Radiation damage near grain boundaries

Samaras, M.; Derlet, P. M.; Swygenhoven, H. Van; Victoria, M.

doi:10.1080/14786430310001600222

Cited by 90 publications

(65 citation statements)

References 29 publications

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“…Moreover, investigation of grain size effects by MD would be computationally limited to nanograin sizes in any case. To date, there have been a limited number of studies carried out to investigate whether and how primary damage formation would be altered in nanograined metals, [116][117][118][119][120][121] and quite strong effects have been observed. 116 The work from Stoller and coworkers 122 will be used here to illustrate the phenomenon because the results of that study can be directly compared with the existing single crystal database that has been discussed above.…”

Section: Influence Of Free Surfacesmentioning

confidence: 99%

Primary Radiation Damage Formation

Stoller

2012

Comprehensive Nuclear Materials

144

111

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Section: Influence Of Free Surfacesmentioning

confidence: 99%

Primary Radiation Damage Formation

Stoller

2012

Comprehensive Nuclear Materials

144

111

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“…Previous work has used atomistic simulations to examine the interaction of point defect and point defect clusters with grain boundaries in 2D columnar and 3D nanocrystalline metals. For example, Samaras and colleagues [24][25][26][27] have used molecular dynamics (MD) studies of nanocrystalline metals to show that grain boundaries act as sinks for self-interstitial atoms after nearby cascade events, which also leads to the formation of stacking fault tetrahedron in the grain interior for fcc Ni. Millett et al used molecular dynamics simulations of 2D columnar nanocrystalline Mo to investigate the ability of grain boundaries to act as both a sink for point defects and a source for vacancies at high homologous temperatures (T > 0.75T m ) 28,29 .…”

Section: Introductionmentioning

confidence: 99%

“…Electronic structure calculations and atomistic simulations in bicrystalline and nanocrystalline structures have provided a fundamental understanding of nanoscale details regarding point defect behavior at grain boundaries in polycrystalline materials [23][24][25][26][27][28][29][30][31][32] as well as interfaces in nano-layered metal composites [33][34][35] . Previous work has used atomistic simulations to examine the interaction of point defect and point defect clusters with grain boundaries in 2D columnar and 3D nanocrystalline metals.…”

Section: Introductionmentioning

confidence: 99%

Probing grain boundary sink strength at the nanoscale: Energetics and length scales of vacancy and interstitial absorption by grain boundaries inα-Fe

et al. 2012

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The energetics and length scales associated with the interaction between point defects (vacancies and self-interstitial atoms) and grain boundaries in BCC Fe was explored. Molecular statics simulations were used to generate a grain boundary structure database that contained ≈ 170 grain boundaries with varying tilt and twist character. Then, vacancy and self-interstitial atom formation energies were calculated at all potential grain boundary sites within 15Å of the boundary. The present results provide detailed information about the interaction energies of vacancies and selfinterstitial atoms with symmetric tilt grain boundaries in iron and the length scales involved with absorption of these point defects by grain boundaries. Both low and high angle grain boundaries were effective sinks for point defects, with a few low-Σ grain boundaries (e.g., the Σ3{112} twin boundary) that have properties different from the rest. The formation energies depend on both the local atomic structure and the distance from the boundary center. Additionally, the effect of grain boundary energy, disorientation angle, and Σ-designation on the boundary sink strength was explored; the strongest correlation occurred between the grain boundary energy and the mean point defect formation energies. Based on point defect binding energies, interstitials have ≈ 80% more grain boundary sites per area and ≈ 300% greater site strength than vacancies. Last, the absorption length scale of point defects by grain boundaries is over a full lattice unit larger for interstitials than for vacancies (mean of 6-7Å vs. 10-11Å for vacancies and interstitials, respectively).

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“…Interactions of defects with GBs have been investigated extensively using classical molecular dynamics (MD) simulations performed on nanocrystalline or bi-crystal samples [14][15][16][17][18][19][20][21][22][23][24][25][26][27] . While these studies provided significant insights into several aspects of cascade-GB interaction, the time scales simulated here mostly capture the primary damage, which occurs between a few tens of a picosecond to a nanosecond at the most, following the damage initiation.…”

Section: Introductionmentioning

confidence: 99%

Role of recombination kinetics and grain size in radiation-induced amorphization

2012

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Using a rate theory model for a generic one-component material we investigated interactions between grain size and recombination kinetics of radiation-induced defects. Specifically, by varying parametrically non-dimensional kinetic barriers for defect diffusion and recombination, we determined the effect of these parameters on the shape of the dose to amorphization vs. temperature curves. We found that whether grain refinement to the nanometer regime improves or deteriorates radiation resistance of a material, depends on the barriers to defect migration and recombination, as well as on the temperature for the intended use of the material. We show that the effects of recombination barriers and of grain refinement can be coupled to each other to produce a phenomenon of interstitial starvation. In interstitial starvation a significant number of interstitials annihilate at the grain boundary leaving behind unrecombined vacancies, which in turn amorphize the material. The same rate theory model with material specific parameters was used to predict the grain size dependence of the critical amorphization temperature in SiC. Parameters for the SiC model were taken from ab initio calculations. We find that the fine grained SiC has a lower radiation resistance when compared to the polycrystalline SiC due to the presence of high energy barrier for recombination of carbon Frenkel pairs and due to the interstial starvation phenomenon.

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Radiation damage near grain boundaries

Cited by 90 publications

References 29 publications

Primary Radiation Damage Formation

Primary Radiation Damage Formation

Probing grain boundary sink strength at the nanoscale: Energetics and length scales of vacancy and interstitial absorption by grain boundaries inα-Fe

Role of recombination kinetics and grain size in radiation-induced amorphization

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