[Ifeffit] problem with Athena's E0 !
Bruce Ravel
bravel at bnl.gov
Wed Jul 1 08:23:52 CDT 2009
>From the Athena User's Guide:
http://cars9.uchicago.edu/~ravel/software/doc/Athena/html/params/e0.html
B
On Wednesday 01 July 2009 07:36:47 am you wrote:
> Hi all,
>
> I am using Athena (version: 08.058) to study the changes in the XANES
> profiles as a function of temperature of an organometallic compound
> containing Fe. I have a problem with the E0 value suggested by Athena : I
> noticed that it is not taking the same maximum in the first derivative. I
> am sending 2 examples of xanes taken at RT ( E0 guessed is 1722.8 eV ) and
> 10 K (1727.3 eV !), can any one help me please to solve this problem ?
> should I force athena to take the first maximum at 1722 eV ? I tough that
> my spectra have been properly calibrated: I first calibrated the iron
> foil -reference channel (E0=1712 eV) of a sample xanes and then I aligned
> the rest of the reference channels to that one. I though this was enough to
> calibrate my data. can you please tell me if my data processing is
> correct?
>
> I need to be sure about the E0 value in order to know the correct shift of
> the different xanes features as a function of temperature. Also, with a
> wrong E0 the normalization is not correct...did I miss an important step?
>
> I am having hard time with these basic questions...before using linear
> combination analysis and peak fitting analysis. Of course I have already
> looked in the IFFEFIT archive, but I did not find such problem. I only
> found a question about a wrong E0 because taken before the edge which is
> not my case.
>
> Thanks so much for your time,
>
>
>
> Bahia
--
Bruce Ravel ------------------------------------ bravel at bnl.gov
National Institute of Standards and Technology
Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2
Building 535A
Upton NY, 11973
My homepage: http://xafs.org/BruceRavel
EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/
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