Large Barkhausen Effect and Matteucci Effect of Amorphous Magnetostrictive Wires

Abstract

Amorphous magnetostrictive wires manufactured by UNITIKA Co. induce sharp and stable voltage pulses against ac fields of more than 0.1 Oe at the frequencies 0.01 Hz-10 kHz, and are suitable for application to pulse generator elements for rotary encoders and magnetic-type security sensors. In this paper, the sensitive, highly stable large Barkhausen effect and Matteucci effect in these amorphous wires are analyzed using a domain-wall propagation model. Theoretical values are compared with the experimental results for the voltage pulse generation characteristics at the pick-up windings and between both ends of the amorphous wires. Effects of applications of tensile and torsional stresses and annealing on these pulse generations are also investigated. The Matteucci voltage increased about to 20 times and about to 6 times due to twisting and annealing under twisting, respectively.