Magnetic properties, phase evolution and coercivity mechanism of Pr-Fe-Ti-B-based nanocomposites with Co/C cosubstitution

The effects of Co and C substitution on the magnetic properties, phase evolution and coercivity mechanism of Pr-poor and B-enriched Pr9Fe76Ti4B11 ribbons have been investigated. Substitution of 10 at.% Co for Fe improves the temperature coefficient of remanence and the temperature coefficient of coercivity but coarsens grain size, limiting its contribution to the enhancement of magnetic properties. Only in C-containing Pr9Febal.Co10Ti4B11-yCy (1 <= y <= 2.5) ribbons does the extremely fine and homogeneous microstructure make Co substitution beneficial for enhancing magnetic properties. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.