Optimizing the magnetic and giant magneto-impedance (GMI) properties of glass-coated amorphous Co-based wires via single- and two-step direct current annealing

Abstract

The effect of both single- and two-step direct current (DC) annealing procedures on the magnetic properties including giant magneto-impedance (GMI) of glass-coated Co66Fe6Si13B15 amorphous wires was evaluated. The GMI ratio initially increased with current intensity and reached a peak value before declining at higher current intensities for both methods. A maximum improvement of the GMI ratio by about 5 times was obtained for the two-step DC annealed sample, while that for single-step DC annealed samples was only 2.44 times. A higher GMI sensitivity is also observed for the two-step DC annealed wires. The better GMI performance for two-step DC annealed samples was attributed to the more homogeneously distributed precipitations in the matrix and ordered circumferential magnetic domains on the surface. The obtained result further implies that DC annealing with higher current intensity but shorter treatment time is a more efficient and energy-saving method to enhance the GMI performance for the Co-based amorphous wires with respect to potential industrial application.

Development and Application of a High-Precision Portable Digital Compass System for Improving Combined Navigation Performance

“…Measurements of the angle dependence of the response of thin-film structures, amorphous ribbon elements, composite wires consisting of a conductive base, and a magnetic covering (GMR or GMI effect) are documented in publications from German, Spanish, and Thai groups [ 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ]. The technology used in this article is to develop a digital compass system based on the TMR effect.…”