Characterization of Tunable Magnetic Sensor Using Bias Magnetic Field of a Hard Magnetic Film Magnetized by Pulsed-Magnetic Field

Abstract

A tunable MR sensor with variable sensitivity and measuring range is fabricated and characterized. The sensor has been fabricated using a combination of Ni-Fe soft magnetic film, Fe-Co-Sm hard magnetic film. The sensor is placed in a magnetizing coil for the process of magnetizing the hard magnetic film. The sensitivity and the measuring range of the sensor are tuned by bias magnetic field produced by the magnetic poles of the hard magnetic film. The sensitivity change was about 60 %, and the measuring range change was about 30 % in the tunable MR sensor from the experimental results. The bias magnetic field is controlled by changing amplitude of the pulsed magnetic field in the magnetizing for the hard magnetic film. The control power for one time tuning is about 18 Wh.Index Terms-Tunable magnetic sensor, variable sensitivity and measuring range, hard magnetic film, soft magnetic film, pulsed magnetic field magnetizing method.

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