Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Mechanism of the defect formation in supported graphene by energetic heavy ion irradiation: the substrate effect.

ABSTRACT: Although ion beam technology has frequently been used for introducing defects in graphene, the associated key mechanism of the defect formation under ion irradiation is still largely unclear. We report a systematic study of the ion irradiation experiments on SiO2-supported graphene, and quantitatively compare the experimental results with molecular dynamic simulations. We find that the substrate is, in fact, of great importance in the defect formation process, as the defects in graphene are mostly generated through an indirect process by the sputtered atoms from the substrate.

SUBMITTER: Li W

PROVIDER: S-EPMC4415598 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Mechanism of the defect formation in supported graphene by energetic heavy ion irradiation: the substrate effect.

Li Weisen W Wang Xinwei X Zhang Xitong X Zhao Shijun S Duan Huiling H Xue Jianming J

Scientific reports 20150430

Although ion beam technology has frequently been used for introducing defects in graphene, the associated key mechanism of the defect formation under ion irradiation is still largely unclear. We report a systematic study of the ion irradiation experiments on SiO2-supported graphene, and quantitatively compare the experimental results with molecular dynamic simulations. We find that the substrate is, in fact, of great importance in the defect formation process, as the defects in graphene are most ...[more]

PMID: 25927476

Similar Datasets

Defect formation in multiwalled carbon nanotubes under low-energy He and Ne ion irradiation.

Project description:The mechanical, structural, electronic and magnetic properties of carbon nanotubes can be modified by electron or ion irradiation. In this work we used 25 keV He+ and Ne+ ion irradiation to study the influence of fluence and sample thickness on the irradiation-induced damage of multiwalled carbon nanotubes (MWCNTs). The irradiated areas have been characterised by correlative Raman spectroscopy and TEM imaging. In order to preclude the Raman contribution coming from the amorphous carbon support of typical TEM grids, a new methodology involving Raman inactive Au TEM grids was developed. The experimental results have been compared to SDTRIMSP simulations. Due to the small thickness of the MWCNTs, sputtering has been observed for the top and bottom side of the samples. Depending on thickness and ion species, the sputter yield is significantly higher for the bottom than the top side. For He+ and Ne+ irradiation, damage formation evolves differently, with a change in the trend of the ratio of D to G peak in the Raman spectra being observed for He+ but not for Ne+. This can be attributed to differences in stopping power and sputter behaviour.

| S-EPMC6071685 | biostudies-literature

Human AHH1 cells heavy ion irradiation LC-MSMS

Project description:Heavy ion radiotherapy has unfolded a great promise for cancer therapy. Understanding the cellular response mechanism to heavy ion radiation is required for exploring the measures of overcoming the devastating side effects. Here, we performed a quantitative proteomics to investigate the mechanism of carbon heavy ion irradiation on human AHH-1 lymphoblastoid cells. Totally we identified 4602 proteins and quantified 4569 proteins among which with high coverage on mitochondria. After stringent filtering, we found 290 proteins were significantly up-regulated and 16 proteins were down-regulated. Functional analysis revealed that these up-regulated proteins specifically enriched in the process of DNA damage repair, mitochondrial ribosome and especially mitochondrial respiratory chain, which occupied approximately fifty percent of the accumulated proteins. Bioinformatics analysis and functional study demonstrated that these up- regulated mitochondrial respiratory chain proteins enhanced ATP production and simultaneously ROS releasing. More importantly, the increased ROS led to organelle secondary injury and the lagged DNA double strand breaks. Consistently, the expression of antioxidant enzymes was up-regulated for free radical scavenging. The mechanism of lagged secondary injury originated from disturbing of mitochondrial respiratory chain, the “target” outside nuclear, explored here may provide a novel target for cell self-repairing against heavy ion radiation induced cellular damage.

2018-11-07 | PXD008351 | Pride

Buckling Behavior of Substrate Supported Graphene Sheets.

Project description:The buckling of graphene sheets on substrates can significantly degrade their performance in materials and devices. Therefore, a systematic investigation on the buckling behavior of monolayer graphene sheet/substrate systems is carried out in this paper by both molecular mechanics simulations and theoretical analysis. From 70 simulation cases of simple-supported graphene sheets with different sizes under uniaxial compression, two different buckling modes are investigated and revealed to be dominated by the graphene size. Especially, for graphene sheets with length larger than 3 nm and width larger than 1.1 nm, the buckling mode depends only on the length/width ratio. Besides, it is revealed that the existence of graphene substrate can increase the critical buckling stress and strain to 4.39 N/m and 1.58%, respectively, which are about 10 times those for free-standing graphene sheets. Moreover, for graphene sheets with common size (longer than 20 nm), both theoretical and simulation results show that the critical buckling stress and strain are dominated only by the adhesive interactions with substrate and independent of the graphene size. Results in this work provide valuable insight and guidelines for the design and application of graphene-derived materials and nano-electromechanical systems.

| S-EPMC5456546 | biostudies-other

Formation Mechanism of Secondary Electron Contrast of Graphene Layers on a Metal Substrate.

