Molecular dynamics simulations of the pure and doped sufaces of γ-alumina have been performed. An onset of surface diffusion is observed in the pure samples near the temperature of 1200 K. The instability is caused by the cation vacancies adjacent to the surface. Silicon ions deposited into the vacancies reduce mobility of the surface ions and prevent the onset of diffusion. This forms a microscopic picture of the role of additives in stabilization of the γ-alumina surfaces. Presence of the vacancies and their closing by the dopant ions also enables a new interpretation of the recent LEIS data.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Condensed Matter Physics
- Atomic and Molecular Physics, and Optics
- Surfaces and Interfaces