Developments in rare earth intermetallics

The general physical and magnetic properties of rare earth intermetallics of the system R(a)B(b) with zero and nonzero-B-moment are reviewed with emphasis on the use of R-3d multicomponent systems as the basis for advanced permanent magnets. It is noted that by varying the structure of pseudobinary systems, it is possible to tailor specific properties of rare earth intermetallics. At the same time, true ternary compounds with crystal structures not observed in the binary systems find new applications, such as permanent magnets. RE-3d alloys with metalloids and nonmetals are discussed with particular reference to the newly developed R-Fe-B permanent magnets.