The energetics and dynamics of electromigration of the oxygen vacancy was investigated using first-principles calculations and kinetic Monte Carlo methods. To simulate the charged oxygen vacancy under external fields within the first-principles approach, a slab model with electron-accepting dopants in the surface was introduced. The analysis of the density of states confirmed that the oxygen vacancies were positively charged. When the external field was applied, the total energy of the slab linearly changed with respect to the position of the charged vacancy in the field direction, which allowed for probing local permittivity around the vacancy site. The activation energy of vacancy migration was lowered along the field direction in a manner that the charge state of the vacancy was maintained along the migration path. Kinetic Monte Carlo simulations based upon the first-principles inputs were also carried out and it was shown that the high-temperature condition was important for the fast redistribution of charged vacancies.

Multiscale Simulation on Electromigration of the Oxygen Vacancies in Metal Oxides. S.H.Jeon, W.J.Son, B.H.Park, S.Han: Applied Physics A, 2011, 102[4], 909-14