What is different about ferromagnetic materials that make them strongly magnetic?
In ferromagnetic materials, the magnetic moments of a relatively large number of atoms are aligned parallel to each other to create areas of strong magnetization within the material. These areas, which are approximately a millimeter in size, contain billions of aligned atoms and are called magnetic domains. Magnetic domains are always present in ferromagnetic materials due to the way the atoms bond to form the material. However, when a ferromagnetic material is in the unmagnetized condition, the magnetic domains are randomly oriented so that the magnetic field strength in the piece of material is zero. In the unmagnetized condition, the material will be attracted to a magnet but will not act as a magnet. That is to say, two unmagnetized pieces of ferromagnetic material will not be attracted to each other. When a ferromagnetic material is magnetized, the magnetic domains align parallel to each other to produce a large net field strength in the material and the material becomes magnetic.
