The Peak Resolution of Diffuse X-Ray Diffraction Pattern of Tibetan Medicine

2012 ◽  
Vol 562-564 ◽  
pp. 1959-1963
Author(s):  
Xin Wen Duan ◽  
Yuan Liu ◽  
Cheng Xi Hu ◽  
Yong De Li
Keyword(s):  
Least Square Method ◽  
Least Square ◽  
Tibetan Medicine ◽  
X Ray Diffraction ◽  
Composite Function ◽  
Xrd Pattern ◽  
X Ray ◽  
Signal Processing Method ◽  
Peak Resolution ◽  
Diffraction Peaks

Modern signal processing method is employed to peak resolution for four kinds of classical Tibetan Medicine X-ray diffraction patterns.Characterizing crystal diffraction peaks with Guass-Cauchy composite function, and combining with seventh polynomial characterizing the non-crystalline peak, the nonlinear least square method are adopted for peak resolution of Tibetan medicine XRD pattern. The result shows good handling effects of peak resolution.

Identification of a deleterious phase in photocatalyst based on Cd1 − xZnxS/Zn(OH)2by simulated XRD patterns

2017 ◽  
Vol 73 (3) ◽  
pp. 360-368 ◽  
Author(s):  
Svetlana Cherepanova ◽  
Dina Markovskaya ◽  
Ekaterina Kozlova
Keyword(s):  
Experimental Data ◽  
Thermogravimetric Analysis ◽  
Variable Temperature ◽  
Interlayer Distance ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Diffraction Peaks ◽  
Xrd Patterns

The X-ray diffraction (XRD) pattern of a deleterious phase in the photocatalyst based on Cd1 − xZnxS/Zn(OH)2contains two relatively intense asymmetric peaks withd-spacings of 2.72 and 1.56 Å. Very small diffraction peaks with interplanar distances of (d) ≃ 8.01, 5.40, 4.09, 3.15, 2.49 and 1.35 Å are characteristic of this phase but not always observed. To identify this phase, the XRD patterns for sheet-like hydroxide β-Zn(OH)2and sheet-like hydrozincite Zn5(CO3)2(OH)6as well as for turbostratic hydrozincite were simulated. It is shown that the XRD pattern calculated on the basis of the last model gives the best correspondence with experimental data. Distances between layers in the turbostratically disordered hydrozincite fluctuate aroundd≃ 8.01 Å. This average layer-to-layer distance is significantly higher than the interlayer distance 6.77 Å in the ordered Zn5(CO3)2(OH)6probably due to a deficiency of CO32−anions, excess OH−and the presence of water molecules in the interlayers. It is shown by variable-temperature XRD and thermogravimetric analysis (TGA) that the nanocrystalline turbostratic nonstoichiometric hydrozincite-like phase is quite thermostable. It decomposes into ZnO in air above 473 K.

Controlled Synthesis of Fe3O4 Nanosheets via P123 Micelle Template

2010 ◽  
Vol 663-665 ◽  
pp. 1125-1128
Author(s):  
De Hui Sun ◽  
De Xin Sun ◽  
Yu Hao
Keyword(s):  
Drug Targeting ◽  
Magnetic Drug Targeting ◽  
Recording Media ◽  
Magnetic Recording Media ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Fundamental Research ◽  
Diffraction Peaks ◽  
Fcc Structure

Magnetic iron oxide nanomaterials (e.g. Fe3O4 and γ-Fe2O3) with different morphologies have aroused extensive attention due to their fundamental research and potential technological applications such as magnetic recording media, magnetic fluids and magnetic drug-targeting. In this article Fe3O4 nanosheets were successfully synthesized using triblock copolymer (PEO)20(PPO)70(PEO)20 (P123) micelles as structure-directing agents in the presence of surfactant-assisted ethylene glycol (EG) and precipitator hexamethylenetetramine (HMTA) at 70 °C for 2 h in N2. The Fe3O4 nanosheets have irregular shape with thickness of the Fe3O4 nanosheets about 10-15 nm. The X-ray diffraction (XRD) pattern confirms the Fe3O4 nanosheets have magnetite structure and its nine distinguishable diffraction peaks can be perfectly indexed to the (111), (220), (311), (222), (400), (422), (511), (440), and (533) planes of the fcc structure of magnetite. Its saturation magnetization (σs) is 58.4 emu/g. The possible formation mechanism of the Fe3O4 nanosheets in present work is proposed.

