MSE Seminar Series: David Bell
Friday, October 23, 2015
1:00 p.m.-2:00 p.m.
Room 2108, Chemical and Nuclear Engineering Building
Gordon McKay Professor of the Practice, Applied Physics
Imaging and Analysis of Quantum Materials using Low Voltage Electron Microscopy
Quantum materials are atomically layered materials such as graphene or hexagonal boron nitride (h-BN). Their properties differ strongly from those of their 3D bulk state. Depending on the composition, quantum materials may act as conductors, insulators, semiconductors or even as superconductors. Especially combinations of different quantum materials are of high interest to explore new phenomena and as the foundation for future electronic devices at the nanometer scale. Our research on quantum materials is widely spread, reaching from defect formation in graphene to the characterization of hybrid quantum materials. With TEM we address the question, where the atoms are placed on the graphene. In addition, we will present our work utilizing Low-Voltage High-Resolution Electron Microscopy (LV HREM). Low voltage imaging has several significant advantages, including increased cross-sections for inelastic and elastic scattering, increased contrast per electron and improved spectroscopy efficiency, decreased delocalization effects and reduced radiation knock-on damage. Together, these often improve the contrast to damage ratio obtained on a large class of samples.
Low-voltage TEM offers significant improvement in contrast for inorganic materials, biological samples and especially nano-biological samples while retaining atomic resolution. Application of Low-Voltage Electron Microscopy and its development and future directions will be presented as well as correlative research using Atom Probe Microscopy.