Internal Standards for Quantitative X-Ray Phase Analysis: Crystallinity and Solid Solution

1980 ◽  
Vol 24 ◽  
pp. 253-264 ◽  
Author(s):  
G.J. McCarthy ◽  
R.C. Gehringer ◽  
D.K. Smith ◽  
V.M. Injaian ◽  
D.E. Pfoertsch ◽  
...  

Quantitative phase analysis by X-ray diffraction (QTXRD) has been an established tool of analytical chemistry for more than four decades. Despite its age, this tool remains ascendant as the only universally applicable method for determining the manner in which elements are combined into crystalline phases in multiphase solids. QTXRD is entering its second renaissance. The first came with the introduction of the counter diffractometer in the late 1940's. The specimen preparation and data collection processes were exacting and tedious, but reasonably accurate analyses could be obtained. The second came with the introduction of computer controlled diffractometers, whose software packages include QTXRD routines, in the late 1970's. With the tedium of data collection and analysis greatly reduced, we can expect even more widespread adoption of this tool in the general analytical laboratory.

2005 ◽  
Vol 20 (3) ◽  
pp. 218-223 ◽  
Author(s):  
Chang-An Wang ◽  
Aiguo Zhou ◽  
Liang Qi ◽  
Yong Huang

Materials in the Ti–Al–C ternary system commonly contain three coexisting phases, Ti3AlC2, Ti2AlC, and TiC. Quantitative phase analysis in this ternary system was investigated using X-ray diffraction. First, nonoverlap diffraction peaks were selected: the (002) peak at 2θ=9.5° for Ti3AlC2 (I∕I0=26.5), the (002) peak at 2θ=13.0° for Ti2AlC (I∕I0=39), and the (111) peak at 2θ=35.9° for TiC (I∕I0=78), respectively. Then, based on the mixing-sample method without internal standards, a set of equations was derived for determining the amounts of Ti3AlC2, Ti2AlC, and TiC in a sample using the intensities of the selected diffraction peaks. Finally, the applicability and error sources for this method were investigated. The method is simple and straightforward, and is applicable to the entire Ti–Al–C ternary system, since the derivation of this equation group is self-checking.


1978 ◽  
Vol 22 ◽  
pp. 181-191 ◽  
Author(s):  
Steven T. Smith ◽  
Robert L. Snyder ◽  
W. E. Brownell

Spray drying is shown to be an effective and rapid method for preparing samples for quantitative analysis by x-ray powder diffraction. Previously intractable problems like the simultaneous analysis of multiple phases in orientation prone systems can be carried out. Using this method, and a computer controlled diffractometer, five and six phase analyses of Devonian shales can be accomplished in approximately forty minutes. A rapid and convenient method for using the absorption diffraction technique for x-ray quantitative analysis is described.


1966 ◽  
Vol 38 (12) ◽  
pp. 1741-1745 ◽  
Author(s):  
R. F. Karlak ◽  
D. S. Burnett

1957 ◽  
Vol 1 ◽  
pp. 39-58
Author(s):  
Ralph H. Hiltz ◽  
Stanley L. Lopata

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.


1982 ◽  
Vol 26 ◽  
pp. 119-128 ◽  
Author(s):  
Ronald C. Gehringer ◽  
Gregory J. McCarthy ◽  
R.G. Garvey ◽  
Deane K. Smith

Solid solutions are pervasive in minerals and in industrial inorganic materials. The analyst is often called upon to provide qualitative and quantitative X-ray phase analysis for specimens containing solid solutions when all that is available are Powder Diffraction File (PDF) data or commercial standards for the end members. In an earlier paper (1) we presented several examples of substantial errors in accuracy of quantitative analysis that can arise when the crystallinity and composition of the analyte standard do not match those of the analyte in the sample of interest. We recommended that to obtain more accurate quantitative analyses, one should determine the analyte composition (e.g., from XRF on grains seen in a SEM or from comparison of cell parameters with those of the end members) and synthesize an analyte standard with this composition and with a crystallinity approximating that of the analyte (e.g., as determined from peak breadth or α1/ α2 splitting).


2011 ◽  
Vol 492 ◽  
pp. 424-428
Author(s):  
Yong Qi Wei ◽  
Wu Yao ◽  
Wei Wang

Quantitative X-Ray diffraction (QXRD) combined with the Rietveld refinement method allows direct determination of crystalline phase content of cement and its hydrates. However, relatively precise results need the correction of proper internal standards and the use of matched peak profile functions with masterly refinement strategies. The aim of this paper is to research and discuss effects of these factors on the quantitative phase analysis results. For this purpose, different internal standards and peak profile functions with corresponding refinement strategies were attempted in experiments and refinements. The results indicate that Al2O3as internal standard is more suitable for cement and its hydrates than ZnO, and the better peak profile function is CW function 2 rather than function 3 in GSAS.


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