Is pipe diffusion in metals vacancy controlled? A molecular dynamics study of an edge dislocation in copper

Huang, Jijie; Meyer, Madeleine; Pontikis, V.

doi:10.1103/physrevlett.63.628

Cited by 84 publications

(49 citation statements)

References 11 publications

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“…This is in disagreement with first results obtained with pair potentials [8,11] but confirms most recent studies using most reliable empirical potentials like EAM [17], TB-SMA [18], or pseudopotentials [15,16]. The corresponding interaction energies are displayed in Tab.…”

Section: Vacancy-dislocation Interactioncontrasting

confidence: 55%

“…Therefore, fast diffusion should occur along two well-separated pipes corresponding to the partial dislocations. Pipe diffusion in a larger zone corresponding to the two pipes linked by a ribbon, as observed by Huang et al [15,16] in their molecular dynamic simulations, should only occur at high temperatures, where the partial dislocation cores spread over the stacking fault.…”

Section: Vacancy-dislocation Interactionmentioning

confidence: 86%

“…On the other hand, EAM and TB-SMA potentials do not suffer such restrictions and have been shown to be well suited to study dislocation behavior. Some authors used these potentials to study the behavior of vacancies in the vicinity of dislocations, in particular to simulate pipe-diffusion in fcc metals [15][16][17][18][19][20]. These studies showed that the most stable position of the vacancy lies at the edge of the supplementary half plane corresponding to a partial dislocation and that diffusion is faster along dislocations than in the bulk.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The vacancy–edge dislocation interaction in fcc metals: A comparison between atomic simulations and elasticity theory

Clouet

2006

Acta Materialia

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The interaction between vacancies and edge dislocations in face centered cubic metals (Al, Au, Cu, Ni) is studied at different length scales. Using empirical potentials and static relaxation, atomic simulations give us a precise description of this interaction, mostly in the case when the separation distance between both defects is small. At larger distances, elasticity theory can be used to predict this interaction. From the comparison between both approaches we obtain the minimal separation distance where elasticity applies and we estimate the degree of refinement required in the calculation. In this purpose, isotropic and anisotropic elasticity is used assuming a perfect or a dissociated edge dislocation and considering the size effect as well as the inhomogeneity interaction.

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Section: Vacancy-dislocation Interactioncontrasting

confidence: 55%

Section: Vacancy-dislocation Interactionmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

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The vacancy–edge dislocation interaction in fcc metals: A comparison between atomic simulations and elasticity theory

Clouet

2006

Acta Materialia

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“…This is consistent with the report 20 that the basal dislocations in sapphire dissociated into two partials with a distance of 4-5 nm as shown in the following equation; In fact, the effective radius for pipe diffusion of 1nm is quite larger comparing the value of r 0.5 nm, which is often used and has been confirmed to be suitable from experiments in metals. 19 ,21 ,22 According to the MD-simulation result obtained for metal Cu, 23 stacking fault layer can contribute to the whole pipe diffusion comparably with partial-dislocation cores. It is thus considered that relatively wide stacking fault ribbon in sapphire basal dislocations might result in the high value of the effective pipe diffusion radius.…”

mentioning

confidence: 97%

Oxygen Pipe Diffusion in Sapphire Basal Dislocation

Nakagawa

Nakamura

Sakaguchi

et al. 2006

J. Ceram. Soc. Japan

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The oxygen self-diffusion behavior in deformed sapphire single crystals a-Al 2 O 3 sapphire with a high density of unidirectional basal dislocations was examined in the temperature range of 1424-1636c C using 18O isotopes and secondary ion mass spectrometry-depth profiling techniques. The pipe and lattice diffusion kinetics were best described by r 2 D p 4.6j10 20 exp 4.8=eV?kT =m 4 s? and D l 2.9j10 1 exp 5.5=eV?kT =m 2 s?, respectively. Both the magnitude of pre-exponential factor and activation energy for oxygen pipe diffusion were in good agreement with that of indirect measurements of pipe diffusion deduced from the annihilation of dislocation dipoles. The measured bulk diffusion coefficient is also in good agreement with previously reported data having activation energies ranged between 5.5-6.1 eV.

