[Ifeffit] XANES Background removal and Normalization

[Jens Kruse]

Hi there,

I have some P L2/L3-edge XANES spectra. I am not sure how to remove the
background and normalize these data. Due to the fact that the pre
edge and the post edge region is not very flat the the edge-step
normalization using AUTOBK dose not work very well.
CLNORM background subtraction seems to work better in some case. But
some spectra get partly negative values after CLNORM (see .prj
attached). So my questions are:
1:Is CLNORM the best choice in my case, especially when I plan to do
linear combination fitting with these data?
2: Athena needs the knowledge of the absorbing atom an the edge to use
CLNNORM, but the spectra contain both L3 an L2. So, which edge do I have
to choose L3 or L2?
3: Would it be also correct to use a Victoreen-Fit for the pre edge
without any further normalization and than do the linear combination
fitting? Or do I have to normalize spectra in general when I am doing
linear combination fitting, to eliminate effects of different
concentrations of the absorbing atom in the mixtures?


thanks, a lot for your help
jens


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