The other difficulty I have experienced with P EXAFS is that a lot of the
second-shell backscatterers are fairly weak, so picking that signal out is
pretty difficult.
I have some spectra of minerals and that's where I've wanted to start with P
EXAFS (since the structures are well-constrained).
Hi,
You could try X-ray emission rather than EXAFS. It has shown some
success in showing changes
in phosphate environment with bonding environment.
e.g. https://pubs.rsc.org/en/content/articlelanding/2021/sc/d1sc01266e
cheers,
-R.
On 2023-09-13 12:47 p.m., matthew marcus wrote:
Good points.
Good points. At these low energies, an EXAFS range is a large fraction
of the total energy range, so there tends to be a lot of curvature of
baselines and post-edges. True about the 4O 1NN shell that dominates,
but the same happens with As. All the interesting stuff is in the
higher shells.
In my experience the main difficulties with EXAFS on P (phosphate) come from
two factors (not signal to noise, it's not hard to get a nice smooth line, but):
1) You've got 4 O atoms, guaranteed, so any other signal will be small and on
top of that very strong signal generated from the first-neig
It's not impossible, but difficult for a couple of reasons:
1. Not too many beamlines can do it. It's hard for soft X-ray beamlines
and soft for hard X-ray beamlines. Air absorption is significant. If a
Si DCM is used, the Bragg angle has to be higher than many
monochromators can reach.
2.
Hi there,
I begin by examining phosphorus adsorption by goethite, hematite, and
gibbsite.
Why is it difficult, if not impossible, to obtain EXAFS spectra at the P-K
edge that can be properly used, i.e., spectra with a high signal-to-noise
ratio, especially for dilute samples?
Would it be possibl
