Conference paper

Powder-Pattem-Fitting Methods in Structure Determination

Biserka Gržeta ; Ruđer Bošković Institute, P. O. B. 1016, 41001 Zagreb, Croatia
Hideo Toraya ; Ceramics Research Laboratory, Nagoya Institute of Technology, Asahigaoka, Tajimi 507, Japan

Abstract

The Rietveld method is a well known powder-pattem-fitting method which consists in adjusting the complete theoretical diffraction pattern, calculated on the basis of the model for the sample crystal structure, to the experimental powder diffraction pattern. In the fitting procedure, the structure model is being refined. The Rietveld method also enables determination of some other structural properties of the material, like crystallite size and strains, and the quantitative phase analysis of a multicomponent mixture. Complementary fitting methods to the Rietveld method are the individual profile fitting method and the whole-powder-pattern decomposition method, which do not require structural models. The individual profile fitting method enables decomposition of the overlapping diffraction lines in a small range of the powder pattern, while the whole-powder-pattern decomposition method simultaneously decomposes the whole powder pattern into individual lines and refines the unit-cell parameters of the sample. Although the powder-pattern-fitting methods are not methods for direct structure determination, they are very powerful tools in the course of structure determination when the sample is not available in a single crystal form. Several examples of the application of the described methods in structure determination are presented.

Keywords

Hrčak ID:

136891

URI

https://hrcak.srce.hr/136891

Publication date:

1.8.1994.

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