[Ifeffit] Very large exafs amplitude in collected data - cause unknown

Jason F. Alvino jason.alvino at adelaide.edu.au
Mon Jun 3 23:25:22 CDT 2013


We have collected fluorescence data of PPh3 protected Au nanoparticles
supported on an anatase surface at the Au L3 edge, which provides some
decent looking exafs and seems to fit a bulk gold model rather well (there
seems to be agglomeration on the surface, even with our low loadings).

We have tried to fit the data using both XFIT and EXAFSPAK, but the strange
thing is that the exafs oscillations have a huge amplitude, up to 80 in
some cases.  Because of this, the only way to fit the data while
maintaining sensible Debye-Waller factors is to allow SO2 to become quite
large, or to allow the coordination numbers to become very large.

We have spoken to a few others in the field and they have yet to be able to
rationalize why there is such a large signal.

I have attached an example of one of the data sets with very large
amplitude, if anyone would be willing to take a look at the data it would
be much appreciated.


Jason F. Alvino
PhD Candidate (Chemistry)
School of Chemistry and Physics
University of Adelaide, AUSTRALIA 5005
Ph     : +61 8 8313 3707
E-mail: jason.alvino at adelaide.edu.au
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