[Ifeffit] Fwd: Athena troubleshooting

[Michel Schlegel]

Hi everybody

>> I have run 14 samples (each 4 times) on the beamline, and I'm looking for a
>> shift in the oxidation state of Uranium (4+ to 6+).  I'm not sure and can't
>> seem to find any literature on how significant the shift must be to prove
>> anything. 
> 
> That surprises me.  The literature on XAFS studies of uranium valence
> is enormous, much of it written by people who read this mailing list.
> Hopefully one of those fine people will offer up a wealth of
> suggestions for places to look.

You may have a look at the following papers:

Sturchio et al, Science, vol. 281, p. 971 (1998)
Hudson et al., Phys. rev B., vol. 52, p 13815-13826 (1995)
Farges et al., Geochim. Cosmochim. Acta, vol 56, p. 4205-4220 (1992)

(sorry for the geochemistry bias)

The edge position is in fact little discussed. More people prefer to 
refer to the presence of a shoulder at ~10-20 eV after the main peak, 
which results from mutliple scattering within the UO2 linear motif.

Best regards - Michel