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Precision Lattice Parameter Measurements with Guinier Camera and Counter Diffractometer: Comparison and Reconciliation of Results

Published online by Cambridge University Press:  06 March 2019

Allan Brown
Allan Brown*
Affiliation:
Studsvik Energiteknik AB, S-611 82 Nyköping, Sweden
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Extract

Different procedures used in precision measurements of lattice parameters are, strictly, only valid if they can be shown to give results that are mutually reproducible. For this purpose reproducibility is defined in terms of the parameters a. and standard deviations a. obtained for X-ray specimens of one or more reference materials. The requirement is that all systematic errors should be minimized to a level below that of the random measurement errors. Where these have a Gaussian distribution the significance of the difference, Δa°, between two , measurements can then be Let;Led by evaluating . Thus, if K < 2 the difference, Δa°, cannot be distinguished from the effects of random measurement errors. This condition should be met for specimens of the same sample if reproducibility is good. For K ≥ 3 the value of Δa° is then taken to reflect real differences in the crystalline Jattice of two X-ray specimens of a given compound. A basis is thus created for the study of solid solubility and for the precise characterization of crystalline compounds.

Type
I. Accuracy in X-Ray Powder Diffraction
Information
Advances in X-Ray Analysis , Volume 26: Thirty-First Annual Conference on Applications of X-ray Analysis, August 1-6, 1982 , 1982 , pp. 11 - 24
Copyright
Copyright © International Centre for Diffraction Data 1982

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References

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