[Ifeffit] determining S02 from ZnO vs. Zn foil

Jeremy Thorbahn thorbahn at gmail.com
Tue Oct 9 14:21:58 CDT 2012

[note: when putting together this post I discovered a possible bug
regarding opening my project files on different PCs. I will submit that
issue separately]

Hi all:

I am writing to probe the community's knowledge regarding my current
problem in measuring S02.
I have data on a series of glass samples containing ZnO. I also measured a
ZnO crystalline powder, and a Zn foil was measured between detectors 2 and
3 (transmission mode) simultaneously with every run.

My goal is to determine coordination numbers around Zn in the glass
samples, which requires an accurate measurement of S02 for zinc.

My main question is if there is any reason why the Zn foil would provide a
more accurate result than the ZnO powder, or vice versa. I see no reason
why it should be different, especially since this method depends entirely
on the 'chemical transferability' of S02 in the first place. Nevertheless,
I obtain different results from each, with S02 ~ 0.75 from the ZnO and
~0.88 from the foil.

Statistically, the Zn foil dataset is "better" since it is a merge of all
of my scans while there are only two scans of ZnO.
However, part of me wants to trust the ZnO data more, for somewhat vague
reasons such as that it is a "more similar" coordination environment to
what I would expect in my samples, and that it was measured between the
same two detectors, etc.

If anyone has any experience that would indicate why one should be better
than the other, I would love to hear about it.
I will attach Artemis project files for each if you'd like to take a look
at my fits. It is entirely possible that the discrepancy is due to an error
in data processing or analysis on my part; I am by no means an expert. I
hope the project files will not clog up anyone's mailbox, at a couple of
megabytes each.

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