November 25-30, 2012 | Boston
Meeting Chairs: Chennupati Jagadish, Thomas Lippert, Amit Misra, Eric Stach, Ting Xu
Kohn-Sham density functional theory is the most widely used method of electronic-structure calculation in materials physics and chemistry because it reduces the many-electron ground-state problem to a computationally tractable self-consistent one-electron problem. Exact in principle, it requires in practice an approximation to the density functional for the exchange-correlation energy. Common approximations fall on one of the rungs of a ladder, with higher rungs being more complicated to construct and use but potentially more accurate: (1) the local spin density approximation, in which the exchange-correlation density at a position is determined by the electron spin densities there; (2) the generalized gradient approximation (GGA), which adds the gradients of the spin densities as another ingredient; (3) the meta-GGA, which further adds the positive orbital kinetic energy densities; (4) the hybrid functional, which adds an exact-exchange ingredient; and (5) the generalized random phase approximation, which adds the unoccupied Kohn-Sham orbitals. The semilocal rungs (1)-(3) are important because (a) they are computationally efficient, (b) they can be constructed nonempirically, (c) they can serve as input to fourth-rung functionals and (d) the meta-GGA by itself can be accurate for equilibrium properties. Recent and continuing improvements to the meta-GGA will be described. (NSF-DMR support) Biography John P. Perdew is a professor of Physics at Tulane University. His research in the density functional theory of electronic structure has helped to establish this theory as the most widely used method to predict the properties of atoms, molecules and solids from the principles of quantum mechanics. He has published 260 research articles and presented 115 invited talks at conferences. His work has been cited more than 87,000 times. He is an elected Fellow of the American Physical Society and an elected member of the International Academy of Quantum Molecular Science and the National Academy of Sciences. The Perdew special issue of the Journal of Chemical Theory and Computation appeared in April 2009. Born in 1943 in western Maryland, Perdew received a BS in Physics and Mathematics from Gettysburg College in 1965, and a PhD in Physics from Cornell University in 1971. After postdoctoral work at the University of Toronto and Rutgers University, he joined the Department of Physics at Tulane University in 1977, and was promoted to full professor in 1982. At Tulane, he served two terms as Chair of Physics, and has supervised the research of 15 doctoral students, 12 postdoctoral research associates and 2 research assistant professors. His research has been supported by the National Science Foundation since 1978.
The ability to directly observe the atomic arrangements in solid-state materials by high-resolution transmission electron microscopy (HREM) has been realized for some time. Taking this one step further, to actually document atomic rearrangements during the application of some externally applied, controlled stimulus such as heating, cooling, etc., allows us to reveal atomic behavior during real material processes. The application of this technique, in situ HREM, will be surveyed, with examples drawn from solid-state amorphization in multilayers and interfaces, metal-mediated crystallization of amorphous semiconductors and phase transformations in materials for advanced integrated circuits. By carefully controlling the conditions, both insight and quantitative analysis of various material phenomena are achieved. As this approach continues to evolve, more complex in situ conditions are being applied such as gaseous or liquid environments, combined external stimuli such as mechanical stress and heating, etc. The future prospects of this field, as aberration-corrected electron microscopes are becoming more widely available, will also be discussed. Biography Robert (“Bob”) Sinclair is currently Professor and Chair of the Department of Materials Science and Engineering at Stanford University. He received his degrees in Materials Science from Cambridge University and came to the United States in 1973 as a postdoctoral researcher at the University of California, Berkeley. He joined the faculty at Stanford in 1977, where he has been ever since. He has had several visiting positions internationally including Grenoble, Cambridge and Matsushita Industrial Semiconductor Research Center in Osaka. His research has involved application of high-resolution electron microscopy to study various processes in materials, and this has culminated in the Distinguished Scientist Award (Physical Sciences) of the Microscopy Society of America in 2009. Sinclair has been Director of the Stanford Nanocharacterization Laboratory, a university-wide user facility, since its inception in 2002, and was Chair of a National Research Council committee to study “Midsize Facilities: The Infrastructure for Materials Research,” which was published in 2006.
