The Rare Earths Problem for Permanent Magnets

The rare earths criticality issue in the permanent magnets implies in a narrower sense the sudden inflation of prices of rare earth oxides and alloys that stared in 2011 and ceased in 2012 as a result of mishandling of the market in China, but more generally, it includes the issues concerning the rare earth resources and/or supply risks caused by rapid increase of the market demands coupled with increasing environmental regulations on mining or smelting operations in developing countries. Thus, there has existed R&D efforts for the development of permanent magnets that do not use or significantly reduce the usage of the rare earth metals for more than a decade, and their importance is ever increasing. In this chapter, this issue is briefly overviewed.