基于磁畴结构分析的磁性微丝GMI效应优化与耦合作用机制

Magnetic amorphous microwires, as a new type of magnetic sensing materials, have the potential for a wide range of engineering applications such as magnetic field measurement, magnetic recording, and earth magnesium navigation due to its giant magneto-impedance (GMI) effect. The research is based on the fundamental understanding that the GMI effect of a microwire is internally connected with its magnetic domain structure, therefore several newly developed techniques, such as micro machining(ring like micro nicking) and micro electrochemical(ring like micro electroplating),besides current annealing， will be employed to modulate the magnetic domain of the wires in order to improve the GMI effect. The mechanism for regulating the magnetic domain and that of the GMI effect, the correlation between GMI and the magnetic domain of wires will be systematically investigated. More interestingly, the coupling effect of GMI by parallel connection of two or more wires in the testing circuit will be studied, with the aim of obtaining overlying or multiplication of GMI effect. It is expected that the mechanism of the interaction between the electromagnetic fields, both between wires(dynamic magnetic domain) and the wire and surroundings will be elucidated. Thus, this work is of much interest both for the improvement of GMI theory and for the development and application of GMI based magnetic sensors. Keywords: Magnetic amorphous microwire; GMI; Magnetic domain

磁性微米丝作为新型磁敏感材料，在微磁测量、磁记录和地磁导航用磁敏传感器中具有巨大的应用潜力。本项目从磁性微丝的"GMI效应"来自于其特殊的"磁畴结构"这一基本认识出发，从磁畴结构调制入手，采用常规退火调制工艺，结合微丝表层机械、化学处理等方法，优化微丝磁畴结构进而改善和提升微丝的GMI效应。并对调控工艺、磁畴结构与GMI效应三者之间的对应关系等基本问题进行深入研究。并结合动态磁畴观测，研究多根微丝、多种方式并联情况下，GMI效应之间的"耦合"作用。揭示多根微丝在电磁场激励下，其本身电磁场（动态磁畴）之间，及与环境磁场之间的相互作用机制，并探讨GMI效应产生的物理本质。以上工作的开展，有助于完善GMI效应的相关理论，为GMI效应的实际应用提供新思路与新方法。 关键词：磁性微米丝 GMI效应 磁畴

作为新型磁敏传感器的核心材料，具有巨磁阻抗效应的磁性微米丝在微磁测量、磁记录和地磁导航用磁敏传感器方面具有重大的应用价值。本项目根据磁性微丝的GMI效应来源于其特殊的表面磁畴结构，采用了对微丝表面进行机械化学处理等方法以及多种调制处理工艺，对微丝表面磁畴结构进行调制，提升了微丝的GMI效应并获得与其相对应的磁畴结构。建立了微丝内部微观结构、微丝表磁畴结构和微丝GMI性能之间的对应关系。通过多根微丝多种方式串联和并联测试，获得了微丝间GMI效应耦合关系符合电阻定律。通过微丝表面镀层处理改善了微丝GMI效应输出的稳定性。以上完成的工作，对GMI理论的完善具有重要意义，并对GMI效应的实际应用提供新思路和新方法。