[Ifeffit] question about Eo and simultaneous fitting

[Kelly, Shelly D.]

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: ifeffit-bounces at millenia.cars.aps.anl.gov [mailto:ifeffit-
> bounces at millenia.cars.aps.anl.gov] On Behalf Of Scott Calvin
> Sent: Wednesday, February 14, 2007 7:52 AM
> To: XAFS Analysis using Ifeffit
> Subject: Re: [Ifeffit] question about Eo and simultaneous fitting
> 
> 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 cases, it may
> require a different E0's, in others, not. Of course, you can try it
> both ways, and see what the fits think.
> 
> --Scott Calvin
> Sarah Lawrence College
> 
> At 05:04 AM 2/14/2007, you wrote:
> >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 am looking for small differences. Is
> >varying one Eo for the three samples the right approach?
> >I am also wondering, should I vary one Eo for samples with different
> >doping concentrations?
> >
> 
> 
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