Design of GMI micro-magnetic sensor based on co-based amorphous alloys for space applications

Giant magneto-impedance (GMI) magnetic sensors have great potential to be next generation of magnetic sensors for space applications. This article concerns the design of a GMI micro-magnetic sensor based on amorphous alloys using the theory of GMI effect, which covers sensing materials, construction of sensor, working principle and signal detection method. Co-based amorphous ribbons are selected as the preferred sensing elements since they have good soft magnetic properties, such as high saturated magnetization, low coercivity, high magnetic permeability and excellent mechanical properties. Co-based amorphous ribbons of 20 ∼ 60 μn thick and 1 ∼ 3mm wide are fabricated and their magnetic properties, mechanical properties and GMI effects are studied for their applications as GMI sensing elements. Sensor output can be acquired by utilizing phase-sensitive detection method with higher noise suppression. This work provides a preliminary investigation into the high performance of a micro-magnetic sensor for space applications.