US Patent 6850140 Layered magnets and methods for producing same

The present invention is directed to layered magnets, magnetic rolls made therefrom, methods for increasing the magnetic field strength of a ferritic magnet, methods for increasing the magnetic field strength of a magnetic roll, methods for increasing the magnetic field uniformity of a rare earth magnet, and methods for increasing the magnetic field uniformity of a magnetic roll. Layered magnets include a rare earth magnet having a magnetic field, and superposed upon the rare earth magnet, a layer of ferritic magnet bonded thereto. Layered magnets exhibit greater magnetic field strength and a substantially more uniform magnetic field.