WEB Modeling of grain boundaries and their effects on oxygen vacancies in SrTiO3 – an atomistic simulation approachFriday (25.09.2020) 11:50 - 12:05 P: Processing and Synthesis 1 Part of:
Oxygen vacancies play an important role in accelerating grain growth in SrTiO3 (STO) and related perovskite compounds under an applied electric field. The underlying mechanisms, especially the redistribution of oxygen vacancies along and across grain boundaries (GB), are not yet fully understood. In order to advance the understanding at the atomic scale, we employ classical atomistic simulations to investigate atomic structures and energetics of both the symmetric tilt GBs (STGB), ∑5(310) and ∑5(210), and the asymmetric tilt GB (430)||(100) in STO. To locate the energetically favored sites, oxygen vacancies on all possible oxygen sites were separately generated in atomistic supercell models, and their formation energies were calculated and analyzed with respect to local electrostatic potentials. The simulation results indicate that oxygen vacancies preferentially form in the vicinity of the GBs, suggesting the specific role of GBs in trapping oxygen vacancies in STO.