Atomic-scale simulations of radiation effects in GaN and carbon nanotubes

2003 ◽  
Vol 792 ◽  
Author(s):  
K. Nordlund ◽  
J. Nord ◽  
A. V. Krasheninnikov ◽  
K. Albe
Keyword(s):  
Carbon Nanotubes ◽  
Radiation Effects ◽  
Ion Irradiation ◽  
Research Community ◽  
Atomic Scale ◽  
High Radiation ◽  
Wide Range ◽  
Basic Physics ◽  
Materials Research ◽  
Dynamics Simulations

ABSTRACTGallium nitride and carbon nanotubes have received wide interest in the materials research community since the mid-1990's. The former material is already in use in optoelectronics applications, while the latter is considered to be extremely promising in a wide range of materials. Common to both materials is that ion irradiation may be useful for modifying their properties. In this paper we overview our recent molecular dynamics simulations results on ion irradiation of these materials. We employ such potentials to study the basic physics of how ion irradiation affects these materials. In particular we discuss the reasons for the high radiation hardness of GaN, and the surprising nature of vacancies and interstitials in carbon nanotubes.

Atomic Assembly of Thin Film Materials

2007 ◽  
Vol 539-543 ◽  
pp. 3528-3533
Author(s):  
X.W. Zhou ◽  
D.A. Murdick ◽  
B. Gillespie ◽  
J.J. Quan ◽  
Haydn N.G. Wadley ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Atomic Scale ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Structures And Properties ◽  
Wide Range ◽  
Scale Structures ◽  
Kinetic Processes ◽  
Dynamics Simulations

The atomic-scale structures and properties of thin films are critically determined by the various kinetic processes activated during their atomic assembly. Molecular dynamics simulations of growth allow these kinetic processes to be realistically addressed at a timescale that is difficult to reach using ab initio calculations. The newest approaches have begun to enable the growth simulation to be applied for a wide range of materials. Embedded atom method potentials can be successfully used to simulate the growth of closely packed metal multilayers. Modified charge transfer ionic + embedded atom method potentials are transferable between metallic and ionic materials and have been used to simulate the growth of metal oxides on metals. New analytical bond order potentials are now enabling significantly improved molecular dynamics simulations of semiconductor growth. Selected simulations are used to demonstrate the insights that can be gained about growth processes at surfaces.

Ion irradiation of electronic-type-separated single wall carbon nanotubes: A model for radiation effects in nanostructured carbon

2012 ◽  
Vol 112 (3) ◽  
pp. 034314 ◽  
Author(s):  
Jamie E. Rossi ◽  
Cory D. Cress ◽  
Alysha R. Helenic ◽  
Chris M. Schauerman ◽  
Roberta A. DiLeo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Radiation Effects ◽  
Ion Irradiation ◽  
Single Wall Carbon Nanotubes ◽  
Nanostructured Carbon ◽  
Single Wall Carbon

scholarly journals Penetration of Chitosan into the Single Walled Armchair Carbon Nanotubes: Atomic Scale Insight

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1174
Author(s):  
Jamoliddin Razzokov ◽  
Kamoladdin Saidov ◽  
Olim Ruzimuradov ◽  
Shavkat Mamatkulov
Keyword(s):  
Carbon Nanotubes ◽  
Nanocomposite Materials ◽  
Umbrella Sampling ◽  
Water Desalination ◽  
Atomic Scale ◽  
Valuable Insight ◽  
Free Energies ◽  
Penetration Process ◽  
Dynamics Simulations ◽  
Insight Into

(1) Background: Currently, nanomaterials have been broadly used in various applications including engineering, medicine and biology. One of the carbon allotropes such as carbon nanotubes (CNTs) implemented for fabrication of nanocomposite materials due to the hypersensitivity. The combined design of nanomaterial with chitosan (CS) and CNT expands the field of exploitation from biosensing and tissue engineering to water desalination. Therefore, the penetration of CS into CNT provides a valuable insight into the interactions between CS and CNT. (2) Methods: We performed molecular dynamics simulations, applying the umbrella sampling method, in order to calculate the potential mean force between CS and CNT. (3) Results: The estimated penetration free energies showed that CS is favorable to the penetration into CNT cavities. However, the penetration nature differs depending on the CNT’s architecture. (4) Conclusions: Our finding revealed the CS penetration process into CNT with nanoscale precision. The investigation results assist in a better understanding of the nanocomposite materials based on CS-CNT.

