Sensitivity enhancement of longitudinally driven giant magnetoimpedance magnetic sensor using magnetoelastic resonance

The enhancement of longitudinally driven giant magnetoimpedance (LDGMI) effect in FeCuNbSiB ribbons was investigated utilizing magnetoelastic resonance. A maximum LDGMI ratio of the order of 10,000% was obtained for the ribbon annealed at 480 °C under optimum driving current frequency and driving current intensity. The dependences of enhancement magnitude on magnetoelastic coupling coefficient k33 and quality factor Q were analyzed in detail. It was found that high k33 and Q were favorable to enhance giant magnetoimpedance effect. The complex permeability of ribbon core was calculated, and the relationship between them and LDGMI enhancement behavior was also discussed. Additionally, a simple magnetic sensor based on this effect was developed. Its output sensitivity and stability were studied as well.