Thank you very much Manuel,
2017-10-27 6:41 GMT-03:00 Manuel MONTE CABALLERO <manuel.mo...@esrf.fr>: > Dear Jesús, > > Why will you choose the maximum at 7722 eV? > I will choose the first one (ignoring the pre-edge), around 7718 eV. > > The problem here, could be that in Co3O4 you have one atom of Co(II) and > two of Co(III) so, there are absorbing at different energies. > But the EXAFS is common so, and error will happen no matter which maximum > you choose. > I have a CoO spectra and the maximums of the derivative (again ignoring > the pre-edge) appear at 7717, 7721 and 7725 eV. > If you had a Co2O3 spectra (I don't) you can compare and decide to choose > the E0 which is closer to that of the Co2O3 as in Co3O4 you have more > Co(III). > > Also, if you make three copies of the spectra and select a different E0 > for each one you can see how it affect the x(k) and the Fourier transform > (to R). > The first E0 (7718 eV) make x(k) to have higher intensity (resulting in > higher intensity of peaks in R). > But the third one (7722) creates an extra feature below 1 in the R space > (for k range 3-9 or 3-10). > > Usually I will just choose the first one or, compare some and see what > happen. > Probably, the different will not so high to make you worry too much. > > > Regards, > > Manuel > > > > On 25/10/2017 17:11, Jesús Eduardo Vega Castillo wrote: > > _________________________________________________________________ > > * WARNING:* Viruses are often found in attached files of type > document (.xls .doc etc.) and compressed (.zip .rar etc.). > Please be *EXTREMELY* careful when opening this kind of file. > In case of doubt, please contact the sender for confirmation. > _________________________________________________________________ > Dear list, > > I enclose an Athena project with a XAFS spectrum of Co3O4 with a metallic > Co reference. > Athena by default has chosen E0 at the absolute maximun of the derivative > curve (at 7727.8eV) which in my opinion is too high because it is at the > white line zone. > > I believe that E0 should be the previous maximun in the derivative at > around 7722eV, which would be at the rising edge. > > Am I wrong? > > I would appreciate some help with the criterion to determine the right > value. > > > Yours, > > Jesús > > > > > _______________________________________________ > Ifeffit mailing > listifef...@millenia.cars.aps.anl.govhttp://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit > > > > _______________________________________________ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit > >
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