Thin Film Magneto-Impedance Sensor Integrated Into ${\rm L}1_{0}$ FePt Thin Film Bias Magnet

A linear magneto-impedance (MI) sensor integrated into a FePt thin film bias magnet which has in-plane isotropic magnetic property was investigated. The maximal bias field of 13.1 Oe was obtained after magnetizing a 1.3-mum thick FePt film in longitudinal direction of the sensor element. The bias field changed with the magnetizing angle. By controlling the angle in the magnetizing direction of the bias magnet and sensing direction, it was shown to be able to adjust the effective bias field after fabrication of the sensor element.