Morphology and structure characteristics of nanoscale carbon materials containing graphene

2021 ◽  
Vol 6 (4) ◽  
pp. 247-255
Author(s):  
Evgeny K. Belonogov ◽  
Sergey B. Kushev ◽  
Sergey A. Soldatenko ◽  
Tatiana L. Turaeva
Keyword(s):  
Electron Microscopy ◽  
Carbon Materials ◽  
Expanded Graphite ◽  
High Energy ◽  
Mutual Orientation ◽  
Graphene Sheets ◽  
Multilayer Graphene ◽  
Thermally Expanded Graphite ◽  
Graphite Phase ◽  
X Ray

A comprehensive study of the nanostructured powders (graphite GSM-2; Taunit-M; thermally expanded graphite (TEG)) by methods of transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffractometry (XRD), reflection high-energy electron diffraction (RHEED), Raman spectroscopy, was carried out. The experimental XRD halo was interpreted by superimposing theoretical diffraction maxima, and an X-ray amorphous graphite phase was revealed. It was found that the X-ray amorphous phase is characterized by the limiting degree of graphite nanostructuring. From the width of the diffraction rings, the maximum sizes of graphite nanocrystals were estimated, which do not exceed 5 and 10 nm in the [0001] and [ ] directions, respectively. Carbon nanotubes and plates of turbostratic graphene were revealed. The structural and morphological parameters of the nanostructured material “Taunit-M” have been established – multi-walled nanotubes with a diameter of up to 10 nm are combined through an interlayer of X-ray amorphous carbon into flat ribbons up to 40 nm wide. Dark-field TEM images (in reflections of ) revealed moiré patterns that appear on overlapping graphene sheets due to double diffraction of the electron beam. It was found that in thermally expanded graphite, the rotation of graphene sheets ranges from 3 to 4°. Within the graphene sheets, complete dislocations with the Burgers vector b = 1/2 were revealed [1010]. The Fourier analysis of moiré images made it possible to determine the mutual orientation of graphene sheets, to reveal regions of multilayer graphene, and to identify turbostratic graphene. It is shown that the combination of RHEED, TEM, and Fourier transformations of periodic contrast of electron microscopic images is a promising approach to the analysis of the substructure and morphology of nanoscale carbon materials containing graphene and other allotropic modifications of carbon.

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.

High Temperature Tribological Behavior of Ball Milled Expanded Graphite/Iron Powders

2012 ◽  
Vol 499 ◽  
pp. 278-281 ◽  
Author(s):  
Hua Wang ◽  
Yong Guo ◽  
Shu Ying Wang
Keyword(s):  
Electron Microscopy ◽  
Tribological Behavior ◽  
Expanded Graphite ◽  
High Energy ◽  
X Ray Diffraction ◽  
Iron Powders ◽  
X Ray ◽  
Friction Effect ◽  
Transmission Electron ◽  
Milled Powders

A mixture of expanded graphite (EG) and iron powders was ball-milled in a high-energy mill. The milled EG/Fe powders were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The tribological behavior of the milled powders used as lubricating additive was investigated by using a tribo-tester. The results show that the milled powders used as lubricating additive have an obvious anti-friction effect, and the more large the applied temperature, the more marked the anti-friction effect.

Fabrication of Ni–Al thin films by the pulsed laser deposition technique

1992 ◽  
Vol 7 (10) ◽  
pp. 2639-2642 ◽  
Author(s):  
R.K. Singh ◽  
Deepika Bhattacharya ◽  
S. Sharan ◽  
P. Tiwari ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Pulsed Laser ◽  
High Energy ◽  
Laser Deposition ◽  
Nanosecond Laser ◽  
X Ray ◽  
Target Composition

We have fabricated Ni3Al and NiAl thin films on different substrates by the pulsed laser deposition (PLD) technique. A high energy nanosecond laser beam was directed onto Ni–Al (NiAl, Ni3Al) targets, and the evaporated material was deposited onto substrates placed parallel to the target. The substrate temperature was varied between 300 and 400 °C, and the substrate-target distance was maintained at approximately 5 cm. The films were analyzed using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry. At energy densities slightly above the evaporation threshold, a slight enrichment of Al was observed, while at higher energy densities the film stoichiometry was close (<5%) to the target composition. Barring a few particles, the surface of the films exhibited a smooth morphology. X-ray and TEM results corroborated the formation of Ni3Al and NiAl films from similar target compositions. These films were characterized by small randomly oriented grains with grain size varying between 200 and 400 Å.

Mechanochemical Synthesis of Intermetallic Compounds in the Gallium–Iridium System

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940067
Author(s):  
P. Vitiaz ◽  
N. Lyakhov ◽  
T. Grigoreva ◽  
E. Pavlov
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Activation ◽  
Intermetallic Compounds ◽  
High Energy ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
X Ray ◽  
Active Liquid ◽  
Scanning Electron

The interaction between a solid inert metal Ir and an active liquid metal Ga during mechanical activation in a high-energy planetary mill is studied by X-ray diffraction and scanning electron microscopy with high-resolution energy dispersive X-ray microanalysis. The effect of mechanical activation on the formation of GaxIry intermetallic compounds and GaxIry/Ir composites and their solubility in acids was investigated. The subsequent extraction of Ga from intermetallic compounds and composites in the mixture of concentrated acids [Formula: see text] makes it possible to produce nanoscale Ir.

