About rare-earth magnets

A rare-earth magnet is a special permanent magnet made out of the elements located in the lanthanides and actinides series of the periodic table. These rare-earth elements are combined with more common elements to form compounds that possess very powerful ferromagnetic properties. The magnetic field produced by these rare-earth permanent magnets can be well over 1.2 teslas which is much stronger in magnitude compared to the more commonly used ferrite or ceramic magnets which only exhibit around 50 to 100 milliteslas. Common applications of rare-earth magnets include computer hard drives and high-end speakers. Some other applications of rare-earth magnets include experiments with diamagnetic levitation, the study of magnetic field dynamics, superconductor levitation as well as countless other applications.

Neodymium

The most powerful and affordable type of rare earth magnet is a neodymium magnet. Neodymium magnets are made of neodymium, iron and boron in the formula Nd2Fe14B. These magnets are found in almost every computer hard drive as well as in various types of speakers.

Samarium-cobalt

Samarium-cobalt magnets (SmCo5) are less common than neodymium magnets because they are more expensive and not as strong. These magnets are generally used in high temperature applications since they have a higher Curie point.