The activation energy for self-diffusion in the Cu3Au alloy

Benci, S.; Gasparrini, G.

doi:10.1016/0022-3697(66)90077-1

Cited by 20 publications

(3 citation statements)

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“…For Cu 3 Au, Eord (d-.o) = 1.6eV (Hashimoto et al, 1976) while E for DAu in d-Cu 3 Au is 1.65eV (Benci et al, , 1966; E for DAu in ordered Cu 3 Au was estimated by Benci and Gasperrini (1966) to be ~2eV. These various comparisons suggest that in cold-worked Ni 3 AI (but not in the other alloys) there is a considerable excess of vacancies above equilibrium, at least during the early stages of ordering.…”

Section: Correlation Of Ordering Kinetics and Diffusivitiesmentioning

confidence: 97%

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Ordering Kinetics and Diffusion in Some L1₂ Alloys

Cahn

1985

MRS Proc.

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A comparison is made of, ordering kinetics for Cu 3 Au, (Tc = 388 0 C), Ni 3 Mn (Tc = 500 0 C) Ni 3 Fe (TC = 517'C) and Ni 3 A1 (Te = 1450 0 C), which all form the L1 2 superlattice, and these kinetics are correlated with diffusion data for the same alloys. Comparing different alloys, it is shown that for a fixed relaxation time for the establishment of order, the lower is the self-diffusivity, Ds, of the slowest-diffusing species, the higher the critical temperature, Tc, for the first appearance of order. Ni 3 A1, in particular, has an estimated D. of about 5 orders of magnitude lower, on average, than the three other alloys. The implications of this inverse relation between Te and Ds are discussed in relation to published models for diffusion in ordered alloys and ordering kinetics. THE RELATION OF DIFFUSIVITIES TO ORDERING KINETICS Formal Kinetic TheoriesThe number of attempts to interpret the kinetics of homogeneous long-range ordering is legion. Bragg and Williams (B * Present address:

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Section: Correlation Of Ordering Kinetics and Diffusivitiesmentioning

confidence: 97%

“…Spot values for d-Ni 3 Fe at 1200 'C, including DFe: Kohn et al, 1970. DAu in d-Cu 3 Au: Benci and Gasperrini, 1966.…”

Section: Input Datamentioning

confidence: 98%

Ordering Kinetics and Diffusion in Some L1₂ Alloys

Cahn

1985

MRS Proc.

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“…The energy barriers for exchanges between gold or copper atoms with a copper vacancy and of a copper atom with a gold vacancy are displayed in figure 5 and lead to migration energies that equal 0.76 eV, 0.66 eV, and 0.61 eV, respectively. The comparison with experimental determinations in the ordered phase from electrical resistivity measurements, 0.9 eV [32], 0.97 eV [33], and 1.07 eV [34], shows the model to significantly underestimate this quantity. The discrepancy persists for the dynamical determination of the migration energy yielding the value, Em = 0.52 eV, in the temperature range 1,000-1,170 K. Despite the above, qualitative features associated with the vacancy diffusion are compatible with experiments indicating that the vacancy spends ~ 82% of its lifetime on the copper sublattice whereas from our calculations the value, 90%, is deduced.…”

Section: Vacancy Formation and Migrationmentioning

confidence: 99%

Thermodynamical properties and defect energetics of an n-body potential adapted to Cu3Au

et al. 1994

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By using molecular statics, molecular dynamics, and Monte Carlo techniques we validate a previously developed empirical n-body potential adapted to Cu3Au. At T = 0 K, predicted cohesive energies, lattice parameters, and elastic constants in CuAu and CuAu3 as well as the formation energy of vacancies in Cu3Au are in good agreement with experimental data. A satisfactory behavior is also obtained at T ~ 0 K in Cu3Au, for atomic mean-square displacements and elastic moduli. However, this model underestimates the vacancy migration energy and the order-disorder critical temperature when the latter is evaluated by Monte Carlo including both exchanges between atoms of different species and atomic moves simulating vibrations.

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