Physical Society Colloquium
Interview for Faculty Position
Nanocrystal structure solution by novel x-ray techniques
Stefan Kycia
LNLS
Brazilian Synchrotron Laboratory
The determination of crystalline structure has traditionally been
accomplished by means of single crystal and polycrystalline x-ray diffraction
techniques. Both have been developed extensively and have had great success
over the years. Nanoscience has presented several fundamental problems that
cannot be solved by current techniques of any kind, therefore hindering the
progress in the understanding of basic issues. For instance, what is the
atomic arrangement and composition of a nanocrystal? New,
`non-traditional' x-ray scattering methods must be developed in
order to answer these questions. A brief introduction to x-ray scattering and
diffraction will be presented, focusing on strong points and limitations of
traditional high-resolution diffraction. Finally, an example in which the
chemical composition, strain and elastic energy are simultaneously evaluated
for self-assembled germanium islands on silicon will be described. These
unique results bear significant importance to the understanding of island
growth and stability.
Wednesday, March 19th 2003, 16:00
Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103)
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