Nanoscale Materials Section
Naval Research Laboratory
The Universe is my Nano-fab: Scanning Transmission Electron Microscopy of Carbonaceous Nanomaterials
Although nanoscience is a relatively new field of study, nanomaterials have existed for billions of years. Technologically important materials, such as graphene, nanodiamond, and SiC formed first not in clean-room fabrication facilities, but in the outflows of ancient dying stars. In the laboratory, the atomic-scale ordering, impurity, and defect content of these materials can be optimized by manipulating the thermodynamic and kinetic growth conditions for specific optical, electrical, or other properties. A better biocompatible quantum dot, for example, comes from careful incorporation of N or Si impurity atoms into nanodiamond. In space, the same thermodynamics and kinetics apply; the atomic-scale structure is a function of pressure, temperature, etc. But in this case, the impurities are fortuitously incorporated and serve as witness to the presolar origin, rather than a commercial purpose. Aberration-Corrected Scanning Transmission Electron Microscopy (AC-STEM) can reveal the structure of carbonaceous nanomaterials, often down to the individual impurity atom, whether from the lab or space. This talk will cover examples of the state-of-the-art in AC-STEM from both the natural and synthetic worlds of carbonaceous nanomaterials.
Dr. Rhonda Stroud is the Head of the Nanoscale Materials Section at the Naval Research Lab, where she oversees the DoD’s most advanced electron microscope facility for nanoscale materials characterization. Her research interests span many classes of materials, from quasicrystals and oxide electronics to aerogel nanocomposites and nanoparticles formed in supernovae. She received her B.A. in Physics from Cornell University in 1991 and her Ph.D. in Physics from Washington University in St. Louis in 1996. She is a fellow of both the American Physical Society and the Meteoritical Society, and has an asteroid named in her honor by the International Astronomical Union. She serves on the NASA Planetary Science Division Advisory Committee and is President-Elect of the Microanalysis Society of America.