The properties required of neodymium-iron-boron magnets for their major applications

In the principal applications for magnets today, the different categories of permanent magnet material generally do not compete with one another. For cost efficiency, ceramic ferrites are used; for volumetric efficiency, the choice is neodymium-iron-boron; and for temperature range or thermal stability, it's usually samarium-cobalt. The magnetic properties of neodymium-iron-boron have been maturing in recent years, and yet it is still used in only a select few major applications. This paper reviews the requirements of the major applications which have been successfully met by present grades of neodymium-iron-boron, but focusses on what improvements still need to be achieved in their properties for this material's continued growth into significant new markets. (orig.)