Wire-length effect on GMI in Co70.3Fe3.7B10Si13Cr3 amorphous glass-coated microwires

The sample length dependence of giant magnetoimpedance (GMI) in Co70.3Fe3.7B10Si13Cr3 amorphous glass-coated microwires has been studied experimentally and theoretically in the frequency range of 1–10 MHz. It has been shown that there exists a critical microwire length, below which the GMI effect is favored in shorter microwires and above which longer microwires possess a more sensitive dependence of the real component of the impedance to the frequency variation. It is demonstrated that once the resistance of the microwires of varied length is determined, it is possible to evaluate the change in GMI profiles with respect to the change of wire length. The simplified skin-effect model has been found to well explain the observed behaviors.