What is domain wall?

A domain wall is a boundary separating different magnetic domains in a ferromagnetic material. In the context of magnetism, a domain is a region within a material where the magnetic moments of atoms are aligned in the same direction. In a ferromagnet, these domains can have different orientations, and the domain wall is the transition region where the alignment changes from one domain to another. Domain walls play a significant role in various phenomena, including the magnetic properties of materials, magnetic hysteresis, and magnetization processes. The width of a domain wall can vary depending on the material and its specific magnetic properties, often on the order of a few nanometers. In addition to their relevance in magnetism, domain walls are also studied in the context of other fields such as spintronics, where they may be used for information storage and processing, and in the study of topological defects in condensed matter physics.