Characterization of Ultra Fine Palladium Particles with the Mean Size of 20 A by X-Ray Diffraction

1981 ◽  
Vol 50 (9) ◽  
pp. 3071-3074 ◽  
Author(s):  
Ken-ichi Ohshima ◽  
Shigeki Yatsuya ◽  
Jimpei Harada
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Mean Size ◽  
The Mean ◽  
Palladium Particles

Synthesis and Characterization of Surface Protected Nanocrystalline Particles of Titania

1998 ◽  
Vol 519 ◽  
Author(s):  
E. Scolan ◽  
C. Sanchez
Keyword(s):  
X Ray Diffraction ◽  
Elastic Light Scattering ◽  
Titanium Butoxide ◽  
X Ray ◽  
Toluene Sulfonic Acid ◽  
Nanocrystalline Particles ◽  
Mean Size ◽  
The Mean ◽  
Cp Mas Nmr

AbstractMonodisperse non-aggregated nanoparticles of titania are obtained through hydrolysis at 60°C of titanium butoxide in the presence of acetylacetone and para-toluene sulfonic acid. After drying the resulting xerosols can be dispersed without aggregation in water-alcoholic or alcoholic solutions. The characterizations of the nanoparticles have been carried out by using quasi-elastic light scattering (QELS), 13C 1H in solution and X-ray diffraction, TEM, TG-DTA, 13C CP-MAS NMR in the solid state. The mean size of the anatase oxide core can be adjusted in the I to 5 nanometer range by a careful tuning of the synthetic conditions. The anatase particles are surrounded by acetylacetonato ligands, para-toluene sulfonate based species and water.

scholarly journals Preparation and electrochemical characterization of Pt nanoparticles dispersed on niobium oxide

2003 ◽  
Vol 28 (2) ◽  
pp. 69-76
Author(s):  
R. L. S. Mello ◽  
F. I. Mattos-Costa ◽  
H. de las M. Villullas ◽  
L. O. de S. Bulhões
Keyword(s):  
Niobium Oxide ◽  
Sol Gel ◽  
Pt Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mean Size ◽  
The Mean ◽  
General Aspects ◽  
Titanium Substrates

Electrodes consisting of Pt nanoparticles dispersed on thin films of niobium oxide were prepared onto titanium substrates by a sol-gel method. The physical characterization of these electrodes was carried out by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The mean size of the Pt particles was found to be 10.7 nm. The general aspects of the electrochemical behavior were studied by cyclic voltammetry in 1 mol L-1 HClO4 aqueous solution. The response of these electrodes in relation to the oxidation of formaldehyde and methanol in acidic media was also studied.

Characterization of Ni Nanopowders Produced by Electrical Explosion of Wire Technique

2006 ◽  
Vol 510-511 ◽  
pp. 710-713
Author(s):  
Hwan Tae Kim ◽  
Won Sik Seo ◽  
Dae Hwan Kwon ◽  
Pyuck Pa Choi ◽  
Ji Soon Kim ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Explosion ◽  
Nickel Wire ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
Argon Gas ◽  
X Ray ◽  
Nickel Powders ◽  
The Mean

Nanosize nickel powders were successfully produced by electrical explosion of wire (EEW). In EEW, the nickel wire was discharged in a chamber filled with nitrogen or argon gas, and the produced powders were subsequently stabilized by air-passivation at room temperature for 2 h. X-ray diffraction only showed the nickel phase of FCC crystal structure, whereas TEM and XPS analyses showed the formation of a very thin oxide layer of NiO on the surface of particles. Particles were spherical in shape, and the mean particle size calculated by specific surface area was about 100 nm. The particle size decreased with increasing charging voltage and with increasing ambient gas pressure. Argon gas was more effective in producing finer particles than nitrogen gas.

Synthesis and Characterization of Silver Nanoparticles Anchored on Montmorillonite via Chemical Reduction

2016 ◽  
Vol 11 ◽  
pp. 30-37 ◽  
Author(s):  
Danica Louise S. Bonga ◽  
Ma. Manna Farrel B. Pinto ◽  
Mary Fatima T. Tayad
Keyword(s):  
Ag Nanoparticles ◽  
Sodium Citrate ◽  
Chemical Reduction ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Clay Particles ◽  
X Ray ◽  
Mean Size

Montmorillonite clay particles were decorated with silver (Ag) nanoparticles by chemical reduction of Ag nitrate with sodium citrate. X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS) confirmed the presence of metallic Ag on the surface of montmorillonite. The average crystallite size of the Ag nanoparticles obtained from the broadening of the 111 Ag peak ranged at 13-16 nm. On the other hand, the apparent particle sizes obtained from the SEM images were about 79-128 nm, suggesting that the nanoparticles are polycrystalline and possibly agglomerated. The increase in the concentration of reducing agent produced smaller Ag nanoparticles with narrower size distribution. The antibacterial test showed that the Ag nanoparticles, with mean size of 79 nm, adsorbed on montmorillonite were able to inhibit the growth of Staphylococcus aureus (S. aureus) with an antimicrobial index of 0.4.

