Self-diffusion in tungsten

Mundy, J. N.; Rothman, S. J.; Lam, Nghi Q.; Hoff, H. A.; Nowicki, L.J.

doi:10.1103/physrevb.18.6566

Cited by 127 publications

(41 citation statements)

References 41 publications

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“…When relaxation effects are taken into account, the calculated formation energies are in excellent agreement with available experimental data in Ta and W. The migration energies-even without relaxation-also compare very well with experiments; however, the relaxation must be performed to obtain more accurate values [9,18]. A deeper comparison should take into account the temperature dependence of these parameters: the migration enthalpy was shown to be temperature dependent in W [5], and the present calculated values are also implicitly temperature dependent, because of the temperature dependence of the electronic contribution to the entropies as discussed in Refs. [9,18].…”

Section: Vacancy Formation and Migration Energies In The 5d Series: Psupporting

confidence: 57%

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Electronic structure calculations of vacancy parameters in transition metals: Impact on the bcc self-diffusion anomaly

Willaime

Satta

Nastar

et al. 2000

Int. J. Quant. Chem.

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ABSTRACT:The group dependence, i.e., the variation with the number of d valence electrons, of vacancy parameters in transition metals with the body-centered cubic (bcc) structure is investigated via a combination of electronic structure calculation techniques. A semiempirical tight-binding d-band approach is proposed that shows that the position of the Fermi level with respect to the pseudogap governs the sharp variations along a transition metal series of (i) the formation energy, (ii) the relaxation energy, (iii) the migration energy, and (iv) the electronic contribution to the formation and migration entropies. These predicted trends are confirmed by first-principles calculations in 5d bcc metals (bcc-Hf, Ta, and W) including structural relaxations within plane-wave pseudopotential computations performed on supercells containing up to 54 sites. The agreement with available experimental data is very conclusive. A fast version of the full potential linear muffin-tin orbital method is then used to show the weak influence of the method within density functional theory in the local density approximation and to generalize these results-without relaxation-to the 3d and 4d series. This data base allows us to test the validity for vacancy studies of spd tight-binding models proposed in the literature.

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Section: Vacancy Formation and Migration Energies In The 5d Series: Psupporting

confidence: 57%

“…However, accurate measurements performed in W strongly support the vacancy mechanism [4,5]. This conclusion can be reasonably generalized to other group VI elements as well as to group V elements, but the question is still open in group IV in the absence of experimental data for H f and H m .…”

supporting

confidence: 52%

Electronic structure calculations of vacancy parameters in transition metals: Impact on the bcc self-diffusion anomaly

Willaime

Satta

Nastar

et al. 2000

Int. J. Quant. Chem.

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“…The obtained migration energy for the self-diffusion in W is equal to 1.67 eV. This result is in good agreement with the measurements (1.63 eV from [33,34]). …”

Section: ϫ4supporting

confidence: 89%

Influence of many‐body interactions on resistance of a grain boundary with respect to a sliding shift

Dorfman

Fuks

Malbouisson

et al. 2002

Int J of Quantum Chemistry

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ABSTRACT:We performed nonempirical simulations of the properties of the tungsten ⌺ 3 (111) grain boundary (GB) with a boron atom and demonstrate the influence of many-body interactions on the resistance of the GB with respect to sliding. We also studied the propagation of relaxations in the vicinity of the GB. The many-body interatomic potentials (IP) used in these simulations were obtained with the recursion procedure from ab initio total energy calculations. At each step of the slip process, the equilibrium positions of the atoms near GB were calculated with the generalized simulated annealing technique. It was demonstrated how the sliding shift influences the penetration of the elastic field inside the grain.

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“…The tungsten ion implantation enhances diffusion via the large number of vacancies produced. Vacancy clusters may also act as nucleation sites for the solute clusters [30][31][32][33]. To quantify the extent of diffusion enhancement, we used the methodology of Lescoat et al [31], which assumes that the particles behave as perfect sinks for point defects to compare these diffusion coefficients.…”

Section: Apt Analysesmentioning

confidence: 99%

Ion-irradiation-induced clustering in W–Re and W–Re–Os alloys: A comparative study using atom probe tomography and nanoindentation measurements

et al. 2015

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This study examines clustering and hardening in W-2 at.% Re and W-1 at.% Re-1 at.% Os alloys induced by 2 MeV W + ion irradiation at 573 and 773 K. Such clusters are known precursors to the formation of embrittling precipitates, a potentially life-limiting phenomenon in the operation of fusion reactor components. Increases in hardness were studied using nanoindentation. The presence of osmium significantly increased postirradiation hardening. Atom probe tomography analysis revealed clustering in both alloys, with the size and number densities strongly dependent on alloy composition and irradiation temperature. The highest cluster number density was found in the ternary alloy irradiated at 773 K. In the ternary alloy, Os was found to cluster preferentially compared to Re. The implications of this result for the structural integrity of fusion reactor components are discussed. Crown

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Self-diffusion in tungsten

Cited by 127 publications

References 41 publications

Electronic structure calculations of vacancy parameters in transition metals: Impact on the bcc self-diffusion anomaly

Electronic structure calculations of vacancy parameters in transition metals: Impact on the bcc self-diffusion anomaly

Influence of many‐body interactions on resistance of a grain boundary with respect to a sliding shift

Ion-irradiation-induced clustering in W–Re and W–Re–Os alloys: A comparative study using atom probe tomography and nanoindentation measurements

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