Bottom-up fabrication of periodic magnetic nanostructures based on ion-induced spontaneous surface nanopatterning

Large-area nanopatterning is a key requirement in diverse applications ranging from photovoltaics to computing and biomolecule detection. We present a simple and scalable bottom-up nanopatterning approach based on ion irradiation of semiconductor surfaces and wellestablished thin film deposition techniques: On crystalline semiconductor substrates, nanoscale surface patterns with well-defined lateral periodicity form via the mechanism of reverse epitaxy, i.e. the nonequilibrium self-assembly of vacancies and ad-atoms under ion irradiation [1]. The nanopatterned surfaces can for instance be employed as substrates for MBE under grazing incidence, producing periodic metal nanostructures by geometrical shading. They can also be the basis for metal nanostructure growth in a variety of pattern morphologies by hierarchical self-assembly [2]. In this contribution, we outline the reverse epitaxy mechanism and present examples of periodic magnetic nanostructures based on the resulting surface patterns. We hope to stimulate discussion of further applications in magnetism by emphasizing the simplicity and versatility of this bottom-up approach.
[1] Ou et al., Nanoscale 7 (2015); [2] Erb et al., Science Advances 1 (2015)