Micromagnetic Calculation of Magnetization in MR Sensor with Sense Current Distribution

抄録

  A three-dimensional micromagnetic simulation employing the Landau-Lifshitz-Gilbert equation is performed for an unshielded magnetoresistive (MR) sensor with a soft adjacent layer (SAL). The influence of a non-uniform sense current distribution on the MR response to a cycle of a transverse external field is studied. The field distribution due to the non-uniform sense current distribution is calculated in three dimensions from the Maxwell equation and adopted to the MR sensor simulation. The MR response of the sensor with electrodes on the MR film (type 1) is compared to that with electrodes on the SAL (type2). The maximum output of the type1 sensor is larger than that of the type 2 sensor. The magnetization in the MR film and SAL of the type 2 sensor tilts more from the longitudinal direction than that of the type 1 sensor without the transverse external field (biasing state). This results from the difference in field distributions between the SALs of the two sensors due to the non-uniform sense current distribution.