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A Method of Background Subtraction for the Analysis of Broadened Profiles

Published online by Cambridge University Press:  06 March 2019

S. Enzo  and
W. Parrish
S. Enzo
Affiliation:
IBM Research Laboratory, San Jose, CA 95193
W. Parrish
Affiliation:
IBM Research Laboratory, San Jose, CA 95193
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Abstract

This method for precisely determining the background level of broadened x-ray profiles assumes that the background under the peak can be approximated by a straight line, and the decay in the tails several profile widths from the peak follows a Cauchy-like law. It uses a plot of I(s)s2 vs. s2 where I(s) is the intensity and the scattering vector s = 2cosθo sin(θ-θo)/ƛ where θo is the centroid, θ the Bragg angle and X the x-ray wavelength. The true background is determined by the slope of the linear portion of the plot and its extension to s2=0 gives the rate of decay of the tails. Results on synthesized and experimental profiles show that the method is useful for Warran-Averbach analysis, because it avoids spurious oscillations and the “hook” effect in the plot of the corrected Fourier coefficients, and makes it possible to correct for overlapping tails of adjacent reflections.

Type
I. J. D. Hanawalt Award Session on Search/Match Methods
Information
Advances in X-Ray Analysis , Volume 27: Thirty-Second Annual Conference on Applications of X-ray Analysis, August 1-5, 1983 , 1983 , pp. 37 - 44
Copyright
Copyright © International Centre for Diffraction Data 1983

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References

(1) Langford, J. I. and Wilson, A. J. C., in Crystallography and Crystal Perfection, edited by Ramchandran, G. M. (Academic Press, London, 1963) pp. 207–222 Google Scholar
(2) Mitra, G. B., “X-Ray Diffraction Profiles from Deformed Metals”, Brit. J. Appl. Phys. 16 (1965) 77–84 Google Scholar
(3) Warren, B. E. and Averbach, B. L., “The Effect of Cold-work Distortion on X-ray Patterns”, J. Appl. Phys. 23 (1950) 595–2Google Scholar
(4) Warren, B. E., X-ray Diffraction, Addison-Wesley, Reading, Massachusets 1969 Google Scholar
(5) Pausescu, P., Manaila, R., M. Popescu and Jijovici, E., “Crystallite Size Distribution in Supported Catalysts”, J. Appl. Cryst. 7 (1974) 281–2Google Scholar
(6) Young, R. A., Gerdes, R. J., Wilson, A. J. C., “Propagation of Some Systematic Errors in X-ray Line Profile Analysis”, Acta Cryst. 22 (1967) 155–2Google Scholar
(7) Allegra, G., “Crystal Powder Statistics.IV. Calculation of the Line Profile Using the Sampling Line Method”, Acta Cryst. A38 (1982) 863–2Google Scholar
(8) de Bergevin, F. and Germi, P., “Corrections des Oscillations dans les Distributions de Tailles des Particules Obtenuees a Partir des Profils des Kaies de Diffraction”, J. Appl. Cryst. 5 (1972) 416–2Google Scholar
(9) Szanto, I. S. and Varga, L., “An X-ray Method for the Determination of the Domain Size from the Tails of the Diffraction Profiles”, J. Appl. Cryst. 2 (1969) 72-76Google Scholar
(10) Hecq, M., “A Fitting Method for X-ray Diffraction Profiles”, J. Appl. Cryst. 14 (1981) 60-61Google Scholar
(11) Wertheim, G. K., Butler, M. A., West, K. W. and Buchanan, D. N. E., “Determination of the Gaussian and Lorentzian Content of Experimental Line Shapes”, Rev. Sci. Instrum. 45 (1974) 1369–21Google Scholar
(12) Wagner, C. N. J., “Analysis of the Broadening and Changes in Position of the Peaks in an X-ray Powder Pattern”, in Local Atomic Arrangement Studied by X-ray Diffraction, edited by Cohen, J. B. and Hilliard, J. E., Gordon & Breach, New York, 1966 Google Scholar