CoPt patterned media in anodized aluminum oxide templates

Abstract

Patterned recording media consisting of a vertically aligned array of L10 phase CoPt nanowires embedded in a thin anodized aluminum oxide (AAO) template on silicon has been prepared. A sputter deposited thin film of aluminum on silicon was anodized and a CoPt magnetic alloy was electrodeposited into the pores of the AAO. The vertically aligned arrays of CoPt nanowires were about ∼100nm tall with ∼20nm average diameter. Since the CoPt nanowire array is laterally constrained by the surrounding AAO, the nanowire diameter is maintained without coarsening during the L10 phase conversion heat treatment at 700°C. After annealing and conversion to the L10 phase, the ∼20nm CoPt nanowires exhibit a large coercivity of ∼8kOe measured in the in-plane and perpendicular directions.