Stoichiometric reconstruction of the Al<sub>2</sub>O<sub>3</sub>(0001) surface

Author(s)
Johanna I. Hütner, Andrea Conti, David Kugler, Florian Mittendorfer, Georg Kresse, Michael Schmid, Ulrike Diebold, Jan Balajka
Abstract

Macroscopic properties of materials stem from fundamental atomic-scale details, yet for insulators, resolving surface structures remains a challenge. We imaged the basal (0001) plane of α-aluminum oxide (α-Al2O3) using noncontact atomic force microscopy with an atomically defined tip apex. The surface formed a complex ([Formula: see text] × [Formula: see text])R±9° reconstruction. The lateral positions of the individual oxygen and aluminum surface atoms come directly from experiment; we determined with computational modeling how these connect to the underlying crystal bulk. Before the restructuring, the surface Al atoms assume an unfavorable, threefold planar coordination; the reconstruction allows a rehybridization with subsurface O that leads to a substantial energy gain. The reconstructed surface remains stoichiometric, Al2O3.

Organisation(s)
Computational Materials Physics
External organisation(s)
Technische Universität Wien
Journal
Science
Volume
385
Pages
1241-1244
No. of pages
4
ISSN
0036-8075
DOI
https://doi.org/10.1126/science.adq4744
Publication date
09-2024
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics, 103043 Computational physics
ASJC Scopus subject areas
General
Portal url
https://ucrisportal.univie.ac.at/en/publications/912866bf-2f23-474e-9b4e-2285edc1e489