Crystal Structure of Al2Cu3Nd Ternary Compound

2016 ◽  
Vol 850 ◽  
pp. 8-12
Author(s):  
De Gui Li ◽  
Liu Qing Liang ◽  
Ming Qin ◽  
Lei Hu ◽  
Chang Sheng Qin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ternary Compound ◽  
Hexagonal Structure ◽  
Argon Atmosphere ◽  
System Alloy ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Arc Melting ◽  
Diffraction Peaks

A new Al-Cu-Nd system alloy, the high-purity Al2Cu3Nd ternary compound, was developed and prepared with the stoichiometric amounts of elemental constituents by arc melting under argon atmosphere. The X-ray diffraction (XRD) data of Al2Cu3Nd was collected by using the Rigaku Smart Lab X-ray powder diffractometer, and all X-ray diffraction peaks of Al2Cu3Nd compound were indexed successfully with the hexagonal structure. The Rietveld refinement results of the XRD pattern for the Al2Cu3Nd compound showed that the Al2Cu3Nd compound is the hexagonal structure, space group P6/mmm (No.191) with a = 5.2397(1) Å, c = 4.1783(1) Å, V = 99.34 Å3, Z = 1. The density of the compound was 6.501 g/cm3, and its reference intensity ratio (RIR) w 1.26.

Second Derivative X-Ray Diffraction Fingerprint of Tibetan Medicine Snow Lotus Herb Based on the Five-Point-Formula Method

2014 ◽  
Vol 543-547 ◽  
pp. 1211-1214
Author(s):  
Wei Wei Zhang ◽  
Wei Feng Yang ◽  
Cheng Xi Hu ◽  
Yu Hui Shi ◽  
Jian Rui Zhu
Keyword(s):  
Tibetan Medicine ◽  
Second Derivative ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Matlab Program ◽  
Snow Lotus ◽  
Formula Method

A MATLAB program was written with the Five-Point-Formula method for obtaining the second derivative (SD) XRD pattern, using which the SD fingerprints of SiO2 and Tibetan medicine Snow Lotus Herb were gotten respectively. The results show that the problem of the diffuse XRD plant-based patterns analysis can be solved effectively, and it also possesses the remarkable zoom function, which is worth being spread.

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.

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

Comparative Studies of Ultra Low-κ Porous Silica Films with 2-D Hexagonal and Disordered Pore Structures

2004 ◽  
Vol 812 ◽  
Author(s):  
Nobutoshi Fujii ◽  
Kazuhiro Yamada ◽  
Yoshiaki Oku ◽  
Nobuhiro Hata ◽  
Yutaka Seino ◽  
...  
Keyword(s):  
Pore Structure ◽  
Nonionic Surfactants ◽  
Porous Silica ◽  
Silica Film ◽  
X Ray Diffraction ◽  
Silica Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Porous Silica Film ◽  
Diffraction Peaks

AbstractPeriodic 2-dimensional (2-D) hexagonal and the disordered pore structure silica films have been developed using nonionic surfactants as the templates. The pore structure was controlled by the static electrical interaction between the micelle of the surfactant and the silica oligomer. No X-ray diffraction peaks were observed for the disordered mesoporous silica films, while the pore diameters of 2.0-4.0 nm could be measured by small angle X-ray scattering spectroscopy. By comparing the properties of the 2-D hexagonal and the disordered porous silica films which have the same porosity, it is found that the disordered porous silica film has advantages in terms of the dielectric constant and Young's modulus as well as the hardness. The disordered porous silica film is more suitable for the interlayer dielectrics for ULSI.

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.

The Microstructure and Electrical Property of Porous Cu Film on Soft PVDF Substrate

2012 ◽  
Vol 472-475 ◽  
pp. 1451-1454
Author(s):  
Xue Hui Wang ◽  
Wu Tang ◽  
Ji Jun Yang
Keyword(s):  
Electrical Properties ◽  
Film Surface ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Cu Films ◽  
Cu Film ◽  
Diffraction Peaks ◽  
Sputtering Pressure ◽  
Effect Method

The porous Cu film was deposited on soft PVDF substrate by magnetron sputtering at different sputtering pressure. The microstructure and electrical properties of Cu films were investigated as a function of sputtering pressure by X-ray diffraction XRD and Hall effect method. The results show that the surface morphology of Cu film is porous, and the XRD revealed that there are Cu diffraction peaks with highly textured having a Cu-(220) or a mixture of Cu-(111) and Cu-(220) at sputtering pressure 0.5 Pa. The electrical properties are also severely influenced by sputtering pressure, the resistivity of the porous Cu film is much larger than that fabricated on Si substrate. Furthermore, the resistivity increases simultaneously with the increasing of Cu film surface aperture, but the resistivity of Cu film still decreases with the increasing grain size. It can be concluded that the crystal structure is still the most important factor for the porous Cu film resistivity.

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