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How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O(2) with silicene

We demonstrate, using first-principles molecular-dynamics simulations, that oxidation of silicene can easily take place either at low or high oxygen doses, which importantly helps clarify previous inconsistent reports on the oxidation of silicene on the Ag(111) substrate. We show that, while the ene...

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Detalles Bibliográficos
Autores principales: Morishita, Tetsuya, Spencer, Michelle J.S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4668378/
https://www.ncbi.nlm.nih.gov/pubmed/26631577
http://dx.doi.org/10.1038/srep17570
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author Morishita, Tetsuya
Spencer, Michelle J.S.
author_facet Morishita, Tetsuya
Spencer, Michelle J.S.
author_sort Morishita, Tetsuya
collection PubMed
description We demonstrate, using first-principles molecular-dynamics simulations, that oxidation of silicene can easily take place either at low or high oxygen doses, which importantly helps clarify previous inconsistent reports on the oxidation of silicene on the Ag(111) substrate. We show that, while the energy barrier for an O(2) molecule reacting with a Si atom strongly depends on the position and orientation of the molecule, the O(2) molecule immediately dissociates and forms an Si-O-Si configuration once it finds a barrier-less chemisorption pathway around an outer Si atom of the silicene overlayer. A synergistic effect between the molecular dissociation and subsequent structural rearrangements is found to accelerate the oxidation process at a high oxygen dose. This effect also enhances self-organized formation of sp(3)-like tetrahedral configurations (consisting of Si and O atoms), which results in collapse of the two-dimensional silicene structure and its exfoliation from the substrate. We also find that the electronic properties of the silicene can be significantly altered by oxidation. The present findings suggest that low flux and low temperature of the oxygen gas are key to controlling oxidation of silicene.
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spelling pubmed-46683782015-12-09 How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O(2) with silicene Morishita, Tetsuya Spencer, Michelle J.S. Sci Rep Article We demonstrate, using first-principles molecular-dynamics simulations, that oxidation of silicene can easily take place either at low or high oxygen doses, which importantly helps clarify previous inconsistent reports on the oxidation of silicene on the Ag(111) substrate. We show that, while the energy barrier for an O(2) molecule reacting with a Si atom strongly depends on the position and orientation of the molecule, the O(2) molecule immediately dissociates and forms an Si-O-Si configuration once it finds a barrier-less chemisorption pathway around an outer Si atom of the silicene overlayer. A synergistic effect between the molecular dissociation and subsequent structural rearrangements is found to accelerate the oxidation process at a high oxygen dose. This effect also enhances self-organized formation of sp(3)-like tetrahedral configurations (consisting of Si and O atoms), which results in collapse of the two-dimensional silicene structure and its exfoliation from the substrate. We also find that the electronic properties of the silicene can be significantly altered by oxidation. The present findings suggest that low flux and low temperature of the oxygen gas are key to controlling oxidation of silicene. Nature Publishing Group 2015-12-03 /pmc/articles/PMC4668378/ /pubmed/26631577 http://dx.doi.org/10.1038/srep17570 Text en Copyright © 2015, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Morishita, Tetsuya
Spencer, Michelle J.S.
How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O(2) with silicene
title How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O(2) with silicene
title_full How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O(2) with silicene
title_fullStr How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O(2) with silicene
title_full_unstemmed How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O(2) with silicene
title_short How silicene on Ag(111) oxidizes: microscopic mechanism of the reaction of O(2) with silicene
title_sort how silicene on ag(111) oxidizes: microscopic mechanism of the reaction of o(2) with silicene
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4668378/
https://www.ncbi.nlm.nih.gov/pubmed/26631577
http://dx.doi.org/10.1038/srep17570
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