scholarly journals Accuracy in the Quantitative Phase Analysis of Eight- to Ten-Component Ceramic Materials Using the Whole-Powder-Pattern Fitting Methods.

1999 ◽  
Vol 107 (1243) ◽  
pp. 249-257 ◽  
Author(s):  
Shigeo HAYASHI ◽  
Hideo TORAYA
Keyword(s):  
Phase Analysis ◽  
Ceramic Materials ◽  
Powder Pattern ◽  
Quantitative Phase Analysis ◽  
Quantitative Phase

Quantitative Phase Analysis of Synthetic Silicon Nitride by X-Ray Diffraction

1979 ◽  
Vol 23 ◽  
pp. 375-379
Author(s):  
Z. Mencik ◽  
M. A. Short ◽  
C. R. Peters
Keyword(s):  
Silicon Nitride ◽  
Phase Analysis ◽  
Gas Turbines ◽  
Ceramic Materials ◽  
Silicon Oxynitride ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Phase ◽  
Typical Material

Synthetically prepared silicon nitride is one of the more promising ceramic materials for structural components of gas turbines. Typical material may contain a-silicon nitride, Si3N4 (which is believed to always contain oxygen and therefore, according to Grievson, Jack and Wild, is more properly written as Si11.5N15O0.5), β-silicon nitride, Si3N4, silicon oxynitride, Si2ON2, silicon metal, Si, and α-cristobalite, SiO2. Because the physical properties of the ceramic parts are dependent on their phase composition, it is essential that a technique be available for performing a phase analysis. An X-ray diffraction procedure has been, developed for the quantitative phase analysis of synthetically prepared silicon nitride. This procedure converts experimentally measured intensities of selected X-ray diffraction peaks to weight fractions of components using empirically determined intensity coefficients.

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.

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.

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 of α- and β-silicon nitrides. II. Round robins

1999 ◽  
Vol 32 (4) ◽  
pp. 716-729 ◽  
Author(s):  
H. Toraya ◽  
S. Hayashi ◽  
T. Nakayasu
Keyword(s):  
Phase Analysis ◽  
Rietveld Method ◽  
Ceramic Materials ◽  
Peak Height ◽  
Quantitative Phase Analysis ◽  
Silicon Nitrides ◽  
Quantitative Phase ◽  
Accuracy And Precision ◽  
Integrated Intensity ◽  
Method R

Two round robins (RRs) of the quantitative phase analysis (QPA) of silicon nitrides (Si3N4) using the mean normalized intensity (MNI) method and the Rietveld method were conducted as one of the projects for establishing standard methods of characterizing advanced ceramic materials. Accuracy and precision of three techniques, namely the MNI method using peak-height intensity (MNI+P), the MNI method using integrated intensity (MNI+I) and the Rietveld method (R), were tested. Precision of the methods was found to follow the order R < MNI+I < MNI+P in the first RR and MNI+I < R < MNI+P in the second RR. Resulting accuracy of the methods was ranked R ≃ MNI+P < MNI+I in the first RR and MNI+P < R ≃ MNI+I in the second. The MNI+P method, which relies upon a simple and routine procedure for measuring peak-height intensities, gave the best precision in both RRs. Both the accuracy and the precision of the Rietveld method were the worst among the three techniques in the first RR. They were, however, significantly improved in the second RR. Although the precision of the MNI+I method was the worst in the second RR, it was better than that in the first, and the accuracy was the best in both the first and the second RR. The degree of improvement from the first to the second RR, in both precision and accuracy, was MNI+P < MNI+I < R, coinciding with the ease of these three techniques in reverse order. This result is largely due to (i) a new protocol for experimental and analytical parameters and (ii) improved skill of the participants in data analysis in the second RR. Magnitudes and signs of the observed errors could be interpreted through results of the theoretical studies.

scholarly journals Challenges of Mechanochemistry: Is In Situ Real-Time Quantitative Phase Analysis Always Reliable? A Case Study of Organic Salt Formation

2017 ◽  
Vol 4 (9) ◽  
pp. 1700132 ◽  
Author(s):  
Adam A. L. Michalchuk ◽  
Ivan A. Tumanov ◽  
Sumit Konar ◽  
Simon A. J. Kimber ◽  
Colin R. Pulham ◽  
...  
Keyword(s):  
Real Time ◽  
Phase Analysis ◽  
Organic Salt ◽  
Quantitative Phase Analysis ◽  
Salt Formation ◽  
Quantitative Phase
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