Bottom-up formation of robust gold carbide

Author(s)
Benedikt Westenfelder, Johannes Biskupek, Jannik C. Meyer, Simon Kurasch, Xiaohang Lin, Ferdinand Scholz, Axel Gross, Ute Kaiser
Abstract

A new phenomenon of structural reorganization is discovered and characterized for a gold-carbon system by in-situ atomic-resolution imaging at temperatures up to 1300 K. Here, a graphene sheet serves in three ways, as a quasi transparent substrate for aberration-corrected high-resolution transmission electron microscopy, as an in-situ heater, and as carbon supplier. The sheet has been decorated with gold nanoislands beforehand. During electron irradiation at 80 kV and at elevated temperatures, the accumulation of gold atoms has been observed on defective graphene sites or edges as well as at the facets of gold nanocrystals. Both resulted in clustering, forming unusual crystalline structures. Their lattice parameters and surface termination differ significantly from standard gold nanocrystals. The experimental data, supported by electron energy loss spectroscopy and density-functional theory calculations, suggests that isolated gold and carbon atoms form - under conditions of heat and electron irradiation - a novel type of compound crystal, Au-C in zincblende structure. The novel material is metastable, but surprisingly robust, even under annealing condition.

Organisation(s)
Physics of Nanostructured Materials
External organisation(s)
Universität Ulm, Medizinische Universität Wien
Journal
Scientific Reports
Volume
5
No. of pages
6
ISSN
2045-2322
DOI
https://doi.org/10.1038/srep08891
Publication date
03-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
104022 Theoretical chemistry, 210006 Nanotechnology, 103009 Solid state physics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/bottomup-formation-of-robust-gold-carbide(6e0d9dab-c95a-4415-9de1-d9d811cb7d80).html