The history of the magnet

5,000 years ago, humans discovered natural magnet (Fe3O4), 1990 atomic gap -Sm-Fe-N magnets come. 1991 German physicist put forward a theoretical basis EF Kenei Le Duplex composite magnet exchange interaction, pointing out the prospects for the development of neodymium block magnet. With the development of society, more and more widespread application of the magnet, from high-tech products to the most simple packaging magnetic, currently the most widely used or NdFeB magnets and ferrite magnets. From the history of the development of the magnet, the turn of the century, people mainly use carbon steel, tungsten steel, chrome steel and cobalt permanent motor magnets for steel.