[Ifeffit] Athena: problems with LCF

[Nina Siebers]

Dear All,

I acquired Cd L3-edge spectra of some binary and ternary mixtures in  
varying proportions and for the individual components. Then, I tried  
to fit the reference spectra to the spectra of the mixtures using  
linear combination fitting of Athena to get their abundance. However,  
results were disappointing despite all spectra were carefully energy  
calibrated and normalized, so I decided to create simple mathematical  
ternary mixtures by summing up the spectra of the individual reference  
spectra (edge step normalized) and tried the fitting again to exclude  
mixing-failures and check sensitivity of LCF with the idealized  
spectra. Unfortunately, LCF was also not able to reliable deconvolute  
these spectra into the individual reference spectra.
Does anybody have an explanation for that?
It would be nice if somebody could give me information about the  
mathematical fitting algorithm implemented in Athena.

Thanks a lot!
Wishes,
Nina