The study on the magnetic interaction between the duel magnetic layers and the FINEMET ribbon

Due to the sensitive magnetic field response of the GMI effect, the peak field in magneto impedance curves obtained from the composite magnetic ribbons shows great dependence on the magnetic interaction, which has gained intensive attention in the study of the diversity and the mechanism of magnetic interaction. In this work, FINEMET/Fe₂₀Ni₈₀/SiO₂/Fe₂₀Ni₈₀ composite ribbons with a fixed thickness of outer Fe₂₀Ni₈₀ layer (200 nm) and variable thickness ratio of the inner Fe₂₀Ni₈₀ and SiO₂ layers, ranging from the 1:4 to 4:1 were prepared. Then the GMI response was utilized to investigate the influence of the exchange couple and the dipole interaction to magnetic properties of the base ribbon. The experimental results indicated that additional SiO₂ layer can successfully induce slight magnetic differences of the two Fe₂₀Ni₈₀ layers, which results in the emergence of four-peak GMI profiles. Besides, the frequency-dependent nature of the peaks was explored, revealing that both dipole interaction and exchange couple influence the magnetic properties, contributing to the occurrence of four-peak GMI curves. Thus, the insights presented in this work are thought to be valuable for understanding the mechanisms of multilayer composite ribbons in future sensing applications.