Ferromagnetism. exchange interaction

The aim of this paper “ferromagnetism. Exchange interaction¨ is to study the nature of ferromagnetic substance. These types of substances are characterized by hysteresis, spontaneous magnetization, magnetic anisotropy. In this paper we discuss the role of exchange interaction in ferromagnetic substances, explain the role of magnetic domains. It should be noted that classical physics can not explain ferromagnetism fully. Quantum mechanics clarified the nature of the forces that caused spontaneous magnetization, which is called exchange interaction. Weiss theory is good phenomenological theory of magnetism, but does not explain the source of the large Weiss field. Later, Dirac and Heisenberg showed that ferromagnetism is a quantum mechanical effect that fundamentally arises from electric interaction.