The HVEM-tandem user facility at Argonne National Laboratory

1988 ◽  
Vol 46 ◽  
pp. 806-807
Author(s):  
C. W. Allen ◽  
E. A. Ryan ◽  
S. T. Ockers
Keyword(s):  
Radiation Effects ◽  
Ion Irradiation ◽  
Noble Gas ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Western Hemisphere ◽  
Accelerator Facility ◽  
Wide Range ◽  
In Situ Experiments

Established in 1981, the High Voltage Electron Microscope-Tandem Ion Accelerator Facility (HVEM-Tandem) is a user-oriented resource for materials research. It is located at Argonne National Laboratory about 20 miles south of O'Hare International Airport near Chicago. The Facility consists of a modified Kratos/AEI HVEM with accelerating voltages ranging continuously from 0.1-1.2 MeV, interfaced to a 2 MV tandem and a 0.65 MV ion implanter-type accelerator. This combination of instruments offers capability, unique in the western hemisphere, for a wide range of in Situ experiments involving ion irradiation and ion implantation with simultaneous microscopy. During 1987 approximately 75% of microscope time was devoted to this type of experiment (Fig. 1) including studies of solid state phase transformations, such as amorphization, radiation damage and defect structures and the implantation of noble gas and metal ions.In situ experiments of various types account for nearly 90% of usage of the HVEM. In addition to the radiation effects studies, this includes experiments performed in the microscope involving deformation, annealing and environmental effects.

scholarly journals 2D Material Science: Defect Engineering by Particle Irradiation

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1885 ◽  
Author(s):  
Marika Schleberger ◽  
Jani Kotakoski
Keyword(s):  
Ion Irradiation ◽  
2D Materials ◽  
Atomic Scale ◽  
Defect Engineering ◽  
Text Book ◽  
Particle Irradiation ◽  
Wide Range ◽  
Defect Creation ◽  
General Defect ◽  
The One

Two-dimensional (2D) materials are at the heart of many novel devices due to their unique and often superior properties. For simplicity, 2D materials are often assumed to exist in their text-book form, i.e., as an ideal solid with no imperfections. However, defects are ubiquitous in macroscopic samples and play an important – if not imperative – role for the performance of any device. Thus, many independent studies have targeted the artificial introduction of defects into 2D materials by particle irradiation. In our view it would be beneficial to develop general defect engineering strategies for 2D materials based on a thorough understanding of the defect creation mechanisms, which may significantly vary from the ones relevant for 3D materials. This paper reviews the state-of-the-art in defect engineering of 2D materials by electron and ion irradiation with a clear focus on defect creation on the atomic scale and by individual impacts. Whenever possible we compile reported experimental data alongside corresponding theoretical studies. We show that, on the one hand, defect engineering by particle irradiation covers a wide range of defect types that can be fabricated with great precision in the most commonly investigated 2D materials. On the other hand, gaining a complete understanding still remains a challenge, that can be met by combining advanced theoretical methods and improved experimental set-ups, both of which only now begin to emerge. In conjunction with novel 2D materials, this challenge promises attractive future opportunities for researchers in this field.

