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Powder Diffraction Profiles and the Pearson VII Distribution

Published online by Cambridge University Press:  06 March 2019

Allan Brown
Affiliation:
Studsvik Energiteknik AB S-611 82 Nyköping, Sweden
Sven Linde
Affiliation:
Studsvik Energiteknik AB S-611 82 Nyköping, Sweden
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Abstract

The background to the use of the Pearson VII function as a model for powder diffraction profiles was summarised in connection with the fitting of data obtained essentially from Guinier patterns (1). The algorithm developed for modelling single-wavelength profiles was found to be less effective when applied to diffractometer data generated by the Kα doublet. Diffractometer, rather than Guinier film data are generally to be preferred, however, for profile measurements. A new approach was accordingly made to devising an algorithm for this particular application. Numerical features of the method highlighted by this task are described below. Attention is also drawn to problems encountered when profiles are measured using a diffracted-beam monochromator (DBM).

Type
VI. Quantitative Phase Analysis by XRD
Copyright
Copyright © International Centre for Diffraction Data 1986

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References

1. Brown, A. and Edmonds, J.W., “The Fitting of Powder Diffraction Profiles to an Analytical Expression, and the Influence of Line Broadening Factors”, Adv. X-ray Anal., 23, 361-374 (1980).Google Scholar
2. Parrish, W., Huang, T.C. and Ayers, G.L., “Profile Fitting a Powerful Method of Computer X-Ray Instrumentation and Analysis”, Trans, Am. Cryst. Assoc., Vol. 12, 5574 (1976).Google Scholar
3. Rietveld, H.M., “A Profile Refinement Method for Nuclear and Magnetic Structures”, J. Appl. Cryst. 2, '65-71 (1969).Google Scholar
4. Sonneveld, E.J. and Visser, J.W., “Automatic Collection of Powder Data From Photographs”, J. Appl. Cryst. 81 (1975).Google Scholar
5. Khattak, C.P. and Cox, D.E., “Profile Analysis of Diffractometer Data”, J. Appl. Cryst. 10, 405 (1977).Google Scholar
6. Alexander, L., “Geometrical Factors Affecting the Contours of X-ray Spectrometer Maxima”, J. Appl. Phys. 19, 1068 (1948).Google Scholar