MSE Colloquium - Prof. Philip E. Batson, Rutgers University
Date: December 02, 2011 from 2:00 pm to 3:00 pm EST
Location: Room 214, S.W. Mudd
Contact: For further information regarding this event, please contact Wesley Hattan by sending email to wjh2121@columbia.edu or by calling 2128547860.
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Plasmonic Forces in Nanoscale Metal Clusters: Playing Nano-Billiards with the Electron Microscope

Philip E. Batson

Institute for Advanced Materials, Devices and Nanotechnology, Departments of Physics and Materials Science Rutgers

Passage of keV-energy electrons near nanometer-sized metal particles is known to transfer energy from the electron to the clusters by excitation of surface plasmons. In groups of particles, these plasmon modes couple, producing inter-cluster bonding forces which can drive coalescence.  A single cluster is also expected to experience a smaller, attractive, force in the presence of a passing electron from simple image charge considerations.  Detailed calculations that evaluate the Maxwell Force Tensor for plasmonic modes confirm this for large impact parameters, but for small impact parameters, comparable or less than the cluster diameter, the plasmonic force becomes repulsive. We have verified this behavior experimentally, using a sub-Angstrom electron beam at 120 KeV to move nano-scale Au clusters, discovering a weak attractive motion for large impact parameters and a stronger, repulsive motion for small impact parameters. We will present this finding and suggest physical reasons for the non-intuitive repulsive behavior.

Short Bio:

Philip E. Batson is a Research Professor with the Institute for Advanced Materials, Devices and Nanotechnology,  Physics, and Materials Science Departments, at Rutgers University, after retirement from the IBM Thomas J. Watson Research Center in 2009.  His education was at Cornell University in Applied and Engineering Physics under the direction of John Silcox. He has helped pioneer spatially resolved Electron Energy Loss Spectroscopy (EELS) in the Scanning Transmission Electron Microscope, and sub-Angstrom HAADF imaging using aberration correction optics, and is currently leading a project to extend EELS to the sub-100 meV level in electron microscopy.  For his contribution to sub-Angstrom imaging, he received the 2002-2003 Scientific American 50 Award for Leadership in Imaging Sciences.  The project to extend EELS resolution was cited by the White House in 2010 as one of "100 Recovery Act Projects that are changing America."  He is a Fellow of the American Physical Society and the Microscopy Society of America.