Multilayer magnetic antidot arrays from block copolymer templates

Abstract

Antidot arrays (films with periodic arrays of holes) with periodicity of 26 or 40 nm have been prepared from Co and CoCuNiFe films using a block copolymer templating method. The magnetic properties of the antidot arrays differ from those of continuous films. The holes raise the coercivity of single-layer Co films and in the multilayers lead to an antiparallel alignment of the moments in the Co and NiFe layers at remanence, as a result of the strong magnetostatic interactions between the layers. These results are confirmed by micromagnetic modeling and the trend in coercivity is explained in terms of the interactions between the nanoscale holes and the domain walls in the films. © 2008 American Institute of Physics.