Effect of temperature on magnetic properties and magnetoimpedance effect in Fe-rich microwires

Herein, the temperature dependence of hysteresis loops and the Giant magnetoimpedance, GMI, effect of amorphous as-prepared and stress-annealed FeSiBC microwires have been thoroughly analyzed. We ob- served a remarkable improvement of GMI ratio and modification of hysteresis loops from rectangular to inclined with increase in temperature for as-prepared FeSiBC microwires. Observed changes have almost completely reversible character. On the other hand, rather different behavior is observed in stress-annealed FeSiBC microwires: a substantial GMI ratio improvement is observed in stress-annealed FeSiBC microwires. However, a decrease in GMI effect is observed with temperature increasing. Observed experimental results are discussed considering relaxation of internal stresses upon heating, Hopkinson effect and modification of the thermal expansion coefficients upon heating.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The temperature dependence of hysteresis loops and Giant magnetoimpedance (GMI) effect in amorphous FeSiBC microwires were studied. As-prepared microwires showed an improvement in GMI ratio and a modification in hysteresis loops with increasing temperature. The changes observed were almost completely reversible. In contrast, stress-annealed microwires exhibited a substantial improvement in GMI ratio, but a decrease in GMI effect with increasing temperature. The observed results were discussed in terms of relaxation of internal stresses, Hopkinson effect, and modification of thermal expansion coefficients.