Micromagnetics

Abstract

Magnetism is a property that all materials possess as a result of the motion of their electrons. It can be enhanced by electric current or by a permanent magnet. In ferromagnetic materials magnetism can be sustained even in the absence of applied forces. The chief ferromagnetic elements are iron (Fe), cobalt (Co) and nickel (Ni). Many ferromagnetic alloys based on these metals also exist. The magnetic moment of a ferromagnetic atom results from the spin of electrons in an unfilled inner shell of the atoms. In materials less susceptible to magnetization, the electron spins (+ or −) cancel each other so that the atom possesses no magnetic moment, unless an external field is applied.