Opportunity at National Institute of Standards and Technology NIST
Atomic-Resolution Chemical Imaging of Individual Nanostructures in an Aberration-Corrected STEM/TEM
Material Measurement Laboratory, Materials Measurement Science Division
Please note: This Agency only participates in the February and August reviews.
|Andrew Anthony Herzing
Electron scattering is uniquely suited to the atomic-scale characterization of individual nanostructures because electrons have small (nm-scale) elastic and inelastic mean free paths and because electromagnetic fields can be used as electron optical lens elements for image formation. Recent breakthroughs in electron optical design and fabrication have allowed the correction of performance-limiting lens aberrations. Our group houses a state-of-the-art (scanning) transmission electron microscope (STEM/TEM) equipped with a monochromator and aberration-corrected electron energy-loss spectroscopy (EELS) imaging energy filter (for sub-0.3 eV spectral resolution) and aberration corrector (sub-0.1 nm spatial resolution), suitable for atomic-resolution chemical imaging of nanoscale structures with single-atom sensitivity. The instrument is also equipped with a specialized data acquisition module that allows STEM high-angle annular dark field (HAADF) and X-ray energy-dispersive spectroscopy (XEDS) spectral images integrated over thousands of frames with "on the fly" drift correction. We seek a creative researcher to work with us to develop and apply various methods of electron scattering for atomic- and nanometer (nm)-scale characterization of individual nanostructures, including techniques for ascertaining the coordinates and elemental identities of all atoms in nanostructures comprised of tens to thousands of atoms (e.g., catalyst particles). Experience in STEM/TEM imaging and microanalysis is preferred but is not a requirement.
Aberration correction; EDS; Electron microscopy; Nanostructure; STEM;
Open to U.S. citizens
Open to Postdoctoral applicants