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The influence of surface roughness on diffracted X-ray intensities in Bragg–Brentano geometry and its effect on the structure determination by means of Rietveld analysis

Published online by Cambridge University Press:  10 January 2013

W. Pitschke ,
H. Hermann  and
N. Mattern
W. Pitschke
Affiliation:
Institut für Festkörper- und Werkstofforschung Dresden Helmholtzstraße 20, D-0-8027 Dresden, Germany
H. Hermann
Affiliation:
Institut für Festkörper- und Werkstofforschung Dresden Helmholtzstraße 20, D-0-8027 Dresden, Germany
N. Mattern
Affiliation:
Institut für Festkörper- und Werkstofforschung Dresden Helmholtzstraße 20, D-0-8027 Dresden, Germany
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Abstract

Measurements of X-ray diffraction patterns of high-Tc superconductor and tungsten–carbide powder samples using a Bragg–Brentano diffractometer showed systematic variations of the intensities for different preparation conditions. For specimens with high surface roughness, an angle-dependent decrease of the intensities is observed which is caused by the microabsorption of the X-rays due to the microstructure of the powder sample. In Rietveld analysis, the thermal parameters are strongly influenced by this effect and may tend to negative values. A realistic description of the surface structure of flat powder samples is proposed. Using an analytical approximation for the microabsorption effect and its dependence on the microstructural parameters the Rietveld refinement yields reasonable values for the thermal parameters.

Type
Research Article
Information
Powder Diffraction , Volume 8 , Issue 2 , June 1993 , pp. 74 - 83
Copyright
Copyright © Cambridge University Press 1993

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References

Brindley, G. W. (1945). Philos. Mag. 36, 347–369.CrossRefGoogle Scholar
Brodt, K., Fuess, H., Paulus, E. F., Assmus, W., and Kowalewski, J. (1990). Acta Cryst. C 46, 354–358.Google Scholar
Bronstein, I. N., and Semendjajew, K. A. (1979). Taschenbuch der Mathematik (Teubner, Leipzig).Google Scholar
Ermrich, M, and Hermann, H. (1990). Phys. Status Solidi A 118, K1–K4.CrossRefGoogle Scholar
Finney, J. L. (1976). Mater. Sci. Eng. 23, 199–206.CrossRefGoogle Scholar
Hermann, H. (1991). Stochastic Models of Heterogeneous Materials (Trans. Tech. Publ. Ltd, Zurich).CrossRefGoogle Scholar
Hermann, H., and Ermrich, M. (1987). Acta Cryst. A43, 401–405.CrossRefGoogle Scholar
Hermann, H., and Ermrich, M. (1989). Powder Diffr. 4, 189–195.CrossRefGoogle Scholar
Hewat, A. W. (1973). J. Phys. C 6, 2559–2572.Google Scholar
Hill, R. J., and Fischer, R. X. (1990). J. Appl. Cryst. 23, 462–468.CrossRefGoogle Scholar
Izumi, F., Asano, H., Ishigaki, T., Takayama-Muromachoi, E., Uchida, Y., Watanabe, N., and Nishikawa, T. (1987). Jap. J. Appl. Phys. 26, L649–L651.CrossRefGoogle Scholar
Kumar, R., Sparks, C. J., Shiraishi, T., Specht, E. D., Zschack, P., Ice, G. E., and Hisatsune, K. (1991). Mat. Res. Soc. Symp. Proc. 213, 369–374.CrossRefGoogle Scholar
Masciocchi, N.Toraya, H., and Parrish, W. (1991). Mater. Sci. Forum 79–82, 245–250.CrossRefGoogle Scholar
Nagakura, S., and Oketani, S. (1968). Trans. Iron Steel Inst. Japan 8, 265–268.CrossRefGoogle Scholar
Otto, J. (1984). Z. Kristallogr. 167, 55–64.CrossRefGoogle Scholar
Rietveld, H. (1969). J. Appl. Cryst. 2, 65–71.CrossRefGoogle Scholar
Sparks, C. J., Kumar, K., Specht, E. D., Zschack, P., and Ice, G. E. (1991). Advances in X-ray Analysis (Plenum, New York), Vol. 35, p. 57.Google Scholar
Stoyan, D., Kendall, W. S., and Mecke, J. (1987). Stochastic Geometry and Its Applications (Wiley, Chichester).Google Scholar
Suortti, P. (1972). J. Appl. Cryst. 5, 325–331.CrossRefGoogle Scholar
Taylor, J. C., and Matulis, C. E. (1991). J. Appl. Cryst. 24, 14–17.CrossRefGoogle Scholar
Toraya, H. (1986). J. Appl. Cryst. 19, 440–444.CrossRefGoogle Scholar
Wiles, D. B., and Young, R. A. (1981a). J. Appl. Cryst. 14, 143–151.CrossRefGoogle Scholar
Wiles, D. B., and Young, R. A. (1981b). J. Appl. Cryst. 17, 325–331.Google Scholar
Will, G., Parrish, W., and Huang, T. C. (1983). J. Appl. Cryst. 16, 681–622.CrossRefGoogle Scholar
Williams, A., Kwei, G. H., Von Dreele, R. B., Larson, A. C., Raistrick, I. D., and Bish, D. L. (1988). Phys. Rev. B37, 7690–7692.CrossRefGoogle Scholar
Young, R. A., Prince, E., and Sparks, R. A. (1982). J. Appl. Cryst. 15, 357.CrossRefGoogle Scholar