[Ifeffit] question for ifeffit mailing list - ATHENA NORMALIZATION

Scott Calvin scalvin at sarahlawrence.edu
Tue Aug 7 15:41:36 CDT 2012


Hi Marie,

Is that as far as your data goes? If so, the lesson for the future is to collect a longer pre-edge and post-edge region, if you don't plan to analyze them. If time is an issue, you can collect every ten eV or so in those extended regions--that's plenty to get a background, and doesn't take much time.

In any case, it's hard to tell from just XANES data how they should be normalized. Maybe what you show is fine, and maybe it's off by a bit--it's too hard to tell the trend of the background.

If you're not doing linear combination analysis or PCA, but are just comparing one spectrum to another, looking for changes, and interpreting them qualitatively, I think what you have is fine--in that cases, what's important is that the spectra be normalized similarly, and that does appear to be what you've done.

--Scott Calvin
Sarah Lawrence College

On Aug 7, 2012, at 4:24 PM, Marie Zwetsloot wrote:

Dear Ifeffit community,

Thanks for your questions. I am very new to this field (M.Sc. student in soil science), so I really appreciate that you are taking the time to give me some advice.
I have attached a picture of some of the normalized spectra I am working with as well as mu(E) spectra (I am sorry for attaching the picture, for some reason my email did not allow me to copy it into this message). I am doing Xanes analysis on phosphorus in bone char. My normalization range is from 15-60 eV and pre-edge range is from -13.5 to -6.75.
Maybe my normalized spectra looked actually fine; they are not that far above 1 (more or less around 0.3 above). I just thought they looked a little strange/skewed.

Let me know what you think.

Thanks,
Marie






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