Journal
PHYSICAL REVIEW MATERIALS
Volume 5, Issue 3, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevMaterials.5.033609
Keywords
-
Categories
Funding
- European Research Council (ERC) under the European Union [787198]
- European Research Council (ERC) [787198] Funding Source: European Research Council (ERC)
Ask authors/readers for more resources
The study investigates the formation and migration kinetics of bound vacancies in magnesium oxide, showing that the diffusion of this bound Schottky defect involves the migration of vacancies at the first and third neighbor sites of the crystal structure. This research provides insights and constraints on the experimentally observed oxygen diffusion mechanism in high-purity MgO samples.
In simple ionic crystals, intrinsic point defects must satisfy electrical neutrality and exist as Schottky defects. In magnesium oxide (MgO), a Schottky defect is then a combination of anionic and cationic vacancies. Since vacancies are charged, the stable configuration of the Schottky defect corresponds to a bound pair of vacancies of opposite signs. In this study, we investigate the kinetics of formation and migration of such a bound pair on long timescales reaching in some cases thousands of seconds using the kinetic activation-relaxation technique, an off-lattice kinetic Monte Carlo method with an event catalog built on-the-fly during static molecular simulations. We show that the diffusion of this bound Schottky defect involves the migration of vacancies bounded to the first and third neighbor sites of the crystal structure with an apparent migration energy which cannot be inferred from the migration energies expected from isolated defects. Overall, this study gives insights and constraints on the oxygen diffusion mechanism reported experimentally in high-purity MgO samples.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available