Rare-earth magnets are strong permanent magnets that are made from rare-earth elements. Two examples of rare-earth magnets put into practical use include Nd-Fe-B magnets and Sm-Co magnets. Among the two, Nd-Fe-B magnets are known to have the strongest magnetic field among commercially available magnets currently on the market. It is this strong magnetism which makes the development of smaller products possible, thus they are widely used in many applications in modern-day products, such as automotive control motors and vibrate features of mobile phones.

Characteristics

Has high magnetic flux density and extremely strong magnetic field.
Mechanically vulnerable and its magnetism varies with temperature change.
Can be used in temperature of up to 80 degrees Celsius, and applications to withstand higher temperatures are also available.
Prone to oxidation, they are usually treated with coating of nickel of epoxy resin for protection.