CuAu, a hexagonal two-dimensional metal

Author(s)
Georg Zagler, Michele Reticcioli, Clemens Mangler, Daniel Scheinecker, Cesare Franchini, Jani Kotakoski
Abstract

Growth of two-dimensional metals has eluded materials scientists since the discovery of the atomically thin graphene and other covalently bound 2D materials. Here, we report a two-atom-thick hexagonal copper-gold alloy, grown through thermal evaporation on freestanding graphene and hexagonal boron nitride. The structures are imaged at atomic resolution with scanning transmission electron microscopy and further characterized with spectroscopic techniques. While the 2D structures are stable over months in vacuum, electron irradiation in the microscope provides sufficient energy to cause a phase transformation-atoms are released from their lattice sites with the gold atoms eventually forming face-centered cubic nanoclusters on top of 2D regions during observation. The presence of copper in the alloy enhances sticking of gold to the substrate, which has clear implications for creating atomically thin electrodes for applications utilizing 2D materials. Its practically infinite surface-to-bulk ratio also makes the 2D CuAu particularly interesting for catalysis applications.

Organisation(s)
Physics of Nanostructured Materials, Computational Materials Physics
External organisation(s)
Università degli Studi di Bologna
Journal
2D Materials
Volume
7
No. of pages
8
ISSN
2053-1583
DOI
https://doi.org/10.1088/2053-1583/ab9c39
Publication date
08-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
103042 Electron microscopy, 103018 Materials physics
Keywords
ASJC Scopus subject areas
Condensed Matter Physics, Mechanics of Materials, Mechanical Engineering, Chemistry(all), Materials Science(all)
Portal url
https://ucris.univie.ac.at/portal/en/publications/cuau-a-hexagonal-twodimensional-metal(74649ac1-9a01-4605-9442-d33129646d92).html