The effect of magnetoelastic interaction on the GMI behaviour of Fe-, Co- and Co–Fe-based amorphous wires

The giant magnetoimpedance is the sensitive change in ac impedance value with the application of dc magnetic field when ac current passes through the sample. In the present work GMI properties of positive (Fe77.5Si7.5B15), negative (Co72.5Si12.5B15) and nearly zero ((Co94Fe6)72.5Si12.5B15) magnetostrictive amorphous wires have been studied. The result indicates that the magnetostriction constant plays an important role in GMI property. The maximum GMI ratio (330%) and maximum field sensitivity (7% per A/m) are observed in (Co94Fe6)72.5Si12.5B15 amorphous wire. The frequency response of the GMI characteristics of the above alloys has been measured and zero magnetostrictive (Co94Fe6)72.5Si12.5B15 material showed better frequency response.