Magnetic interactions and magnetoimpedance effect in FINEMET/SiO2/FePt composite ribbons

Giant Magnetoimpedance (GMI) is attracting attention for its high sensitivity in the presence of an applied magnetic field. Although the GMI effect has been studied for many years, it is difficult to analyze the magnetic interactions between coating layer and ribbon by hysteresis loops for composite ribbons with a large difference in thickness between the soft magnetic alloy and film. Therefore, the magnetic interactions of FINEMET ribbon coated with different thicknesses of SiO2 and FePt films on the free side were thoroughly analyzed by GMI. The dipolar interactions decrease with the increase of thickness of SiO2 layer. The GMI ratio of FINEMET/SiO2/FePt composite ribbons reaches 57