scholarly journals Study of structural characteristics of vitrinites of Kuznetsk basin coals

2020 ◽  
Vol 63 (7) ◽  
pp. 54-59
Author(s):  
Anna N. Popova ◽  
Keyword(s):  
Structural Characteristics ◽  
Structural Parameters ◽  
Xrd Analysis ◽  
Interplanar Distance ◽  
Kuznetsk Basin ◽  
X Ray ◽  
Longitudinal Size ◽  
Bituminous Coals ◽  
Linear Nature ◽  
Good Agreement

The article is devoted to research of the main structural parameters of vitrinites of bituminous coals of various metamorphism degrees carried out by methods of X-ray phase and X-ray structural analysis. Vitrinite concentrates were obtained from coal of the Kuznetsk Basin. The main X-ray structural parameters were estimated: the number of carbon atoms in the lamellae (natC), the longitudinal size of the lamellae, and the height of their stacking (La and Lc), the number of polyaromatic layers in the package (N), and the packing density of the lamellae (ρ). It is shown in the work that in vitrinite concentrates, an increase in all analyzed structural parameters (Lc, La, natC, N, ρ) is observed with an increase in the degree of metamorphism, at the same time, a decrease in the value of the interplanar distance (d002) is observed. The XRD analysis showed that for the average number of layers in a package and carbon atoms per monolayer, in the samples of vitrinite concentrates of bituminous coals of high stages of metamorphism (Ro, r = 1.41%) varies from 7 to 8 and 14-15, respectively. It was found a correlation between the linear nature of the number of polyarene-layers and the height of their stacking. The results obtained were in good agreement with the literature data given for coals of various deposits.

scholarly journals Preparation and Characterization of Immobilized Molybdenum Complex on Pillared Montmorillonite K-10

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Farah Wahida Harun ◽  
Siti Balkis Mahamat Nor ◽  
Siti Salhah Othman
Keyword(s):  
Structural Characteristics ◽  
Xrd Analysis ◽  
Attenuated Total Reflection ◽  
Basal Spacing ◽  
Molybdenum Complex ◽  
X Ray ◽  
Pillared Montmorillonite ◽  
Sem Micrograph ◽  
Pillaring Solution

This study was carried out to immobilize molybdenyl (VI) acetylacetonate (MoO2(acac)2) complex on alumina pillared montmorillonite K-10 (MMT K-10). Pillar MMT K-10 was produced by introducing MMT K-10 with a hydrolysis solution of NaOH with AlCl3. Different concentrations of pillaring solution were prepared in terms of OHto Al3+ ratio (0.5, 1.0, 1.5 and 2.0) to observe the structural characteristics of MMT K-10. The pillared materials were then immobilized with 0.1 M MoO2(acac)2 and were characterized using X-ray diffractometry (XRD), scanning electron microscopy coupled in an energy dispersive X-ray spectrometer (SEM-EDX) and Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR) techniques. FTIR bands at ca. 890 – 930 cm-1 indicate that the Mo complex was immobilized on the surface of pillared MMT K-10 not in between the layers. This is supported by the SEM and XRD analysis where the SEM micrograph showed deposition of Mo on the surface of MMT K-10 as well as no modification of basal spacing was observed by XRD. Meanwhile, the d(001) spacing of the alumina pillared MMT K10 samples were seen to increase slightly as the concentration of OH/Al3+ increased.

Synthesis, Structural and Dielectric Properties of Pure and Ni Substituted Bismuth Ferrite

2014 ◽  
Vol 938 ◽  
pp. 140-144 ◽  
Author(s):  
S. Blessi ◽  
S. Vijayalakshmi ◽  
S. Pauline
Keyword(s):  
Dielectric Properties ◽  
Hydrothermal Method ◽  
Bismuth Ferrite ◽  
Synthesis Method ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Practical Application ◽  
X Ray ◽  
Wide Range ◽  
Good Agreement

Multiferroics have been known as materials exhibiting both ferroelectric and ferromagnetic properties in same phase, they have interesting physical properties as well as possibility of practical application in some new memories, spintronics and sensor devices. The present work reports the fabrication of pure and Nickel substituted Bismuth Ferrite by simple hydrothermal method at 180oC for 11 hours. The structural study was carried out using X-ray powder diffraction (XRD), and the Dielectric properties were investigated over a wide range of frequency and temperature. The image of SEM is in good agreement with the XRD analysis. The synthesis method is simple and cost effective. KEYWORDS: Multiferroics; Dielectric loss; Hydrothermal method; XRD.

