I'm at the University of New Mexico, trying to wind up my dissertation
problem, and am dealing with the same problem. Dr. Neil Coville, also of
Wits, is here working with us until end of May, and I'm to pass on his warm
regards - I mentioned to him that I had seen your query and asked if he
knew you!
None of the Rietveld packages deal well enough with X-ray absorption
contrast, at least for my samples - I'm currently working diligently on the
problem as we 'speak', as my samples are not supposed to be undergoing
absorption effects, due to the particle sizes and morphologies, according
to the information available. I use both DBWS and GSAS. I have DBWS
version 9411, and can send the original distribution along to you, if you
don't have it.
I can recommend several papers which allow one to correct for absorption
contrast by hand:
1. Journal of applied crystallography, volume 24, pp 14-17.
Authors J.C. Taylor and C.E. Matulis
2. Physica (Utrecht), vol. 13, pp 62-78. Author P.M. de Wolff
3. Philosophy Magazine; vol. 35, pg. 215 and pg. 404. Author A.
Taylor
4. Philosophy Magazine; vol. 36, pp.347-69. Author: G.W. Brindley
(original theory)
5. A text: A. Taylor: "X-ray Metallography", p. 259. Publisher: Wiley
New York, 1961.
I hope to have one out on the subject by end of June, also. I can keep you
informed on my progress.
Hope that helps!
Regards,
Linda
Linda D. Mansker | 213 Farris Engineering Center
mansker@unm.edu | Albuquerque, NM 87131-1341
Chemical and Nuclear Engr. Dept | Ph: (505)277-5841
University of New Mexico | Fax: (505)277-5433
================================================================
"Never been lonely, never been lied to,
Never had to scuffle in fear, nothing denied to,
Born at the instant church bells chime,
And the whole world whispering, born at the right time ... "
from Rhythm of the Saints, Paul Simon
================================================================