Simulation of Giant Magnetic Impedance (GMI) Effect in Co-based Amorphous Ribbons with Demagnetizing Field

Abstract

Considering the role of demagnetizing field, based on linear Maxwell’s equations and the Landau-Lifshitz equation, the expressions of permeability and impedance were obtained using the improved theoretical model in this article. A numerical simulation was conducted using Matlab, and the results of calculations were well matched with the experimental results, indicating the importance of the demagnetizing field and that it should not be ignored. Utilizing the equivalence relation between the shape of the samples and the demagnetization factor which determined the value of the demagnetizing field, the influence of the aspect ratio of the samples on giant magnetic impedance (GMI) effect was researched. The calculations showed that the most significant GMI effect was obtained when the aspect ratio of samples was about 44. In addition, the optimal frequency to obtain the most significant GMI effect of the given sample was calculated. These researches may provide theoretical guidance for the development and use of a GMI sensor.