Preparation of a SiO2-covered amorphous CoFeSiB microwire and study on the current amplitude effect on the transverse giant magnetoimpedance

A SiO2-covered amorphous wire was prepared by the melt spinning technique for investigation of the current amplitude effect on the giant magnetoimpedance (GMI). The raw alloy (CoFeSiB) was placed in a SiO2 tube and heated by induced current (600 A) for 50 s, then the SiO2-covered amorphous wire was formed through external traction and cooling water. The current amplitude effects on the transverse GMI, giant magnetoresistance (GMR) and giant magnetoreactance (GMX) in the SiO2-covered amorphous CoFeSiB wire were studied thoroughly. It was observed that the transverse GMI ratio, GMR ratio, and GMX ratio all increase with decreasing the current amplitude, demonstrating the possibility of using them to design low-consumption, high-sensitive and muti-dimension magnetometer.