On the Magnetic After Effect due to the Irreversible Displacement of the Domain Boundary (IV)

Abstract

The magnetic after effect in 65-permalloy under various tensions was observed. In this case the reversal of magnetization occurs in several or a single Barkhausen jumps according to the amount of the applied tension. The value of dB⁄dH along the descending branch of the hysteresis curve has a very sharp maximum with comparatively narrow breadth. In the cases for small tension, magnetization in the course of after effect shows almost no change until the time t reaches a critical value t_c, and after t_c changes in the usual manner of the after effect. The value of t_c, decreases with decreasing final field. When the total reversal of magnetization occurs in a single Barkhausen jump, even a slight change in the magnetization can not be observed until t_c, and the whole reversal takes place in a very short time interval after t_c. These can be interpreted on the assumption that the after effect is closely related to the irreversible displacement of domain boundaries.