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


------------------------------------------------------------------------------------------------------
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
-------------------------------------------------------------------------------------------------------


Reply via email to