(1. 江苏科技大学 数理学院，镇江 212003；
2. 江苏大学 材料科学与工程学院，镇江 212013)
摘 要: 采用溶胶-凝胶结合静电仿丝技术制备Co0.5Ni0.5Fe2O4纳米纤维，然后将其氢热还原合成了一系列不同合金含量、平均直径在67~85 nm的Fe-Co-Ni合金/Co0.5Ni0.5Fe2O4复合纳米纤维。采用TG-DTA、XRD、FE-SEM、TEM和VSM对所得纤维样品进行表征。结果表明：随着还原温度由290 ℃升高到350 ℃，纤维直径逐渐减小，微观形貌向串珠状结构演变，还原产物中Fe-Co-Ni合金的质量分数由15.2%逐步增加到约95.7%；所制得的Fe-Co-Ni合金/Co0.5Ni0.5Fe2O4复合纳米纤维的两磁性相晶粒间具有良好的磁交换耦合，其磁化行为如同单相磁性材料的；随Fe-Co-Ni合金含量的增加，其饱和磁化强度和剩磁均增大，而相应的矫顽力则呈现出一个先增大后减小的变化趋势；Fe-Co-Ni合金相的形成不仅能够明显提高复合纳米纤维的软磁性能，而且通过调节其含量还可有效实现对材料磁参数的宽范围调控。
关键字: Co-Ni铁氧体；Fe-Co-Ni合金；复合纳米纤维；磁性能；静电纺丝；氢热还原
（1. School of Mathematics and Physics, Jiangsu University of Science and Technology, Zhenjiang 212003, China;
2. School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China）
Abstract:A series of Fe-Co-Ni alloy/Co0.5Ni0.5Fe2O4 composite nanofibers with average diameters from 67 to 85 nm and various alloy contents were synthesized by hydrogen-thermal reduction of Co0.5Ni0.5Fe2O4 nanofibers prepared via sol-gel methode and electrospinning. The obtained nanofiber samples were characterized by TG-DTA, XRD, FE-SEM, TEM and VSM. The results show that the mass fraction of Fe-Co-Ni alloys in the reduced products progressively increases from 15.2% to about 95.7% with increasing the reduction temperature of Co0.5Ni0.5Fe2O4 nanofibers from 290 ℃ to 350 ℃. Meanwhile, the fiber diameter gradually decreases and the fiber surface morphology evolves toward the bead-like structures. The magnetic field dependence of the magnetization behaves as if the as-prepared Fe-Co-Ni alloy/Co0.5Ni0.5Fe2O4 composite nanofibers are single-phase magnetic materials, which indicates that the two magnetic phases in composites are effectively exchange-coupled and that the magnetization of both phases reverses cooperatively. The saturation magnetization and remanence of the samples increase monotonically with the increase of Fe-Co-Ni alloy content, while the corresponding coercivity shows a trend of first increase and then decrease. The formation of Fe-Co-Ni alloy phase can not only obviously improve the soft magnetic performance of the composite nanofibers, but also effectively realize the wide-range control for the magnetic parameters through adjusting the Fe-Co-Ni alloy content in composites.
Key words: Co-Ni ferrite; Fe-Co-Ni alloys; composite nanofiber; magnetic property; electrospinning; hydrogen-thermal reduction
