Quantitative phase analysis of natural products using whole-powder-pattern decomposition

2000 ◽  
Vol 15 (2) ◽  
pp. 86-90 ◽  
Author(s):  
Shigeo Hayashi ◽  
Hideo Toraya
Keyword(s):  
Natural Products ◽  
Phase Analysis ◽  
Raw Materials ◽  
Fluorescence Analysis ◽  
Weight Percent ◽  
Powder Pattern ◽  
Quantitative Phase Analysis ◽  
X Ray ◽  
Quantitative Phase ◽  
Pattern Decomposition

The capability of whole-powder-pattern decomposition in the quantitative phase analysis (QPA) of natural products was investigated using three- to six-component mixtures and pottery bodies. Here, the term pottery body means plastic clay suitable for making pottery and it is compounded of ceramic raw materials. Average errors of the weight fractions for each phase were within 1 weight percent in each mixture of natural products. The amounts of reduced oxides in pottery bodies derived from the X-ray diffraction technique were in good agreement with results obtained by X-ray fluorescence analysis. The present procedure does not require knowledge of crystal structures; it appears adequate for the QPA of natural products.

Quantitative Phase Analysis Using the Whole–Powder– Pattern Decomposition Method: II. Solution Using External Standard Materials

1994 ◽  
Vol 38 ◽  
pp. 69-73
Author(s):  
Hideo Toraya
Keyword(s):  
Phase Analysis ◽  
Decomposition Method ◽  
Weight Fraction ◽  
Powder Pattern ◽  
Quantitative Phase Analysis ◽  
Chemical Compositions ◽  
Absorption Coefficients ◽  
Quantitative Phase ◽  
Mass Absorption ◽  
Pattern Decomposition

Abstract A new procedure for the quantitative phase analysis using the whole–powder–pattern decomposition method has been proposed (Toraya and Tsusaka, 1995). The procedure is based on the determination of the scale factor for the profile intensity of each phase in a mixture, which is identical to the ratio of integrated intensity in a mixture to that of the corresponding reflection in a single component sample. Weight fractious were obtained by solving the simultaneous equations, of which coefficients include the scale factors and the mass absorption coefficients. In a previous study, the mass absorption coefficients were calculated from chemical compositions and u,/p data of respective phases. In the present study, an alternative way of deriving the weight fraction without using the knowledge of chemical composition is proposed.

Estimation of statistical uncertainties in quantitative phase analysis using the Rietveld method and the whole-powder-pattern decomposition method

2000 ◽  
Vol 33 (6) ◽  
pp. 1324-1328 ◽  
Author(s):  
H. Toraya
Keyword(s):  
Phase Analysis ◽  
Decomposition Method ◽  
Goodness Of Fit ◽  
Rietveld Method ◽  
Weight Fraction ◽  
Relative Magnitude ◽  
Powder Pattern ◽  
Quantitative Phase Analysis ◽  
Quantitative Phase ◽  
Pattern Decomposition

Formulae for estimating statistical uncertainties in quantitative phase analysis using the Rietveld method and the whole-powder-pattern decomposition method have been derived. The relative magnitude of statistical uncertainty for a derived weight fraction of a component in a mixture is given by σ(Wm)/Wm= (1/Wm− 1)1/2F(D\textstyle\sum_{i = 1}^NYoi)−1/2, whereWmis the weight fraction of themth component,Fis the goodness-of-fit index,D(≤1) is a factor depending on the degree of peak overlap, and ∑Yoiis the total sum of profile intensities in the 2θ range used for whole-powder-pattern fitting. If the step width Δ2θ in step scanning is halved, ∑Yoiis almost doubled; on the other hand, ∑Yoiis proportional to the fixed counting timeT. Therefore, σ(Wm)/Wm∝ (Δ2θ/T)1/2. Extension of the 2θ range for whole-powder-pattern fitting towards the high-angle region is not effective for improving the precision of the derived weight fractions if the profile intensities in that region are weak. The formulae provide guidelines for optimizing experimental parameters in order to obtain a required precision.

Quantitative Phase Analysis by X-Ray Diffraction.

1966 ◽  
Vol 38 (12) ◽  
pp. 1741-1745 ◽  
Author(s):  
R. F. Karlak ◽  
D. S. Burnett
Keyword(s):  
Phase Analysis ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Phase

Quantitative Phase Analysis in Titanium by X-Ray Diffraction

1957 ◽  
Vol 1 ◽  
pp. 39-58
Author(s):  
Ralph H. Hiltz ◽  
Stanley L. Lopata
Keyword(s):  
Phase Analysis ◽  
Quantitative Phase Analysis ◽  
Metallographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Phase ◽  
Method Of Measurement ◽  
Graphic Methods

AbstractIn view of present difficulties encountered in met alio graphic methods of phase analysis of titanium and its alloys, the possibility of utilizing integrated X-ray intensities for phase analysis was investigated. Power Formula variables were calculated for titanium, and relative areas of three alpha and one beta peak were determined. Recorded X-ray intensities were obtained from a large number of titanium specimens. The recorded intensities were analyzed and the results compared with those from metallographic analysis. The errors in the method arising from the nature of titanium, texture and peak overlapping, were studied and where possible, compensated for by adjusting the method of measurement and calculation.

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