Sensitivity of a Fluxgate Sensor Using Magnetic-Domain-Controlled Amorphous Core

Previously, we reported that the output of a fluxgate sensor depends on the magnetic domain structure of the core materials [1]. Therefore, to ensure low noise and high sensitivity of the sensor, the domain change applying the AC magnetic field must be repeatable. In this study, the jitter noise was reduced by cutting an amorphous ribbon at its edge prior to annealing. The resulting domain structure of the amorphous core was observed by using a Kerr microscope. The relationship between the noise in the fluxgate sensors and the repeatability of the domain change was examined.