The effect of SiO2 interlayer on magnetic interactions in multilayer composites ribbons

Abstract

This article studies the influence of dipole interactions on the magnetic properties. Specifically, FINEMET/SiO2 and FINEMET/SiO2/Fe20Ni80 composite ribbons were prepared by magnetron sputtering. During the manufacturing process, the Fe20Ni80 film with a fixed thickness of 260 nm and the FINEMET ribbon were separated by the SiO2 layer, and the SiO2 layer thickness could be adjusted within a range of 0–150 nm. This configuration enabled the exchange coupling gradually reduced with the SiO2 layer thickness increased, allowing dipole interactions to become the dominant factor. This study not only excludes the influence of the SiO2 in the composite ribbons but analyzes the effect of the exchange couple and dipole interactions for the GMI, respectively. The experimental results show the GMI ratio decreases initially and then increases with the thickness of SiO2, where the optimization of GMI ratio was explored in FINEMET/Fe20Ni80 ribbons. On the other hand, the minimum peak field was shown with the SiO2 thickness of 5 nm. Furthermore, the results also elucidate that both dipole interactions and exchange couple have affected the peak field of GMI, which could be used for the design of multilayer composite ribbons with better performance. Thus, the analysis we showed in this work is thought to be valuable in revealing the mechanism of multilayer composite ribbons for future sensing applications.