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Refinement of unit-cell parameters by whole-powder-pattern fitting technique

Published online by Cambridge University Press:  10 January 2013

H. Toraya  and
T. Ochiai
H. Toraya
Affiliation:
Ceramics Research Laboratory, Nagoya Institute of Technology, Asahigaoka, Tajimi 507, Japan
T. Ochiai
Affiliation:
Ceramics Research Laboratory, Nagoya Institute of Technology, Asahigaoka, Tajimi 507, Japan
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Abstract

The accuracy of the unit-cell parameters refined by using the whole-powder-pattern decomposition method is discussed. Powders of W, ZnO, TiO2, BaTiO3 Mg2SiO4, Al2SiO5 (+α-SiO2), and monoclinic ZrO2 were used as test samples. Two internal standard reference materials of Si and CeO2 and two types of powder diffractometers were used for data collections. The systematic peak-shift was corrected by determining the unit-cell parameters and the error function simultaneously during the whole-pattern-fitting. The estimated standard deviations for sample means ranged from <10 ppm (10−6) in cubic symmetry to 20∼50 ppm in monoclinic symmetry. These analyses could be carried out almost automatically in a computation time of less than l min for each sample on a workstation. The use of symmetric experimental profiles, obtained by the suppression of axial divergence, is very effective and of essential importance for improving the accuracy of unit-cell parameters.

Type
Research Article
Information
Powder Diffraction , Volume 9 , Issue 4 , December 1994 , pp. 272 - 279
Copyright
Copyright © Cambridge University Press 1994

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References

Caglioti, G., Paoletti, A., and Ricci, F. P. (1958). “Choice of Collimators for a Crystal Spectrometer for Neutron Diffraction,” Nucl. Instrum. 3, 223–228.Google Scholar
Hart, M., Cernik, R. J., Parrish, W., and Toraya, H. (1990). “Lattice-Parameter Determination for Powders Using Synchrotron Radiation,” J. Appl. Cryst. 23, 286–291.CrossRefGoogle Scholar
Hill, R. J. (1992). “International Union of Crystallography Commission on Powder Diffraction Rietveld Refinement Round Robin. I. Analysis of Standard X-ray and Neutron Data for PbSO4,” J. Appl. Cryst. 25, 589–610.CrossRefGoogle Scholar
Hubbard, C. R. (1983). NIST Certificate for SRM 674 CeO2 powder.Google Scholar
International Tables for X-ray Crystallography, Vol. IV (1974) (Kynoch, Birmingham).Google Scholar
“JCPDS-International Center for Diffraction Data Task Group on Cell Parameter Refinement” (1986). Powder Diffraction 1, 66–76.CrossRefGoogle Scholar
Klug, H. P., and Alexander, L. E. (1974). X-ray Diffraction Procedures for Polycrystalline and Amorphous Materials (Wiley, New York).Google Scholar
Le Bail, A., Duroy, H., and Fourquet, J. L. (1988) “Ab-Initio Structure Determination of LiSbWO6 by X-ray Powder Diffraction,” Mat. Res. Bull. 23, 447–452.CrossRefGoogle Scholar
Pawley, G. S. (1981). “Unit-Cell Refinement from Powder Diffraction Scan,” J. Appl. Cryst. 14, 357–361.CrossRefGoogle Scholar
Rasberry, S. D. (1987). NIST Certificate for SRM 640b Si powder.Google Scholar
Rietveld, H. M. (1969). “A Profile Refinement Method for Nuclear and Magnetic Structures,” J. Appl. Cryst. 2, 65–71.Google Scholar
Toraya, H. (1986). “Whole-Powder-Pattern Fitting Without Reference to a Structural Model: Application to X-ray Powder Diffractometer Data,” J. Appl. Cryst. 19, 440–447.CrossRefGoogle Scholar
Toraya, H. (1987). “Characterization of Multicomponent Ceramic Powders by X-ray Whole-Powder-Pattern Fitting,” in Advances in Ceramics (American Ceramic Society, Westerville), Vol. 21, pp. 811–819.Google Scholar
Toraya, H., and Kitamura, M. (1990). “Simultaneous Peak-Shift Correction in the Least-Squares Determination of Unit-Cell Parameters of a Sample with Standard Reference Material,” J. Appl. Cryst. 23, 282–285.CrossRefGoogle Scholar
Toraya, H. (1990). “Array-Type Universal Profile Function for Powder Pattern Fitting,” J. Appl. Cryst. 23, 485–491.CrossRefGoogle Scholar
Toraya, H., and Parrish, W. (1992). “Accurate Determination of Unit-Cell Parameters Using Conventional X-ray Powder Diffractometry,” Adv. X-ray Anal. 35, 431–438.Google Scholar
Toraya, H. (1993). “The Determination of Unit-Cell Parameters from Bragg Reflection Data Using a Standard Reference Material but Without a Calibration Curve,” J. Appl. Cryst. 26, 583–590.CrossRefGoogle Scholar
Toraya, H. (1994). “Applications of Whole-Powder-Pattern Fitting Technique in Materials Characterization,” Adv. X-ray Anal. 37 (accepted).Google Scholar
Young, R. A., Mackie, P. E., and Von Dreele, R. B. (1977). “Application of the Pattern-Fitting Structure-Refinement Method to X-ray Powder Diffractometer Patterns,” J. Appl. Cryst. 10, 262–269.CrossRefGoogle Scholar
Wilson, A. J. C. (1980). “Accuracy in Methods of Lattice-Parameter Measurement,” Natl. Inst. Stand. Tech. Spec. Publ. 567, 325–351.Google Scholar