Quantum Effects on Thin Film Structure and Properties
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Date: 02-22-2006
Start Time:
3:30pm
End Time: 4:30pm
Speaker: Tai C Chiang
From:
University of Illinois at Urbana-Champaign
Location: Interschool Lab, 7th floor, Schapiro/CEPSR
Hosted by:
Center for Integrated Science
Abstract:
Atomically uniform films of Ag and Pb have been successfully grown on
several substrates (Fe, Si, and Ge). The potential barrier at the
interface confines the electrons in a film to form quantum well states.
The resulting electronic structure of the film is substantially
different from the bulk counterpart, and the physical properties of the
film can vary significantly as a function of film thickness. These
variations generally follow a damped oscillatory behavior, and the
underlying physics is similar to the shell effect associated with the
periodic property variations of elements in the period table. This talk
discusses the basic electronic structure of thin metal films as
measured by angle-resolved photoemission and the connections to
physical properties including the surface energy, thermal stability,
work function, electron-phonon coupling, etc. Quantum size effects can
also affect morphological evolution during film growth and heat
treatment. X-ray diffraction studies show that the observed development
of nanoscale features can be related to the energetics of the system.
Bio Info:
EDUCATION
University of California at Berkeley (1973-1978), Ph.D. Physics.
National Taiwan University (1967-1971), B.S. Physics.
EMPLOYMENT
Associate Director (1999-), Head, Solid State Sciences and Materials
Chemistry Program (1991-), Frederick Seitz Materials Research
Laboratory, University of Illinois at Urbana-Champaign.
Professor (1988-), Associate Professor (1984-1988), Assistant Professor
(1980-1984), Department of Physics, University of Illinois at
Urbana-Champaign.
Postdoctoral Research Associate, IBM T. J. Watson Research Center (1978-1980).