Preparation and Characterization of Lignin Powder Micronized by a Supercritical Antisolvent (SAS) Process

2011 ◽  
Vol 233-235 ◽  
pp. 1642-1645 ◽  
Author(s):  
Qi Lu ◽  
Yuan Gang Zu ◽  
Lei Yang ◽  
Xiu Hua Zhao ◽  
Wen Jun Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Optimal Conditions ◽  
Orthogonal Array Design ◽  
X Ray Diffraction ◽  
Array Design ◽  
X Ray ◽  
Mean Particle Size ◽  
Supercritical Antisolvent ◽  
The Mean

Nanoscale lignin was successfully prepared with a supercritical antisolvent (SAS) apparatus using acetone as a solvent and superciritical carbon dioxide as an antisolvent. Four factors were studied and optimized by a four-level orthogonal array design (OAD). According to analysis of variance, precipitation pressure had a significant effect on mean particle size. The optimal conditions are as follows: precipitation temperature 35 °C, precipitation pressure 30 MPa, temperature difference +10 °C and concentration of lignin solution 0.5 mg/mL. The micronized lignin under the optimal conditions was characterized by Scanning Electron Microscopy (SEM), Fourier-transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and X-Ray Diffraction (XRD) analyses. The results showed the mean particle size of micronized lignin was 0.144 ± 0.03 μm and had no degradation. The solubility of micronized lignin was improved significantly in distilled water.

scholarly journals Synthesis, Spectroscopic and X-Ray Structural Characterization of [Cd(linpen)]2+, a Model for Metal Complexes of the Chelating Polymer Polyethyleneimine (linpen = Linear Pentaethylenehexamine)

1992 ◽  
Vol 47 (6) ◽  
pp. 829-836 ◽  
Author(s):  
Henry Strasdeit
Keyword(s):  
Metal Ion ◽  
X Ray Diffraction ◽  
Linear Isomer ◽  
X Ray ◽  
Chelating Polymer ◽  
The Mean ◽  
Hexadentate Ligand ◽  
Solid Compounds ◽  
Strong Distortion

The isolation of 3,6,9,12-tetraazatetradecane-1,14-diamine (linear isomer of pentaethylenehexamine, linpen) from a technical polyamine mixture is described. In methanol, linpen acts as a hexadentate ligand towards cadmium(II). The solid compounds [Cd(linpen)](BPh4)2 (1), [Cd(linpen)](BPh4)2•2 DMSO (2) and [Cd(linpen)](BF4)2 (3) have been isolated and characterized by elemental analysis, spectroscopy and X-ray powder diffraction. The 113Cd NMR resonance of 1 is at 351 ppm (0.30 M in DMSO-d6, standard: 0.10 M Cd(ClO4)2 in D2O).2 and 3 have been structurally characterized by single-crystal X-ray diffraction. 2: C 2/c; a = 19.337(1)Å, b = 17.937(1)Å, c = 18.584(1)Å, β = 111.54(1)°; Z = 4, R = 0.034, Rw = 0.033.3: P21/n; a = 8.607(1)Å, b = 14.851(2)Å, c = 15.703(2)Å, ß = 91.21(2)°; Z = 4,R = 0.083, Rw = 0.072. Both compounds contain discrete [Cd(linpen)]2+ complexes. The hexamine wraps around the metal ion in a helical manner. This results in a strong distortion of the coordination polyhedron. The mean Cd-N bond lengths are 2.38Å and 2.37Å for 2 and 3, respectively.Models for MN6 centers in metal-polyethyleneimine (PEI) complexes are derived from the structure of [Cd(linpen)]2+. For example, loops at the MN6 site in molecules of linear PEI are proposed.

Preparation of hexagonal cerium oxide nanoflakes by a surfactant-free route and its optical property

2007 ◽  
Vol 22 (11) ◽  
pp. 3006-3013 ◽  
Author(s):  
X. Yu ◽  
P. Ye ◽  
L. Yang ◽  
S. Yang ◽  
P. Zhou ◽  
...  
Keyword(s):  
Cerium Oxide ◽  
Visible Region ◽  
Blue Shift ◽  
Emission Peak ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strong Reflection ◽  
Mean Size ◽  
The Mean ◽  
Pl Emission

Hexagonal cerium oxide nanoflakes have been synthesized by using a surfactant-free route. Transmission electcron microscopy (TEM), x-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric and differential thermal analysis (TG-DTA), Brunauer–Emmett–Teller adsorption isotherm (BET), photoluminescence (PL), and ultraviolet–visible (UV–VIS) were used to characterize the sample. The mean size of the nanoflakes is about 30 nm and the specific surface is about 70.08 m2·g−1 when annealed at 400 °C. The acidity and superfluous NH4NO3 play a key role on the formation of nanoflakes in which there exists Ce (IV) and very little Ce (III). The nanoflakes exhibit a wide PL emission peak among 350–400 nm, strong absorption ranged from 200–450 nm, and strong reflection in the visible region. As the sizes of as-prepared samples decrease, a clear blue shift in the absorbing edge is observed. The linear relationship between ΔEg and D is shown in a log–log plot. The as-prepared cerium oxide nanoflakes can be widely used as UV absorbent and polishing materials.

