The effects of a nanocrystalline structure on the magnetic properties of isotropic melt spun Fe-Nd-B alloy ribbon are discussed. Three classes of alloys are considered: a) low Nd (8-10 at.%) which also contain α-Fe; b) near-stoichiometric Nd contents (11-13 at.%) which are single phase Fe14Nd2B; c) high Nd (16-20 at.%) which also contain a Nd-rich phase. For types a) and b), as the scale of the nanostructure decreases, the remanence Jr is increasingly above Js/2 while the coercivity Hcj is decreased, with a linear Jr-Hcj relationship. No Jr enhancement occurs for type c) alloys, even for a nanocrystalline structure, but rather a decrease due to volume dilution of the Fe14Nd2B phase. These effects are discussed in terms of inter-grain exchange coupling and de-coupling and the implications with respect to permanent magnets with improved properties are considered. In particular, it is demonstrated that the benefits to enhanced Jr in terms of improved energy product are limited by corresponding attenuation of the coercivity.
|Number of pages||3|
|Journal||IEEE Transactions on Magnetics|
|Issue number||6 pt 1|
|Publication status||Published - Nov 1993|
|Event||Proceedings of the International Magnetics Conference - Stockholm, Swed|
Duration: 13 Apr 1993 → 16 Apr 1993