Effect of Grain Boundary Stresses on Sink Strength

Jiang, Chao; Swaminathan, Narasimhan; Deng, Jie; Morgan, Dane; Szlufarska, Izabela

doi:10.1080/21663831.2013.871588

Cited by 53 publications

(41 citation statements)

References 35 publications

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“…In that sense, the high-angle GBs studies here might also have higher sink efficiencies than their low-angle counterparts. However, this hypothesis is also up for debate, since Jiang et al 29. demonstrated the contrary results that the larger stress fields of low-angle GBs lead to them having higher sink strength than high-angle GBs, which, in our case, is shown by the larger vacancy absorption length scales of low-angle GBs.…”

Section: Discussioncontrasting

confidence: 61%

“…Future works are underway to explore the influence of different GB character and states on the segregation energetics of impurities such as hydrogen and helium in bcc W. The obtained energetics and defect absorption length scales will provide useful inputs to the modelling and simulation of defect evolution and absorption at experimental time scales. For example, a rate-theory model on GB sink strength requires point defect formation energetics, absorption length scales, or defect migration barriers that can be readily obtained by atomistic simulations2934. This will contribute to addressing the lifetime issue confronting the W-based plasma-facing components in future nuclear fusion devices.…”

Section: Discussionmentioning

confidence: 99%

“…On this very topic, density functional theory calculations2021 and atomistic simulations910112223242526272829 have been frequently used to describe the segregation energetics of point defects (including impurities) to a series of GBs. For example, Tschopp, Solanki and coworkers have performed extensive atomistic simulations to investigate the effects of GB character on the formation energetics of point defects, such as vacancy922232430, self-interstitial9, hydrogen2526, helium2627, carbon2628 and various other impurities2326.…”

mentioning

confidence: 99%

“…Aiming to mitigate radiation damage, Uberuaga, Demkowicz and coworkers have conducted massive multiscale simulations193132333435363738 to understand the effects of interface structure on point defect segregation, defect mobility, defect recombination and GB sink efficiency. Jiang et al 29. demonstrated that GB types can make a difference in determining the sink strength and radiation tolerance of GBs.…”

mentioning

confidence: 99%

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Energetics of vacancy segregation to [100] symmetric tilt grain boundaries in bcc tungsten

Chen

Niu

Zhang

et al. 2016

Sci Rep

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The harsh irradiation environment poses serious threat to the structural integrity of leading candidate for plasma-facing materials, tungsten (W), in future nuclear fusion reactors. It is thus essential to understand the radiation-induced segregation of native defects and impurities to defect sinks, such as grain boundaries (GBs), by quantifying the segregation energetics. In this work, molecular statics simulations of a range of equilibrium and metastable [100] symmetric tilt GBs are carried out to explore the energetics of vacancy segregation. We show that the low-angle GBs have larger absorption length scales over their high-angle counterparts. Vacancy sites that are energetically unfavorable for segregation are found in all GBs. The magnitudes of minimum segregation energies for the equilibrium GBs vary from −2.61 eV to −0.76 eV depending on the GB character, while those for the metastable GB states tend to be much lower. The significance of vacancy delocalization in decreasing the vacancy segregation energies and facilitating GB migration has been discussed. Metrics such as GB energy and local stress are used to interpret the simulation results, and correlations between them have been established. This study contributes to the possible application of polycrystalline W under irradiation in advanced nuclear fusion reactors.

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Section: Discussioncontrasting

confidence: 61%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Energetics of vacancy segregation to [100] symmetric tilt grain boundaries in bcc tungsten

Chen

Niu

Zhang

et al. 2016

Sci Rep

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“…More recently, atomic-level simulations have been employed to study the sink strength of grain boundaries (Tschopp et al, 2012;Jiang et al, 2014). These simulations revealed that the sink strength can exceed the theoretical strength of GBs due to the effect of GB stress fields.…”

Section: Point-defect Interaction Ratesmentioning

confidence: 99%

Multi-Timescale Microscopic Theory for Radiation Degradation of Electronic and Optoelectronic Devices

Huang¹,

Gao²,

Cardimona³

et al. 2015

American Journal of Space Science

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A multi-timescale hybrid model is proposed to study microscopically the degraded performance of electronic devices, covering three individual stages of radiation effects studies, including ultra-fast displacement cascade, intermediate defect stabilization and cluster formation, as well as slow defect reaction and migration. Realistic interatomic potentials are employed in molecular-dynamics calculations for the first two stages up to 100 ns as well as for the system composed of layers with thicknesses of hundreds of times the lattice constant. These quasi-steady-state results for individual layers are input into a ratediffusion theory as initial conditions to calculate the steady-state distribution of point defects in a mesoscopic-scale layered-structure system, including planar biased dislocation loops and spherical neutral voids, on a much longer time scale. Assisted by the density-functional theory for specifying electronic properties of point defects, the resulting spatial distributions of these defects and clusters are taken into account in studying the degradation of electronic and optoelectronic devices, e.g., carrier momentum-relaxation time, defect-mediated non-radiative recombination, defect-assisted tunneling of electrons and defect or charged-defect Raman scattering as well. Such theoretical studies are expected to be crucial in fully understanding the physical mechanism for identifying defect species, performance degradations in field-effect transistors, photo-detectors, light-emitting diodes and solar cells and in the development of effective mitigation methods during their microscopic structure design stages.

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