Magnetic Films on Nanoparticle Arrays

Abstract

Novel properties originating from the combination of magnetism with the reduced dimensionality of nanoobjects are of considerable interest for fundamental science but are also readily used in a wide range of technological applications. To fulfill the demand for larger capacities of storage systems, complex magnetic heterostructures of a nanometer size are envisioned as future magnetic storage media. Here we review recent advances on a novel gradient nanomaterial fabricated by deposition of magnetic thin films onto self-assembled arrays of nonmagnetic spherical particles, resulting in arrays of magnetic caps. Due to the curvature of the particle's surface, magnetic and structural properties of the magnetic thin films differ substantially from their planar counterparts with respect to the equilibrium magnetic domain pattern as well as magnetization reversal behavior. It will be shown that varying the size of the particles as well as the thickness of the deposited layers, the magnetostatic and exchange coupling between the neighboring caps can be systematically modified, providing direct access to the change of fundamental magnetic interactions at the nanoscale. Furthermore, these magnetic cap structures were employed to realize so called bit patterned magnetic media, which is one of the most promising concepts in magnetic data storage to provide areal densities beyond 1 Tbit/inch 2 . In this respect, important aspects regarding the potential application of the magnetic cap structures in magnetic data storage will be addressed.