Jeremy, Thanks for your fast reply ! Actually I have used the data-calibrate tab to calibrate the reference channels. I will check the settings-preferences. thanks, Bahia ----------------------------------------------------------------- Dr. Bahia Arezki + UNIVERSITÄT SIEGEN FB7- Festkörperphysik Emmy-Noether-Campus, 57072 Siegen ( +49 2 71/ 740-3713 Ê +49 2 71/ 740-3763 Room ENC- B012 . bahia.arezki@uni-siegen.de web-site: www.fkp-siegen.de ----------------------------------------------------------------- ________________________________________ De : ifeffit-bounces@millenia.cars.aps.anl.gov [ifeffit-bounces@millenia.cars.aps.anl.gov] de la part de Kropf, Arthur Jeremy [kropf@anl.gov] Date d'envoi : mercredi 1 juillet 2009 14:07 À : XAFS Analysis using Ifeffit Objet : Re: [Ifeffit] problem with Athena's E0 ! Athena attempts to find a reasonable Eo to make it faster for you to look at your data. After that, it is your responsibility to tell Athena what Eo value to use, and not the other way around. Some tools are provided to make it easier to choose consistent values, particularly in the data-calibrate tab. Also be aware that several selections in the settings-preferences tab affect Athena's initial guess for Eo. Jeremy Kropf
-----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Arezki, Bahia Sent: Wednesday, July 01, 2009 6:37 AM 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,
Bahia
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