Comparative Study on the Structure and Properties of Japanese and Self-Made Precursors

2011 ◽  
Vol 317-319 ◽  
pp. 292-296
Author(s):  
Bao Hua Ji
Keyword(s):  
Comparative Study ◽  
Crystal Size ◽  
Cyano Group ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Compact Structure ◽  
Cross Sectional ◽  
Xrd Pattern ◽  
X Ray ◽  
Infrared Spectrometer

In order to release the important information on the structural constitution of Japanese precursor, comparative study on structure and properties of Japanese and self-made precursors were carried out by X-ray Diffraction (XRD), infrared spectrometer (FTIR), element content analysis and the breaking tenacity. It was found that Japanese precursor contains cyano group (–CN) and may contain styrene sulfonic acid amine, while not containing the carboxyl and ester carbonyl, that is, not containing MA. The XRD pattern of Japanese precursor around 10° appears a new crystalline diffraction peak, and the crystal size becomes lower. The cross-sectional shapes of Japanese precursor are circle, with uniform and compact structure, thus its mechanical properties is superior.

Structure and Properties of C-Axis Oriented AlN Films Reactively Deposited by DC Planar Magnetron Sputtering

1989 ◽  
Vol 167 ◽  
Author(s):  
Takakazu Takahashi ◽  
Fumio Takeda ◽  
Masahiko Naoe
Keyword(s):  
Magnetron Sputtering ◽  
Film Plane ◽  
Dielectric Constants ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Planar Magnetron ◽  
Diffraction Peaks ◽  
Ambient Gas

AbstractAluminum nitride (AlN) films have been deposited by reactive DC planar magnetron sputtering at a low substrate temperature of 80°C. An Al disk and either N2 or NH3 were used as a target and an ambient gas, respectively. In films deposited in N2, the c-axis of AlN crystallites was perpendicular to the film plane. On the other hand, in NH3, X-ray diffraction peaks from (100), (110) and (200) were observed. The surface and the cross-sectional microstructures of AlN films deposited in N2 were significantly different from that deposited in NH3. The surface of films deposited in NH3 was smoother than that deposited in N2. The transmittivity of films deposited in NH3 was superior to that deposited in N2 in wavelength of 275∼450 nm. Resistivities of films deposited in N2 and in NH3 were 1014sim;1015 Ω · cm. Dielectric constants of films deposited in N2, and of that deposited in NH3, were 9.7, and 9, respectively, in a frequency range of 20 kHz to 20 MHz. The structure and the properties of AlN films deposited by this method depended on kind of ambient gas.

Neutron and X-ray diffraction study of ferrite nanocrystals obtained by microwave-assisted growth. A structural comparison with the thermal synthetic route

2014 ◽  
Vol 47 (1) ◽  
pp. 414-420 ◽  
Author(s):  
Eduardo Solano ◽  
Carlos Frontera ◽  
Teresa Puig ◽  
Xavier Obradors ◽  
Susagna Ricart ◽  
...  
Keyword(s):  
Crystal Size ◽  
Annealing Temperature ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Structural Comparison ◽  
X Ray ◽  
Microwave Assisted ◽  
Cationic Distribution ◽  
Lower Annealing Temperature ◽  
Microstructure And Magnetic Properties

Neutron and X-ray powder diffraction have been used to investigate the differences between the crystal growth of ferrite magnetic nanoparticles (MFe2O4withM= Mn, Fe, Co, Ni, Zn) by two methodologies: microwave radiation and thermal decomposition routes. Rietveld refinement has been used to extract the cationic distribution, the microstructure and magnetic information. Results for the nanoparticles produced by the two procedures evidence similar cationic distribution, microstructure and magnetic properties: complete cationic disorder forM= Mn and Co, crystal size around/below 10 nmetc. It is thus proven that microwave-assisted growth is a promising eco-friendly synthetic technique for the generation of high-quality nanocrystals with comparable structure and properties to those produced by the thermal methodology, even though the microwave route needs a shorter time and lower annealing temperature to obtain the final crystal nanoparticles.

Effect of Solvent Residuals on the Structure and Properties of Polyacrylonitrile Fibers

2011 ◽  
Vol 79 ◽  
pp. 254-257 ◽  
Author(s):  
Bao Hua Ji
Keyword(s):  
Crystal Size ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Initial Temperature ◽  
Exothermic Peak ◽  
Structure And Properties ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effect Of Solvent

In order to study the effect of solvent residuals on structure and properties of polyacrylonitrile fibers, the morphology, crystallinity and thermal properties of the fibers were discussed by Electron Microprobe Analysis, X-Ray Diffraction and DSC Analysis. It showed that the cross-section of the fibers with a lower solvent residual tends to be circular. The higher the solvent residuals are, the lower the crystallinity of the fibers and the bigger the crystal size. With the increase of solvent residual, the initial temperature of the fibers’ exothermic peak is in advance and the terminal temperature lags behind, the peak temperature increases, and the heat release also increases. Excessive solvent residuals make the heatrelease reaction very violent and the heatrelease increases. The ladder-shaped cyclation structure formed during the preoxidation process often breaks down because of the instant vast heatrelease.

scholarly journals Garcinia Mangostana Peel Extract as Sustainable Fuel Source on Ceria Synthesis under Hydrothermal Condition

2019 ◽  
Vol 8 (3) ◽  
pp. 255-261
Author(s):  
Salprima Yudha S ◽  
◽  
Morina Adfa ◽  
Aswin Falahudin ◽  
Deni Agus Triawan ◽  
...  
Keyword(s):  
Crystal Size ◽  
Hydrothermal Reaction ◽  
Hydrothermal Condition ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
Garcinia Mangostana ◽  
Reaction Conditions ◽  
Xrd Pattern ◽  
X Ray ◽  
Fuel Source