Precipitation- and stress-influenced coarsening in Mg-based Mg–Zn–Sn–Y and Mg–Zn–Sn–Sb alloys

2008 ◽  
Vol 23 (5) ◽  
pp. 1228-1236 ◽  
Author(s):  
Anton Gorny ◽  
Alexander Katsman
Keyword(s):  
Electron Microscopy ◽  
Research Work ◽  
Mutual Orientation ◽  
Face Centered Cubic ◽  
Two Phase ◽  
X Ray ◽  
High Resolution Tem ◽  
Interphase Boundaries ◽  
Different Temperatures ◽  
The Face

Extensive experimental research work has been carried out to investigate precipitation peculiarities in Mg–Zn–Sn-based alloys during aging at different temperatures. This in-depth research was conducted on Mg–4.4wt%Zn–4.0wt%Sn–0.6wt%Y and Mg–4.4wt%Zn–4.4wt%Sn–1.1wt%Sb using x-ray diffraction (XRD), transmission electron microscopy (TEM) including high-resolution TEM, and scanning electron microscopy (SEM) equipped with an energy-dispersive x-ray spectrometer (EDS). It was found that, first, a hexagonal close-packed (hcp)-MgZn2 phase nucleates and grows in the form of needles having coherent interphase boundaries with α-Mg matrix. Then the face-centered cubic (fcc)-Mg2Sn-phase nucleates heterogeneously, mainly at the tips of MgZn2 needles. A very certain mutual orientation of crystal lattices of MgZn2, Mg2Sn, and α-Mg matrix was revealed. The orientation of Mg2Sn precipitates is perpendicular to that of MgZn2 needles. They grow in the form of plates parallel to the basal planes of α-Mg matrix. Two-phase T-like particles are very typical of alloys aged for 1 to 16 days at 175 to 225 °C. The width/length ratio of MgZn2 needles inside T-like particles differs substantially from that found in single needles. The elastic/surface energy balance of needles and its influence on the morphology and coarsening behavior has been analyzed.

scholarly journals Preparation and examination of multilayer graphene nanosheets by exfoliation of graphite in high efficient attritor mill

2011 ◽  
Vol 9 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Péter Kun ◽  
Ferenc Wéber ◽  
Csaba Balázsi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Graphene Nanosheets ◽  
Multilayer Graphene ◽  
X Ray Diffraction ◽  
Mechanical Method ◽  
X Ray ◽  
High Efficient ◽  
Dispersion Media ◽  
Scanning Electron

AbstractGraphene multilayers have been prepared by mechanical method based on milling graphite in high efficient attritor mill. The results showed that the best dispersion media is ethanol, and 10 hours of intensive milling proved to be the most efficient way to separate the graphite layers as it was shown by scanning electron microscopy and X-ray diffraction measurements.

Anti-Friction Effect of Ball-Milled and Subsequently Annealed Expanded Graphite/Iron Powder Mixture

2012 ◽  
Vol 182-183 ◽  
pp. 319-322
Author(s):  
Yu Shan Li
Keyword(s):  
Size Range ◽  
Expanded Graphite ◽  
High Energy ◽  
X Ray Diffraction ◽  
Iron Powders ◽  
X Ray ◽  
Friction Effect ◽  
Air Atmosphere ◽  
Vacuum Atmosphere ◽  
Better Than

A mixture of expanded graphite (EG) and iron powders was ball-milled in a high-energy mill under an air atmosphere and subsequently annealed under a vacuum atmosphere. The products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their anti-friction effect used as lubricating additive was investigated by using a tribo-tester. On the surface of the products, graphite encapsulated iron nanoparticles with a size range of 50-150 nm were formed. Compared with only milled EG/Fe powders, the products exhibit a higher crystallinity of graphite and iron. The products have a marked anti-friction effect, and this effect is better than that of the only milled EG/Fe powders.

Nano structure of low crystallinity carbon materials analyzed by using high energy X-ray diffraction

Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
Kyoichi Oshida ◽  
Tatsuo Nakazawa ◽  
Kozo Osawa ◽  
Morinobu Endo
Keyword(s):  
Carbon Materials ◽  
Lithium Ion ◽  
High Energy ◽  
Experimental Results ◽  
Disordered Materials ◽  
X Ray Diffraction ◽  
Structural Units ◽  
Nano Structure ◽  
X Ray ◽  
Low Crystallinity

AbstractIn this study, we tried to characterize a kind of low crystallinity carbon materials. The structure of polyparaphenylene(PPP)-based carbon was analyzed by means of high energy X-ray diffraction using the apparatus of SPring-8. The experimental results revealed the existence of basic structural units (BSU) in the highly disordered materials like PPP-based carbon. It is thought that the PPP-based carbons consist of small turbostratic particles, which have a few piled up poly-aromatic layers. The structure of the PPP-based carbon which seemed to be amorphous was estimated to have hexagonal carbon layers with the size of up to 1 nm. The pores in the PPP-based carbon seem to be clearances formed among the BSUs and amorphous carbon. The pore size of PPP-based carbon was estimated from the result of N2 absorption measurement. The experimental results suggested that the lithium ion charge mechanism in the PPP-based carbon differs from that in graphite.

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