ON THE COUPLING BETWEEN THE DOMAIN-WALL COERCIVITY AND SUSCEPTIBILITY

The experimental value of the domain wall coercive field does not depe nd on magnetic parameters and material defects only, but it is also st rongly influenced by the current domain configuration in the sample. T he investigation of the global conditions of the domain walls (the wal l position restoring forces expressed through the effective field grad ients and/or the domain structure differential susceptibility) is the proper key to the description of this influence. As far as it is possi ble to introduce domain structures with different values of susceptibi lity into the same sample (e.g. by conditioning the sample history or by currently applied fields), that far the actual domain wall coercive field value can be modified. Based on a previously published theory a nd in agreement with the presented experiments in epitaxial magnetic g arnet films, a roughly linear proportionality is exhibited between the domain wall coercive field and the reciprocal value of the sample dom ain structure susceptibility. The way of a magnetostatic control of th e domain wall coercive field and hysteresis losses in soft magnetic ma terials is suggested and tested.