A magnetic domain is a region sharing an ordered magnetic orientation. Different magnetic domains can reduce the total magnetic moment without erasing the local magnetic order. A zero total magnetization therefore does not by itself establish antiferromagnetism.
A magnetic domain wall separates differently oriented magnetic domains. Its motion changes their volumes and average magnetization. It is a magnetic domain wall.
An original two-magnetic domain model makes the collective change explicit. Suppose opposite regions have magnetizations and along the measuring axis, where is the local saturation magnetization. If a magnetic domain wall sweeps volume from the negative region into the positive one, in a specimen of fixed volume , thenThe factor two comes from replacing by . The local magnitude stays fixed while the average magnetization changes; the event size depends on the swept volume, rather than a universal single-spin increment.
Spatial variations in energy, including crystal defects, can trap a magnetic domain wall. This is magnetic domain-wall pinning. Increasing the applied magnetic field can release the wall into a collective jump.
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A magnetic domain is a region within a magnetic material where the magnetic moments of atoms are aligned in a uniform direction due to interactions between them. In such domains, the magnetic moments, which arise from the spin and orbital angular momentum of electrons, point in the same direction, resulting in a net magnetic moment for that domain. In ferromagnetic materials, which include elements like iron, cobalt, and nickel, these domains can vary in size and orientation.