Phase Evolution During Ball Milling of Al In NH3 and Subsequent Annealing

1997 ◽  
Vol 481 ◽  
Author(s):  
J. I Nikolov ◽  
J. S. Williams ◽  
D. J. Llewellyn ◽  
A. Calka
Keyword(s):  
Electron Microscopy ◽  
Ball Milling ◽  
Hollow Spheres ◽  
Analytical Techniques ◽  
Phase Evolution ◽  
X Ray Diffraction ◽  
Combustion Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
O Phase

ABSTRACTPhase evolution during ball milling of Al in both N2 and NH3 gas has been compared and the annealing behaviour studied in some detail. X-ray diffraction, differential thermal analysis, combustion analysis and scanning and transmission electron microscopy have been used as analytical techniques. Results have shown that a nitride is not formed in N2 but that Al forms into many small, hollow spheres during milling. In contrast, milling in NH3 results in an amorphous AlxNy(O) phase which transforms into crystalline AIN and A12O3 on annealing to 1000°C.

Non-Equilibrium Formation Of Silicon Nitride During Both Ball Milling And Ion Bombardment

1997 ◽  
Vol 481 ◽  
Author(s):  
Z. L. Li ◽  
J. S. Williams ◽  
D. J. Llewellyn ◽  
J. Wong-Leung ◽  
M. Giersig ◽  
...  
Keyword(s):  
Ball Milling ◽  
Analytical Techniques ◽  
Ion Bombardment ◽  
Phase Evolution ◽  
X Ray Diffraction ◽  
Combustion Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Nitride Formation ◽  
Amorphous Si

ABSTRACTPhase evolution during ball milling of Si in NH3 gas and during subsequent annealing has been studied and compared with nitride formation during ion bombardment of Si. X-ray diffraction, differential thermal analysis, Rutherford backscattering and channeling, combustion analysis and transmission electron microscopy have been used as analytical techniques. Results have shown that an amorphous SixNy(Fe) phase forms during milling which transforms into α-Si3N4 and FeSi2 on annealing. During ion bombardment, slightly N-rich Si3N4 is formed but it is mostly crystalline at temperatures between 150 and 450°C.

The Evaporative Decomposition of Solutions Method (Eds) for the Production of Ultrafine Y1Ba2Cu3O7 from Nitrate and Mixed Anion Precursor Solutions

1989 ◽  
Vol 169 ◽  
Author(s):  
Rollin E. Lakis ◽  
Sidney R. Butler
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Barium Carbonate ◽  
Hollow Spheres ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

AbstractY1Ba2Cu3O7 has been prepared by the evaporative decomposition of solutions method. Nitrate and mixed anion solutions were atomized and decomposed at temperatures ranging from 300°C to 950°C. The resulting materials have been characterized using x-ray powder diffraction, Thermal Gravimetric Analysis (TGA), particle size analysis, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The powder consists of 0.3 micron agglomerated hollow spheres with a primary particle size of 0.06 micron. TGA and x-ray diffraction indicate the presence of barium nitrate and barium carbonate due to incomplete decomposition and/or product contamination by the process environment.

Effect of Au on the Performance of Porous Silicon/V2O5 Nanorods Heterojunctions to NO2 Gas

NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650079 ◽  
Author(s):  
Wenjun Yan ◽  
Ming Hu ◽  
Jiran Liang ◽  
Dengfeng Wang ◽  
Yulong Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Analytical Techniques ◽  
Heating Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

A novel composite of Au-functionalized porous silicon (PS)/V2O5 nanorods (PS/V2O5:Au) was prepared to detect NO2 gas. PS/V2O5 nanorods were synthesized by a heating process of pure vanadium film on PS, and then the obtained PS/V2O5 nanorods were functionalized with dispersed Au nanoparticles. Various analytical techniques, such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), have been employed to investigate the properties of PS/V2O5:Au. Herein, the PS/V2O5:Au sample exhibited improved NO2-sensing performances in response, stability and selectivity at room temperature (25[Formula: see text]C), compared with the pure PS/V2O5 nanorods. These phenomena were closely related to not only the dispersed Au nanoparticles acting as a catalyst but also the p-n heterojunctions between PS and V2O5 nanorods. Whereas, more Au nanoparticles suppressed the improvement of response to NO2 gas.

scholarly journals Collagen-Coated Superparamagnetic Iron Oxide Nanoparticles as a Sustainable Catalyst for Spirooxindole Synthesis

2021 ◽  
Author(s):  
Shima Ghanbari ◽  
Maryam Esmkhani ◽  
Shahrzad Javanshir
Keyword(s):  
Electron Microscopy ◽  
Crosslinking Agent ◽  
Superparamagnetic Iron Oxide ◽  
Analytical Techniques ◽  
Sio2 Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Bet Analysis ◽  
Characterization Studies

Abstract In this work, a novel magnetic organic-inorganic hybrid catalyst was fabricated by encapsulating magnetite@silica (Fe3O4@SiO2) nanoparticles with Isinglass protein collagen (IGPC) using epichlorohydrin (ECH) as crosslinking agent. Characterization studies of the prepared particles were accomplished by various analytical techniques specifically, Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), and Brunauer−Emmett−Teller (BET) analysis. The XRD results showed a crystalline and amorphous phase which contribute to magnetite and isinglass respectively. Moreover, the formation of the core/shell structure had been confirmed by TEM images. The synthesized Fe3O4@SiO2/ECH/IG was applied as bifunctional heterogeneous catalyst in the synthesis of spirooxindole derivatives demonstrating excellent catalytic properties, stability and recyclability.

