[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:



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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