Super-oxidation of silicon nanoclusters: magnetism and reactive oxygen species at the surface

Sergey Lepeshkin; Vladimir Baturin; Evgeny Tikhonov; Nikita Matsko; Yurii Uspenskii; Anastasia Naumova; Oleg Feya; Martin A Schoonen; Artem R Oganov

doi:10.1039/c6nr07504e

Super-oxidation of silicon nanoclusters: magnetism and reactive oxygen species at the surface

Nanoscale. 2016 Nov 10;8(44):18616-18620. doi: 10.1039/c6nr07504e.

Authors

Sergey Lepeshkin¹, Vladimir Baturin¹, Evgeny Tikhonov², Nikita Matsko¹, Yurii Uspenskii³, Anastasia Naumova⁴, Oleg Feya⁵, Martin A Schoonen⁶, Artem R Oganov⁷

Affiliations

¹ P.N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Leninskii prosp. 53, Moscow, Russia. lepeshkin@lpi.ru and Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
² Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia and Physics Department, Moscow State University, Leninskie Gory, Moscow 119991, Russia.
³ P.N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Leninskii prosp. 53, Moscow, Russia. lepeshkin@lpi.ru.
⁴ Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia and Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, Nobel St. 3, Moscow 143026, Russia.
⁵ Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
⁶ Brookhaven National Laboratory, Upton, NY 11793-5000, USA.
⁷ Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia and Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, Nobel St. 3, Moscow 143026, Russia and Department of Geosciences and Center for Materials by Design, Stony Brook University, Stony Brook, NY 11794, USA and Northwestern Polytechnical University, Xi'an, Shaanxi 720072, PR China.

PMID: 27786331
DOI: 10.1039/c6nr07504e

Abstract

Oxidation of silicon nanoclusters depending on the temperature and oxygen pressure is explored from first principles using the evolutionary algorithm, and structural and thermodynamic analysis. From our calculations of 90 Si_nO_m clusters we found that under normal conditions oxidation does not stop at the stoichiometric SiO₂ composition, as it does in bulk silicon, but goes further placing extra oxygen atoms on the cluster surface. These extra atoms are responsible for light emission, relevant to reactive oxygen species and many of them are magnetic. We argue that the super-oxidation effect is size-independent and discuss its relevance to nanotechnology and miscellaneous applications, including biomedical ones.