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Precision X-Ray Diffractometry using Powder Specimens*

Published online by Cambridge University Press:  06 March 2019

L. F. Vassamillet  and
H. W. King
L. F. Vassamillet
Affiliation:
Mellon Institute, Pittsburgh, Pennsylvania
H. W. King
Affiliation:
Imperial College, London, England
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Abstract

The counter tube diffractometer method for determining d spacings is often rejected for precision work because of lack of information concerning the nature and significance of the inherent errors. Errors concerned with the geometry of the method, the nature of the X-ray source, and the technique of collecting data have all been analyzed previously in some detail. The findings of these analyses, which are scattered throughout the literature, are reviewed briefly. Errors arising from imperfections in the instrument and misalignment of the X-ray source with respect to the diffractometev have been studied experimentally. The results are presented and discussed in terms of the resultant error in the determination of the lattice parameter of a cubic crystal. Errors determined both analytically and empirically are discussed in relation to the extrapolation procedures commonly used for diffractometers. It is shown that, depending on the construction of the instrument, the effect of imperfections in the gears may almost double the error in the final extrapolated value of a lattice parameter.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 6: Eleventh Annual Conference on Applications of X-ray Analysis, August 8-10, 1962 , 1962 , pp. 142 - 157
Copyright
Copyright © International Centre for Diffraction Data 1962

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Footnotes

†

Former Fellow of the Mellon Institute, Pittsburgh 13, Pennsylvania.

*

This work was supported in part by the U.S. Atomic Energy Commission, Washington, D.C.

References

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