Study on the microstructure and magnetic properties of Nd sub 2 Fe sub 14 (BC)/ alpha -Fe nanocomposite

• Published in: Journal of magnetism and magnetic materials 2002-05, Vol.247 (1), p.26-33
• Main Authors: Chen, X Y, Jiang, Z L, Zhang, L, Yang, C P, Bai, P M, Han, L, Chen, H M, Zhu, J
• Format: Article
• Language: English
• ISSN: 0304-8853

The composition, processing, microstructure, phase constitution, magnetic domain structure and properties of nanocomposite Nd sub(2)Fe sub(14)(BC)/ alpha -Fe are studied. A new alloy of Nd sub(9)Fe sub(85.5)Nb sub(1.0)B sub(4)C sub(0.5 ) is given. Adding some Nb is effective to refine grains, and the grain refinement leads to remanence enhancement resulting from increasingly significant ferromagnetic exchange coupling between the grains. Adding of C and grain-size refinement have a significant influence on coercivity. Relatively high magnetic performance is obtained: J sub(r) = 10.99 kGs, sub(i)H sub(c) = 6.51 kOe, (BH) sub(max) = 17.31 MGOe with annealing processing: 700 degree C x 15 min. Magnetic force microscope was used to observe the magnetic domain structure. The length of the magnetic contrast shows a significant dependence on the microstructure and phase constitution, and the longer length corresponds with the larger exchange coupling effect between the soft and hard magnetic phases. Thus, the length of magnetic contrast in nanocomposite alloy is much longer than in single-phase alloy. copyright 2002 Elsevier Science B.V. All rights reserved.