“…The commercial alloys are, in fact, fiveelement alloys, with composition based on Sm 2 Co 17 phase with additions of Cu, Fe and Zr. The microstructure of the SmCo 2:17 magnets is nanocrystalline and has three main phases, all of them crystallographically coherent: the cell phase Sm 2 (Co,Fe) 17 , the cell boundary phase Sm(Co,Cu) 5 and the lamellar or platelet phase (ZrSm) 1 (CoFeCu) 3 with PuNi 3 structure [6,7] (also described as BeNb 3 structure [8])…”