Anti-radiation mechanisms in nanoporous gold studied via molecular dynamics simulations

Zhang, C.G.; Li, Y.G.; Zhou, Wang-Huai; Hu, Lulu; Zeng, Zhao

doi:10.1016/j.jnucmat.2015.08.003

Cited by 19 publications

(8 citation statements)

References 32 publications

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“…For the electronic regime, Khara et al [66] simulated tracks in bulk W using the TTM-MD approach and found no defects at the end of simulations for S e < 40 keV/nm, while in our simulations, a few single vacancies are left inside the W NW for S e ∼ 10.8 keV/nm. This difference on defect formation between a bulk system and a finite nanostructure has also been observed for an alternative approach such as the primary knock-on atom (PKA) for MD simulations of Au NWs [43]. These showed defect production dependent on the PKA distance from the surface of the wires, while for Au bulk, defect production is position-independent of the PKA.…”

Section: Resultsmentioning

confidence: 55%

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Electronic heat transport versus atomic heating in irradiated short metallic nanowires

et al. 2019

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The two-temperature model (TTM) is commonly used to represent the energy exchange between atoms and electrons in materials under irradiation. In this work we use the TTM coupled to molecular dynamics (TTM-MD) to study swift heavy ion irradiation of Au and W finite nanowires. While no permanent structural modifications are observed in bulk, nanowires behave in a different way depending on thermal conductivity and the electronphonon coupling parameter. Au is a good heat conductor and it does not transfer energy from electrons to phonons too efficiently. Therefore, energy is quickly carried away from the track so that both electronic and lattice temperatures remain quite uniform across the sample at all times. W has a lower thermal conductivity and a larger electron-phonon coupling, thus supporting an inhomogeneous lattice temperature profile with temperatures well above melting lasting several picoseconds in the irradiated region. Both W and Au nanowires display radiation-induced surface roughening. However, in the case of W there is also sputtering and the formation of a hole in the central part of the wire, purely due to the energy transferred to the atoms by the electrons. The physical mechanisms underlying these findings are rationalized in terms of a combination of sputtering, vacancy formation, and melt flow phenomena. The role of the electron-phonon coupling parameter g is analyzed.

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Section: Resultsmentioning

confidence: 55%

“…To understand the behavior of nanofoams, they have been considered as collections of connected nanowires (NWs), and the behavior of individual irradiated NWs has been studied to infer the behavior of the whole nanostructure [33,[40][41][42][43]. An aspect ratio between length and diameter in the range 1-3 is typically used [33,41,44].…”

Section: Introductionmentioning

confidence: 99%

Electronic heat transport versus atomic heating in irradiated short metallic nanowires

et al. 2019

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“…Typical metallic nanofoam is an important model to study the radiation behaviors of surfaces. In the Au nanofoam, the migration energies of point defects decreased, resulting in point defects continuously diffusing towards free surface, which retards the formation and growth of defect clusters around the free surfaces [100]. A series of studies [101][102][103] reported the radiation response of nanoporous Au in the experiments.…”

Section: Free Surfaces and Ligament Sizementioning

confidence: 99%

Recent progress of radiation response in nanostructured tungsten for nuclear application

Pei

et al. 2021

Tungsten

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Engineering materials for nuclear reactors exposed to high-dose irradiation breed various radiation damage, leading to performance degradation of materials, which seriously limits the application of materials in the future advanced nuclear reactors. Tungsten-based materials applied in future nuclear reactors have to withstand not only the attack of high-energy neutron and plasma, but also the repeated impact of steady-state or even transient thermal load. Researches in the past decades have proved that tailored nanostructure have advantage in annihilating radiation defects. With the rapid development of nanostructured tungsten, probing radiation application of nanostructured tungsten is of great significance in promoting the development of novel radiation-resistant materials. Herein, the development status of three kinds of nanostructured tungsten namely nanocrystalline, nanofilm and nanoporous tungsten designed for radiation tolerance and the performance enhancement mechanism of diverse nanostructure in irradiation environment is reviewed. Finally, future perspectives and technical challenges are discussed, to inspire more creative designs of novel nanostructured tungsten for radiation tolerance.

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“…W nanofoams, called fuzz, form under fusion reactor conditions [2] and are expected to take heat loads that would crack bulk tungsten [3,4]. In order to understand the behavior of nanoscale foams, they could be considered, within a coarse approximation, as collections of connected nanowires (NWs) [5], and thus study the behavior of individual irradiated NWs to infer the behavior of the whole nanostructure [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

MeV irradiation of tungsten nanowires: structural modifications

Grossi

Kohanoff

Bringa

2020

Mater. Res. Express

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In this work we use the Two Temperature Model coupled to Molecular Dynamics (TTM-MD) to study swift heavy ion irradiation of W finite nanowires. Au projectiles are considered with energies ranging from 20 to 50 MeV, which correspond to electronic stopping values less than 20 keV nm −1 in the regime where electronic stopping is larger than nuclear stopping. Nanowires with diameters much smaller than the electron mean free path are considered for two different sizes with an aspect ratio ∼3.7 between length and diameter. Nanowires display radiation-induced surface roughening, sputtering yields and the formation of point defects and di-vacancies. For the smallest size, a hole stays opened in the central part of the wire for S e > 12.6 keV nm −1 . W nanofoams, considered as collections of connected nanowires like those simulated here, are expected to behave similarly under irradiation displaying radiation resistance for the electronic stopping range that has been considered. In fact, nanowires larger than tens of nm would be needed for defect accumulation and lack of radiation resistance.

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Anti-radiation mechanisms in nanoporous gold studied via molecular dynamics simulations

Cited by 19 publications

References 32 publications

Electronic heat transport versus atomic heating in irradiated short metallic nanowires

Electronic heat transport versus atomic heating in irradiated short metallic nanowires

Recent progress of radiation response in nanostructured tungsten for nuclear application

MeV irradiation of tungsten nanowires: structural modifications

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