Rietveld quantification of amorphous portions with an internal standard-Mathematical consequences of the experimental approach

被引：54

作者：

Westphal, Torsten ^{[1
]}

Fuellmann, Thomas ^{[2
]}

Poellmann, Herbert ^{[3
]}

机构：

[1] Tech Univ Bergakad Freiberg, D-09596 Freiberg, Germany

[2] PANalytical BV, Almelo, Netherlands

[3] Univ Halle Wittenberg, Halle, Germany

来源：

POWDER DIFFRACTION | 2009年 / 24卷 / 03期

关键词：

amorphous; internal standard; Rietveld; uncertainty;

D O I：

10.1154/1.3187828

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

The Rietveld method is increasingly used for amorphous portion determination. This article describes the quantification of amorphous portions using an internal standard in a formal mathematical way. From a set of basic assumptions and postulations, equations for the amorphous portion quantification, the optimum amount of internal standard, and the slope of the amorphous portion calculation formula were derived. With this tool set, the influence of the method principle on the analytical uncertainty is discussed. It is shown that the amount of internal standard has a strong influence on the precision of the amorphous portion determination. A poor choice can make the determination impossible, while a clever choice can enhance the precision compared to the precision of the Rietveld refinement. (C) 2009 International Centre for Diffraction Data. [DOI: 10.1154/1.3187828]

引用

页码：239 / 243

页数：5