Abstract
We report a first-principles density functional theory investigation on the vacancy segregation near the nickel Σ5(210) grain boundary (GB) under applied stress. Our total energy calculations within generalized-gradient approximation reveal that the applied stress can hardly alter the energy preference of a vacancy at different atomic layers away from the GB plane, especially in the range of practical stresses. The segregation enthalpy, nevertheless, gets more (less) significant with the increasing compressive (tensile) stress as a result of the vacancy being smaller in volume at the boundary. Our first-principles result that high-angle tilt GBs in nickel are likely to act as a source (sink) in emitting (absorb) vacancies under a tensile (compressive) stress is not in accordance with the prediction based on a thermodynamic model. The numerical results are discussed with electronic structure analysis.
Published Version
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