Mar 26 2012
The Materials Research Society's (MRS) Innovation in Materials Characterization Award honors an outstanding advance in materials characterization that notably increases knowledge of the structure, composition, in situ behavior under outside stimulus, electronic behavior, or other characterization feature, of materials. This year's award will be presented to Stephen J. Pennycook, Corporate Fellow of Oak Ridge National Laboratory (ORNL).
He also holds a joint faculty appointment at the University of Tennessee-Knoxville, and is being acknowledged "for pioneering use of aberration-corrected Z-contrast scanning transmission electron microscopy in the characterization of materials at the atomic scale."
Pennycook will deliver his talk, Scanning Transmission Electron Microscopy-Seeing the Atoms More Clearly, at the 2012 MRS Spring Meeting on Tuesday, April 10, at 5:15 p.m. in the San Francisco Marriott Marquis. He will be presented with the 2012 Innovation in Materials Characterization Award at the MRS Awards Ceremony on Wednesday, April 11, at 6:30 p.m., also in the San Francisco Marriott Marquis.
Pennycook has pioneered the rapid expansion of aberration-corrected scanning transmission electron microscopes (ASTEMs) to materials research from catalysis to structural materials, spintronics and optoelectronics, and nanoscience. In the area of superconductivity, for example, where it had been known that calcium doping improved the grain-boundary critical current in yttrium barium copper oxide (YBCO), the mechanism was thought to involve substitution of calcium for yttrium at the boundary. However, transmission electron microscopy (TEM) imaging and spectroscopy showed that calcium occupies a variety of sites around the boundary, normally associated with yttrium, barium, or copper solute. Theory showed this reduced the strain, and the strain reduction allowed oxygen to return, improving the performance.
More recently, Pennycook and his colleagues identified individual light atoms in monolayer boron nitride (BN) and graphene. In an example where they imaged carbon and oxygen impurities in monolayer BN, they showed that the oxygen atoms always occupy the nitrogen sites, whereas the carbon atoms always substitute for a BN pair. Pennycook and his group demonstrated that annular darkfield imaging in an aberration-corrected STEM optimized for low voltage operation can resolve and identify all individual atoms in non-periodic solids, advancing the field of materials analysis.
Pennycook holds BA, MA, and PhD degrees from the University of Cambridge, UK. For the development and application of Z-contrast scanning transmission electron microscopy, he received a Research and Development R&D 100 Award in 1990, the Microbeam Analysis Society Heinrich Award in 1992, the Materials Research Society Medal in 1992, and the Institute of Physics Thomas J. Young Medal and Award in 2001. He is a Fellow of the American Physical Society, American Association for the Advancement of Science, Microscopy Society of America, Institute of Physics and the Materials Research Society. He recently was awarded the Hsun Lee Award of the Chinese Academy of Sciences. He is co-editor of the book Scanning Transmission Electron Microscopy: Imaging and Analysis (Springer, 2011) and served as co-Guest Editor of the January 2012 issue of MRS Bulletin on spectroscopic imaging in electron microscopy. He has over 350 journal publications, 38 book chapters, three encyclopedia articles, and one patent.