Micromagnetism of dense permalloy antidot lattices from anodic alumina templates

Hexagonally ordered Py antidot arrays were prepared by sputtering onto anodic alumina membrane templates, with varying antidot diameter and lattice constant parameter. Experimental magnetic characterization together with micromagnetic simulations was performed to unveil the coercivity mechanism. Experimental measurements show that coercivity monotonically increases with the antidot diameter in reasonable agreement with simulations. This is understood considering the presence of geometrical micrometric domains with perfect hexagonal order. Contrarily, simulations for a single crystal sample predict that the coercivity should decrease with the antidots diameter