Atomistic Simulation Study of Vacancy Clusters in Copper.
Abstract
Defect properties of copper are calculated using molecular statics with an interatomic potential recently derived from first principles. Tri- and tetravacancies are found to be very mobile with migration energies of 0.56 and 0.39 eV, respectively, compared to previously calculated single and divacancy migration energies of 0.82 and 0.55 eV, respectively. Using the binding and migration energies calculated with the interatomic potential, annealing kinetics in copper and modeled using rate equations. The effective activation energy of annealing in the model is within 0.02 eV of single vacancy migration energy over a wide range of sink and initial single vacancy concentrations, which conforms to experimental results. In two cases, however, the larger clusters affect the activation energy and no definitive conclusions about whether or not the calculated cluster migration energies are correct for copper can be made. The stability and structure of larger vacancy clusters with ten to forty vacancies were also investigated using the first principles copper potential. Small vacancy platelets with as few as ten vacancies collapsed into stacking fault tetrahedra and faulted loops, depending on the shape of the platelet. Stacking fault tetrahedra are found to be the most stable large clusters.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1985
- Accession Number
- ADA166742
Entities
People
- Michael John Sabochick
Organizations
- Air Force Institute of Technology