Application of the Rietveld method to quantitative analysis of impurities in synthetic diamond powder

2004 ◽  
Vol 19 (2) ◽  
pp. 141-144 ◽  
Author(s):  
Rashmi ◽  
Nahar Singh ◽  
A. K. Sarkar
Keyword(s):  
Phase Composition ◽  
Quantitative Analysis ◽  
Synthetic Diamond ◽  
Rietveld Method ◽  
Diamond Powder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Content ◽  
A Minor ◽  
Synthetic Diamond Powder

Synthetic diamonds are an important class of industrial material. During synthesis impurities may get introduced into diamond. Identification and quantification of impurities is important as they affect the properties and suitability of the diamonds for their application. Impurities in an industrial synthetic diamond powder sample were analyzed by X-ray diffraction (XRD) and also by chemical methods. X-ray diffraction pattern showed diamond as the major phase and α-iron as a minor phase. Quantitative analysis of crystalline phases was done by performing Rietveld refinement of the XRD profile. Chemical analysis showed the presence of several other impurities as well, though in small amounts. It was considered that the impurities other than iron were in amorphous form and an estimate of the amorphous content was made on this basis. Relative phase composition of diamond and iron as estimated by XRD were corrected for the amorphous content to obtain absolute phase composition.

Rietveld-based mineralogical quantitation of deferrified oxisol clays

Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 224 ◽  
Author(s):  
M. E. Alves ◽  
Y. P. Mascarenhas ◽  
D. H. French ◽  
C. P. M. Vaz
Keyword(s):  
Quantitative Analysis ◽  
Management Practices ◽  
Rietveld Method ◽  
Clay Fraction ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Analyses ◽  
Soil Clay ◽  
Derived Data

Although the mineralogical quantitative analysis of the soil clay fraction can provide useful information for the improvement of soil management practices, the quantitation of all clay components normally requires a combination of different analytical techniques, which makes this determination expensive and time-consuming. One alternative for more expeditious mineralogical quantitations consists of using the Rietveld method for the treatment of X-ray diffraction (XRD) data. In this study we evaluate the accuracy of the mineralogical quantitative analyses of oxisol deferrified clays carried out with the application of the Rietveld method to XRD data obtained for both non-spray- and spray-dried samples. Linear regression analyses were carried out for comparing the XRD-Rietveld results with those calculated from X-ray fluorescence spectroscopy (XRF) data. Correspondence was observed between the XRD-Rietveld and XRF-derived data, confirming the potential utility of the Rietveld method for soil clay mineralogical quantitative analysis. Although sample preparation by using the spray drying procedure tended to improve XRD mineralogical quantitation, accurate results can be also achieved when this procedure is not available in the XRD laboratory.

scholarly journals The Influence of Surface Preparation, Chewing Simulation, and Thermal Cycling on the Phase Composition of Dental Zirconia

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2133
Author(s):  
Markus Wertz ◽  
Florian Fuchs ◽  
Hieronymus Hoelzig ◽  
Julia Maria Wertz ◽  
Gert Kloess ◽  
...  
Keyword(s):  
Phase Composition ◽  
Rietveld Method ◽  
Tetragonal Zirconia ◽  
Surface Preparation ◽  
Dental Restoration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chewing Simulation ◽  
Yttria Content ◽  
Dental Restorative

The effect of dental technical tools on the phase composition and roughness of 3/4/5 yttria-stabilized tetragonal zirconia polycrystalline (3y-/4y-/5y-TZP) for application in prosthetic dentistry was investigated. Additionally, the X-ray diffraction methods of Garvie-Nicholson and Rietveld were compared in a dental restoration context. Seven plates from two manufacturers, each fabricated from commercially available zirconia (3/4/5 mol%) for application as dental restorative material, were stressed by different dental technical tools used for grinding and polishing, as well as by chewing simulation and thermocycling. All specimens were examined via laser microscopy (surface roughness) and X-ray diffraction (DIN EN ISO 13356 and the Rietveld method). As a result, the monoclinic phase fraction was halved by grinding for the 3y-TZP and transformed entirely into one of the tetragonal phases by polishing/chewing for all specimens. The tetragonal phase t is preferred for an yttria content of 3 mol% and phase t″ for 5 mol%. Mechanical stress, such as polishing or grinding, does not trigger low-temperature degradation (LTD), but it fosters a phase transformation from monoclinic to tetragonal under certain conditions. This may increase the translucency and deteriorate the mechanical properties to some extent.

