Figure 1
AC-HRTEM images at 80 keV showing the atomic arrangements of gold atoms explored from tiny clusters towards small crystallites (scale bars are 2 nm).
(a) Isolated heavy gold atoms trapped in carbon contamination on graphene, example indicated by an arrow. A larger gold particle is present in the upper left corner. Insets (i, ii) show small clusters that form under irradiation and heat within the carbon contamination layer on top of graphene. (i) One very rare example found to be consistent with the interatomic distance of traditional gold clusters. Here, it has been determined to be 2.6 Å. (ii) One of the frequently observed clusters having a larger spacing of 3.35 Å. (b) A repeated and abrupt switching of a mono-layer and bi-layer structure in the same position. (c) A connected single- and double-layer region. The circles illustrate the atoms of the first and the second layer, respectively. (d) A few-layer graphene sheet with edges folded into a 90° angle. This side view enables occasionally also the side view on the Au-X structure (see marked region where 3 folded Au-X layers are found on top of folded 3-layer graphene.
