Effect of interaction on the magnetization of single-domain particles

A model is proposed to permit the calculation of the remanence in a magnetic tape that is subject to various magnetizing processes. A combination of a regenerative local field and the Preisach diagram is proposed to account for particle interaction. It is shown that, although the Preisach diagram is not stable, its shape does not have to change as it moves, due to changes in the bulk magnetization I. In fact, the Preisach density function J(H+, H-) could be replaced by J(H+ + αI, H- -αI). The regenerative action is necessary to reduce the calculated spread of the distribution, which is many times the observed value. The best agreement between calculation and experiments is obtained by assuming that the fundamental magnetic particle is spherical, which is consistent with the "chain of spheres" model for interaction-free magnetization.