Dear Rietvelders,
I am using Fullprof to microstructural analysis of particles. I have
one type of particle but different sample with different sizes
(particles increase after heat treatment). Their crystallites size
fluctuates between 10nm and 1µm. I know that 1µm is big for a refinement
Rietveld. To calculate the size, I refine Y (Lorentzian componant) then
Ig (Gauss component).
If the crystallites are small (<20nm) I can only refine the Y parameter.
If I try to refine Ig, I have a error message "negative Gaussian
parameter" and no crystallites size.
For bigger crystallites, I can refine Y and Ig. If I only refine Y, the
crystallite size is smaller than the size with Y and Ig refinement.
For the biggest crystallites if I only refine Y parameter the size is
"99999nm". However if I refine Ig parameter too, I succeed to have a
size (1300nm for example)...
I don't understand why I can't refine Ig whatever the crystallites
size... Is ther any reason to that?
Should I only refine Y for all my samples? Or refine Y and Ig when it's
work and only Y when Ig bugs?
Have you ever seen this problem?
Thanks a lot for your help.
Best regards,
Alice
--
Laboratoire des Multimatériaux et Interfaces - CNRS UMR 5615
Université Claude Bernard Lyon 1
3ème étage - Bâtiment Berthollet
43, boulevard du 11 Novembre 1918
69622 VILLEURBANNE Cedex
Mail: alice.courl...@univ-lyon1.fr
Tél: 04.72.43.12.34
