Clusters of interacting single domain Co nanomagnets for multistate perpendicular magnetic media applications

In this work we develop prototype elements for multistate (beyond binary) perpendicular data storage using interacting nanomagnet clusters. This experimental work confirms earlier theoretical work that predicted multiple discrete values of stable remanent magnetization for such clusters. The fabrication scheme is based on ultrahigh resolution electron beam lithography performed on a thin suspended silicon nitride membrane to reduce the secondary backscattered electrons from the substrate. A Co nanomagnet cluster array is deposited into the nanotemplate via pulse-reverse electrodeposition to create nanomagnets with the favored uniaxial perpendicular anisotropy. Magnetic force microscopy (MFM) measurements show the perpendicular magnetization of individual Co nanomagnets and the combined multiconfiguration behavior of a nanomagnet cluster. In concept, the discrete values of net remanent magnetization of the cluster, which represent distinct information states, can be programmed by a uniform applied field. (c) 2008 American Institute of Physics.