SPHERICAL CENTER FOR NUCLEATION BY CURLING IN A BULK FERROMAGNET

The process of nucleation of magnetization reversal in bulk materials by the magnetization curling mode is investigated by a numerical integ ration of an approximate differential equation. This computation shows that limiting the curling to a spherical shell does not lead to a sad dle point, and that the energy which has to be overcome for reversing the magnetization by the curling mode is larger than that required for the previous, tilting mode. Therefore, the latter is left as the only practical nucleation center in bulk materials.