Question

What is ferromagnetism?

Answer 1

Ferromagnetism is a kind of magnetism that is associated with iron, cobalt,  nickel, and some alloys or  compounds containing one or more of these elements. It also occurs in  gadoliniumand a few other rare-earth elements. In contrast to other substances, ferromagnetic materials are magnetized easily, and in strong magnetic fields the magnetization approaches a definite limit called saturation. When a field is applied and then removed, the magnetization does not return to its original value—this phenomenon is referred to as hystersis (q.v.). When heated to a certain temperature called the  curie poin(q.v.), which is different for each substance, ferromagnetic materials lose their characteristic properties and cease to be magnetic; however, they become ferromagnetic again on cooling.