Fabrication and characterization of nanostructured magnetic particles for applications in data storage

Abstract

Arrays of nanostructured magnetic particles ('nanomagnets') have potential applications in ultra-high-density data storage devices and dynamic magnetic memories, and are model systems for the study of magnetic phenomena at deep sub-micron length scales. We use interference lithography to pattern 200 nm-period arrays of nickel and cobalt nanomagnets. The nickel and cobalt are deposited via electroplating or evaporation/lift-off processes. Magnetometry techniques are used to characterize the bulk magnetic behavior of the arrays. Magnetic force microscopy is used to image the stray magnetic fields of individual nanomagnets as well as to measure particle switching fields. We compare our experimental results to predictions based on micromagnetic models and models of magnetostatic interactions. In particular, the influence of shape, size, inter-particle spacing and material properties on the remanence state of nanomagnets is evaluated. Finally, we examine the suitability of the fabricated nanomagnet arrays for applications in magnetic data storage.