Behavior of domain structure in a Co/Ag superlattice with dispersion of magnetic anisotropy

It is found that the magnetization reversal of an array of superthin Co fil ms coupled by the ferromagnetic exchange interaction through the Ag layers may result in a domain structure of an unexpected new type. Due to the inco herent different-sense spin rotation upon lowering the field perpendicular to the easy axis, the specific macrodomains first form in a sample. They ar e separated not by the Neel domain wall but by a wide transition region con taining high-density microdomains of sizes correlating with the grain sizes in the films. Further magnetization reversal proceeds through the formatio n of standard domain walls in the macrodomain in a magnetostatic field at t he plate edge and through their shifting toward the transition region. Thes e processes are explained with taking into account the character of the rev ealed magnetic anisotropy dispersion. (C) 2000 MAIK "Nauka/Interperiodica".