Magnets are not invented by humans, they are natural magnetite. Ancient Greeks and Chinese discovered a natural magnetized stone called "Magnet." This kind of stone can magically suck up small pieces of iron and always point in the same direction after swinging freely. Early navigators identified the magnet as its earliest compass at sea. The earliest discovery and use of magnets should be Chinese, that is, the use of magnets to make "compass" is one of China's four inventions.
After thousands of years of development, today, the magnet has become a powerful material in our lives. By synthesizing different materials, the alloy can achieve the same effect as magnet, and can also improve the magnetic force. Artificial magnets emerged 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, the ferrite (ferrite) was manufactured in the 1950s and the rare Earth magnets were manufactured in the 70 [rare magnet including NdFeB (NdFeB) and samarium cobalt (SMCO)]. At this point, magnetic technology has been rapid development, strong magnetic materials also make components more miniaturization.