logo icmab ochoa 02 01 logo icmab ochoa 02 01
  • NEWS

Neutral and Charged Oxygen Vacancies Induce Two-Dimensional Electron Gas Near SiO2/BaTiO3 Interfaces

Anna V. Kimmel*, Jorge Íñiguez, Markys G. Cain, and Peter V. Sushko

J. Phys. Chem. Lett., 2013, 4 (2), pp 333–337

An atomistic model of the SiO2/BaTiO3 interface was constructed using ab initio molecular dynamics. Analysis of its structure and electronic properties reveals that (i) the band gap at the stoichiometric SiO2/BaTiO3 interface is significantly smaller than those of the bulk BaTiO3 and SiO2, and (ii) the interface contains 5.5 nm–2 oxygen vacancies (V2+) in the outermost TiO2 plane of the BaTiO3 and 11 nm–2 Si–O–Ti bonds resulting from breaking Si–O–Si and Ti–O–Ti bonds and subsequent rearrangement of the atoms. This structure gives rise to the interface polar region with positive and negative charges localized in the BaTiO3 and SiO2 parts of the interface, respectively. We propose that high dielectric response, observed experimentally in the SiO2-coated nanoparticles of BaTiO3, is due to the electron gas formed in oxygen-deficient BaTiO3 and localized in the vicinity of the polar interface.
See more posts on ICMAB related to: Methodologies for materials science and nanotechnology

Related Topics: Methodologies for materials science and nanotechnology

Also on ICMAB...

Trending on ICMAB...

Search

Your experience on this site will be improved by allowing cookies Cookie Settings