Title :
Asymmetrical magneto-impedance effect in torsion-annealed Co-rich amorphous wire for MI micro magnetic sensor
Author :
Kawashima, K. ; Ogasawara, I. ; Ueno, S. ; Mohri, K.
Author_Institution :
R&D Center, UNITIKA Ltd., Kyoto, Japan
fDate :
9/1/1999 12:00:00 AM
Abstract :
An asymmetrical magneto-impedance (MI) effect in almost zero magnetostrictive amorphous wires is obtained using torsion annealing and then magnetizing with a high frequency current biased with a DC current. A highly sensitive MI characteristic showing a field detection sensitivity of more than 100%/Oe was realized in the wire annealed with 450 turn/m torsion at 500°C, inducing a spiral anisotropy. The change of the torsion direction from clockwise to anti-clockwise inverts the asymmetrical MI effect. A sensitive linear field sensor is successfully constructed using a pair of the asymmetrical MI heads without bias coils
Keywords :
amorphous magnetic materials; annealing; boron alloys; cobalt alloys; ferromagnetic materials; iron alloys; magnetic sensors; microsensors; silicon alloys; 500 C; Co-Fe-Si-B wires; Co-rich amorphous wire; CoFeSiB; asymmetrical magneto-impedance effect; field detection sensitivity; micro magnetic sensor; sensitive linear field sensor; spiral anisotropy; torsion annealing; Amorphous magnetic materials; Amorphous materials; Anisotropic magnetoresistance; Annealing; Frequency; Magnetic anisotropy; Magnetostriction; Perpendicular magnetic anisotropy; Spirals; Wires;
Journal_Title :
Magnetics, IEEE Transactions on