Nano dots for high density magnetic storage materials
Recent developments of nanometre-size structures such as nano dots have demonstrated their potential for major advantages over the use of traditional materials. Although technological challenges still present, nanoscale structures are increasingly the focus of novel materials development and computational approaches used to explore their unique properties. The 'Bridging atomistic to continuum - multiscale investigation of self-assembling magnetic dots during Epitaxil growth' (Magdot) project sought to examine the self-assembly of magnetic nano dots and the importance of materials governing this phenomenon. The study employed an integrated approach spanning the range from atomistic to continuum scales, with a view to developing models enabling the first-principle design of novel super-high density magnetic storage materials. On the strength of successes in the field of electronic and optoelectronic applications, Magdot proposed to computationally study the nanoscale self-assembly of magnetic dots during heteroepitaxy. This is a method used to deposit a monocrystalline film on a monocrystalline substrate (epitaxy) using materials that are different to each other. Understanding of dot formation enhanced through computational approaches and experimental validation can advance the development of processing methods that yield regular arrays of magnetic nano dots. This is important for the next generation of magnetic storage materials. Being able to store one bit of information on a single nano-sized island can drastically increase storage density by as much as a factor of 100 over traditional thin-film magnetic media. However, to develop such materials a regular pattern of nano-sized magnetic dots is required. To this end, project partners made from-scratch calculations of various factors such as surface energies, surface stress, and of the evolution of nanostructural morphology and composition during the process leading to self-assembly. Magdot activities looked to uncover how the interplay between kinetic and thermodynamic effects results in nanostructure formation and what factors control spatial and size distributions. Successes in these still enigmatic areas can facilitate the development of integrated computational models needed to produce large-scale self-organised arrays of magnetic dots.
