ESTIMATION OF THE RADIUS OF THE INNER CORE AND THE ANGLE OF THE EASY AXIS OF ITS MAGNETIZATION FOR AS-PREPARED AMORPHOUS MAGNETOSTRICTIVE WIRE

This paper demonstrates the estimation of the domain structure of an as-prepared amorphous magnetostrictive wire (Fe77.5 Si7.5 B15, 125μm diameter). Through this investigation, it is clarified that the second harmonic component of the voltage induced in a pick-up coil wound about the wire is generated essentially from the inner core only, when a sufficiently small sinusoidal field is applied in the direction of the wire axis. Using this property, the angle of the easy axis of magnetization in the inner core is estimated. The radius of the inner core is also calculated from the estimated value. In the estimation, we assume that the angle of the easy axis is proportional to the distance from the center line of the wire. Based on this assumption, calculation of rectangularity and of the magnitude of pulse voltage are carried out. The validity of the estimation is confirmed by comparing the magnitude of the pulse voltage obtained when the estimated values are substituted into the expression for the pulse voltage with that measured by Sixtus-Tonks experiment. © 1990 IEEE