钴基非晶纳米晶复相合金的巨磁阻抗效应.docVIP

 钴基非晶纳米晶复相合金的巨磁阻抗效应# 孙强强1，宋玉军1，张涛1，蒋颜玮2，房建成2** （1. 教育部空间材料与服役重点实验室，北京航空航天大学材料科学与工程学院，北京 5 10 15 20 25 30 35 100191； 2. 北京航空航天大学新型惯性仪表与导航系统技术国防重点实验室，北京 100191） 摘要：通过快速凝固方法制备了宽 1-2 mm、厚约 20 μm 的钴基非晶条带，并通过可控退 火调节来优化其巨磁阻抗效应（GMI），同时对不同处理条件下条带的巨磁阻抗效应与其内 在的微观相结构、磁性能和电性能的相关性进行了研究。结果表明对非晶条带在 450 oC 退 火 30 分钟，可以获得优异的 GMI 效应，此时合金条带的微观相结构为超精细纳米晶合金。 该纳米晶合金的微观相结构特点是以晶粒间距为 0.4 ± 0.2 nm、晶粒尺寸为 3.5 ± 0.4 nm 的纳米晶均匀弥散在非晶基体内。磁场退火制备的纳米晶合金在 10 MHz 的频率下，最高磁 阻抗比率可达 520 %，其直流磁场灵敏度也达到了 250 %/Gs；无磁场退火制备的纳米晶合金 在 15 MHz 下，最高磁阻抗比率为 324 %，直测的低磁场下(0-10 Gs 或 0-100 mT)的磁场灵敏 度可达(1.33 %/mT)。 关键词：功能材料；磁性材料；非晶合金；纳米材料；巨磁阻抗 中图分类号：TG113.2 Amorphous-Nanocrystalline Composite Cobalt-rich Alloys for Giant Magneto-impedance SUN Qiangqiang1, SONG Yujun1, ZHANG Tao1, JIANG Yanwei2, FANG Jiancheng2 (1. Key Laboratory of Aerospace Materials and Performance, School of Materials Science and Engineering, Beihang University, Beijing 100191; 2. Key Laboratory of Fundamental Science for National Defense of Novel Intertial Instrument Navigation System Technology, Beihang University, Beijing 100191) Abstract: Co-rich amorphous ribbons with thickness of 20 μm and width of 1-2 mm are fabricated by the rapid-quenching process. Controlled annealing is performed on these ribbons for enhanced giant magneto-impedances (GMI), which are further correlated with their intrinsic crystal structures, magnetic and electric properties. The results indicate that ultra-fine nano-structural alloys are formed by field-annealing the amorphous ribbons at 450 °C for 30 minutes, featured by the formation of primary nano-crystals with size of 3.5 ± 0.4 nm uniformly dispersing in the amorphous residues with inter-spacing of 0.4 ± 0.2 nm. This kind of ultra-fine nano-structural alloys preserves a MI ratio of 520 %, much higher than the as-quenched sample with only 84 %, and a dc magnetic-field sensitivity of 250 %/Gs at a given frequency of 10MHz. Samples annealed without field exhibit a dual peak MI feature with a MI ratio of 324 % and a lo