A new method for Rietveld clay analysis. Part I. Use of a universal measured standard profile for Rietveld quantification of montmorillonites

A new method for the quantification of montmorillonite by full-profile Rietveld analysis of the XRD profile is presented. A measured standard XRD pattern of Algerian bentonite was used to construct a universally applicable montmorillonite (hkl) file for use with a P.C. based Rietveld XRD quantitative analysis system, SIROQUANT. “Universal” means that the standard file can be used for montmorillonites from other localities. The validity of the montmorillonite standard profile was tested with weighed mixtures of quartz and different standard montmorillonites. The results show the montmorillonite observed (hkl) file is generally applicable (i.e., universal), and can be used to quantify montmorillonite in any mineral without modification or chemical treatment of the sample. Two halfwidth functions were used for the montmorillonite, corresponding to the sharp (hk0) and broad (hkl) classes of reflections. A March preferred orientation parameter for montmorillonite was also refined.

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Full-profile Rietveld quantitative XRD analysis of Portland cement: Standard XRD profiles for the major phase tricalcium silicate (C3S: 3CaO.SiO2)

Powder Diffraction ◽

10.1017/s0885715600018054 ◽

1993 ◽

Vol 8 (3) ◽

pp. 138-144 ◽

Cited By ~ 38

Author(s):

J. C. Taylor ◽

L. P. Aldridge

Keyword(s):

Portland Cement ◽

Xrd Analysis ◽

Xrd Pattern ◽

Major Phase ◽

Full Profile ◽

Phase Quantification ◽

Analysis System ◽

Standard Profile ◽

Best Fit ◽

Low Symmetry

The calculated XRD profiles of alite (impure Ca3SiO5, the major phase in Portland cement) derived from seven postulated crystal structures for alite were compared with a measured alite profile, extracted from the XRD pattern of a standard Portland cement. Only two of these profiles were found suitable for multiphase Rietveld phase quantification, namely those given by the monoclinic superlattice and triclinic models. These, however, gave very slow computing times because the large low-symmetry structures generated many X-ray reflections over the pattern. Also tested was an “observed” standard profile for alite, derived from experimental alite profiles, and generated using the (hkl) file feature of the SIROQUANT P.C. quantitative analysis system. This file was based on rhombohedral pseudosymmetry and contained very few (hkl) reflections, compared to the low-symmetry models (64 reflections instead of 951 for the monoclinic and 1691 for the triclinic models, respectively). The latter standard profile gave the best fit to the known phase concentrations and gave computing times which were shorter by factors of 2.5 and 4.9 than those for the monoclinic and triclinic standard profiles, respectively.

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Synthesis and Solid-State Structure of a Pt-Ru-P Ternary Metal Phosphide (PtRuP2) as a Carbon Nanocomposite

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.099 ◽

2008 ◽

Vol 8 (6) ◽

pp. 3146-3152 ◽

Cited By ~ 1

Author(s):

William D. King ◽

Krzysztof C. Kwiatkowski ◽

Charles M. Lukehart

Keyword(s):

Rietveld Analysis ◽

Carbon Powder ◽

Metal Phosphide ◽

Xrd Pattern ◽

Cscl Type ◽

Unknown Substance ◽

Full Profile ◽

Ternary Metal ◽

Powder Composites ◽

A Cell

Reactive thermal degradation of Pt(PPh3)(Cl)(μ2-Cl)2 Ru(Cl)(η3:η3-C10H16)/Vulcan carbon powder composites gives a nanocomposite powder containing nanocrystals of the expected PtRu alloy phase along with nanocrystals of an unknown substance. Yields of the unknown phase increase when PPh3 is added to the composite prior to thermal treatment. The new substance has been identified as a ternary metal phosphide, PtRuP2. Full-profile Rietveld analysis of the XRD pattern of this phase is consistent with a primitive Pm3m cubic unit cell (CsCl-type) having a cell constant of 2.78 Å. Fully disordered Pt and Ru atoms occupy the (0 0 0) atomic positions with P atoms occupying interstitial sites at the (1/2 1/2 1/2) atomic positions.

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New Method for On-line Quantitative Analysis of Regional Wall Motion Using Color Kinesis

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(97)84253-2 ◽

1998 ◽

Vol 31 (2) ◽

pp. 127A

Author(s):

T Fujino

Keyword(s):

Quantitative Analysis ◽

Wall Motion ◽

Regional Wall Motion ◽

New Method ◽

Regional Wall ◽

Color Kinesis ◽

On Line

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A New Approach for the Analysis of Mixture Toxicity Data

Water Science & Technology ◽

10.2166/wst.1992.0733 ◽

1992 ◽

Vol 26 (9-11) ◽

pp. 2345-2348 ◽

Cited By ~ 2

Author(s):

C. N. Haas

Keyword(s):

Quantitative Analysis ◽

Mixture Toxicity ◽

New Method ◽

Metal Exposure ◽

Positive Interactions ◽

Toxicity Data ◽

Data Set ◽

New Approach ◽

Negative Interactions

A new method for the quantitative analysis of multiple toxicity data is described and illustrated using a data set on metal exposure to copepods. Positive interactions are observed for Ni-Pb and Pb-Cr, with weak negative interactions observed for Ni-Cr.

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