Barkhausen noise emission in soft magnetic ribbons heat treated in an external magnetic field

Abstract

This paper deals with Barkhausen noise emission in the soft magnetic ribbon produced by planar flow casting and subsequent heat treatment in an external magnetic field. Barkhausen noise measurements were carried out in the direction of the domain wall alignment as well as in the perpendicular direction. Barkhausen noise bursts exhibit three separate regions in all cases. The first region is associated with the nucleation and growth of reversed domains, whereas the strongest pulses can be detected in the second region in which the 180° domain wall motion plays the major role. The last region is associated with the annihilation of reversed domains. Hysteresis loops extracted from the Barkhausen noise also exhibit three separate avalanches. The first and third regions produce a high number of weaker pulses in contrast to the second region, which emits a lower number of very strong pulses.