Intramolecular and Liquid Structures of Tetramethylurea Studied by Means of X-Ray Diffraction

1992 ◽  
Vol 47 (9) ◽  
pp. 1003-1010 ◽  
Author(s):  
T. Radnai ◽  
H. Ohtaki
Keyword(s):  
Gas Phase ◽  
Random Distribution ◽  
Structural Parameters ◽  
Diffraction Method ◽  
Methyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Ordering ◽  
Amide Derivatives ◽  
Good Agreement

Abstract The intramolecular and liquid structures of tetramethylurea (TMU) were investigated by the liquid x-ray diffraction method. It is confirmed that in the liquid state the four methyl groups are out of the plane which is constructed by the O, C, and the two N atoms, the molecular structure being similar to what had been found in the gas phase. All structural parameters are in good agreement with those of TMU determined in the gas phase and with those of amide derivatives in the liquid phase. The liquid is characterized by a random distribution of molecules as predominant, but a weak molecular ordering characterized by approximately two intermolecular nonbonding Me ··· O distances at 340 pm is proposed

X-Ray Standing Wave and High Resolution Diffraction Study of Si/Ge Superlattices

1995 ◽  
Vol 379 ◽  
Author(s):  
S. Lagomarsino ◽  
P. Castrucci ◽  
P. Calicchia ◽  
A. Cedola ◽  
A. Kazimirov
Keyword(s):  
High Resolution ◽  
Standing Wave ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Phase 1 ◽  
Modern Technology ◽  
Characterization Methods ◽  
X Ray ◽  
Optimal Behavior ◽  
Strong Reflection

ABSTRACTIn modern technology more and more attention is given to epitaxial superlattices. III/V, and more recently Si/Ge superlattices are widely studied because of their applications in integrated optoelectronics. Since the physical properties are strongly dependent on structural characteristics, it is evident that accurate characterization methods are required in order to improve their quality and obtain optimal behavior. X-ray high resolution diffraction is extensively and successfully used to this purpose. In general diffracted intensity is measured close to strong substrate reflections where satellite peaks from superlattice take place. If the crystalline quality, mainly concerning thickness layer uniformity and interface abruptness is good, several orders of diffraction from the superlattice are visible, and fitting based on kinematical or dynamical diffraction can provide information about many structural parameters of the superlattice. However from diffracted intensity the information about the phase of the structure factor is lost. It is well known that the X-ray Standing Wave (XSW) technique can provide direct information about the phase [1]. In this paper we present measurements and calculations relative to the extension of the XSW method to the study of MBE-grown Si/Ge superlattices. The novelty consists in using the superlattice satellite peaks close to a strong reflection from the substrate to form the standing wave field which in turn excites the atoms whose fluorescence is measured. These satellite peaks correspond to high-order diffraction for the superlattice periodicity.

scholarly journals Thermoelectric Power, Electrical Resistivity and Magnetic Properties of Ni-Sm Nano-particles

2020 ◽  
Vol 11 (1) ◽  
pp. 7835-7846
Keyword(s):  
Thermoelectric Power ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Combustion Method ◽  
Xrd Analysis ◽  
Lattice Parameter ◽  
Differential Method ◽  
Nano Particles ◽  
Auto Combustion

Nanocrystalline Samarium doped Nickel ferrites having compositional formula NiSmXFe2-XO4 (0.00≤X≥0.10) were prepared by the citrate-gel auto combustion method and sintered at 5000C. The structural characteristics such as XRD analysis were shown cubic spinel structure, and the structural parameters like lattice parameter, X-ray density, bulk density, and porosity variations with Sm doping were studied. The surface morphology of prepared samples was observed by Scanning Electron Microscopy (SEM). The magnetic parameters were studied at room temperature with VSM, and the observed results are discussed with composition. The DC electrical properties were studied using a two-probe method in the temperature range from room temperature to well beyond Curie temperature. Thermoelectric power studies were carried out from room temperature to well beyond transition temperature with a differential method. The Seebeck coefficient variation with temperature was studied, and it shows the prepared samples are classified as n-type semiconductors. The observed results can be explained on the basis of the conduction mechanism.

Study of structural characteristics of the FePt nanosystem by TEM

2020 ◽  
Vol 63 (7) ◽  
pp. 79-84
Author(s):  
Yury A. Zaharov ◽  
◽  
Nikita S. Zaharov ◽  
Anna N. Popova ◽  
Dmitry M. Russakov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Analysis ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Fept Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Tem Method

In this work, using the example of a bimetallic nanoscale system FePt, a new approach to the assessment of the structural parameters of nanoscale mono- and polymetallic systems by transmission electron microscopy (TEM) is proposed. The data obtained by the TEM method are compared with the data obtained by the method of X-ray structural analysis. Some crystallographic parameters, such as the interplanar distances, average sizes, and phase compositions of the studied nanoparticles of the FePt system are calculated. The most widespread method for obtaining information about the crystal structure of nanosized particles is the method based on the phenomenon of X-ray diffraction. It allows one to determine the phase composition and perform structural analysis of a substance, as well as to estimate the size of the resulting particles. In this method, crystallographic information arises due to X-ray diffraction from the entire surface of the powder. Thus, the researcher sees an integral diffraction pattern. In this case, the study of individual nanoparticles by X-ray structural analysis is extremely difficult. However, the number of methods for assessing structural parameters is not limited to X-ray diffraction methods. In this work, an approach is made to study the structural characteristics of FePt nanoparticles by transmission electron microscopy (TEM), since high-resolution microimages obtained by the TEM method provide a unique opportunity to distinguish individual atoms of the crystal lattice of the objects under study.

