Physics and chemistry

Rare-Earth Metals are a family of metals consisting of Scandium, Yttrium and the 15 elements from Lanthanum to Lutetium (see Periodic table of elements). Not all of the rare-earth elements are rare. Cerium, for example, is three times more abundant than lead in the Earth's crust.

The rare-earth elements are never found as free metals and no pure minerals exist in nature. All their minerals consist of mixtures of the various elements. All the elements are chemically similar because of their similarity in atomic structure. They all have three electrons in their outermost shell of their atoms. Therefore they are trivalent in their compound. They form extremely stable borides, carbides and oxides.

 
   
Magnetic Properties

We use magnets to almost everything we do: Magnets are essential parts in electric motors, our stereo speakers, compact disc players, microwave ovens, telephones and audio systems... The compass needle is so common that we take it for granted. Some common materials such as iron, display strong magnetism, other substances like Aluminium seem to be unaffected by magnetic fields. Rare-earth metals, in contrast, are used for the strongest magnets known and find several applications in different fields.

 
   
Applications

The major benefit of the use of rare-earth metals in magnets is that the greater magnetic strength translates into the production of much smaller permanent magnets. For example small in-ear earphones are now commonplace. There are many other uses but the difficulty of extracting these metals means that their use can be expensive.

 
 
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