Magnetic domain formation in perforated permalloy films

The magnetization behavior of permalloy films containing a square array of holes has been studied using magnetometry, magneto-optical imaging, and mag netic force microscopy. Two types of domain boundaries are observed. The ho le array induces a strongly pinned, complex domain structure on the microsc opic level (i.e., within one unit cell of the hole array). We show that mag netization reversal occurs through the nucleation and motion of a domain wa ll that separates areas of oppositely polarized microscopic domain patterns . These walls display highly mobile kinks that induce the reversal of the m icroscopic patterns. The interplay between intrinsic anisotropy and pinning by the hole array induces a pronounced anisotropy in the domain patterns a nd switching mechanism. (C) 2001 American Institute of Physics.