非晶态合金薄带与膜的巨磁电阻抗效应理论及计算

通过建立具有平面近横向各向异性场的非晶态合金薄带及膜的磁畴结构模型，利用线性化Maxwell方程组及Landau-Lifshitz方程，推出了在高频交变磁场及外加面内轴向直流磁场H_ex作用下的铁磁材料的与取向相关的磁导率表达式，得到了对方位角平均的相对磁导率及阻抗的计算式，导出了磁导率与张量磁化率分量间的关系，对材料磁导率的实部及虚部随H_ex的变化进行了计算，并给出了对应的磁谱图.建立的磁导率与外磁场的理论关系可将Panina及Kraus给出的理论结果统一起来. 关键词： 非晶态合金薄带及膜 取向相关磁导率 GMI效应理论与计算 近横向各向异性场

Theory and calculation of giant magneto-impedance effect in amorphous alloy ribbons and films

The detailed expressions of orientation-related relative permeability in amorphous alloy ribbons and films with in-plane nearly transverse uniaxial anisotropy under applied driving ac current flowing through the ferromagnetic materials and dc external magnetic field are derived by simultaneously solving the Maxwell's equations and the Landau-Lifshitz equation of motion and establishing the magnetic domain structure model. The calculation formula of mean relative permeability averaging over 90°orientation angle and the magneto-impedance are obtained. The relation between permeability and the component of tensor susceptibility is deduced. The dependences of the real part and imaginary part of the relative permeability on frequency at several values of the applied external field are calculated, and the corresponding magnetic permeability spectra are plotted. The calculation formula of permeability which were inferred by Panina et al and Kraus can be unified by our theoretical result which is in good agreement with the experimental data under lower external magnetic field for both amorphous ribbons and films.