Hysteresis-loop overskewing in the light of a novel nucleation mode

It is demonstrated that the magnetostatic demagnetizing factor is not the o nly sample-shape dependent contribution to the hysteresis loop. There are a lso exchange contributions, which lead to interesting effects, particularly in nanostructures. An example is the recently discovered bulging mode in t wo-phase nanomagnets. The bulging mode exhibits the angular symmetry of the coherent mode, but it is incoherent due to its radial variation and gives rise to negative demagnetizing factors. (C) 2000 American Institute of Phys ics. [S0021-8979(00)74908-5].