Simulation of Radiation-Induced Segregation by the Hybrid Potts-Phase Field Model

2014 ◽  
Vol 783-786 ◽  
pp. 1872-1879
Author(s):  
Efraín Hernández-Rivera ◽  
Veena Tikare ◽  
Lu Min Wang
Keyword(s):  
Hybrid Model ◽  
Phase Field ◽  
Radiation Effects ◽  
Field Model ◽  
Ion Irradiation ◽  
Phase Field Model ◽  
Surface Roughening ◽  
Wide Range ◽  
Radiation Induced ◽  
Chemical Segregation

A hybrid model of microstructural evolution of a coupled multi–field system that is subjected to ion irradiation is presented. Materials exposed to low energy ion irradiation experience a wide range of radiation effects, e.g. surface roughening and chemical segregation. The hybrid model combines Monte Carlo methods and a phase field model to simulate the kinetic and radiation-induced processes that lead to radiation induced chemical segregation with associated phase transformations of a binary system by differential diffusivity.

Structures of Water Molecules in Carbon Nanotubes Induced with Electric Fields and its Application for Water-Methanol Separation

2016 ◽  
Vol 842 ◽  
pp. 453-456 ◽  
Author(s):  
Winarto ◽  
Daisuke Takaiwa ◽  
Eiji Yamamoto ◽  
Kenji Yasuoka
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Electric Field ◽  
Electric Fields ◽  
Electrostatic Interaction ◽  
Water Molecules ◽  
Ordered Structures ◽  
Separation Effect ◽  
Wide Range ◽  
Dynamics Simulations

Water confined in carbon nanotubes (CNTs) under the influence of an electric field has interesting properties that are potential for nanofluidic-based applications. With molecular dynamics simulations, this work shows that the electric field induces formation of ordered structures of water molecules in the CNTs. Formation of the ordered structures strengthens the electrostatic interaction between the water molecules. As a result, water strongly prefers to fill CNTs over methanol and it produces a separation effect. Interestingly, the separation effect with the electric field does not decrease for a wide range of CNT diameter.

scholarly journals Heavy-Ion Microbeams for Biological Science: Development of System and Utilization for Biological Experiments in QST-Takasaki

2019 ◽  
Vol 3 (2) ◽  
pp. 13 ◽  
Author(s):  
Tomoo Funayama
Keyword(s):  
Radiation Effects ◽  
Cultured Cells ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Biological Research ◽  
C Elegans ◽  
Beam Focusing ◽  
Wide Range ◽  
Vertical Beam ◽  
Beam Collimation

Target irradiation of biological material with a heavy-ion microbeam is a useful means to analyze the mechanisms underlying the effects of heavy-ion irradiation on cells and individuals. At QST-Takasaki, there are two heavy-ion microbeam systems, one using beam collimation and the other beam focusing. They are installed on the vertical beam lines of the azimuthally-varying-field cyclotron of the TIARA facility for analyzing heavy-ion radiation effects on biological samples. The collimating heavy-ion microbeam system is used in a wide range of biological research not only in regard to cultured cells but also small individuals, such as silkworms, nematode C. elegans, and medaka fish. The focusing microbeam system was designed and developed to perform more precise target irradiation that cannot be achieved through collimation. This review describes recent updates of the collimating heavy ion microbeam system and the research performed using it. In addition, a brief outline of the focusing microbeam system and current development status is described.

Modeling of thermocapillary flow to purify single-walled carbon nanotubes

RSC Advances ◽  
2014 ◽  
Vol 4 (80) ◽  
pp. 42454-42461 ◽  
Author(s):  
Jizhou Song ◽  
Chaofeng Lu ◽  
Chenxi Zhang ◽  
Sung Hun Jin ◽  
Yuhang Li ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Properties ◽  
Electronic Materials ◽  
Single Walled Carbon Nanotubes ◽  
Research Community ◽  
Thermocapillary Flow ◽  
Single Walled Carbon ◽  
Significant Interest ◽  
Materials Research ◽  
Walled Carbon Nanotubes

Single walled carbon nanotubes (SWNTs) are of significant interest in the electronic materials research community due to their excellent electrical properties.

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