Impact of stress-induced anisotropic modifications on magneto-impedance behavior of rapidly quenched CoFe-based microwires

Abstract

The investigation addresses the role of Al in the devitrification stage of a series of (Co94Fe6)72.5Si12.5-xAlxB13Cr2 (X = 0, 2, 4, 6 at%) rapidly quenched microwires. The incorporation of Al displayed a reduction in primary onset and activation energy (A.E) while it facilitated the widening of the span between primary and secondary crystallization onsets. The Giant Magneto-Impedance (GMI) behavior was influenced by Al concentration as well as applied uniaxial stress. Optimal Al-containing alloy (x & SIM; 2 at%) displayed the signature of the asymmetric dual peak at the operating frequency of 1 MHz and its prospective application as a very low magnetic field sensor in pre-stressed conditions. However, with increasing stress, the asymmetric character transformed to the symmetric dual peak which is attributed to the transition of transverse anisotropy to circular anisotropy via helical anisotropy. High-stress sensitivity has been attributed to either dominant transverse or circular anisotropy. The transition of stress-induced anisotropies in microwires has been portrayed schematically to elucidate the transitions. & COPY; 2023 Elsevier B.V. All rights reserved.