Correlated Visible-Light Absorption and Intrinsic Magnetism of SrTiO3 Due to Oxygen Deficiency: Bulk or Surface Effect?
- Correlated Visible-Light Absorption and Intrinsic Magnetism of SrTiO3 Due to Oxygen Deficiency: Bulk or Surface Effect?
- 최희채; 송진동; 이광렬; 김승철
- Density Functional Theory; First-principles calculations; SrTiO3; Oxygen vacancy; surface defects; magnetism
- Issue Date
- Inorganic chemistry
- VOL 54, NO 8, 3759-3765
- The visible-light absorption and luminescence of wide band gap (3.25 eV) strontium titanate (SrTiO3) are wellknown, in many cases, to originate from the existence of natural oxygen deficiency in the material. In this study based on density functional theory (DFT) calculations, we provide, to the best of our knowledge, the first report indicating that oxygen vacancies in the bulk and on the surfaces of SrTiO3 (STO) play different roles in the optical and magnetic properties. We found that the doubly charged state of oxygen vacancy (VO 2+) is dominant in bulk SrTiO3 and does not contribute to the sub-band gap photoexcitation or intrinsic magnetism of STO. Neutral oxygen vacancies (VO 0 ) on (001) surfaces terminated with both TiO2 and SrO layers induce magnetic moments, which are dependent on the charged state of VO. The calculated absorption spectra for the (001) surfaces exhibit mid-infrared absorption (<0.5 eV) and sub-band gap absorption (2.5−3.1 eV) due to oxygen vacancies. In particular, VO 0 on the TiO2-terminated surface has a relatively low formation energy and magnetic moments, which can explain
the recently observed spin-dependent photon absorptions of STO in a magnetic circular dichroism measurement
- Appears in Collections:
- KIST Publication > Article
- Files in This Item:
There are no files associated with this item.
- RIS (EndNote)
- XLS (Excel)
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.