Acquisition of an Aberration Corrected Analytical Electron Microscope for Nanocharacterization of Materials

Lehigh University, Bethlehem PA

Investigators

Abstract

This grant supports the acquisition of an aberration corrected Analytical Electron Microscope (AEM) for the characterization of materials at the nanometer scale at Lehigh University. The ability to locate and simultaneously identify the nature of the atoms in crystalline materials is one goal of researchers involved in the characterization of materials. This goal is now achievable in the Analytical Electron Microscope (AEM) because of the recent successful commercial development of spherical aberration (Cs) correctors. A Cs-corrector permits the refinement of the electron probe dimensions to the atomic level while increasing the amount of current in the probe, thus increasing the quality of all the signals generated and detected in the Cs corrected AEM. Calculations and recent experiments confirm that the Cs corrector will improve all present performance metrics by 2-10 times, thus creating a truly unique instrument. The Lehigh instrument will complement other national and international projects employing Cs-corrected instruments that emphasize high-resolution imaging and in-situ experiments rather than analytical techniques. The research performed on the new instrument will offer new insights into the nature of nanometer-level interfacial segregation that controls the brittle failure of materials, the enhancement of mechanical properties in ceramics, the behavior of microelectronic devices and the creation of passive oxide layers on steels. The elucidation of the chemistry of sub-nanometer catalyst particles used for nitrous oxide reduction, oxidation of carbon monoxide to carbon dioxide, and environmental remediation of groundwater will be enhanced. Even beam sensitive polymers have proven amenable to X-ray mapping in the AEM, and the Cs-corrector will permit quantitative measurements of the microstructure and nano-scale chemistry of ion containing polymers. Lehigh's electron microscope laboratory and the AEM in particular already act as a center for researchers from a wide range of industries and universities. Lehigh also serves as a center for microscopy education and training, for thousands of researchers, technicians and engineers from industrial and governmental research labs, through its annual Microscopy School. The Cs-corrected AEM will be the only Cs-corrected instrument available for such broad-based instruction and training and will be integrated into ongoing courses on AEM and Characterization of Nanostructures. The research enabled by the Cs-corrected instrument will be infused into the learning experience of graduate and senior undergraduate students at Lehigh via a new course, 'Materials for Nanotechnology.' This course is also available to students and researchers at other universities, via an interactive, multi-institutional learning initiative accessible via real-time video/audio/internet connections to graduate students in similarly equipped classrooms at the University of Pennsylvania, Carnegie-Mellon University, Drexel University, the University of Pittsburgh and Penn State University. Other schools have expressed interest in participating in this program via Internet2 video-conferencing, including several universities strong in under-represented groups such as Florida A&M, Howard, Prairie View A&M, Savannah State and Southern University.