Magnetoimpedance effect of nanocrystalline FeNiSiB and FeCuVSiB ribbons

Abstract

The magnetoimpedance (MI) effect of Fe-based nanostructured alloy ribbons Fe72Ni8Si10B10 (А) and Fe72Cu1V4Si15B8 (B) was studied, compared for the two ribbons, and finally correlated with their composition and microstructure. The nanostructured ribbons were prepared by melt-spinning on a cold rotating disk. Basic characterization of the studied ribbons was performed by XRD and SEM-EDX techniques. It was found that the MI ratio of ribbon A is significantly lower than that of ribbon B, but the effects were observed at different frequencies. The maximal MI ratio of ribbon A was detected at 57.57 MHz, while in the case of ribbon B, that was the frequency of about 13 MHz. The structure of both ribbons consists of a certain amount of nanocrystals, α-(Fe, Ni) for the ribbon A and α-Fe(Si) for the ribbon B, which are embedded in an amorphous matrix. The MI effect and the frequency of its maximum are determined by the mobility of the magnetic domains in the samples, which is correlated with the microstructural specificities of individual ribbons.