Magnetic Saturation

the state of a paramagnet or ferromagnet in which its magnetization J has reached a maximum value J_∞, the saturation magnetization, which does not change upon further increase in the intensity of the magnetizing field.

For ferromagnets J_∞ is reached upon completion of the processes of “technical magnetization”: (1) growth of domains whose magnetic moments are oriented along the direction of easy magnetization as a result of displacement of the domain boundaries; (2) rotation of the magnetization vector of a specimen in the direction of the magnetizing field (the rotation process); (3) the paraprocess, which is the increase, under the influence of a strong external field, in the number of spins oriented along the field at the expense of spins that have an antiparallel orientation. In practice, technical magnetic saturation is usually produced (at 20°C in fields ranging from several oersteds to about 10⁴ oersteds), since very strong fields are required to produce the paraprocess (far from the Curie point). A condition close to magnetic saturation is reached for paramagnets in fields of the order of 10 kilooersteds (about 10³ kiloamperes per meter) at temperatures of the order of 1°K.