subject: The Simple Power Of Rare Earth Magnets [print this page] Since their discovery around the 1960s, magnets rare earth have been continuously developed until today their application extends into many manufacturing realms. The reduced cost of these magnets since the 90s has allowed their widespread use. The term rare earth is misleading as the elements involved are not particularly rare. They are advantageous to manufactures because their incredible strength allows magnets included in various devices to be smaller and lighter. Rare earth magnets are the strongest magnets available.
Common modern uses for these super strong magnets include hard drives, speakers and headphones, magnet motors for cordless tools and electric guitar pickups. The great advantage of these magnets for industrial purposes is that they are strongly magnetized in one direction.
The rare earth magnets are of two typessamarium-cobalt and neodymium. Although they are not radioactive or in any other way damaging to health, the strength of these magnets has been known to cause injury and even death. Limbs caught between powerful magnets can be subjected to enough pressure to be crushed or damaged. Two attracted magnets striking each other can cause either one or both to shatter, resulting in flying fragments. Placed near a computer or other electronic device, these magnets will erase magnetic content.
The strength of magnets rare earth comes about because of the compounding of rare earth elements with transition metals like iron, nickel, and cobalt. This combination creates a substance with a very high magnetic anisotropy, or mono-directional magnetization. The strength of the magnetic field, or remanence, its resistance to being demagnetized, or coercivity, the density of magnetic energy, and the Curie temperature, or the temperature at which a material loses its magnetism are all superior in rare earth magnets. This results from the molecular structure of the constituent compounds. Electrons in orbit around the atoms of the magnet are strongly localized, easily retaining strong magnetism.
Exploring some practical applications for rare earth magnets will help to explain their advantages. In the case of electric guitar pick-ups, a rare earth magnet is wrapped with copper wire and mounted on the instrument. The nearby vibration of the magnetized metal strings of the guitar creates modulations in the magnetic flux linking the coil inducing an alternating current carried by the copper wire. This signal can then be transmitted to an amplifier or recording device. Though the configuration is simple, it is made infinitely more effective by the strength and stability of these powerful magnets.
Hard discs for computers utilize rare earth magnets to create a directional magnetism. Sequential changes in the direction of magnetization is translated into binary data bits. In both of these examples, the reliable properties of magnets rare earth are the basis for a sequence of events that makes fine control over data and systems possible. These magnets, although not complicated in and of them, are an essential foundation block for many of todays cutting edge technologies.
