[Ifeffit] problem with Athena's E0 !

Zajac, Dariusz A. dariusz.zajac at desy.de
Wed Jul 1 06:54:37 CDT 2009

Hi Bahia
I have opened your file and I see that everything is ok
Fe:K edge, reference at 7112 eV and your samples s11 at 7122.8 s32 at
7127 as a maxi of 1st derivative (for s32 is the highest maximum, but I
would take 7121.97 as E0)
it seams that Fe in your samples is not metallic one...

>-----Original Message-----
>From: ifeffit-bounces at millenia.cars.aps.anl.gov 
>[mailto:ifeffit-bounces at millenia.cars.aps.anl.gov] On Behalf 
>Of Arezki, Bahia
>Sent: Wednesday, July 01, 2009 1:37 PM
>To: Bruce Ravel; XAFS Analysis using Ifeffit
>Subject: [Ifeffit] problem with Athena's E0 !
>Importance: High
>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, 

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