In situ electron microscope study on the formation and morphological evolution of carbon aggregates

Wang, Heng-Zhi; Zhu, Heguo; Li, Dan; Wang, Xin

doi:10.1016/s0008-6223(02)00062-3

Cited by 6 publications

(4 citation statements)

References 24 publications

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“…It was reported that the oxidized amorphous carbon can have an order of magnitude higher electron yields than other areas (Díaz et al , ). The tip is a dominating occurrence of the magnitude of electric charges, and one driving force of evolution process of the morphologies can be thereof the surface tension of amorphous carbon under the irradiation of electron beam in a vacuum system (Wang et al , ). Fujita et al observed the local enhanced electric field around the apex of long protruded tip in a low accelerating voltage 5 kV of SEM, the local field intensity can reach ∼100 V/μm (Fujita et al , ).…”

Section: Resultsmentioning

confidence: 99%

Revealing the 1 nm/s extensibility of nanoscale amorphous carbon in a scanning electron microscope

Zhang

2012

Scanning

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In an ultra-high vacuum scanning electron microscope, the edged branches of amorphous carbon film (∼10 nm thickness) can be continuously extended with an eye-identifying speed (on the order of ∼1 nm/s) under electron beam. Such unusual mobility of amorphous carbon may be associated with deformation promoted by the electric field, which resulted from an inner secondary electron potential difference from the main trunk of carbon film to the tip end of branches under electron beam. This result demonstrates importance of applying electrical effects to modify properties of carbon materials. It may have positive implications to explore some amorphous carbon as electron field emission device.

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Section: Resultsmentioning

confidence: 99%

Revealing the 1 nm/s extensibility of nanoscale amorphous carbon in a scanning electron microscope

Zhang

2012

Scanning

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“…Under certain conditions of deposition, the aggregates tend to ramify and form tree-like carbon objects on the nanoscale (Banhart 1994;Reyes-Gasga et al . 1997;Wang et al . 2002).…”

Section: Further Irradiation Effects In Carbon Nanostructuresmentioning

confidence: 99%

Formation and transformation of carbon nanoparticles under electron irradiation

Banhart

2004

Philosophical Transactions of the Royal Society of London. Seri

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This article reviews the phenomena occurring during irradiation of graphitic nanoparticles with high-energy electrons. A brief introduction to the physics of the interaction between energetic electrons and solids is given with particular emphasis on graphitic materials. Irradiation effects are discussed, starting from microscopic mechanisms that lead to structural alterations of the graphite lattice. It is shown how random displacements of the atoms and their subsequent rearrangements eventually lead to topological changes of the nanoparticles. Examples are the formation of carbon onions, morphological changes of carbon nanotubes, or the coalescence of fullerenes or nanotubes under electron irradiation. Irradiation-induced phase transformations in nanoparticles are discussed, e.g. the transformation of graphite to diamond, novel metal-carbon phases in nanocomposite materials or modified phase equilibria in metal crystals encapsulated in graphitic shells.

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“…TEM is a versatile microscopy analytical technique, by which we may effectively investigate the crystal orientation, morphology and size of nanomaterials, and evaluate the dispersion of the nanoparticles [14,15]. Our research group have also investigated the formation and morphological evolution of carbon aggregates in situ electron microscope [16]. Although much research work has been focused on TEM as a powerfully analytical tool, there are only a few reports on how the high electron beams affects the structures and components of the detected samples in situ TEM experiments [17].…”

Section: Introductionmentioning

confidence: 99%

Sputtering Phenomena of ZnS Nanoparticles with Graphite Sheaths by Impacting of High-Energy Electron in a Transmission Electron Microscope

Zhang

Tong

Liu

et al. 2011

AMR

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This paper presents an interesting sputtering phenomenon when high-energy beams irradiated ZnS nanoparticles with graphite sheaths in a transmission electron microscope (TEM). Sputtered nanoparticles were spherical and well dispersed on the copper grids. Results of high-resolution TEM and X-ray diffraction showed that sputtered particles were ZnS nanoparticles. The sizes of deposited ZnS nanoparticles appeared a good gradient distribution according to their distance away from the sputtering target. These nanoparticles had gradual changes in diameter from about 0.5 to 12 nm. We also discussed the mechanism of this sputtering phenomenon. This research may afford a simple and efficient method to prepare well-dispersed semiconductor nanocrystals in a small size range.

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In situ electron microscope study on the formation and morphological evolution of carbon aggregates

Cited by 6 publications

References 24 publications

Revealing the 1 nm/s extensibility of nanoscale amorphous carbon in a scanning electron microscope

Revealing the 1 nm/s extensibility of nanoscale amorphous carbon in a scanning electron microscope

Formation and transformation of carbon nanoparticles under electron irradiation

Sputtering Phenomena of ZnS Nanoparticles with Graphite Sheaths by Impacting of High-Energy Electron in a Transmission Electron Microscope

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