The magnetoimpedance effect in a stress-annealed Fe-rich amorphous microwire with induced magnetic anisotropy in a surface region is studied theoretically. The static magnetization distribution within the microwire is described in the framework of the core–shell magnetic structure. It is assumed that the microwire has an axial magnetic anisotropy in the inner core and a helical anisotropy in the external shell appearing due to the stress-annealing. Both the diagonal and off-diagonal magnetoimpedance responses are found in terms of the surface impedance tensor. The influence of the bias current on the magnetoimpedance is analyzed. The obtained theoretical dependences are shown to be in a qualitative agreement with the results of recent experimental studies of the magnetoimpedance effect in stress-annealed Fe-rich glass–coated amorphous microwires.

理论上研究了在应力退火后的富Fe非晶态微丝表面区域具有感应磁各向异性的磁阻效应。微线内的静态磁化强度分布在核-壳磁结构的框架中进行了描述。假定由于应力退火，微线在内核中具有轴向磁各向异性，而在外壳中具有螺旋各向异性。就表面阻抗张量而言，发现对角和非对角磁阻响应。分析了偏置电流对磁阻的影响。结果表明，所获得的理论依赖性与近期对应力退火，富铁的玻璃包覆非晶微丝中的磁阻效应的实验研究在质量上相吻合。