engleski

Dependence of Microstucture on Errors in X-Ray Diffraction Profile Measurement

The determination of microstructure of a material depends on the accuracy by which X-ray diffraction line profiles are measured. The obtained microstructural parameters depend, among others, on the treatment of the profile background level error and on the profile tail truncation error, which are inherent in X-ray powder diffraction line profile analysis and in structure refinement in general. This combined error was calculated for several bell-shaped functions usually used in description of diffraction line profiles. The functions were truncated at points where they fall to one hundredth of their maximum. It has been shown that, in agreement with qualitative facts known in literature, the error more affects the functions which are usually used to describe the crystallite size parameter than the ones used to describe the strain parameter. The dependence of the integral breadth on the background level error was found for the pure diffraction profile obtained by the Stokes deconvolution. The steps and precautions, which are necessary in order to minimize the error, were suggested through simple examples. The values of the crystallite size and strain parameters, obtained from integral breadths derived by the Stokes deconvolution, were compared with those which followed from the Warren-Averbach treatment of broadening.

X-ray powder diffraction; diffraction profile analysis errors; crystallite size; strain

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