[Ifeffit] S XANES question

[Matthew Marcus]

The gypsum spectrum looks nothing like any spectrum of gypsum or other sulfate I've ever seen.  I'm deeply suspicious.
	mam

On 11/26/2014 1:36 PM, Lyle Gordon wrote:
> Matthew,
>
> Paris et al in 2001 reported higher S K-edge white line energies for SO4 in Apatite, 2 eV above Gypsum.
>
> THE VALENCE AND SPECIATION OF SULFUR IN GLASSES
> BY X-RAY ABSORPTION SPECTROSCOPY
> The Canadian Mineralogist
> Vol. 39, pp. 331-339 (2001)
>
> -Lyle
>
> On Wed, Nov 26, 2014 at 12:39 PM, Matthew Marcus <mamarcus at lbl.gov <mailto:mamarcus at lbl.gov>> wrote:
>
>     A user on ALS 10.3.2 is taking S K-edge XANES and consistently finding a strong peak at 2484eV (calibration: gypsum white line = 2482.75eV).
>     There's a shoulder at the nominal position of the sulfate peak.  Now, peaks below sulfate I can understand, but since there's no such
>     thing as heptavalent sulfur, what could give a peak *above* the sulfate white line?  Anybody ever seen that?  Yes, we checked calibration.
>              mam
>     _________________________________________________
>     Ifeffit mailing list
>     Ifeffit at millenia.cars.aps.anl.__gov <mailto:Ifeffit at millenia.cars.aps.anl.gov>
>     http://millenia.cars.aps.anl.__gov/mailman/listinfo/ifeffit <http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit>
>
>
>
>
> _______________________________________________
> Ifeffit mailing list
> Ifeffit at millenia.cars.aps.anl.gov
> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
>