Advances in Transmission Electron Microscopy
Friday, April 21, 2017 at 1 PM Eastern Time
Dr. Thomas Sharpis a mineralogist interested in mineral reactions, phase transitions and deformation and how these can be used to understand processes that occur within and on the surface of Earth and other planetary bodies. This research combines experimental mineralogy and petrology with detailed physical and chemical characterization of rocks and minerals with transmission and scanning electron microscopy, SIMS, thermal emission infrared spectroscopy and other techniques. Applications include: Phase transitions in Earth's deep mantle; High-pressure minerals in meteorites as indicators of impact history; and Chemical weathering of basalt and its implications for the remote sensing of Mars. In addition to his research, Professor Sharp is the ASU Associate Director of the NASA Arizona Space Grant Consortium.
Transmission electron microscopy (TEM) has been an essential tool for characterization of defects solid materials. High-resolution TEM (HRTEM) has allowed us to image the structure of materials at the atomic scale, but resolution has been limited by spherical aberration of the lenses. In the last two decades, aberration correctors have been developed that allow for spatial resolution beyond 1 Å. At ASU, we have three aberration corrected TEM instruments that provide imaging and microanalysis at the atomic scale.