Laminated magnetic film for micro magnetic flux concentrators

Abstract

The effect of a laminated structure on Conetic films made with sputtering deposition is investigated for application in micro magnetic flux concentrators. It is demonstrated that even with the total magnetic thickness being several micrometers, laminated magnetic films can exhibit significantly reduced coercivity and saturation field compared to single-layer films with the same total magnetic thickness. On the micrometer level, reduction of stress and magnetostriction should be the major reason for significantly improved softness of laminated Conetic films, while cross-layer magnetostatic coupling is also helpful. The improved softness is available not only at room temperature but also at low temperatures. Therefore, with laminated micro magnetic flux concentrators applied in magnetic sensors, the improved softness due to the laminated structure should yield improved reversibility and sensitivity of magnetic sensors at room temperature or low temperatures.