ABSTRACT
One possible system which could replace the current technology, involves the use of a single domain, ferromagnetic nanodot for each bit. These are then largely independent of each other. They consist either of pillars with easy axis of magnetisation perpendicular to the substrate, or elements with the easy axis in the plane of the substrate. Work has been conducted by Ross et al [1,2,3] using magnetic force microscopy (MFM) and superconducting quantum interference devices (SQUID) to characterise the magnetic properties of arrays of pillars fabricated using interference lithography or nanolithography with block copolymer templates. The magnetic properties have been shown to depend on size and shape, as one would expect. The work has shown that tall pillars, i.e. long axis perpendicular to the substrate show a stable magnetisation direction parallel to the pillar axis.
