High performance α-Fe/Nd2Fe14B-type nanocomposites

The alpha-Fe/R2Fe14B-type exchange-coupled NdFeB nanocomposites with a coercivity (H-i(c)) of more than 11 kOe and energy product, (BH)(max), of more than 16 MGOe have been successfully obtained on melt spun (Nd0.95La0.05)(7.5+x)FebalCr2B10 alloy powders, where x ranged from 3 to 3.5. It was found that a slight substitution of Cr for Fe suppresses the formation of the R2Fe23B3 and Fe3B phases during crystallization and results in the formation of an alpha-Fe/R2Fe14B mixture. Increasing the total rare earth content was found to enhance theremanence, and the H-i(c) of (Nd0.95La0.05)(7.5+x)Fe80.5-xCr2B10 ribbons was also increased drastically with increasing values of x. A B-r of 9.2-9.7 kG, H-i(c) of 11.1-13.2 kOe, and (BH)(max) of 16.5-18.0 MGOe have been obtained on (Nd0.95La0.05)(7.5+x)Fe80.5-xCr2B10 (x = 3-3.5). (C) 1998 American Institute of Physics.