In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 27, No. 4 ( 2012-02-28), p. 725-729
Abstract:
The Fe 64 B 22.8 Nd 6.6 Y 3.9 Nb 2.7 nanocomposite permanent magnets in the form of rods of 2 mm in diameter and 25 mm in length have been prepared by annealing the amorphous precursors. The phase evolution, microstructure, and magnetic properties of Fe 64 B 22.8 Nd 6.6 Y 3.9 Nb 2.7 nanocomposite permanent magnets have been investigated by x-ray diffractometry, transmission electron microscopy, and magnetometry techniques. The exchange coupling between the magnetically soft and hard magnetic phase is evidenced by the δ M curves. The hard magnetic properties of the nanocomposites were found to be sensitive to the annealing process. The microstructure of the annealed nanocomposite consists of magnetically soft α-Fe (15–25 nm) and Fe 3 B (25–35 nm) grains and hard magnetic Nd 2 Fe 14 B (45–55 nm) grains. The optimum hard magnetic properties, such as j H c = 961.6 kA/m (12.0 kOe), B r = 0.65 T (6.5 kG), and BH max = 65.17 kJ/m 3 (8.19 MGOe), were obtained by annealing the alloy at 700 °C for 15 min and are related to the more refined nanostructure leading to strong exchange coupling between the soft and hard magnetic grains. Annealing above 700 °C induces a decoupling effect due to the coarsening of soft and hard magnetic phases.
Type of Medium:
Online Resource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/jmr.2011.413
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2012
detail.hit.zdb_id:
54876-5
detail.hit.zdb_id:
2015297-8
