Illustration: Alan Stonebraker

Figure 1: (Left) Carbon dome structure on an iridium substrate, indicating the tightly bound atoms at the edge of the island (C), the weakly bound atoms at the center (B) and intermediate atoms (A). (Right) Photoelectron spectrum at $970K$ showing the contributions from the edge (C), center (B), and intermediate (A) atoms in the dome structure. (In this simplified schematic diagram, the dome structure is shown to consist of three types of carbon atoms; the actual structure is more complex.)