贫稀土Pr4.5Fe77B18.5非晶合金晶化动力学研究

利用X射线衍射分析仪、透射电镜、振动样品磁强计和差示扫描量热仪研究贫稀土非晶Pr4.5Fe77B18.5合金中Fe3B/Pr2Fe14B复合纳米晶的晶体结构、磁性能及其晶化动力学.结果表明,经650℃晶化退火处理后,Pr4.5Fe77B18.5合金的晶化相主要由软磁相Fe3B和硬磁相Pr2Fe14B组成,而且退火后复合纳米晶磁体晶粒细小、分布均匀,磁滞回线呈现单一的硬磁特征,表明其具有较强的交换耦合作用.晶化动力学研究表明,软磁相Fe3B易成核、难生长和Pr2Fe14B相的难成核易生长的晶化行为是Fe3B/Pr2Fe14B复合纳米磁体具有较好磁耦合性能的根本原因.

Crystallization Kinetics of Lean Rare-Earth Pr4.5Fe77B18.5 Amorphous Alloy

The crystal structure, magnetic properties and crystallization kinetics of the Fe3B/Pr2Fe14B nanocomposite prepared from lean rare-earth Pr4.5Fe77B18.5 amorphous alloy have been investigated by X-ray diffractometer (XRD), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and differential thermal analysis (DTA). The results indicate that the phases of this sample are composed of Fe3B soft-magnetic phase and Pr2Fe14B hard-magnetic phase as the alloy annealed at 650 oC for 10 min, and the grains are very small and homogeneously distributed in this nannocomposite alloys. The result of VSM analysis presents a single hard-magnetic phase behavior in this alloy. The study on crystallization kinetics for the Fe3B/Pr2Fe14B nanocomposite alloy indicates that the crystallization behavior with easy nucleation and difficult growth of Fe3B phase and with difficult nucleation and easy growth of Pr2Fe14B phase, essentially results in a stronger exchange-coupling effect in Fe3B/Pr2Fe14B nanocomposite.