Dear all,

 

I have the same problem with Hashem.

 

My sample is nanocrystal Wurtzite InN (XRD and AFM results). I do the absorption experiment at In L3-edge at room temperature. After an data processing process, I get 2 broad peaks in FT. When i try to fitting a Wurtzite InN model to the EXAFS spectra for the first and second shells, I always get unacceptable parameters. First of all, I try to change my WZ InN model (changing lattice constant a and c, u-parameter) but it is inefficiently. How could I do?

 

This figure 1 shown a FT of In-L3 EXAFS spectra, the Blue line is my 2 broad peaks and red line is calculate with my WZ InN model which set all parameter to initial value (not guess any thing).

 

figure 1 >> http://nanotech.sytes.net/kaswat/01.emf

 

After I have read Bruce's mail ("If your sigma^2 parameter is negative, perhaps you have too much structural disorder in your model and the fit is compensating by inflating those paths with a negative sigma^2."). How do I construct a WZ InN model which have too many structural disorder.

 

P.S. I have read some papers, they have use model of nanocrystalline alloy which containing amorphous model. How to construct an amorphous model like they.