Effect of Ni content on the crystallization, soft magnetic properties and GMI effect in amorphous Co68Fe7−xNixSi15B10 (x = 0, 1.5, 3, 4.5) ribbons

Soft ferromagnetic amorphous ribbons are widely used for a wide range of applications, including high-frequency transformers and magnetic sensors . The recent discovery of a so-called giant magnetoimpedance (GMI) effect in these alloys has made them very attractive candidates for making highly sensitive magnetic sensors. GMI effects have been reported in Co-based amorphous ribbons owing to the high transverse permeability, due to the presence of a transversely oriented domain configuration. Like Co-based amorphous wires, ribbons with CoFeSiB composition and nearly zero but negative magnetostriction, were found to show the largest GMI ratio among Co-based ribbons. The GMI ratio reached a value as high as 160% at a frequency of 1 MHz in the (Co_1-xFe_x)₇₀Si₁₂B₁₈ (x = 0 .057) amorphous ribbon with nearly zero magnetostriction . The research on GMI effect sensors is now focused on the material composition and structure of sensitive components. In this presentation, we attempt to improve the GMI ratio of amorphous Co₆₈Fe₇Si₁₅B₁₀ alloy ribbons by introducing Ni element .