A 11:55 20/12/2007 +0530, Murugesan S a écrit :
Dear Rietveld users,
This is very simple question, even though, please help me,
I get a Williamson - Hall plot in the Fullprof (winplotr window) using my
instrumental resolution file (IRF =4), after the linear fit I got the
values of equation
y = ax + b
a = 0.01841
b = 0.95438
chi2 = 0.327242
I calculated size from the intercept such as (1/b * 1000) = (1 / 0.95438)
* 1000 = 1047.80 angstroms
How can I calculate the strain,
please explain,
with best regards
SM
Isotropic apparent strains and size can be estimated from a
(beta*/d*)**2 = f(beta*/(d*)**2) plot rather than from a Williamson-Hall
plot (beta*=f(d*)). The switching from a HW plot to a ASS one can be
performed in WinPLOTR through 'X_space / change to ASS plot' menu option.
"Calculation / linear fit" option will fit the data with a linear equation
and will calculate automatically apparent size and apparent strain values.
For detailed explanations about the separation of size and strain effects,
see for example the following paper:
Langford J.I., Accuracy on Powder Diffraction, Ed. E. Prince and J.K.
Stalick (NIST Special Publ. 846, 1992) pp 110-126
Regards
Thierry Roisnel
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Thierry Roisnel
Centre de Diffractométrie X
UMR 6226 CNRS-Université de Rennes 1 "Sciences Chimiques de Rennes"
Avenue du Général Leclerc
35042 Rennes cedex, France
Fax: 02.23.23.68.40
Tél: 02 23 23 59 02
WinPLOTR web site: http://www.cdifx.univ-rennes1.fr/winplotr/winplotr.htm
FullProf web site at ILL: http://www.ill.fr/dif/Soft/fp/index.html
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