| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1330828 | Journal of Solid State Chemistry | 2011 | 5 Pages |
Based on first-principles electronic structure calculations we find that the bridging oxygen vacancies on the (1 1 0) surface is more favorable and may be responsible for the unexpected ferromagnetism in undoped rutile TiO2. Our results show that the ferromagnetism largely originates from the d orbitals of low-charge-state Ti ions converted from Ti4+ ions induced by the surface oxygen vacancies. The second-nearest neighbors of these ions (fivefold coordinated Ti) also contribute to the total magnetic moments. The spins induced by the local oxygen vacancies form a ferromagnetic arrangement.
Graphical AbstractThe study investigates the magnetic properties of the oxygen-deficient rutile TiO2(1 1 0) surface from first principle calculations. The adjacent oxygen vacancies form a ferromagnetic arrangement due to the double exchange interaction.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► There should be more VO’s than VTi’s on the (1 1 0) surface layer of TiO2. ► Magnetic moments induced by the isolated VO form a paramagnetic arrangement. ► Magnetic moments induced by the concentrated VO’s form a ferromagnetic arrangement. ► Double exchange is the dominant coupling mechanism of the ferromagnetism.