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“…6 On the theoretical side, all atomistic simulations have been performed using empirical potentials. For example, the embedded-atom method ͑EAM͒ has been widely employed to study pipe diffusion in Al, 7 Cu, 8 and Al-Mg alloys. 9 However, generally speaking, empirical potentials are less accurate in dealing with phenomena involving bond breaking, bond formation, and charge transfer, etc., which are usually present at a dislocation core during pipe diffusion.…”

mentioning

confidence: 99%

Calculation of fast pipe diffusion along a dislocation stacking fault ribbon

Zhang

Lü

2010

Phys. Rev. B

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The diffusion of an interstitial Si atom along an edge dislocation in Al is studied by using a quantummechanics/molecular-mechanics coupling method. It is found that the diffusing Si atom follows approximately a sinusoidal trajectory. The diffusion energy barrier along the partial dislocation core is in excellent agreement with the experimental value. We predict that the stacking fault ribbon could provide a fast pathway for diffusion which increases the diffusivity by 6-7 orders of magnitude comparing to the bulk value at 700 K. At the same temperature, the diffusivity along the stacking fault is found to be three to four orders of magnitude greater than that along the partial dislocation core. Dislocation core acts as fast paths for diffusing atoms whose mobility can be orders of magnitude higher than in bulk diffusion and this phenomenon is often referred as "pipe diffusion." By creating a short-circuit pathway, pipe diffusion can affect many kinetic processes in bulk materials, including creep, 1 dynamic-strain aging, 2 and crystallization. 3 In thin films and nanocrystals, pipe diffusion can become even more crucial due to the reduced material dimensions. For example, pipe diffusion can significantly influence oxidation, corrosion, recovery of radiation damage, and electromigration in nanoelectronic devices. 4 Despite its importance, an accurate determination of diffusivity and diffusing mechanism has remained challenging. On the experimental side, owing to the difficulty in tracking atomic motion, very few direct measurements have been reported 5,6 to date. Among them, a recent experiment on Si diffusing in Al stands out. 6 On the theoretical side, all atomistic simulations have been performed using empirical potentials. For example, the embedded-atom method ͑EAM͒ has been widely employed to study pipe diffusion in Al, 7 Cu, 8 and Al-Mg alloys. 9 However, generally speaking, empirical potentials are less accurate in dealing with phenomena involving bond breaking, bond formation, and charge transfer, etc., which are usually present at a dislocation core during pipe diffusion. Moreover, when multiple elements are involved, the empirical potentials such as EAM are even more prone to giving wrong results. On the other hand, although quantum-mechanical simulations are capable of capturing these phenomena, they are often too computationally expensive to deal with dislocations. To the best of our knowledge, there is no literature reporting quantum-mechanical study of pipe diffusion.Previous studies have shown that the quantum-mechanics ͑QM͒/molecular-mechanics ͑MM͒ method can accurately describe the structure of dislocations in Al. 10,11 Motivated by the recent experiment which has observed "giant diffusivity" of Si interstitial pipe diffusion in Al, 6 we have carried out corresponding QM/MM simulations for Si diffusions in an edge dislocation in Al. By combining computational efficiency and accuracy, the present QM/MM method links quantum-mechanical simulations based on the Kohn-Sham density-functional theory ͑K...

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Is pipe diffusion in metals vacancy controlled? A molecular dynamics study of an edge dislocation in copper

Cited by 84 publications

References 11 publications

The vacancy–edge dislocation interaction in fcc metals: A comparison between atomic simulations and elasticity theory

The vacancy–edge dislocation interaction in fcc metals: A comparison between atomic simulations and elasticity theory

Oxygen Pipe Diffusion in Sapphire Basal Dislocation

Calculation of fast pipe diffusion along a dislocation stacking fault ribbon

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