Template-assisted colloidal self-assembly of macroscopic magnetic metasurfaces


We demonstrate a template-assisted colloidal self-assembly approach for magnetic metasurfaces on macroscopic areas. The choice of anisotropic colloidal particle geometry, assembly pattern and metallic film is based on rational design criteria, taking advantage of mirror-charge effects for gold nanorods placed on gold film. Monodisperse gold nanorods prepared utilizing wet-chemistry are arranged with high precision on wrinkled templates to form linear array-type assemblies and subsequently transferred to a thin gold film. Due to the obtained particle-to-film distance of 1.1 nm, the plasmonic mode of the nanorod is able to couple efficiently with the supporting metallic film, giving rise to a magnetic mode in the visible spectrum (721 nm). Conventional UV-vis-NIR measurements in close correlation with electromagnetic simulations provide evidence for the presence of a magnetic resonance on the macroscopic area. The herein presented scalable lithography-free fabrication process paves the road towards colloidal functional metasurfaces with an optical response in the effective magnetic permeability.

negative-index metamaterial, gold nanorods, optical-properties, resonators, resonance, growth, modes, nanoparticles, nanoscale, patterns
Mayer, M., Tebbe, M., Kuttner, C., Schnepf, M. J., König, T. A. F., & Fery, A. (2016). Template-assisted colloidal self-assembly of macroscopic magnetic metasurfaces. Cambridge [u.a.] : Soc. https://doi.org//10.1039/c6fd00013d