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Iron-bearing phases affecting the colour of upper Neogene clayey sediments from Dymaczewo Stare, west-central Poland

Klęsk Jakub, Błachowski Artur, Diduszko Ryszard, Kruszewski Łukasz, Widera Marek

Geologos

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2022

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Vol. 28, No. 2

129--139

EN

The present paper investigates the colour dependence of mineral compositions in clay-rich sedimentary strata, mainly clayey silts, the emphasis being on iron-bearing minerals (rather than clay minerals) by using powder X-ray diffraction (PXRD) and 57Fe Mössbauer spectroscopy (57Fe-MS). The PXRD-based phase analysis has demonstrated the variable compositions of samples, consisting of, inter alia, quartz, calcite or gypsum, and admixtures of potassium feldspars and plagioclase. Hematite + goethite (sample D1, dark red), goethite (sample D2, pinkish brown), poorly crystalline goethite (sample D3, orange) and jarosite (sample D4, yellow) have been distinguished. A very low jarosite content was detected in sample D5 (light grey); this did not affect its colour. The potential yellow/brown shades in sample D6 (dark grey), coming from trace amounts of jarosite, are masked by macroscopically visible organic matter. In the case of the two last-named samples (D5 and D6), with trace amounts of Fe-bearing minerals, it is most likely that the organic matter was effective in influencing the light and dark grey colour of the sediment, respectively.

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X-ray diffraction study of the elastic properties of jagged spherical CdS nanocrystals

Dey Pijush Ch., Sarkar Sumit, Das Ratan

Materials Science Poland

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2020

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Vol. 38, No. 2

271--278

EN

In this work, jagged spherical CdS nanocrystals have been synthesized by chemical method to study their elastic properties. The synthesized CdS nanocrystal has been characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The transmission electron microscope images show that the average size of the nanocrystal is 100 nm approximately. X-ray diffraction (XRD) study confirms that the CdS nanocrystals are in cubic zinc blende structure. The size calculated from the XRD is consistent with the average size obtained from the TEM analysis. The XRD data have been analyzed to study the elastic properties of the jagged spherical CdS nanocrystals, such as intrinsic strain, stress and energy density, using Williamson-Hall plot method. Williamson-Hall method and size-strain plot (SSP) have been used to study the individual effect of crystalline size and lattice strain on the peak broadening of the jagged spherical CdS nanocrystals. Size-strain plot (SSP) and root mean square (RMS) strain further confirm the results obtained from W-H plots.

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Alkaline earth yttrium borates: synthesis, characterization and calculation of unit cell parameters

Gül G. Ç., Kurtuluş F.

Archives of Materials Science and Engineering

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2016

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Vol. 78, nr 1

5--9

EN

Purpose: Purpose of this paper, our object is solid state synthesis and investigation of structural and chemical characterization properties of Ba3Y(BO3)3 and Sr3Y2(BO3)4 as members of alkaline earth yttrium borates. Design/methodology/approach: In the synthesis procedure; barium carbonate, strontium carbonate, yttrium oxide and boric acid weighed an appropriate molar ratio and homogenized in an agate mortar. The mixture placed into a porcelain crucible to heat in high temperature oven at 900°C for 4 hours. After intermediate grindings, samples were cooled down to room temperature. Homogenized powders were characterized by Powder X-ray Diffractometer (XRD) to determine crystal structures. FTIR spectrum was taken to support the functional groups. Morphological properties and semi-quantitative analyse of the sample was performed by Scanning Electron Microscope/Energy dispersive (SEM/EDX). Findings: The XRD patterns of Ba3Y(BO3)3 and Sr3Y2(BO3)4 compounds indicate that crystallization procedure were completed successfully. The unit cell parameters of the compounds was calculated by Rietveld refinement method. In FTIR spectrum the vibrations of B-O bonds are determined via comparison to literature Research limitations/implications: Implication the synthesis method has some disadvantages such as low homogeneity, non-uniform product etc. We tried to minimize these negative aspects in our research and succeeded. Practical implications: Alkaline earth yttrium borates Ba3Y(BO3)3 and Sr3Y2(BO3)4 compounds were synthesized by solid state technique at 900°C. Unit cell parameters of the compounds were calculated by Rietveld refinement method and vibrations of functional group was indicated in FTIR spectrum. Originality/value: Value of the paper is first time conventional synthesis of Ba3Y(BO3)3 and Sr3Y2(BO3)4 compounds, calculation of unit cell parameters, and investigation of morphological and thermal properties

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New Ferrocenylpyridinium Salts with Bulk Second-Order Nonlinear Optical Properties

Plażuk D., Zakrzewski J., Nakatani K.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 12

2105-2111

EN

Protonation of (E)-1-ferrocenyl-2-(pyridin-4-yl)-ethylene with (+)-camphor-10-sulfonic and picric acid afforded salts displaying high second harmonic generation (SHG) efficiencies (70 and 10 × urea, respectively). Powder X-ray diffraction study confirmed crystallization of these salts in a noncentrosymmetric space group (P2). The electronic structure of the cationic part of the salts was studied by the DFT method.