Self-assembled ferrite nanodots on multifunctional Au nanoparticles

Abstract

The fabrication of magnetic oxide nanodots was studied without the use of conventional lithographic techniques and patterning masks. Self-assembled Au nanoparticles with an average size of approximately 17 nm were formed via simple sputtering and used as the underlayer for the magnetic oxide film. Subsequently, hexagonal ferrite, SrFe12O19, was sputtered on the Au nanoparticles, resulting in an SrFe12O19/Au sample. Self-assembled SrFe12O19 nanodots were obtained with an average size of 40-50 nm. The morphology of the Au nanoparticle underlayer acted as a template for the SrFe12O19 film, such that the self-assembled SrFe12O19 nanodots were formed. In addition, the fabrication of the SrFe12O19 film on the Au nanoparticles induced the down-sizing of the magnetic domain structures of SrFe12O19 to the nanoscale. Importantly, although the nanodots showed nanometric magnetic domains, a sufficient magnetization magnitude in the SrFe12O19 nanodots was revealed. Furthermore, the SrFe12O19 nanodot fabrication area was ∼8.5 cm2, thereby the current technique can be applied to the development of future functional magnetic nanodots. © 2013 The Author(s).