Transmission EBSD from 10 nm domains in a scanning electron microscope

The spatial resolution of electron diffraction within the scanning electron microscope (SEM) has progressed from channelling methods capable of measuring crystallographic characteristics from 10 mu m regions to electron backscatter diffraction (EBSD) methods capable of measuring 120 nm particles. Here, we report a new form of low-energy transmission Kikuchi diffraction, performed in the SEM. Transmission-EBSD (t-EBSD) makes use of an EBSD detector and software to capture and analyse the angular intensity variation in large-angle forward scattering of electrons in transmission, without postspecimen coils. We collected t-EBSD patterns from FeCo nanoparticles of diameter 10 nm and from 40 nm-thick Ni films with in-plane grain size 15 nm. The patterns exhibited contrast similar to that seen in EBSD, but are formed in transmission. Monte Carlo scattering simulations showed that in addition to the order of magnitude improvement in spatial resolution from isolated particles, the energy width of the scattered electrons in t-EBSD is nearly two orders of magnitude narrower than that of conventional EBSD. This new low-energy transmission diffraction approach builds upon recent progress in achieving unprecedented levels of imaging resolution for materials characterization in the SEM by adding high-spatial-resolution analytical capabilities.