jp506114k_si_003.avi (2.04 MB)
Solid-State Growth of One- and Two-Dimensional Silica Structures on Metal Surfaces
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posted on 2014-09-11, 00:00 authored by Ferdaous Ben Romdhane, Torbjörn Björkman, Arkady V. Krasheninnikov, Florian BanhartCrystalline
or vitreous silica layers are new two-dimensional (2D) nanomaterials,
which have shown surprising structural similarities with graphene
and promise interesting properties. In this study, one-dimensional
(1D) silica structures are formed on metal surfaces. In an in situ
electron microscopy experiment it is demonstrated that lines of silica
grow along step edges on metal surfaces. The growth of 1D silica occurs
in competition with the formation of 2D networks and adopts the crystalline
symmetry of the metal surface. Transformations between 1D and 2D structures
are observed. Density functional theory calculations show that 1D
silica is energetically favorable over 2D structures if surface steps
prevail on the substrate. Our results indicate that lateral heterostructures
with interesting properties may be developed on metal substrates.