Project description:Scanning electron microscopy (SEM) is widely used to observe graphene on metal substrates. However, the origin of the SEM image contrast of graphene is not well understood. In this work, we performed in situ SEM imaging of layer-number-controlled graphene on a Ni substrate using a high-pass energy filter for secondary electrons. We found that the graphene layer contrast was maximized at 15-20 eV, corresponding to the π-σ* interband transition in graphene. Our results indicate that the SEM image of graphene is produced by attenuation of the electrons emitted from the metal substrate by the monoatomic layers of graphene.

| S-EPMC6645151 | biostudies-literature

Effects of energetic ion irradiation on WSe<sub>2</sub>/SiC heterostructures.

Project description:The remarkable electronic properties of layered semiconducting transition metal dichalcogenides (TMDs) make them promising candidates for next-generation ultrathin, low-power, high-speed electronics. It has been suggested that electronics based upon ultra-thin TMDs may be appropriate for use in high radiation environments such as space. Here, we present the effects of irradiation by protons, iron, and silver ions at MeV-level energies on a WSe2/6H-SiC vertical heterostructure studied using XPS and UV-Vis-NIR spectroscopy. It was found that with 2 MeV protons, a fluence of 1016 protons/cm2 was necessary to induce a significant charge transfer from SiC to WSe2, where a reduction of valence band offset was observed. Simultaneously, a new absorption edge appeared at 1.1 eV below the conduction band of SiC. The irradiation with heavy ions at 1016 ions/cm2 converts WSe2 into a mixture of WOx and Se-deficient WSe2. The valence band is also heavily altered due to oxidation and amorphization. However, these doses are in excess of the doses needed to damage TMD-based electronics due to defects generated in common dielectric and substrate materials. As such, the radiation stability of WSe2-based electronics is not expected to be limited by the radiation hardness of WSe2, but rather by the dielectric and substrate.

| S-EPMC5482891 | biostudies-literature

LET-dependent change in rice gene expression profile after heavy-ion beam irradiation

Project description:This SuperSeries is composed of the SubSeries listed below.

2016-07-01 | GSE78998 | GEO

Surface stress of graphene layers supported on soft substrate.

Project description:We obtain the surface stress of a single layer and multilayers of graphene supported on silicone substrates by measuring the deformation of the graphene-covered substrates induced by the surface tension of liquid droplets together with the Neumann's triangle concept. We find that the surface stress of the graphene-covered substrate is significant larger than that of the bare substrate, and it increases with increasing graphene layers, and finally reaches a constant value of about 120?mN/m on three and more layers of graphene. This work demonstrates that the apparent surface stress of graphene-substrate systems can be tuned by the substrate and the graphene layers. The surface stress and the tuning effect of the substrate on it may have applications in design and characterization of graphene-based ultra-sensitive sensors and other devices. Moreover, the method may also be used to measure the surface stress of other ultrathin films supported on soft substrates.

| S-EPMC4863371 | biostudies-literature

LET-dependent change in rice gene expression profile after heavy-ion beam irradiation [LET]

Project description:Linear energy transfer (LET) is an important factor affecting several aspects of the irradiation effect, e.g. cell survival and mutation frequency, making the heavy-ion beam an effective mutagen. To study the mechanisms behind LET-dependent effects, expression profiling was performed after heavy-ion beam irradiation of imbibed rice seeds. Array-based experiments at three time points (0.5, 1, 2 h after the irradiation) revealed that the number of up- or down-regulated genes was highest 2 h after irradiation. Array-based experiments with four different LETs at 2 h after irradiation identified LET-independent regulated genes that were up/down-regulated regardless of the value of LET; LET-dependently regulated genes, whose expression level increased with the rise of LET value, were also identified.

2016-07-01 | GSE78994 | GEO

LET-dependent change in rice gene expression profile after heavy-ion beam irradiation [time]

2016-07-01 | GSE78997 | GEO

LET-dependent change in rice gene expression profile after heavy-ion beam irradiation

Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series

2016-07-01 | E-GEOD-78998 | biostudies-arrayexpress