International
Tables for
Crystallography
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

International Tables for Crystallography (2006). Vol. C, ch. 5.2, p. 500

Section 5.2.11. Intensity standards

W. Parrish,a A. J. C. Wilsonb and J. I. Langfordc

aIBM Almaden Research Center, San Jose, CA, USA,bSt John's College, Cambridge CB2 1TP, England, and cSchool of Physics & Astronomy, University of Birmingham, Birmingham B15 2TT, England

5.2.11. Intensity standards

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The measurement of intensity falls within the scope of Parts 6[link] and 7[link] . However, powder methods are much used in quantitative analysis, and the National Institute of Standards and Technology provides five standards for use as internal standards for this purpose and for checking the accuracy of diffractometer and camera intensity measurements. The five materials, certified as SRM 674, are α-Al2O3 (corundum), ZnO, TiO2 (rutile), Cr2O3, and CeO2. Table 5.2.11.1[link], taken from the NIST certificate, is a partial list of pertinent data. The lattice parameters have an uncertainty of 3 parts in 105, which must be increased by a factor of 2 or 3 because of uncertainty in internal standards and thermal expansion. The five materials have a wide range of absorption coefficient and the crystallite size (about 2 µm) causes a small profile broadening. The table gives the intensities of the second- and third-strongest lines relative to the strongest = 100, and the final column gives the ratio of the strongest peak to the strongest peak of Al2O3.

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NIST intensity standards, SRM 674

StandardCrystal systema0  (Å)c0 (Å)Irel hklI1/Ic(113)
23
Al2O3 (corundum) Trigonal 4.75893 (10) 12.9917 (7) 92.5 (26)  116 87.4 (19)  104
ZnO Hexagonal 3.24981  (12) 5.20653 (13) 57.6 (11)  100 40.2 (14)  002 5.17 (13)  101
TiO2 (rutile) Tetragonal 4.59365 (10) 2.95874 (8) 56.9 (28)  211 44.0 (17)  101 3.39 (12)  110
Cr2O3 Trigonal 4.95916 (12) 13.5972 (6) 94.5 (22)  116 87.1 (23)  110 2.10 (5)  104
CeO2 Cubic 5.41129 (8) 53.5 (20)  220 43.4 (23)  311 7.5 (2)  111








































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