Cerium (IV) oxide or ceria (CeO2) was fabricated by heating an aqueous extract of Garcinia mangostana and cerium (III) nitrate in hydrothermal autoclave reactor at 200 °C for 3 hours, followed by calcination at 600 °C for 5 hours. The powder X-ray diffraction (XRD) pattern of the precipitate from cerium(III) nitrate under hydrothermal reaction conditions shows no clear XRD peaks, indicating its amorphous nature. In contrast, the products from the calcinated samples exhibit XRD peaks, which correspond to cubic fluorite structure with an average crystal size of 7.55 nm. The elemental mapping using the energy-dispersive X-ray (EDX) analysis reveals the main elements present were cerium and oxygen, with minor impurities in low amounts. The presence of Garcinia mangostana extract is predicted to be the key component and fuel source to obtain CeO2 particles with narrow crystal size.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

scholarly journals Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Crystal Size ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Flow Rates ◽  
X Ray ◽  
N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

scholarly journals Multi-Scale Studies of 3D Printed Mn–Na–W/SiO2 Catalyst for Oxidative Coupling of Methane

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 290
Author(s):  
Tim Karsten ◽  
Vesna Middelkoop ◽  
Dorota Matras ◽  
Antonis Vamvakeros ◽  
Stephen Poulston ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Oxidative Coupling Of Methane ◽  
Operating Conditions ◽  
Homogeneous Distribution ◽  
Silica Support ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Multi Scale ◽  
3D Printed

This work presents multi-scale approaches to investigate 3D printed structured Mn–Na–W/SiO2 catalysts used for the oxidative coupling of methane (OCM) reaction. The performance of the 3D printed catalysts has been compared to their conventional analogues, packed beds of pellets and powder. The physicochemical properties of the 3D printed catalysts were investigated using scanning electron microscopy, nitrogen adsorption and X-ray diffraction (XRD). Performance and durability tests of the 3D printed catalysts were conducted in the laboratory and in a miniplant under real reaction conditions. In addition, synchrotron-based X-ray diffraction computed tomography technique (XRD-CT) was employed to obtain cross sectional maps at three different positions selected within the 3D printed catalyst body during the OCM reaction. The maps revealed the evolution of catalyst active phases and silica support on spatial and temporal scales within the interiors of the 3D printed catalyst under operating conditions. These results were accompanied with SEM-EDS analysis that indicated a homogeneous distribution of the active catalyst particles across the silica support.

Determination of crystallinity of Chinese handmade papers by means of X-ray diffraction

2020 ◽  
Vol 41 (2) ◽  
pp. 69-86
Author(s):  
Peng Liu ◽  
Hongbin Zhang ◽  
Sinong Wang ◽  
Hui Yu ◽  
Bingjie Lu ◽  
...  
Keyword(s):  
Negative Influence ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Eulaliopsis Binata ◽  
Different Types ◽  
Powder Samples ◽  
Xrd Patterns ◽  
Xrd Method

AbstractThe crystallinity indices (CrI) of Chinese handmade papers were investigated using the X-ray diffraction (XRD) method. Four Chinese handmade papers, Yingchun, Zhuma, Yuanshu and Longxucao papers were used as model substrates of mulberry bark, ramie, bamboo and Eulaliopsis binata papers, respectively. Two forms of the paper samples, paper sheets and their comminuted powders, were used in this study. The results showed that their XRD patterns belong to the cellulose-I type and Iβ dominates the cellulose microstructure of these paper samples. Moreover, it was found that the microstructures and CrIs of cellulose of these papers were changed by the grinding treatment. This work suggested that the sheet form of the handmade papers is suitable to determine CrI by XRD, despite the contribution of non-cellulosic components in the papers. The order of CrIs for these paper sheet samples was Yingchun, Zhuma, Longxucao and Yuanshu papers. Besides CrIs, differences in cross-sectional areas of the crystalline zone of cellulose can be used for comparing different types of handmade papers. It was also found that the CrIs and crystallite size of paper cellulose varied between the sheet samples and the powder samples, illustrating that the pulverisation has a negative influence on the microstructure of the handmade papers.

Hydrothermal Synthesis and Characterization of BiFeO3 Polyhedral Crystallites

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.

Structural changes in titanium dioxide nanocrystals during plastic deformation

2005 ◽  
Vol 38 (5) ◽  
pp. 749-756 ◽  
Author(s):  
Ulrich Gesenhues
Keyword(s):  
Structural Changes ◽  
Crystal Size ◽  
Lower Layer ◽  
High Energy ◽  
Primary Crystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hall Method ◽  
Means Of Transmission

The polygonization of 200 nm rutile crystals during dry ball-milling at 10gwas monitored in detail by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD). The TEM results showed how to modify the Williamson–Hall method for a successful evaluation of crystal size and microstrain from XRD profiles. Macrostrain development was determined from the minute shift of the most intense reflection. In addition, changes in pycnometrical density were monitored. Accordingly, the primary crystal is disintegrated during milling into a mosaic of 12–35 nm pieces where the grain boundaries induce up to 1.2% microstrain in a lower layer of 6 nm thickness. Macrostrain in the interior of the crystals rises to 0.03%. The pycnometrical density, reflecting the packing density of atoms in the grain boundary, decreases steadily by 1.1%. The results bear relevance to our understanding of plastic flow and the mechanism of phase transitions of metal oxides during high-energy milling.

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