6533b81ffe1ef96bd1277153
RESEARCH PRODUCT
Adsorbate-Induced Oxygen Vacancy Mobility in Ultrathin Oxide Films
Karoliina HonkalaLuca BellarosaNúria Lópezsubject
Materials scienceOxidechemistry.chemical_elementNanotechnologyInsulator (electricity)02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesOxygenOxygen vacancy0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialschemistry.chemical_compoundGeneral EnergychemistryChemical physicsResidual chargeMetal substrateDensity functional theoryPhysical and Theoretical Chemistry0210 nano-technologyHigh electronta116description
Oxides at the nanometric scale show a behavior markedly different from that of their bulk counterparts. Ultrathin oxides grown on metals do not reach the full insulator regime, and they cannot decouple the electronic clouds of incoming adsorbates from that of the metal substrate. Although oxygen vacancies control the chemical and physical properties of ultrathin oxide films, the role of intrinsic defects has been overlooked so far. By means of density functional theory methods, we show that the addition of atoms with high electron affinity, such as Au, to ultrathin MgO grown either on a Ag or Mo support, completely reverses the preferential positions of oxygen vacancies, decreases their residual charge, and enhances their mobility. Oxygen vacancies behave completely different for the MgO/M systems compared to the Au/MgO/M systems, which opens a new way to tune the reactivity of adsorbates.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2013-10-15 | The Journal of Physical Chemistry C |