Ferromagnetism

What is ferromagnetism?

Ferromagnetism is the type of magnetism exhibited by iron, nickel and cobalt. The effect in iron is much stronger than in nickel or cobalt. Compared to paramagnetism and diamagnetism, ferrormagnetism is several of orders of magnitude stronger. Ferromagnetic materials are also able to retain magnetization outside of an external current or magnetic field. This is because iron and other ferromagnetic materials naturally form "magnetic domains" where a large group of atoms (in the billions) naturally align to each other to create an area with a net magnetic field. There are millions of these magnetic domains and their magnetic moments are randomly aligned so that your average piece of iron is magnetically neutral. Otherwise any old piece of iron would be an incredibly strong magnet.