A study on the modeling of the optimal configuration of ferromagnetic materials

Abstract

The most distinctive property of ferromagnetism is the observation of hysteresis loops. It is the feature showing the fact that ferromagnetism can remain as a nonzero magnetization after applying an external field and then removing it. The natural domain theory is about one of the physical mechanisms influencing the observed phenomenon. According to this, “Ferromagnetic material is subdivided into regions, called magnetic domains”[1]. In each domain, the magnetic moments are aligned via the molecular field, but the orientation of spontaneous magnetization can vary from domain to domain. When the magnetization is averaged over volumes large enough to contain many domains, magnetization may be close to zero. It turns out to be the minimalenergy state. This sounds reasonable to the thermodynamic balance principle. By using the finite element analyst method, we have figured out the origin domain configuration of the sustainable energy state of ferromagnetic material and the rearrangement to a new structure under an external field.