Four Lab researchers win LANL Distinguished Postdoctoral Awards

Accomplishments display unusual creativity, innovation, or dedication

Mar. 3, 2010—Stosh Kozimor, Jian Wang, Andrey Kovalevsky, and Suzanne "Zoe" Fisher have been honored with the Los Alamos National Laboratory Distinguished Postdoctoral Award for fiscal year 2009. The award, which is limited to current Lab postdoctoral researchers or those who were a Lab postdoc during the fiscal year of note, recognizes individuals or small teams who have made outstanding contributions to the Lab's programmatic or scientific work during a fiscal year. Their accomplishments display unusual creativity, innovation, or dedication.

Kozimor of the Lab’s Inorganic, Isotope, and Actinide Chemistry group was a Distinguished Frederick Reines Postdoctoral Fellow who measured covalency in thorium, uranium, and transuranic elements. He used ligand K-edge X-ray absorption spectroscopy (XAS) and nonresonant inelastic X-ray scattering (NRIXS) to determine the extent of covalent bonding interactions between actinide ions and their ligands. He synthesized air-sensitive transition metal and actinide complexes and developed experimental techniques. His publications demonstrate that covalent interactions between actinide ions and chloride ligands are much greater than was originally thought. This may give insight for the reason why sulfur-based extractants are effective at separating lanthanide from actinide ions. His achievement is especially impressive because the experiments required safe handling of air-sensitive, radiological materials at the Stanford Synchrotron Radiation Laboratory and Argonne's Advanced Photon source.

Wang of Materials Science and Technology was a postdoctoral research associate who employed atomistic simulations to reveal defect interactions controlling the mechanical response of nanomaterials, such as the unprecedented high strength copper-niobium nanolayered composites. He showed that these interfaces have multiple atomic structures with nearly identical energies, which enables them to absorb glide dislocations by locally shearing. Wang used atomistic modeling and dislocation theory to show that an enormous applied stress is required to compact this spread dislocation core and transmit it across the interface. His determination of the yield strength of the nanolayered composites agrees with experiments at the Center for Integrated Nanotechnologies (CINT). Wang and Amit Misra of Materials Physics and Applications, Dick Hoagland of Materials Science and Technology, and former Director's Postdoctoral Fellow Mike Demkowicz, currently at the Massachusetts Institute of Technology, wrote invited papers and a book chapter on the research, which also was featured as a journal cover image for Scripta Materialia. Wang also discovered that the deformation behavior of some structurally important metals with hexagonal-close-packed structures (titanium, magnesium, and zirconium) deform by nucleating twins in addition to dislocation slip.

Kovalevsky, a Director's Postdoctoral Fellow, and Fisher, a postdoctoral research associate, received a team award for successfully running the Protein Crystallography Station (PCS) at the Lab's Lujan Center and the effective application of X-ray and neutron crystallography to understand enzyme mechanisms related to three proteins. The researchers, both of Bioenergy and Environmental Science, provided full scientific and technical coverage for the PCS, coordinated the peer review process, and scheduled beam time—the Bioscience Division operates the PCS as part of the LANSCE users program, which the DOE Office of Science funds. The team's research on understanding the mechanisms of three different enzymes resulted in publications in major scientific journals such as the Journal of Molecular Biology, the Journal of American Chemical Society, and the Journal of Medical Chemistry.

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Stosh Kozimor

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Jian Wang

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Andrey Kovalevsky

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Suzanne "Zoe" Fisher