Microstructure and Anti-Friction Effect of Ball-Milled Expanded Graphite

2013 ◽  
Vol 704 ◽  
pp. 110-113
Author(s):  
Hong Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ball Milling ◽  
Expanded Graphite ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Friction Effect ◽  
Air Atmosphere ◽  
Transmission Electron

Expanded graphite (EG) was ball-milled in a high-energy mill (planetary-type) under an air atmosphere. The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The anti-friction effect of milled EG used as lubricating additive was investigated. After ball-milling, the relatively ordered graphene planes of original EG become deformed, and the d002 spacing becomes broadened. The milled EG used as lubricating additive have an anti-friction effect, and the effect is more marked than that of original EG.

scholarly journals Facile Synthesis of Calcium Carbonate Nanoparticles from Cockle Shells

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Kh. Nurul Islam ◽  
A. B. Z. Zuki ◽  
M. E. Ali ◽  
Mohd Zobir Bin Hussein ◽  
M. M. Noordin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Carbonate ◽  
Large Scale ◽  
Low Cost ◽  
Analytical Techniques ◽  
Variable Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir

A simple and low-cost method for the synthesis of calcium carbonate nanoparticles from cockle shells was described. Polymorphically, the synthesized nanoparticles were aragonites which are biocompatible and thus frequently used in the repair of fractured bone and development of advanced drug delivery systems, tissue scaffolds and anticarcinogenic drugs. The rod-shaped and pure aragonite particles of30±5 nm in diameter were reproducibly synthesized when micron-sized cockle shells powders were mechanically stirred for 90 min at room temperature in presence of a nontoxic and nonhazardous biomineralization catalyst, dodecyl dimethyl betaine (BS-12). The findings were verified using a combination of analytical techniques such as variable pressure scanning electron microscopy (VPSEM), transmission electron microscopy (TEM), Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), and energy dispersive X-ray analyser (EDX). The reproducibility and low cost of the method suggested that it could be used in industry for the large scale synthesis of aragonite nanoparticles from cockle shells, a low cost and easily available natural resource.

The structural transformation of anatase TiO2 by high-energy vibrational ball milling

1999 ◽  
Vol 14 (3) ◽  
pp. 841-848 ◽  
Author(s):  
Suchitra Sen ◽  
M. L. Ram ◽  
S. Roy ◽  
B. K. Sarkar
Keyword(s):  
Electron Microscopy ◽  
Ball Milling ◽  
Structural Transformation ◽  
Milled Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
First Time ◽  
Pressure Phase

The structural transformation of anatase TiO2 by high-energy vibrational ball milling was studied in detail by different analytical methods of x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). This structural transformation involves both phase transition and nanoparticle formation, and no amorphization was observed. The crystallite size was found to decrease with milling time down to nanometer size ∼13 nm and approaching saturation, accompanied by phase transformation to metastable phases, i.e., TiO2(II), which is a high-pressure phase and TiO2(B), which was identified in ball-milled powder reported for the first time in this paper. These phases eventually started transforming to rutile by further milling.

Influence of boron content on the amorphization rate of Co–B mixtures by mechanical alloying

1993 ◽  
Vol 8 (6) ◽  
pp. 1327-1333 ◽  
Author(s):  
A. Corrias ◽  
G. Ennas ◽  
G. Marongiu ◽  
A. Musinu ◽  
G. Paschina
Keyword(s):  
Electron Microscopy ◽  
Ball Milling ◽  
Ball Mill ◽  
Room Temperature ◽  
Boron Content ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
State Amorphization

Amorphous cobalt-boron alloy powders have been prepared by a high energetic ball mill at room temperature starting from different Co/B ratios. They were characterized by means of x-ray diffraction, scanning and transmission electron microscopy, and differential scanning calorimetry. Ball milling of Co–B mixtures induces solid-state amorphization which becomes faster with increasing boron content. After maximum amorphization ball milling leads to crystallization of t-Co2B in all the binary samples.

Amorphization mechanisms of NiZr2 by ball-milling

1997 ◽  
Vol 12 (3) ◽  
pp. 688-696 ◽  
Author(s):  
D. Galy ◽  
L. Chaffron ◽  
G. Martin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ball Milling ◽  
Amorphous Phase ◽  
Shear Waves ◽  
Nanocrystalline Structure ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

The microstructure of NiZr2 in the course of amorphization by ball-milling is studied by transmission electron microscopy (TEM) and x-ray diffraction (XRD). The evolution from the initial fully crystalline alloy to a fully amorphized material is described. It is shown that prior to amorphization, the powder aggregates achieve a 100% nanocrystalline structure; the amorphous phase then appears and develops to the expense of the nanocrystalline phase. No massive chemical disordering is observed, but a small amount cannot be ruled out. It is proposed that amorphization occurs by chemical disordering at interfaces, induced by the scattering of shear waves.

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