Re: [Ifeffit] Vanadium pre edge peak contributes to K-space?

25 Aug 2009


      Richard Mayes wrote:
...
Chris,
You'll answer this question when you post a project file; but since
you mention the pre-edge feature, have you reset the Eo to approx.
halfway up the absorption edge instead of on the pre-edge feature itself?
-Richard
On Tue, Aug 25, 2009 at 11:10 AM, Carlo Segre mailto:segre@iit.edu> wrote:
Hi Chris:
If you could attach an Athena project file, it would help us to answer
    your question.
Carlo
On Tue, 25 Aug 2009, Chris Patridge wrote:
> Hello all,
    >
    > After calibration, alignment and merging V K edge data, there
    seems to
    > be a large peak in R space below 1 A.  From most examples and
    readings,
    > this would seem to be noise since atoms do not reside that close
    to each
    > other.  Adding a background addresses this noise but then the
    number of
    > variables becomes too large and meaningless to the first shell R
    space
    > range.  I believe the problem lies with the large pre edge
    feature seen
    > with high valence state Vanadium compounds.  Any suggestions on
    how to
    > work through this and make realistic EXAFS analysis on these
    compounds.
    >
    > Thanks everyone,
    >
    >
--
    Carlo U. Segre -- Professor of Physics
    Associate Dean for Graduate Admissions, Graduate College
    Illinois Institute of Technology
    Voice: 312.567.3498            Fax: 312.567.3494
    segre@iit.edu mailto:segre@iit.edu   http://www.iit.edu/~segre
    http://www.iit.edu/%7Esegre   segre@debian.org
    mailto:segre@debian.org
    _______________________________________________
    Ifeffit mailing list
    Ifeffit@millenia.cars.aps.anl.gov
    mailto:Ifeffit@millenia.cars.aps.anl.gov
    http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
------------------------------------------------------------------------
_______________________________________________
Ifeffit mailing list
Ifeffit@millenia.cars.aps.anl.gov
http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
I did set the E0 past the edge feature approximately halfway up and then
set that E0 to all before merging.  I included a merge project file of V
compound.  Thank you.

--
Christopher J. Patridge
Graduate Student
SUNY Buffalo - Dept of Chemistry
716-645-6800 x 2110
315-529-0501