MAGNETO-INDUCTIVE EFFECT IN TENSION-ANNEALED AMORPHOUS WIRES AND MI SENSORS

Small sized and sensitive M I elements are presented using cold drawn and then tension-annealed zero-magnetostrictive amorphous wires having a 50 gn diameter and a 2 mn length. An amplitude of an inductive voltage induced between both ends of the wire which is circumferentially magnetized with a wire ac current decreased about 80 % against an external dc field of about 200 A/m. While, the voltage amplitude increased from almost zero value for an external dc field when a rectified or dc-biased ac field is applied to the wire. New MI effect is also presented. That is, an amplitude of a double frequency voltage induced between both ends of a folded amorphous wire due to magnetizing with a circumferential flux in a adjacent amorphous wire increased about ten times for a perpendicularly applied external dc field.