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.

Characterization of kaolinite in the hardsetting clay fraction using atomic force microscopy, X-ray diffraction, and the Rietveld method

2017 ◽  
Vol 17 (8) ◽  
pp. 2144-2155 ◽  
Author(s):  
Luis Valério Prandel ◽  
Nívea Maria Piccolomini Dias ◽  
Sérgio da Costa Saab ◽  
André Maurício Brinatti ◽  
Neyde Fabíola Balarezo Giarola ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Rietveld Method ◽  
Clay Fraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

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.

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.

scholarly journals QUANTIFICAÇÃO DE MULLITA PROVENIENTE DE RESÍDUOS DE CAULIM DA REGIÃO AMAZÔNICA: USO DO MÉTODO DE RIETVELD

Química Nova ◽  
2020 ◽  
Author(s):  
Marlice Martelli ◽  
Eric Mochiutti ◽  
João Lima ◽  
Roberto Neves
Keyword(s):  
Rietveld Method ◽  
Internal Standard ◽  
Amazon Region ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Mineral Phases ◽  
Precursor Material ◽  
Quantitative Analyses

QUANTIFICATION OF MULLITE FROM KAOLIN WASTES FROM THE AMAZON REGION: USE OF THE RIETVELD METHOD. Mullite is used to obtain a refractory material, there are several factors that influence the synthesis process of mullite: the preparation of the mixture, the precipitation and the reaction of SiO2 and Al2O3. For the synthesis of mullite, samples of kaolin processing residues were used as precursor material, because it presents SiO2 and Al2O3 in its composition. This work aimed to identify, by X-ray diffraction, and quantify the mineral phases present in samples of kaolin processing residues from the Amazon region calcined at 1300, 1400 and 1500 ºC, using the Rietveld method. The method allowed the refinement of the complex crystalline structures and was applied to the data supply for quantitative analyses with satisfactory results of good accuracy. The results of the quantification of crystalline and non-crystalline phases (with internal standard) in the samples calcined at 1500 ºC presented approximate values of mullite (62%), cristobalite (32%) and non-crystalline phases (6%), for both samples, indicating that the refinement model applied is optimal. These results obtained from the quantification of the phases by the method of Rietveld are presenting coherent and satisfactory values, in comparison with the theoretical ones by the phase diagram Al2O3 and SiO2

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

scholarly journals Provenance and Sedimentary Context of Clay Mineralogy in an Evolving Forearc Basin, Upper Cretaceous-Paleogene and Eocene Mudstones, San Joaquin Valley, California

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Andrew Hurst ◽  
Michael Wilson ◽  
Antonio Grippa ◽  
Lyudmyla Wilson ◽  
Giuseppe Palladino ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Upper Cretaceous ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Bulk Rock ◽  
X Ray Diffraction ◽  
Arc Volcanism ◽  
X Ray ◽  
Magmatic Arc ◽  
Tropical Weathering

Mudstone samples from the Moreno (Upper Cretaceous-Paleocene) and Kreyenhagen (Eocene) formations are analysed using X-ray diffraction (XRD) and X-ray fluorescence (XRF) to determine their mineralogy. Smectite (Reichweite R0) is the predominant phyllosilicate present, 48% to 71.7% bulk rock mineralogy (excluding carbonate cemented and highly bio siliceous samples) and 70% to 98% of the <2 μm clay fraction. Opal CT and less so cristobalite concentrations cause the main deviations from smectite dominance. Opal A is common only in the Upper Kreyenhagen. In the <2 μm fraction, the Moreno Fm is significantly more smectite-rich than the Kreyenhagen Fm. Smectite in the Moreno Fm was derived from the alteration of volcaniclastic debris from contemporaneous rhyolitic-dacitic magmatic arc volcanism. No tuff is preserved. Smectite in the Kreyenhagen Fm was derived from intense sub-tropical weathering of granitoid-dioritic terrane during the hypothermal period in the early to mid-Eocene; the derivation from local volcanism is unlikely. All samples had chemical indices of alteration (CIA) indicative of intense weathering of source terrane. Ferriferous enrichment and the occurrence of locally common kaolinite are contributory evidence for the intensity of weathering. Low concentration (max. 7.5%) of clinoptilolite in the Lower Kreyenhagen is possibly indicative of more open marine conditions than in the Upper Kreyenhagen. There is no evidence of volumetrically significant silicate diagenesis. The main diagenetic mineralisation is restricted to low-temperature silica phase transitions.

X-ray powder diffraction data of LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites

2021 ◽  
pp. 1-6
Author(s):  
Mariana M. V. M. Souza ◽  
Alex Maza ◽  
Pablo V. Tuza
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Pechini Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Modified Pechini Method ◽  
Scanning Electron

In the present work, LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites were synthesized by the modified Pechini method. These materials were characterized using X-ray fluorescence, scanning electron microscopy, and powder X-ray diffraction coupled to the Rietveld method. The crystal structure of these materials is orthorhombic, with space group Pbnm (No 62). The unit-cell parameters are a = 5.535(5) Å, b = 5.527(3) Å, c = 7.819(7) Å, V = 239.2(3) Å3, for the LaNi0.5Ti0.45Co0.05O3, a = 5.538(6) Å, b = 5.528(4) Å, c = 7.825(10) Å, V = 239.5(4) Å3, for the LaNi0.45Co0.05Ti0.5O3, and a = 5.540(2) Å, b = 5.5334(15) Å, c = 7.834(3) Å, V = 240.2(1) Å3, for the LaNi0.5Ti0.5O3.

scholarly journals Analytical study of Buddha sculptures in Jingyin temple of Taiyuan, China

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaojian Bai ◽  
Chen Jia ◽  
Zhigen Chen ◽  
Yuxuan Gong ◽  
Huwei Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Analytical Study ◽  
Energy Dispersive Spectrometry ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Ancient China ◽  
X Ray ◽  
Unique Style ◽  
Scanning Electron

AbstractWith exquisite design and unique style, the painted sculptures of Tutang Buddha and two attendants Buddha in Jingyin Temple are precious cultural heritages of China. The sculpture of Tutang Buddha, which was carved from a mound and painted by ancient craftsmen, was rarely found in ancient China. However, due to natural and human factors, the sculptures were severely damaged. Obviously, they require urgent and appropriate protection and restoration. In this study, samples taken from the sculptures were analysed through multiple analytical techniques, including scanning electron microscopy with energy dispersive spectrometry (SEM–EDS), Raman spectroscopy, X-ray diffraction (XRD), optical microscopy (OM) and granulometry. The analysis results enable us to infer the techniques used by the craftsmen in making the sculptures and provide a reliable evidence for the conservation and future protection of these and similar sculptures.

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