Stability of vacancy-type defect clusters in Ni based on first-principles and molecular dynamics simulations

摘要

AbstractUsing first-principles calculations based on density-functional theory, the energetics of different vacancy-type defects, including voids, stacking fault tetrahedra (SFT) and vacancy loops, in Ni are investigated. It is found that voids are more stable than SFT at 0K, which is also the case after taking into account the volumetric strains. By carrying outab initiomolecular dynamics simulations at temperatures up to 1000K, direct transformations from vacancy loops and voids into SFT are observed. Our results suggest the importance of temperature effects in determining thermodynamic stability of vacancy clusters in face-centered cubic metals.Graphical abstractFirst-principles calculations indicate voids are more stable than SFT in a typicalfccmetal at zero temperature. Direct transformations of voids and loops to SFT are revealed at finite temperatures.Display Omitted]]>