The discovery and composition of magnets:
magnets are iron, cobalt, nickel and other atoms, the internal structure of the atom is very special, itself has magnetic moment.
Magnets can produce magnetic fields and have the properties of attracting ferromagnetic materials such as iron, nickel and cobalt. Magnet Type: Shape class Magnet: Square magnet, Tile magnet, abnormity magnet, cylindrical magnets, ring magnets, round-chip magnets, magnet magnets, magnetic force magnets, attribute-type magnets: samarium Cobalt Magnets, NdFeB magnets (strong magnets), ferrite magnets, aluminum-nickel cobalt magnets, iron-chromium cobalt magnets, industry-type magnets: magnetic components, motor magnets, Rubber magnet, plastic magnet and other kinds. Magnets are divided into permanent magnets and soft magnets, permanent magnets are coupled with strong magnetism, so that the spin of the magnetic material and the electronic angular momentum in a fixed direction, soft magnetic is coupled with electricity. (also a method with magnetic force), such as electric current remove the soft iron will slowly lose its magnetism. Magnets are not invented by humans, they are natural magnetite. The ancient Greeks and Chinese found a naturally magnetized stone called "Magnet" in nature. The stones can magically suck up small pieces of iron and always point the same direction after swinging freely. The early navigators used the magnet as their earliest compass to discern the direction at sea.
The first to find and use magnets should be the Chinese, that is, the use of magnets to make "compass", is one of China's four major inventions. After thousands of years of development, today's magnets have become a powerful material in our lives. By synthesizing different materials of the alloy can achieve the same effect as magnet, but also can improve the magnetic force. Artificial magnets appeared in the 18th century, but the process of making stronger magnetic materials was slow until the 1920s, when aluminum-nickel-cobalt (Alnico) was produced. Subsequently, Ferrite (Ferrite) was manufactured in the 1950s, and Rare-earth magnets were produced in the 70 [Rare Earth Magnet including neodymium-iron-boron (NdFeB) and samarium cobalt (SMCO)]. At this point, the magnetic technology has been developed rapidly, strong magnetic materials also make components more compact.