High-Sensitivity GMR Sensor Using Domain-Wall Oscillation

S. Nakashima, S. Arai, T. Kato, S. Iwata, S. Tsunashima
2010 Journal of the Magnetics Society of Japan  
The high sensitivity detection of magnetic fields was demonstrated using the oscillatory domain-wall displacing method for a GMR sensor. A micro-wire with a width of 30 µm and a length of 200 µm of a spin valve film, Al(20 nm)/MnIr(20 nm)/CoFe(3 nm)/Cu(2.2 nm)/CoFeB(10 nm), was fabricated as a magnetic sensor device. The domain walls in the free layer, whose easy axis was perpendicular to the wire, were oscillatorily displaced by an alternating magnetic field produced by a current with 140 kHz
more » ... hrough the micro-wire. The oscillatory wall displacement reduced the influence of wall coercivity and the linear relationship between the external field with 1 kHz and an output signal for the sensor circuit was obtained down to 10 -3 Oe.
doi:10.3379/msjmag.1002r0006 fatcat:nzc4fsgr6bdy7gef3qk7fmaety