In ancient times, the smart Greeks and Chinese people found that there was one kinds of natural stone which had the magnetism and then they called such kind of stone as magnet. As is known to all, such stone can absorb a small piece of sheet iron, which just likes the magic show. At the same time, after the swing at random, they always point in the same direction. Based on such feature, in the early time, sailors invented the earliest magnetic compass to discern the direction on the sea used such stone as raw material.

After thousands of years of development, nowadays, the magnet has become a strong material in our lives. For example, after combining alloy made from different materials, they would have the same effect as natural magnet and what’s more the magnetic force is also improved. In the 18th century, artificial magnets was invented, however the process of producing more stronger magnetic materials is too slow. Up to 1920s, Alnico was invented, Subsequently, in the 1950s, Ferrite was invented and in 1970s, Rare Earth magnets including NdFeB or named as Neodymium Magnets and SmCo were invented. Right now, he magnetic technology has been developed rapidly and the size of strong magnetic material become more and more smaller.