Magnetic materials are important functional materials which have wide applications and consist of a wide variety.The development of magnetic materials was extremely rapid during the 1990's,when magnetic alloys of the rare earth-3d iron group,such as rare earth permanent magnets,giant magnetostriction materials,giant magnetocaloric materials,magnetooptic materials,magnetic amorphous materials,and nanocrystalline magnetic materials,appeared one by one.The discovery of giant magnetoresistance led to a new rese...