Linear Anisotropic Magnetoresistive Sensor Without Barber-Pole Electrodes

Abstract

Traditional anisotropic magnetoresistive (AMR) sensors used barber-pole electrodes to rotate the current direction by 45° in order to obtain a linear electrical response. However, the adoption of barber-pole electrodes reduced the working area of the sensor. Moreover, the traditional AMR sensors need large-flipping stripes or permanent magnets for stabilization of the magnetization. Here, we report the AMR sensor using an antiferromagnetic layer to regulate the magnetization-current angle. The proposed sensor, without consuming extra area and power, could fully use the magnetoresistive area, and the stabilized magnetization could help in suppressing magnetic noise, enhancing stability, and improving linearity. The presented sensor has a stable response with a disturbing field of −1.5 T, while the commercial sensors need to be reset after being exposed to a small disturbing field of 5 Oe.