High-pressure single-crystal study on AlPO4 with synchrotron radiation

1990 ◽  
Vol 23 (5) ◽  
pp. 397-400 ◽  
Author(s):  
H. Sowa ◽  
K. Reithmayer ◽  
J. Macavei ◽  
W. Rieck ◽  
H. Schulz ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Single Crystal ◽  
Diamond Anvil Cell ◽  
Structural Parameters ◽  
X Rays ◽  
X Ray ◽  
Single Crystal Study ◽  
Diamond Anvil ◽  
Counting Statistics ◽  
Good Agreement

A single-crystal study on AlPO4 was performed at 2.90 (7) GPa with synchrotron radiation using a diamond-anvil cell with a beryllium gasket. For the data collection the radiation wavelength of only 0.54 Å, was chosen to minimize the absorption of X-rays in the pressure cell. The diffracted intensity was high enough to measure even weak reflections with sufficient counting statistics. The refined structural parameters are in good agreement with those determined from data collected with a conventional X-ray tube.

scholarly journals Synthesis, Crystal Structure, and DFT Study ofN′-(2,4-Dinitrophenyl)-2-Fluorobenzohydrazide

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Aamer Saeed ◽  
Ifzan Arshad ◽  
Ulrich Flörke
Keyword(s):  
Molecular Structure ◽  
Density Functional ◽  
Structural Parameters ◽  
Basis Set ◽  
X Ray Diffraction ◽  
X Ray ◽  
Functional Methods ◽  
Hydrazide Derivative ◽  
Crystal Structural ◽  
Good Agreement

A new hydrazide derivativeN′-(2,4-dinitrophenyl)-2-fluorobenzohydrazide was synthesized and characterized by NMR and IR spectroscopy. The molecular structure was also studied by X-ray diffraction, and the results of the optimized molecular structure are presented and compared with density functional methods with 631-G basis set. The calculated results show that the optimized geometry can well reproduce the crystal structural parameters, for example, bond lengths and angles show good agreement with the experimental data.

scholarly journals Crystallography of Vanadium-bearing Micas (Bol'shoi Karatau Range, Kazakhstan)

2014 ◽  
Vol 70 (a1) ◽  
pp. C1102-C1102
Author(s):  
Galiya Bekenova ◽  
Kulyash Dyussembayeva
Keyword(s):  
Crystal Structure ◽  
Cell Parameter ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Vanadium Content ◽  
Polished Section ◽  
X Ray ◽  
North West ◽  
Mineralogical Study ◽  
Crystal Structural

The mineralogical study of vanadium and vanadium-bearing micas from Cambrian carbonaceous-cherty formation of North-West of Bol'shoi Karatau range has allowed to establish four basic groups: 1. chernykhite (V2O3+V2O4 up to 23%); 2. Ba-roscoelite (V2O3 up to 18%) [1]; 3. vanadium-bearing muscovite and phengite (V2O3 up to 5%) and 4. secondary mica – V-Ba-phengite (V2O3+V2O4 up to 6-8%) [2]. Physical, optical properties as well as crystal structural parameters depend on vanadium content. The crystal structure of micas was determined by X-ray and electron diffraction techniques. The polytypes and unit cell parameter b (Å) are the main structural characteristics [3]. 2M1 polytype is spread among vanadium micas. Polytypes 1M and (1M+2M1) are only in vanadium-bearing micas – muscovite and phengite. The minimum b 9.03-9.04 Å is typical for this group. For secondary mica - V-Ba-phengite the parameter b varies from 9.6 to 9.09 Å. On the figure the secondary mica (1) is associated with mica without vanadium (2) and carbon-clay-chert (3) into polished section, where epoxy resin (4). For Ba-roscoelite b is equal 9.07-9.15 Å; for chernykhite - b 9.18 Å.

XRD Analysis of Ferrite Ceramics with Different Heat Treatment

2019 ◽  
Vol 970 ◽  
pp. 314-319
Author(s):  
Anatoly P. Surzhikov ◽  
Sergei A. Ghyngazov ◽  
Vitaly A. Vlasov ◽  
Oldrich Stary ◽  
Alexey N. Sokolovskiy
Keyword(s):  
Heat Treatment ◽  
Rietveld Method ◽  
Structural Characteristics ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Qualitative And Quantitative ◽  
Diffraction Patterns

A comparative analysis of the structural characteristics of LiZnTi ferrites sintered at the temperature of 1280 and 1360 K was performed. The qualitative and quantitative X-ray diffraction (XRD) analysis of the samples, main phase structural analysis, and unit cell parameters were carried out using the non-standard method (Rietveld method). Diffraction patterns were recorded on an ARL X'TRA diffractometer in the CuKα1+α2 and CuKβ scanning modes.

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