Experimental study of bloch wall bowing anomaly due to wall surface pinning

An experimental study of Bloch wall bowing has been performed on a (110) [001] monocrystalline lamination of Fe-Si 3%. An instability related to an abrupt change of wall tilting with respect to the plane normal to the lamination surface at each inversion of the wall displacement direction has been evidenced, showing that the mechanism of tilting variation is different from the ruckling effect predicted by the theory developed by Bishop1. Results concerning the amplitude and phase behaviour of the surface wall displacement with respect to the bulk one are also reported. Surface pinning of the wall and surface Barkhausen noise are probably at the origin of these discrepancies.