Pinning of graphene to Ir(111) by flat Ir dots

Compact flat Ir islands form and are stable at 400 K when < 0.1 monolayer of Ir is evaporated onto a graphene flake preadsorbed on Ir(111). Local density approximation calculations account for the Ir islands' two dimensionality and their preferred sites on the substrate. They show that local sp(3) bonding at once chemisorbs the dots above the graphene and firmly pins the graphene layer to the underlying metal.