Samarium cobalt permanent magnet is widely used second generation high energy material. Using samarium and cobalt as its rare earth element, it exhibits high magnetic performance characteristics in energy products and coercive force. There are two compositions of magnets in this family: Sm1Co5 and Sm2Co17. The highest commercially available energy products of Sm2Co17 are in the 30MGOe range.
Samarium Cobalt holds its standard property in higher maximum temperature than NdFeB magnet, although it (BH)max is less. The cost of material is the most expensive, so it is recommended only when its performance in a high temperature environment is a concern.

Representative magnets much used are NdFeB Magnet and Ferrite Magnet.
NdFeB Magnet is an anisotropic sintered magnet, neodymium, iron, and boron are its main elements.
Its dominant molecule is the intermetallic compound Nd2Fe14B, which has a tetragonal crystalline structure.
It has the most powerful magnetic properties of all magnets, so you can downsize motors with using it, namely, it is essential magnet for leading edge technology of wide fields.
Ferrite magnets, their residual magnetic flux density is relatively low, but they consist mainly of iron oxides, they are therefore the material having the most excellent cost performance.
So, ferrite magnets are most produced, and the popular choice, serving all kinds of applications in all market sectors.