介观结构对Fe基纳米晶粉末巨磁阻抗效应的影响

The Influence of the Mesoscopic Structure of Fe_(73.5)Cu_1Nb_3Si_(13.5)B_9 Powder on Its Giant Magneto-Impedance Effect

根据Fe基纳米晶粉末、粉芯的制作和巨磁阻抗(GMI)效应的测试,经过抽象化处理,提出了解释Fe基纳米晶粉末GMI效应的理论模型——球介观模型。分析表明,影响Fe基纳米晶粉末磁阻抗的根本因素有:与纳米晶粒磁化场强度相关的D函数,决定D函数的因素为纳米晶粒的半径R,磁导率μ,电导率σ,外加直流磁场的大小Hex,外加交变磁场的角频率ω和幅值H0,而且μ,σ,ω,R之间又相互影响、相互竞争、相互制约。利用该模型成功地解释了外加直流磁场对Fe基纳米晶粉末磁阻抗频谱曲线的共振频率、共振幅值、灵敏度变化规律的影响。

Based on the producing and the measuring impedance of Fe73.5Cu1Nb3Si13.5B9 nanocrystalline powder, through abstraction, we propose a model （spherical mesoscopic structure model） exploring for the influence of the mesoscopic structure on the giant magneto-impedance（GMI） effect this kind of Fe-based nanocrystalline powder. Analysis shows that the GMI effect is closely related to the D- function, which is dependent on the following factors, such as μ （the effective magnetic permeability of the nanocrystalline grain）, σ （its the electrical conductivity）, R （its radius）, ω （the driving field frequency）, H0 （the driving field effective magnitude）, Hex （the external DC magnetic field magnitude）, and there exist mutual influences amongμ,σ,ω, R. With this model, we can succeed in exploring the influence of Hex on the resonance frequency, the resonance amplitude value, the sensitivity of the impedance curves of Fe73.5Cu1Nb3Si13.5B9 nanocrystalline powder.