Fabrication and magnetic characterization of permalloy antidot arrays

Ordered nanoscale permalloy antidot arrays with different sizes and lattice geometries have been prepared on top of nanoporous alumina membranes (NAMs) used as, templates and have been magnetically characterized. Two different NAMs with high order hexagonal symmetry have been used, i.e. NAMs with pore diameters ranging between 35 nm and 95 nm, but with a constant lattice parameter of 105 nm, and NAMs with pore diameter of 180 nm and a lattice parameter of 500 nm. In addition we have also prepared antidot array where the antidot size has been changed by varying the thickness of the permalloy thin film grown on top of the NAM template. The results show a significative increase of the coercivity as well as a reduction of the remanence of the antidot arrays, as compared with their parent continuous film, that depends on the size and on the density of holes introduced in the permalloy thin film. (C) 2008 WILEY-VCH verlag GmbH & Co. KGaA, Weinheim.