scholarly journals Rietveld Analysis on X-Ray Diffraction Of South Kalimantan Kaolin Clays

2018 ◽  
Vol 6 (2) ◽  
pp. 171
Author(s):  
Ruliana Febrianti ◽  
Firda Herlina ◽  
Muhammad Saukani
Keyword(s):  
Quantitative Analysis ◽  
Goodness Of Fit ◽  
Least Squares Method ◽  
Rietveld Method ◽  
Rietveld Analysis ◽  
Peak Height ◽  
Peak Position ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Difference

At least 13 million tons of kaolin claystone lie in several regencies of South Kalimantan covering Banjar, Tapin, Hulu Sungai Utara and Kotabaru regencies. This paper reports an attempt to explore their crystalline state characteristics, projecting their potential use for geopolymer. Sungai Tabuk, Cintapuri and Tatakan, due to their largest kaolin claystone deposits, were chosen as the sampling sites. The kaolin samples were prepared by syphoning method prior to X-ray diffraction (XRD) characterizations in determining their crystalline phases. X’Pert HighScore Plus and Rietica software were respectively responsible for the qualitative and quantitative phase analyses. The qualitative analysis used search and match method at peak position and peak height between measured and calculated diffraction patterns. Our study revealed the existence of two main phases in the sample, i.e. quartz (SiO2) and kaolinite (Al2Si2O5(OH)4). In addition, the Quantitative analysis used the Rietveld method with the least squares method approach. Rietveld refinement was based on a goodness of fit score of less than 4% by minimizing the difference in the character of the diffraction pattern (position, height, width and peak shape) between the observed and the calculated XRD patterns. The Rietveld quantitative analysis shows, Tatakan is an area with kaolinite-richest deposit (±84%), followed by Cintapuri (±76%) and Tabuk (±70%); quartz is found in reverse.

Effect of microabsorption on the determination of amorphous content via powder X-ray diffraction

2018 ◽  
Vol 33 (1) ◽  
pp. 26-37 ◽  
Author(s):  
Nicola V. Y. Scarlett ◽  
Ian C. Madsen
Keyword(s):  
Rietveld Method ◽  
Relative Weight ◽  
Common Method ◽  
X Ray Diffraction ◽  
Routine Procedure ◽  
X Ray ◽  
Amorphous Content ◽  
Absorption Contrast

Powder X-ray diffraction has become a routine procedure for the quantification of phases in mixtures. The most common method for this measurement is the Rietveld method, which generally returns the relative weight percentages of the crystalline components within the mixture. However, in many instances, it is also desirable to obtain an estimate of the amorphous content of a sample. There are several methods that may be used for this measurement and their accuracy has been assessed previously with a number of ideal, synthetic mixtures. Many samples, especially in the mineralogy sphere, are far from ideal and contain multiple phases of varying absorption contrast. This creates a microabsorption problem which affects the accuracy of the determination of both the crystalline and amorphous components. This paper assesses commonly used methods of amorphous determination with a series of synthetic samples designed to create a considerable microabsorption problem.

