For 10 points, name this property of permanent magnet formation, found in nickel, cobalt, and its namesake element, iron.
Weiss domains with this property change size rapidly with Barkhausen jumps and can be observed with Kerr microscopes. Those domains with this property are separated from each other by Bloch and Néel walls. This phenomenon is described by a model whose two-dimensional form was solved by Lars Onsager, called the [*] Ising model. The "anti" form of this property disappears above the Néel temperature, and materials displaying it exhibit hysteresis loops below the Curie temperature. For 10 points, name this property of permanent magnet formation, found in nickel, cobalt, and its namesake element, iron.
Weiss domains with this property change size rapidly with Barkhausen jumps and can be observed with Kerr microscopes.
ferromagnetism