[Ifeffit] [Ext] [ifeffit] Intensity difference in XANES

[Carlo Segre]

Hi Danting:

It is hard to answer you on this without knowing a bit more.  Did you
measure in fluorescence or  transmission?  What about the data from the
paper you extracted?  There might be self-absorption issues in one or both
of the data sets.  Did you measure any standards during your experiment to
make sure you have a reasonable amplitude reduction factor?  Have you tried
to fit the EXAFS yet?  You cannot really draw a lot of conclusions about
peak heights until you extract the parameters from a fitting.

Carlo

On Mon, Mar 7, 2022 at 8:51 AM Chen, Danting <danting.chen.19 at ucl.ac.uk>
wrote:

> Dear All,
>
>
>
> I have been studied Zn XANES and EXAFS for my environmental samples. Due
> to the unknow Zn speciation in my samples, called ‘A’, I do not have
> adequate Zn reference materials. I found some Zn reference materials from
> others work, called ‘B’, and extracted the data from their paper.
>
>
>
> I found quite similar features, e.g., the location of each peak and
> bottom. However, the intensity of these peaks or bottoms does not
> correspond very well. I am guessing that the features of XANES is mainly
> decided by the bond lengths, ligands and oxidation states of the core atom.
> The intensity of these features may be influenced by the multiple
> scattering from the neighbouring atoms beyond the first coordination. Can I
> conclude that the Zn speciation in my sample ‘A’ has a similar first
> coordination as other work ‘B’, but the coordination environment beyond the
> first coordination may be different.
>
>
>
> I compare their Fourier Transform ‘B’ with my samples ‘A’, and found each
> peak location correspond well but the intensity is different. I am guessing
> that their surrounding atoms are heavier than my samples.
>
>
>
> I am unsure if my explanation. Would you mind providing some suggestions
> regarding the factors influencing the intensity and also the references for
> this explanation?
>
>
>
> I will appreciate your help and many thanks.
>
>
>
> Best Wishes,
>
> Danting
>
>
>
> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows
>
>
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-- 
Carlo U. Segre (he/him) -- Duchossois Leadership Professor of Physics
Professor of Materials Science & Engineering
Director, Center for Synchrotron Radiation Research and Instrumentation
Illinois Institute of Technology
Voice: 312.567.3498            Fax: 312.567.3494
segre at iit.edu   http://phys.iit.edu/~segre   segre at debian.org
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