Title :
Magneto-impedance element
Author :
Mohri, K. ; Bushida, K. ; Noda, M. ; Yoshida, H. ; Panina, L.V. ; Uchiyama, T.
Author_Institution :
Dept. of Electr. Eng., Nagoya Univ., Japan
fDate :
7/1/1995 12:00:00 AM
Abstract :
The magneto-impedance (MI) effect is a phenomenon in which the voltage induced by a high frequency current source in a ferromagnetic wire changes with the application of an external field. A giant MI effect was found in amorphous magnetic wires having a composition of (Fe 0.06Co0.94)72.5Si12.5B 15 and a magnetostriction of (-10-7). The amplitude of the wire voltage decreased by 40% at 1 MHz, 60% (600 kHz) and 50% (150 kHz), for wires having diameters 30 μm, 50 μm and 124 μm, respectively, under the influence of an external longitudinal field of about 10 Oe (800 A/m). A highly sensitive and quick-response field sensor was constructed using a 200 MHz resonant multivibrator bridge-circuit combining two MI-effect elements of 1 mm length with two field effect transistors (FET). Highly sensitive flux detection was carried out by using the small MI sensor head on a rotary encoder magnet having 512 poles and a diameter of 30 mm. Discussion of a mechanism for the MI effect considers the skin effect in an amorphous wire with high circumferential anisotropy
Keywords :
amorphous magnetic materials; boron alloys; bridge circuits; cobalt alloys; ferromagnetic materials; iron alloys; magnetic flux; magnetic hysteresis; magnetic sensors; magnetoelectric effects; magnetoresistive devices; magnetostriction; multivibrators; silicon alloys; skin effect; (Fe0.06Co0.94)72.5Si12.5 B15; 150 kHz to 1 MHz; 200 MHz; 30 to 124 mum; amorphous magnetic wires; external longitudinal field; ferromagnetic wire; field effect transistors; giant MI effect; high circumferential anisotropy; highly sensitive flux detection; hysteresis loops; magneto-impedance effect; magnetostriction; quick-response field sensor; resonant multivibrator bridge-circuit; rotary encoder magnet; skin effect; wire diameter; wire voltage amplitude; Amorphous magnetic materials; Amorphous materials; FETs; Magnetic anisotropy; Magnetic flux; Magnetic sensors; Magnetostriction; Perpendicular magnetic anisotropy; Voltage; Wire;
Journal_Title :
Magnetics, IEEE Transactions on
