As an alternative choice to ferrite, as well as other types of magnets, rare earth magnets were conceived in the 1970s. These types of magnets are made from alloys of elements that are relatively rare. Generally, these magents will have a strength in the magnetic field of more than 1.4 tesla.
Advanced devices, which traditionally need stronger magnets, commonly use these rare earth magnets. Since the power of these magnets greatly exceeds normal ferrite magnets, smaller magnets may be used with the same effect. While these magnets are used largely in consumer electronics, they also have uses in the research and recreational fields.
The most costly rare earth magnet is made from Samarium-cobalt. This is mainly due to their resistance to very high temperatures, which is valuable in industrial applications. Cheaper and stronger magnets can be made from Neodymium and are usually put in less expensive products, such as hard disks, speakers, and children’s toys.
As rare earth magnets have a very high strength compared to their more common counterparts, they must be used with extreme caution. Very strong magnets can easily lead to injuries in human body parts. Also, any stored magnetic data, such as on computer disks and credit cards, is succeptible to erasure around these strnger magnets.
It is easy to see that there are many plausible uses for strong rare earth magnets. These uses can range from industrial, to commercial, to hobbyist. But for larger magnets, they are normally reserved for industry and are not available for purchase by a private individual.