Applications of X-ray Diffraction Crystallite Size/Strain Analysis to Seismosaurus Dinosaur Bone

1990 ◽  
Vol 34 ◽  
pp. 473-482 ◽  
Author(s):  
Steve J. Chipera ◽  
David L. Bish
Keyword(s):  
New Mexico ◽  
Crystallite Size ◽  
Profile Analysis ◽  
Rietveld Method ◽  
Strain Analysis ◽  
Morrison Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Minor ◽  
20 Nm

AbstractRecently, the remains of a giant Cretaceous Sauropod (~150 My old) were discovered in the Morrison Formation west of Albuquerque, New Mexico. This dinosaur, tentatively named Seismosaurus, was found in an exceptional state of preservation. Although it has been known since the 180Q's that fossilized bone is often composed of the mineral apatite, very few studies have been conducted to characterize farther the fossilized material. In an effort to gain insight into the state of preservation and Hie processes occurring in the bone since deposition, apatite in bone from Seismosaurus was compared with that from a contemporary elk from the Jemez Mountains, New Mexico, and with well-crystallized mineral apatite using X-ray powder diffraction and profile analysis techniques. Crystallite size/strain analyses were conducted using the Scherrer equation, the Warren-Averbaca and single-line methods, and the Rietveld method using the program GSAS. Heating the contemporary elk bone produced a decrease in the full-width-at-half-maximum (FWHM) of the reflections in the diffraction pattern. This decrease in FWHM is due to a decrease in microstrain along with a minor increase in crystallite size. Results from crystallite size/strain analysis show that both Seismosaurus and contemporary elk bone crystallites are elongate parallel to the c-axis. However, Seismosaurus bone crystallites are larger (-20-65 nm) with less strain than the contemporary elk bone crystallites (-8-20 nm), suggesting that if elk bone is an appropriate analog, then Seismosaurus bone must have undergone recrystallization.

A standardless X-ray diffraction method for the quantitative analysis of multiphase mixtures

1987 ◽  
Vol 20 (6) ◽  
pp. 457-460 ◽  
Author(s):  
J. Rius ◽  
F. Plana ◽  
A. Palanques
Keyword(s):  
Phase Composition ◽  
Quantitative Analysis ◽  
Qualitative Analysis ◽  
Least Squares ◽  
Diffraction Method ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Absorption Coefficients ◽  
X Ray ◽  
Pure Phases

An X-ray diffraction method is described that determines calibration constants using only diffracted intensities and calculated phase absorption coefficients through a least-squares procedure. The conditions necessary for the application of this method are that the qualitative analysis be complete, that sufficient samples with essential differences in the quantitative phase composition be available and that the chemical compositions of the phases be known approximately. It does not require the use of pure phases or the measuring of the sample absorption coefficients. It allows the easy introduction of known calibration constants, thus reducing the number of samples needed and increasing the versatility of the method.

Quantitative analysis of phase composition using X-ray diffraction methods

1972 ◽  
Vol 5 (5) ◽  
pp. 343-347 ◽  
Author(s):  
A. J. Majumdar ◽  
L. S. Vallance ◽  
C. G. G. Born
Keyword(s):  
Phase Composition ◽  
Quantitative Analysis ◽  
X Ray Diffraction ◽  
X Ray

The Comparative Study of Phase Composition of Steels Using X-Ray Diffraction and Mössbauer Spectroscopy Methods

2013 ◽  
Vol 203-204 ◽  
pp. 150-155
Author(s):  
Piotr Pawluk ◽  
Emilia Skołek ◽  
Michał Kopcewicz ◽  
Wiesław Świątnicki
Keyword(s):  
Mössbauer Spectroscopy ◽  
Phase Composition ◽  
Retained Austenite ◽  
Mossbauer Spectroscopy ◽  
Rietveld Method ◽  
Bainitic Ferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Diffraction Patterns

In this paper phase composition of several steels was investigated by X-ray diffraction and conversion electron Mössbauer spectroscopy (CEMS) methods. Different heat treatments were performed on steel samples in order to obtain various phase compositions (containing bainitic ferrite, martensite and retained austenite). The diffraction patterns were analysed using the Rietveld method. Mössbauer spectra were fitted and studied for existent phases. A comparison between results obtained by each method was performed. Both methods revealed some supersaturation of carbon in the retained austenite and in the bainitic ferrite phases, various after different treatments. The quantitative phase composition measured by X-ray diffraction results differ significantly from the Mössbauer spectroscopy results. The possible reasons of the observed differences were discussed.

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