Magnetic patterns in dipolar films with close packed structures

It is described and explained the dynamics of the transition from in-plane to perpendicular magnetization for dipolar films with close packed structures when the c/a ratio, with c the interlayer separation and a the two-dimensional lattice constant, is varied. Several arrangements of distinct number of stacked layers are considered. Magnetization switching follows a mechanism based on the role of the interlayer coupling, which is understood as the contribution of the interaction between dipoles of different layers to the studied effects. Calculations for sufficiently low temperatures show that each magnetic configuration transition leaves a fingerprint as an entropy maximum when the latter is plotted as a function of c/a. Thus the entropy allows to determine the c/a range of stability of the different magnetic patterns.