The ability to pattern functional materials in planar and three-dimensional forms is of critical importance for several emerging applications, including flexible electronics and photovoltaics, lightweight structural materials and tissue engineering scaffolds. Direct-write assembly enables one to rapidly design and fabricate materials in arbitrary forms without the need for expensive tooling, dies or lithographic masks. Recent advances in the direct-write assembly of viscoelastic inks will be highlighted, including pen-on-paper electronics, electrodes for flexible photovoltaics and conformal 3D antennas, printed origami metallic and ceramic structures and 3D hydrogel scaffolds and microvascular architectures for tissue engineering. Ongoing efforts to enable high-throughput printing of large-scale architectures will also be described. Biography Jennifer A. Lewis joined the faculty of the materials science and engineering department at the University of Illinois at Urbana-Champaign in 1990 where she is currently appointed as the Hans Thurnauer Professor of Materials Science and Engineering and serves as the director of the Frederick Seitz Materials Research Laboratory. In 2013, she will join the faculty of the School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering at Harvard University. Her research group has made pioneering contributions to the directed assembly of soft functional materials. To date, her work has resulted in over 120 peer-reviewed papers and eight patents. She has served on the editorial advisory boards of Langmuir and Soft Matter and as an associate editor for the Journal of the American Ceramic Society. Lewis is the recipient of the NSF Presidential Faculty Fellow Award (1994), the Brunaeur Award from the American Ceramic Society (2003) and the Langmuir Lecture Award from the American Chemical Society (2009). In addition, she is a fellow of the American Ceramic Society (2005), the American Physical Society (2007), the Materials Research Society (2011) and the American Academy of Arts and Sciences (2012).
The atoms at the surface of materials are the frontier separating the bulk from the surrounding medium. Over the last decades, scientists have studied intensely the structure and properties of the surfaces with the goal of understanding and improving electronic and chemical properties of materials. This is because the surface-medium interaction determines wetting, friction, chemical, biological, and electronic properties. The activity of catalysts, the phenomena occurring in water droplets and particles in the atmosphere, and the electronic properties of semiconductor devices are direct consequences of surface-environment interactions. While the need to pursue studies in the normal environment that surrounds a material, i.e., under gases or liquids, has always been recognized, the techniques used in the past have only partially fulfilled this need, as they work best under high-vacuum conditions. His research over the last 10 years has focused on discovering the surface structures and their dynamics in real life, everyday environments, an endeavor that often required the development of new techniques and methods. He will present some of the new tools developed in his laboratory and what new properties were discovered with their application to study phenomena in the area of environmental science, surface chemistry, electrochemistry, and catalysis. Biography Miquel Salmeron graduated in physics from the University of Barcelona and obtained his PhD from the Autonomous University of Madrid, Spain. He is currently a Senior Scientist in the Lawrence Berkeley National Laboratory, Materials Science Division, which he directed until August 2012. He is also Adjunct Professor in the Materials Science and Engineering Department at the University of California, Berkeley. His research focuses on the structure, reactions, and mechanical properties (friction, lubrication) of materials surfaces and nanomaterials. He pioneered the development of scanning tunneling microscopy for studies of materials surfaces in vacuum and in atmospheric pressures of gases and liquids. He also developed x-ray photoelectron spectroscopy for studies under gases at ambient pressures. His interests include the atomic scale origin of friction, nanoparticle structure and reactivity, solid-electrolyte interfaces for energy-storage applications, and electronic properties of organic films. He received the Outstanding Research and the Outstanding Scientific Accomplishment Awards from the U.S. Department of Energy in 1995. He is a Fellow of the American Physical Society (1996) and of the American Vacuum Society (2003). In 2008, he received the Medard Welch Award of the American Vacuum Society and the Langmuir Lectureship Award of the American Chemical Society.