For 10 points, identify this type of magnetism typified in cobalt, nickel, and iron.
One intrinsic property of materials that exhibit this phenomenon can be determined using Arrott plots. One model of this phenomenon leaves out the non-diagonal terms of the spin matrices, keeping only the components along the field direction, in studying the Heisenberg Hamiltonian. It is a result of the quantum mechanical exchange interaction. Although its constituents do not exhibit this phenomenon, Heusler alloys do. For materials with this property, plotting M against H yields a value for remanence when H equals 0 on a hysteresis curve. Weiss suggested that materials that exhibit this phenomenon were composed of domains. It disappears above the Curie temperature. This phenomenon occurs when the spins of unpaired electrons line up parallel to each other. For 10 points, identify this type of magnetism typified in cobalt, nickel, and iron.
One intrinsic property of materials that exhibit this phenomenon can be determined using Arrott plots.
ferromagnetism [prompt on magnetism; accept antiferromagnetism around \"exchange interaction\"]