Study of inelastic mean free path of metal nanostructures using energy filtered transmission electron microscopy imaging

J Microsc. 2015 Jun;258(3):253-8. doi: 10.1111/jmi.12240. Epub 2015 Mar 18.

Abstract

We report a simple method for measuring the inelastic mean free path of nanostructures of known geometry using energy filtered transmission electron microscopy imaging. The mean free path of inelastic electrons was measured by using systems having known symmetry, such as cylindrical or cubic, combined with Poisson statistics without employing the knowledge of microscope parameters, namely the convergence angle and the collection angle. Having inherent symmetry of such systems, their absolute thickness can be measured from their two-dimensional projection images. We have calculated mean free path of inelastic scattering of electrons in gold, silver and nickel doing case study research by employing gold nanorod, silver nanocube and nickel nanorod lying on a carbon-coated TEM grid at two different electron energies (viz. 200 and 300 keV) following this alternative approach. Results obtained using such alternative approach were verified using microscope parameters.

Keywords: Electron energy loss spectroscopy; electron inelastic mean free path; energy filtered transmission electron microscopy; thickness map.