Amorphous CoFeCrSiB ribbons for strain sensing applications

Abstract Magnetoelastic properties of amorphous Co 71− x Fe x Cr 7 Si 8 B 14 ribbons, with 2⩽ x ⩽12, were investigated. The magnetostriction constant λ s changes linearly from −0.8×10 −6 to +4.0×10 −6 with increasing x . Stress-annealing at 350°C induces an easy plane magnetic anisotropy perpendicular to the ribbon axis. Magnetization reversal takes place by the moment rotation and the magnetizing curves are linear up to the anisotropy field, which is proportional to the stress applied during annealing. Simple strain sensors based on these materials show practically constant sensitivity nearly up to the mechanical strength of the ribbon and acceptable reproducibility of measurements.