[Ifeffit] [Question about XANES] Hello I'm a graduate student in Korea

[Matt Newville]

Dear Doyoub,



On Thu, Mar 16, 2017 at 10:59 PM, 김도엽(신소재공학과) <mdyk100 at postech.ac.kr> wrote:

> Hello
>
>
>
> I'm a graduate student at POSTECH in Korea.
>
> Currently, I obtained XANES spectra over a narrow energy range and
> looked through the Athena manual
>
>
> But, I'm kind of lost as to how exactly I'm supposed to normalize raw data
>
> which only has XANES spectra.
>
>
> It would be very generous of you if you help me figure this out
>

It's hard for us to answer questions that are so vague.

Generally, it is recommended to collect XANES spectra out to at least 100
eV (and better 300 eV) above the edge in order to get a decent
normalization.  Well, for "normal" hard X-ray spectra: for edges below
about 3000 eV, you can often get by with less energy range.

If you don't have that, it is sometimes OK to pick an energy as far above
the edge as possible and pick an edge step so that all the spectra is 1.0
at that energy.  That is definitely prone to systematic biases in
normalization.   Furthermore, if your data is particularly noisy, it can
add a lot of variation in the normalization to use just a single energy.

Which just brings me back to the original point: it's hard to say in
general how to best handle XANES with a short energy range.

--Matt
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