Hi,
first I would like to thank all experienced people answering in this forum!! I
have learned really a lot from you.
And now my question:
Should I fit EXAFS spectra of a doped material and the same material, but
oxidized and reduced (three spectra) simultaneously? In my opinion: yes, as I
Hi Tony,
A quick answer before I try to fight my way through an ice storm to
get to work. :)
Fitting the three spectra simultaneously makes sense, but if
oxidation state is expected to be different, then you really need
different E0's.
As far as doping, it depends on the details. In some
Hi Tony,
The approach that I like to take, is to vary the choice of E0 in the
background subtraction step so that the chi(k) spectra are well aligned
with each other and the theory. Then only one Ezero parameter is
needed.
Cheers,
Shelly
-Original Message-
From: [EMAIL PROTECTED]
Hi Shelly,
Interesting--I've never tried that method with samples that I expect
to differ in oxidation state. If it's differing in oxidation state,
the local environment is probably different too...particularly,
nearest-neighbor distances should be changed significantly. So how do
you align
Hi Scott,
The change in frequency is a bigger affect at high k than the energy
shift parameter. The energy shift parameter affects the data more
strongly at low k. So I align the data to each other at low k, and then
they become out of phase with each other at high k. A similar effect is
seen
It is true that in many cases oxidation/reduction affects the low k-range
behavior in chi(k), but if the second shell (metal-metal) frequency is not
affected, the data can still be aligned by focusing at the high k-portion of
the data, so what Shelly suggested, may be, in principle, done.
Anatoly
Tony --
Should I fit EXAFS spectra of a doped material and the same material, but
oxidized and reduced (three spectra) simultaneously? In my opinion: yes, as
I am looking for small differences. Is varying one Eo for the three samples
the right approach?
I am also wondering, should I vary one
Dear Bruce
We have used Athena and Artemis software to analyses the EXAFS. When we do
the analysis, we used different S2o for each path for fitting of Cu2O data.
I succeeded to obtain good fitting by this way. Documents related to percent
EXAFS analysis have been mentioned S2o is one value
Hi again to everybody,
Thank you for the answers. They are all helpful.
Just to specify a little more: all samples are measured at the K edge of the
doped metal oxide. I expect relation between the coordination environments of
the different samples as the reduced and oxidized samples are