The Determination of Crystallite Size and Size Distribution from Broadened X-Ray Diffraction Lines

1961 ◽  
Vol 5 ◽  
pp. 94-103 ◽  
Author(s):  
H. F. Quinn ◽  
P. Cherin
Keyword(s):  
Harmonic Analysis ◽  
Size Distribution ◽  
Fourier Coefficients ◽  
Distribution Functions ◽  
Composite Sample ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mean Size ◽  
The Mean

AbstractMagnesium oxide crystallites having mean dimensions in the range of 25–1000 A can be prepared by controlled thermal decomposition of the carbonate.Following some earlier investigations of Birks and Friedman, we have determined the mean size and size distribution of several such MgO samples from the broadened X-ray diffraction lines which they exhibit. Contrary to the procedure of the above investigators, the harmonic analysis due to Stokes has been used to correct for instrumental broadening and values of mean-size and size-distribution functions obtained from the Fourier coefficients by the methods of Warren and Averbach.The results obtained are compared with average sizes and distributions obtained by direct examination of the samples in an electron microscope.A composite sample has been prepared by mixing known quantities of the sample previously studied. The distribution function obtained by harmonic analysis of one diffraction line of the composite sample is compared with the function calculated from the distributions of its components.Conclusions are drawn concerning the significance of the results obtained by the Warren technique: in particular, the average sizes obtained by this method are compared with those given by the approximate method used by Birks and Friedman.

scholarly journals Модификация структурно-морфологических свойств германия в многослойной нанопериодической структуре Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-/Ge с промежуточными слоями Si при отжиге

2021 ◽  
Vol 55 (10) ◽  
pp. 882
Author(s):  
М.В. Байдакова ◽  
Н.А. Берт ◽  
В.Ю. Давыдов ◽  
А.В. Ершов ◽  
А.А. Левин ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Annealing Temperature ◽  
Electron Beam Evaporation ◽  
X Ray Diffraction ◽  
Bimodal Size Distribution ◽  
X Ray ◽  
Transmission Electron ◽  
Mean Size ◽  
The Mean

Multi-layered nanosized Al2O3/Ge/Si structures manufactured by electron-beam evaporation and annealed at a temperature within the range 700−900◦C are examined using transmission electron microscopy, Raman spectroscopy and X-ray diffraction techniques. The periodic structure with a good layer planarity is confirmed to retain after heat treatment up to 900◦C. At an annealing temperature above 700◦C, nanocrystallites with a bimodal size distribution start to form within initially amorphous Ge layers, the mean size of small crystallites being determined by Ge layer thickness and annealing temperature. An essential loss of Ge from multi-layered structure after 900oC anneal and development of Ge1−x Six solid solution with x up to 0.07 in the nanocrystallites is revealed.

scholarly journals Characterization of Radium Sulphate

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Hanna Hedström ◽  
Ingmar Persson ◽  
Gunnar Skarnemark ◽  
Christian Ekberg
Keyword(s):  
Substitutional Solid Solution ◽  
Barium Sulphate ◽  
X Ray Diffraction ◽  
Lead Sulphate ◽  
X Ray ◽  
Cell Parameters ◽  
Barium Strontium ◽  
The Mean ◽  
Sulphate Media

This paper examines the crystal structure of radium sulphate and compares its structure to barium sulphate, strontium sulphate, and lead sulphate. The radium sulphate powder was measured by both powder X-ray diffraction and EXAFS. The unit cell was determined to be orthorhombic, belonging to the Pnma (no. 62) space group with the cell parameters a=9.07 Å, b=5.52 Å, c=7.28 Å, and V=364.48 Å3. These data support the fact that radium sulphate is isostructural with barium, strontium, and lead sulphate. The bond distances were determined using EXAFS. The mean Ra–O and S–O bond distances were found to be 2.96(2) Å and 1.485(8) Å, respectively, and the Ra–O–S bond angle was 127(2)∘. Findings of EXAFS data are quite consistent and support the XRD data. These findings show that it is possible for radium to coprecipitate with barium, strontium, and lead in sulphate media to form a substitutional solid solution.

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