National Synchrotron Light Source Seminar

In view of increasing demands for new material with advanced physical properties, which should provide further progress in development of e.g. nano-electronic devices, novel magnetic nanostructures with well controllable parameters are highly requested. On the other hand, magnetic nanostructures are also of interest for fundamental science because they often reveal new physical phenomena having no analogies in bulk materials. We examined possibility to use field- and surface-induced ordering of ferrofluids [1] for production of thin magnetic heterostructures consisting of single-domain nano-units periodically embedded into non-magnetic matrix. Particularly we studied ordering of ferrofluid at the bottom interface with a solid substrate [2], at the top interface with gas [3] and ordering of magnetic nanoparticles in the Langmuir layers. From simultaneous treatment of reflectivity and grazing incidence diffraction data we found that interfacial structures of bulk ferrofluids are essentially inhomogeneous, depend on the liquid carrier and type of the surfactant and can be manipulated by the external magnetic fields. Langmuir technique is described as the most straightforward way to create desired mono- or multilayered systems of laterally ordered magnetic nanoparticles on solid substrates. 1. R. E. Rosensweig, Ferrohydrodynamics (Cambridge University Press, Cambridge, England, 1985). 2. A. Vorobiev, J. Major, H. Dosch, G. Gordeev, and D. Orlova, Phys. Rev. Lett. 93, 267203 (2004). 3. A. Vorobiev, G. Gordeev, O. Konovalov, and D. Orlova, Phys. Rev. E. 79, 031403 (2009).