Magnetism and Magnetic Materials

Hard materials are also called permanent materials. Rare earth magnetic materials, utilized for permanent magnets in signaling devices and computers. Signaling devices have forces up to ten times of that ordinary magnets. They are of numerous types. Rare earth-cobalt magnets are made by compressing and extruding the powders with a binder of plastic or soft metal into small accuracy shapes. They have high durability. Magneto-optic magnets are made with thin wafers which are used for memory system in computers, are spot-size magnets. Spot-size magnets of europium oxide only 4 μm in diameter implement reading and writing operations well. Films of this ceramic has less wavelength. Thickness are utilized as memory storage mediums. Hard magnets are usually applied in data storage analog and digital also.