Mica sheets with embedded metal nanorods: Chemical imaging in a topographically smooth structure

Abstract

We demonstrate the concept to combine topographical smoothness and plasmonic properties to produce flat substrates with surface enhanced Raman spectroscopy activity—properties that may find use in nanotribology and other thin film applications. Preliminary findings to this end are described. A dual-beam focused ion beam(FIB) system is used to drill large arrays of small pores in single crystals of mica, 2 – 6 μ m thick, yielding controlled cross sections (squares, triangles, and circles), sizes ( 100 nm to many microns), and arrangements (square, hexagonal, and random). When filled with metals, arrays result to embedded nanorods with their long axis oriented normal to the surface. As an extension of this method, arrays of nanorods standing perpendicular to a supporting surface can also be produced.