Description
Oxygen vacancies are believed to play a major role in the conduction mechanisms that enable resistive switching in oxide materials. Employing density functional theory (DFT) and the DFT+U model,we use the full-potential linearized augmented plane wave method as implemented in the FLEUR code to study the formation of point defects in the perovskite SrTiO3 with varying coordination. We calculated the formation energy of an O-vacancy in both bulk supercells and (100) surface including different, c(2×2) and p(2×2), in-plane unit cells and different terminations. After performing full relaxation, we found that the bulk and SrO-terminated surface have a nonmagnetic, while TiO2-terminated surface has a ferromagnetic solution. Using the c(2×2) unit cell, the vacancy formation energy was smaller for the bulk than for the SrO- and even TiO2-terminated surface. On the other hand, the p(2×2) unit cell shows that TiO2-terminated surface has the lowest formation energy, more than 1 eV lower than the bulk value. Similar comparisons will be presented when including the the DFT+U model that is used to correct the bulk bandgap and improve the localization of the defect states.| Period | 15 Mar 2013 |
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| Event title | DPG Spring Meeting: Condensed Matter Section |
| Event type | Conference |
| Conference number | Regensburg 2013 |
| Location | Regensburg, Germany, BavariaShow on map |
| Degree of Recognition | International |