Korngrößenabhängigkeit der Ummagnetisierungsvorgänge im Reineisen

Abstract

Abstract The Barkhausen-Spectra of pure iron have been measured for four recrystallized wire specimens of different grain size. The pulse size distributions show a strong dependence on this parameter. The number of the Barkhausen-pulses increases with decreasing grain size. The comparison of the spectra measured at an external field in the vicinity of the coercive force with those measured at a field where domain rotation begins shows that in the latter region the size and number of jumps is larger. Measurements of the counting rate of the Barkhausen jumps versus the external magnetic field show two maxima instead of normally one at the coercive force. This unusual behaviour could be explained with the successive change of Bloch wall types in certain sections of the hysteresis loop and their different interaction with dislocations.