To highly sensitively detect a minute magnetic field by measuring the deformation by use of a magnetic thin film.
This sensor has a magnetic thin film 1, a support means 2, a chip 4, a cantilever 5 for supporting the chip 4, a piezo element 6, an ammeter 7, and a power source 8. Magnetic anisotropy is imparted to the magnetization 3 of the magnetic thin film 1 so as to be turned in x-direction. The piezo element 6 is used so as to carry a tunnel current between the chip 4 and the magnetic thin film 1 in the state where the magnetic field is zero, and the distance between the chip 4 and the magnetic thin film 1 is controlled. When a magnetic field is generated in y-direction, the magnetization 3 is rotated to y-direction, and, according to it, the magnetic thin film 1 is curved by magnetostrictive effect. Therefore, the distance between the chip 4 and the magnetic thin film 1 is increased to reduce the tunnel current. Then, the tunnel current is monitored, whereby the presence of the magnetic field can be detected. Since the tunnel current is extremely sensitive to the distance between the chip 4 and the magnetic thin film 1, a highly precise magnetic field measurement can be performed.
KOIKE KAZUYUKI
FURUKAWA TAKASHI
TAKAHASHI TERUO
OGINOYA CHITSUMI
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