Phase transition of nanocrystalline-amorphous Sm10.9Co66.5Fe22.6 alloy: Nucleation, growth kinetics and atomic process
Phase transition of nanocrystalline-amorphous Sm10.9Co66.5Fe22.6 alloy: Nucleation, growth kinetics and atomic process
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纳米晶-非晶 Sm10.9Co66.5Fe22.6 合金的相变：成核、生长动力学和原子过程
DOI：
10.1016/j.jallcom.2015.11.067
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发表时间：
2015
影响因子：
6.2
通讯作者：
Zhang Xiangyi
中科院分区：
文献类型：
--
作者：
Zhang Qian;Song Wenpeng;Huang Guangwei;Lou Li;Cheng Siyuan;Zhang Hongyangsu;Ji Yinhuan;Li Xiaohong;Zhang Xiangyi
研究了退火后纳米晶非晶sm10.9 co66.5 fe22.6合金中原有α-(Fe, Co)纳米晶和新形成的smco7纳米晶的成核、生长动力学和原子过程。α-(Fe, Co)相的生长活化能为eg0.6 eV，小于新形成的SmCo 7相的成核活化能eg0.8 eV和生长活化能eg1.4 eV。α-(Fe, Co)/SmCo 7纳米复合磁体的α-(Fe, Co)纳米晶易于生长，而SmCo 7相的形成相对困难，这导致α-(Fe, Co)软相的晶粒尺寸较大。得到了α-(Fe, Co)和SmCo 7纳米晶生长的活化体积Δ V g∗= 0.67 Ω和Δ V g∗= 0.99 Ω （Ω=平均原子体积），表明α-(Fe, Co)和SmCo 7生长过程中的原子扩散都是由热空位辅助的。这些发现为SmCo基纳米复合磁体的结晶过程提供了一个基本的认识。
The nucleation, growth kinetics and atomic process of the preexisting α-(Fe, Co) and newly-formed SmCo 7 nanocrystals in the annealed nanocrystalline-amorphous Sm 10.9 Co 66.5 Fe 22.6 alloy have been investigated. The preexisting α-(Fe, Co) phase possesses a growth activation energy of E g= 0.6 eV, smaller than the nucleation activation energy E n= 0.8 eV and growth activation energy E g= 1.4 eV for the newly-formed SmCo 7 phase. This demonstrates an easy growth of the α-(Fe, Co) nanocrystals and a relatively difficult formation of the SmCo 7 phase, which leads to a large grain size for the α-(Fe, Co) soft phase in the α-(Fe, Co)/SmCo 7 nanocomposite magnets. The activation volumes Δ V g∗= 0.67 Ω and Δ V g∗= 0.99 Ω (Ω= average atomic volume) for the growth of α-(Fe, Co) and SmCo 7 nanocrystals were obtained, indicating that the atom diffusion during the growth of both the α-(Fe, Co) and the SmCo 7 are assisted by thermal vacancies. These findings provide a fundamental understanding to the crystallization of the SmCo based nanocomposite magnets.