University of Oulu

Takat B. Rawal, Marco Smerieri, Jagriti Pal, Sampyo Hong, Matti Alatalo, Letizia Savio, Luca Vattuone, Talat S. Rahman, and Mario Rocca (2018) Deciphering complex features in STM images of O adatoms on Ag(110), Phys. Rev. B 98, 035405,

Deciphering complex features in STM images of O adatoms on Ag(110)

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Author: Rawal, Takat B.1; Smerieri, Marco2; Pal, Jagriti2,3,4;
Organizations: 1Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
2IMEM-CNR, UOS Genova, Via Dodecaneso 33, 16146 Genova, Italy
3Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, Genova, Italy
4Fritz Haber Institute der Max Planck Gesellschaft, Faradayweg 4–6, Berlin 14195, Germany
5Division of Physical Sciences, Brewton-Parker College, Mount Vernon, Georgia 30445, USA
6Nano and Molecular Systems Research Unit, University of Oulu, P.O. Box 8000, FI-90400 Oulu, Finland
7Department of Applied Physics, Aalto University, FI-00076 Aalto, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.1 MB)
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Language: English
Published: American Physical Society, 2018
Publish Date: 2019-09-26


Recently it was demonstrated that atomic oxygen can cause the extraction of substrate atoms off metal surfaces thus generating chemically different active sites. For Ag(110) this process occurs when O2 is dosed at 175 K leading, at low coverage, to the formation of single Ag vacancies. Vacancy creation proceeds thereby via the formation of O-Ag-O complexes, which involve a local reconstruction of the surface and ignite the disruption of the Ag substrate. In this paper, we report on the details of such processes and on the isolated structures formed by the O adatoms in the limit of very low coverage. We employ scanning tunneling microscopy and density functional theory to unravel the complex structures of O/Ag(110) which are transiently present under specific reaction conditions. A variety of features such as isolated gray dots, sombreros, shallow gray and white structures oriented along [001] and [1¯10], gray stripes, and lozenges were identified and assigned to O adatoms in different configurations. The zigzag chains interact strongly with the STM tip and are easily disrupted, giving rise to highly mobile, sombrero-shaped, isolated O adatoms also far away from the scanned area, i.e., from the current injection spot. Around 200 K, not only Ag vacancies, which are mobile with anisotropic migration, can merge together into rather complex features, but also the mobile Ag atoms are trapped by O adatoms, thus facilitating the formation of an oxygen-decorated Ag chain along [001] which ultimately induces the well-known added-row reconstruction.

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Series: Physical review. B
ISSN: 2469-9950
ISSN-E: 2469-9969
ISSN-L: 2469-9950
Volume: 98
Issue: 3
Article number: 035405
DOI: 10.1103/PhysRevB.98.035405
Type of Publication: A1 Journal article – refereed
Field of Science: 114 Physical sciences
Funding: We acknowledge the financial support by ICTP through a postdoctoral grant and by Compagnia San Paolo. [...] T.B.R., S.H., and T.S.R. thank Duy Le for fruitful discussion on simulated STM images and US NSF for partial support under Grant No. CHE-1310327.
Copyright information: © 2018 American Physical Society.