Re: [Ifeffit] Ifeffit Digest, Vol 114, Issue 6

9 Aug 2012

      Hi Matthew,

It's so exciting to see your response in here because I've been reading
your paper! It's very recent paper and I couldn't be found in Google
Scholar yesterday, but I was lucky to find it in your website. In fact,
seeing your response makes me feel, ah, I've come to the right place!
Anyway, I'll continue my information-digging and see what I can find.

Andrew, thanks for your input. I also tried in OriginLab like you did, but
no good fitting was achieved. I'll see if I can try some other ways...

Enyuan

On Thu, Aug 9, 2012 at 11:06 AM,
wrote:
...
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Today's Topics:
1. Re: pre-edge centroid (Andrew Korinda)
   2. Re: Ifeffit Digest, Vol 114, Issue 5 (Enyuan Hu)
   3. Re: Ifeffit Digest, Vol 114, Issue 5 - Mn XANES (Matthew Marcus)
----------------------------------------------------------------------
Message: 1
Date: Thu, 9 Aug 2012 08:26:32 -0500
From: Andrew Korinda 
To: XAFS Analysis using Ifeffit 
Subject: Re: [Ifeffit] pre-edge centroid
Message-ID:

Content-Type: text/plain; charset=ISO-8859-1
Enyuan,
I've had trouble with fitting in Athena as well and just used Excel
and a Gaussian function for the peak. As Domink stated, fitting the
edge as an arctan function simultaneously is a large help. I had tried
extracting the pre-edge and fitting the peak in Origin as a
pseudo-Voight function; however, I couldn't get a reliable fit of the
edge alone.
In summary, it's a bit of all or nothing. When fitting the arctan
function, I typically stopped at 2 eV below the edge.
Andy Korinda
On Thu, Aug 9, 2012 at 8:11 AM, Dominik Samuelis 
wrote:
...
Dear Enyuan,
in my experience, peak fitting works very well with Athena. Try not to
fit
only the prepeak, but maybe include an arctan describing the edge (see
attached pdf, the fit was made using athena). This makes isolating the
prepeak much more reliable.
Best regards,
Dominik
On 09.08.2012 06:21, Enyuan Hu wrote:
...
Dear all,
I was wondering if anyone could comment on how to get the centroid of
pre-edge by fitting the pre-edge peak by pseudo-Voigt functions. I tried
to do that in Athena, but it seemed that peaking fitting part is the
relatively less developed function in the software. Any comment would be
appreciated.
Enyuan
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--
Dr. Dominik Samuelis
d.samuelis@fkf.mpg.de
Max-Planck-Institut f?r Festk?rperforschung
Max Planck Institute for Solid State Research
Heisenbergstr. 1
70569 Stuttgart
Germany
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------------------------------
Message: 2
Date: Thu, 9 Aug 2012 10:53:32 -0400
From: Enyuan Hu 
To: ifeffit@millenia.cars.aps.anl.gov
Subject: Re: [Ifeffit] Ifeffit Digest, Vol 114, Issue 5
Message-ID:
        <
CAJud35PZaf7HDS4digfUZk8RkDsXxLR06i1FqB_ugeRtDXJXnA@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
Hi Dominik,
Thank you so much for your quick response. Indeed, it's really nice fitting
according to your result. But my situation seems a little bit different as
I'm dealing with the Mn XANES data and there're doublets and sometimes
triplets in the pre-edge. Actually, I might as well explain my interest of
doing such fitting. I read in the paper *(F Farges, PHYSICAL REVIEW B 71,
155109 (2005))* that the centroid of pre-edge peak is a more accurate
measurement of the oxidation state of the element of interest, compared to
the more conventional inflection point or half-way method. So I was trying
to follow the paper and see if it also works for my samples. Anyway, thanks
again for your help!
Enyuan
On Thu, Aug 9, 2012 at 9:11 AM,
wrote:
...
Send Ifeffit mailing list submissions to
        ifeffit@millenia.cars.aps.anl.gov
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or, via email, send a message with subject or body 'help' to
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You can reach the person managing the list at
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When replying, please edit your Subject line so it is more specific
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Today's Topics:
1. Re: question for ifeffit mailing list - ATHENA    NORMALIZATION
      (Marie Zwetsloot)
   2. Re: question for ifeffit mailing list -   ATHENA  NORMALIZATION
      (Scott Calvin)
   3. pre-edge centroid (Enyuan Hu)
   4. Re: pre-edge centroid (Dominik Samuelis)
----------------------------------------------------------------------
Message: 1
Date: Wed, 8 Aug 2012 13:17:59 -0400
From: Marie Zwetsloot 
To: ifeffit@millenia.cars.aps.anl.gov
Subject: Re: [Ifeffit] question for ifeffit mailing list - ATHENA
        NORMALIZATION
Message-ID:

Content-Type: text/plain; charset="iso-8859-1"
Hi Scott Calvin,
Thanks for your help. Yes, this is as far as my pre- and post-edge range
go. I realized I should have made them longer; it was my first time doing
this and wasnt aware that i should lengthen my pre and post-edge for
later
on analysis. This will be good lesson for the future.
So you would not recommend doing linear combination fitting? I was
planning
on trying it out.. But I wouldnt want to do it if with my pre- and
post-edge range, I am bound to derive wrong conclusions from the data.
Best,
Marie