Observation of the One-Dimensional Diffusion of Nanometer-Sized Dislocation Loops

Arakawa, Kazuto; Ono, Kotaro; Isshiki, Minoru; Mimura, Kouji; Uchikoshi, Masahito; Mori, Hirotarô

doi:10.1126/science.1145386

Cited by 318 publications

(191 citation statements)

References 22 publications

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“…28 However, many questions still remain regarding self-interstitial cluster mobility for sizes that are visible under TEM. While some experiments point to activation energies of self-interstitial clusters of over 1 eV, 30 simulations predict that these clusters should move almost athermally. 31 Moreover, experiments show the presence of 100 loops in irradiated α-Fe under many different conditions of irradiation (electrons or ions), temperatures, and doses, 30,32,33 even though 111 loops are the lowest energy configuration.…”

Section: Kmc Simulations For Damage Accumulationmentioning

confidence: 99%

“…While some experiments point to activation energies of self-interstitial clusters of over 1 eV, 30 simulations predict that these clusters should move almost athermally. 31 Moreover, experiments show the presence of 100 loops in irradiated α-Fe under many different conditions of irradiation (electrons or ions), temperatures, and doses, 30,32,33 even though 111 loops are the lowest energy configuration. At high temperatures (T > 300 • C), the transformation of 111 loops into 100 loops has been observed experimentally 30 and explained theoretically.…”

Section: Kmc Simulations For Damage Accumulationmentioning

confidence: 99%

“…31 Moreover, experiments show the presence of 100 loops in irradiated α-Fe under many different conditions of irradiation (electrons or ions), temperatures, and doses, 30,32,33 even though 111 loops are the lowest energy configuration. At high temperatures (T > 300 • C), the transformation of 111 loops into 100 loops has been observed experimentally 30 and explained theoretically. 34,35 Other explanations for the presence of 100 loops even at low temperature point to the formation of both 111 and 100 loops in the collision cascade and the growth of these loops by coalescence with small mobile clusters.…”

Section: Kmc Simulations For Damage Accumulationmentioning

confidence: 99%

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Influence of the picosecond defect distribution on damage accumulation in irradiatedα-Fe

2012

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The importance of the defect distribution produced in the first few picoseconds of a collision cascade on long-term damage evolution is studied with molecular dynamics and kinetic Monte Carlo (KMC) methods. Three different interatomic potentials are used to obtain the primary damage produced by energetic recoils in α-Fe. Contrary to previous results, a dependence of cluster-size distribution with recoil energy is obtained. Moreover, large variations in this distribution are observed depending on the interatomic potential. Using the results for 50 keV collision cascades, damage accumulation is modeled with KMC. The accumulation rate of damage visible under transmission electron microscopy predicted by KMC depends significantly on the database used for cascade damage and, therefore, on the interatomic potential. Based on these results, we show that the comparison of cluster-size distributions with experiments can be used to test the reliability of interatomic potentials.

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Section: Kmc Simulations For Damage Accumulationmentioning

confidence: 99%

Section: Kmc Simulations For Damage Accumulationmentioning

confidence: 99%

Section: Kmc Simulations For Damage Accumulationmentioning

confidence: 99%

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Influence of the picosecond defect distribution on damage accumulation in irradiatedα-Fe

2012

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“…The model succeeds in explaining several striking observations, for example, enhanced swelling rates near grain boundaries [16] and in materials with small grain size [17], and under neutron compared to electron irradiation [18,19]. This is due to the recognition of two distinguishing features of defect production by high-energy recoils: first, the formation of SIA clusters directly in displacement cascades, as shown both experimentally [20] and in MD simulations [14,21,22] (see also review [23]); and, second, the 1-D mobility of SIA clusters [14,[24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

