ABSTRACT
When all domains have been aligned with their spontaneous magnetization vectors parallel to the field, the material consists of a single magnetic domain and is said to have reached technical saturation magnetization. Since according to the domain theory the atomic magnetic moments are ordered even in the demagnetized state in a ferromagnet, the difference between the demagnetized state and the magnetized state must be due to the configuration of the domains. The properties of ferromagnets can be explained if long-range magnetic order exists within the solid but the volumes, known as domains, containing the magnetic moments are randomly aligned in the demagnetized state. Providing that the decrease in magnetostatic energy is greater than the energy needed to form magnetic domain walls, and then multidomain specimens will arise. The Faraday effect, which is less useful for domain observations, is similar except that the rotation of the axis of polarization is caused during transmission of a polarized light beam through a ferromagnetic solid.
