Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1607254 | Journal of Alloys and Compounds | 2016 | 7 Pages |
Abstract
The nucleation, growth kinetics and atomic process of the preexisting α-(Fe,Co) and newly-formed SmCo7 nanocrystals in the annealed nanocrystalline-amorphous Sm10.9Co66.5Fe22.6 alloy have been investigated. The preexisting α-(Fe,Co) phase possesses a growth activation energy of Eg = 0.6 eV, smaller than the nucleation activation energy En = 0.8 eV and growth activation energy Eg = 1.4 eV for the newly-formed SmCo7 phase. This demonstrates an easy growth of the α-(Fe,Co) nanocrystals and a relatively difficult formation of the SmCo7 phase, which leads to a large grain size for the α-(Fe,Co) soft phase in the α-(Fe,Co)/SmCo7 nanocomposite magnets. The activation volumes ÎVgâ = 0.67 Ω and ÎVgâ = 0.99Ω (Ω = average atomic volume) for the growth of α-(Fe,Co) and SmCo7 nanocrystals were obtained, indicating that the atom diffusion during the growth of both the α-(Fe,Co) and the SmCo7 are assisted by thermal vacancies. These findings provide a fundamental understanding to the crystallization of the SmCo based nanocomposite magnets.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Qian Zhang, Wenpeng Song, Guangwei Huang, Li Lou, Siyuan Cheng, Hongyangsu Zhang, Yinhuan Ji, Xiaohong Li, Xiangyi Zhang,