Acquisition of an Automated Digital Transmission Electron Microscope

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9626279 Smith The transmission electron microscope (TEM) has been a mainstay of materials research for about forty years and remains one of the world's most important scientific instruments. Over the last 20 years Lehigh has maintained a leadership position in analytical TEM research and in the education of TEM users. This award provides funds in partial support of the purchase of an automated digital transmission electron microscope (ADTEM) for chemical and structural imaging of materials with an emphasis on in-situ studies. The ADTEM will combine better than 0.23 nm resolution with 30 of tilt in a variety of side entry specimen holders. The microscope will feature an electron energy filter which can produce high clarity energy-filtered images and diffraction patterns. Included is support for enhancing and up-grading the specimen preparation equipment and image analysis facilities. The digitally acquired images will be accessible from any networked terminal on or off campus. %%% The acquisition of the proposed ADTEM will impact these ongoing or planned research programs in the four thrust areas of: 1) thin films, 2) amorphous and nanoscale structures, 3) ceramics and ceramic composites, and 4) environment-sensitive fracture. The research programs of more than 20 faculty will be impacted by the proposed ADTEM. The research programs in the area of thin films include a study of CoPt for magnetic information storage and the role of grain structure and grain boundary diffusion in the reaction of Nb/Al, Ni/Al and Ti/Al multilayers. Under the thrust area of amorphous and nanoscale structures a variety of studies in inorganic and organic materials are being pursed: crystallization of amorphous silicon, development of copper interconnects with optimized grain structures, determination of structure around light atoms in inorganic glasses by EXELFS, novel design concepts in core/shell particles for toughening engineering plastics, and energy filtered diffracti on of beam sensitive catalyst materials. In the thrust area of ceramics and ceramic composites, tailoring of grain boundary chemistry for the development of super creep-resistant oxides, processing and properties of nanocomposites, and reaction forming of functionally gradient aluminum oxide/aluminum composites for optimal mechanical properties are under investigation. The research programs in the last thrust area of environment- sensitive fracture address environmental and stochastic aspects of creep crack growth in super-alloys and corrosion and fatigue of aluminum alloys. The educational role of the ADTEM will be to demonstrate high resolution structure imaging, advanced diffraction, and energy filtered microscopy in the laboratory section of a variety of undergraduate and graduate courses. Digital images from this microscope will be analyzed by students off-line in our existing cluster of IBM RS6000s and proposed cluster of Macintosh 8100s. ***