In the absence of an applied magnetic field, can maintain their own magnetic objects for a long time. Permanent magnets can be used with ferromagnetic materials, such as iron, nickel and other made.
Its atomic structure is special, the atom itself has a magnetic moment. Generally speaking, the arrangement of these mineral molecules is chaotic. Magnetic regions do not show any magnetic interaction with each other. However, when the external forces such as magnetic field guide the alignment of molecules in the same direction, magnetism appears, that is, commonly known as magnets, iron, cobalt and nickel are most commonly used Of magnetic material. Basically the magnet is divided into a permanent magnet and a soft magnet. The permanent magnet is coupled with a strong magnetic flux to align the spin of the magnetic substance and the electron angular momentum into a fixed direction. The soft magnet is added current, so the current is removed, the soft iron slowly loses magnetic. Magnet is just a generic term, refers to the magnetic, the actual composition does not necessarily contain iron. Relatively pure metal state of the iron itself is not permanent magnet, only near the permanent magnet will produce induction of magnetism, the general permanent magnet which is added with other impurities such as carbon to stabilize the magnetic stability, but this will reduce the freedom of electrons But not easily conductive, so when the current through the lamp does not light up, iron is a common magnetic element, but many other elements have a stronger magnet, like a lot of powerful magnets are neodymium, iron, boron and other mixed.