The magnetization-reversal process within a [100] [010] [001] picture-frame FeSi (3.5 wt% Si) crystal has been investigated by means of the time-dependent neutron-depolarization technique, applying a periodic block-shaped magnetic field. Various distinct states are observed in the magnetization-reversal process: firstly, nucleation of regions of reversed magnetization; subsequently, the merging of these regions into two wavy domain walls according to a sandwich structure and the motion of these straightening walls towards the center.

• Received 23 June 1978

DOI:https://doi.org/10.1103/PhysRevLett.41.767