Atom-by-Atom Nanoengineering
Plasmonic and Nanocatalysis Research Goals
The research in the Ringe group focuses on identifying and characterizing the structural and compositional features of multicomponent nanomaterials. These are critical to control sensing, plasmonic light localization, and catalysis. We aim to develop new functional nanomaterials for monitoring and controlling reactions on the nanoscale. To approach the interdisciplinary field of nanoengineering we use a variety of advanced techniques with a special focus on electron microscopy and spectroscopy, theoretical modeling, and optical techniques. We collaborate with a wide range of scientists within the university,nationally, and internationally.
Advanced Electron Microscopy
A central theme of the group is to use and develop atomic resolution structure and composition analysis tools in order to unravel properties of catalytic and plasmonic nanomaterials. Students in the group learn and become proficient in electron microscopy and spectroscopy, a very sought-after skill in today’s job market, both in industry and academia. We focus mainly on:
- High resolution imaging of single atoms and atomic columns using high-angle annular dark field (HAADF) in aberration-corrected scanning transmission electron microscope (STEM)
- Nanodiffraction to map grain orientation within materials, unravelling texture and alignment
- Elemental analysis of alloys and multiphase nanostructures. Sub-nanometer probes in STEM mode allow us to analyze small areas and single atomic columns using energy dispersive X-ray spectroscopy (EDS) and electron-energy loss spectroscopy (EELS)
- 3D structural reconstruction of complex nanostructures and branched materials
- Electric field mapping in the low-loss region (1-5 eV) for plasmonic particles
Composition analysis of magnetically separable catalytic particles. The core is metallic Co, and shell is Fe3O4. Knappett, Abdulkin, Ringe, Jefferson, Lozano-Perez, Rojas, Fernandez, and Wheatley, Nanoscale 5 (2013) 5765