Magnetization State and Magnetic Structure of Wiegand Wire Evaluated by External Magnetic Field Measurement

We analyzed the magnetization state and magnetic structure in Wiegand wire by measuring a magnetic field from the wire. The Wiegand wire exhibits a unique fast magnetization reversal feature in an externally applied alternating magnetic field. The mechanism and magnetization states that yield a large Barkhausen jump have not been sufficiently elucidated. We defined a three-layer magnetic structure of the Wiegand wire, as well as analyzed the magnetization state and magnetization process of these layers in the applied alternating magnetic field. We determined a switching field of each layer and specified the magnetization states that resulted in the large Barkhausen jump.

I. Introduction

WIEGAND wires have been recognized as having a bistable magnetization state [1]. Owing to this magnetic structure, the wire exhibits a fast magnetization reversal, called a large Barkhausen jump. The unique performance of the Wiegand wire generates a pulse voltage in the pickup coil wound around the wire. Recently, Wiegand wires have been used in self-powered rotary encoders [2], and various circuits and applications have been studied [3] - [5].