On the onset of void ordering in metals under neutron or heavy-ion irradiation

Barashev

Golubov

2010

Philosophical Magazine

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HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. On the onset of void ordering in metals under neutron or heavy-ion irradiationAlexander V Barashev, Stanislav I Golubov To cite this version:Alexander V Barashev, Stanislav I Golubov. On the onset of void ordering in metals under neutron or heavy-ion irradiation. Philosophical Magazine, TaylorFrancis, 2010, 90 (13) Formation of void lattices is observed in a number of metals and alloys under high-energy particle bombardment. Here we derive the conditions for destabilisation of homogeneous void arrangement using an approach developed for the description of lane formation in pedestrian crowds. The model is based on the Foreman's mechanism of void alignment due to onedimensionally-migrating clusters of self-interstitial atoms. The results show that spatial correlations between voids should exist above some very small size, unless correlations with other defects prevail. It is shown that spatial correlations of voids with dislocations and secondphase precipitates should also evolve and provide a powerful driving force for further swelling.

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“…In our experiments, 4H-SiC sample was first irradiated by 1 MeV Kr at 600 °C at a flux of 2.5×10 12 atoms/(cm 2 s) to a dose of 3×10 14 Kr atoms/cm 2 , 4° off the [0001] direction, producing a peak damage of 0.4 displacement per atom (dpa) at 0.3 μm depth, as estimated using the Stopping and Range of Ions in Matter software [19]. STEM samples were prepared by wedge polishing and argon ion milling with beam energy of 3.5 keV first, then 2 keV, and finally 0.5 keV.…”

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confidence: 99%

Radiation-induced mobility of small defect clusters in covalent materials

Jiang¹,

He²,

Morgan³

et al. 2016

Phys. Rev. B

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Although defect clusters are detrimental to electronic and mechanical properties of semiconductor materials, annihilation of such clusters is limited by their lack of thermal mobility due to high migration barriers. Here, we find that small clusters in bulk SiC (a covalent material of importance for both electronic and nuclear applications) can become mobile at room temperature under the influence of electron radiation. So far, direct observation of radiationinduced diffusion of defect clusters in bulk materials has not been demonstrated yet. This finding was made possible by low angle annular dark field (LAADF) scanning transmission electron microscopy (STEM) combined with non-rigid registration technique to remove sample instability, which enables atomic resolution imaging of small migrating defect clusters. We show that the underlying mechanism of this athermal diffusion is ballistic collision between incoming electrons and cluster atoms. Our findings suggest that defect clusters may be mobile under certain irradiation conditions, changing current understanding of cluster annealing process in irradiated covalent materials. Main textDefect clusters can form in covalent materials during ion implantation (e.g., in semiconductor applications) [1,2] or during irradiation (e.g., in nuclear reactor applications) [3][4][5][6]. Accumulation of such clusters is highly detrimental to electronic, optical, and mechanical properties of these materials [1,4,7]. While point defects can often be eradicated by mutual recombination or diffusion to defect sinks, clusters of defects in covalent materials are known to be immobile and resist annealing because of their high energy barriers to migration [8,9]. For SiC specifically, accelerated molecular dynamics (MD) simulations have shown that the barrier to migration of clusters as small as just three C interstitials is ~4.3 eV [8], which means that these clusters are immobile below 1,200 K on typical experimental annealing time scales (i.e., 1 hour whereas the cluster performs less than 1 hop/day). Such high barriers explain why models of defect evolution in SiC have assumed clusters to be immobile even at elevated temperatures (e.g., Ref. [10,11]) and why the nature of such clusters, their resistance to high-temperature annealing, and their effects on opto-electronic properties have been a subject of many discussions in the semiconductor literature [12,13].In this letter, we report a direct observation of interstitial clusters diffusion in bulk SiC under the influence of electron radiation at room temperature. Although it is known that in metals

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Observation of the One-Dimensional Diffusion of Nanometer-Sized Dislocation Loops

Cited by 318 publications

References 22 publications

Influence of the picosecond defect distribution on damage accumulation in irradiatedα-Fe

Influence of the picosecond defect distribution on damage accumulation in irradiatedα-Fe

On the onset of void ordering in metals under neutron or heavy-ion irradiation

Radiation-induced mobility of small defect clusters in covalent materials

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