Epitaxial orientations of O2 monolayers on graphite by superlattice formation

Abstract

A search for registered superlattices containing as many as 841 molecules has been conducted which shows that they provide a mechanism for understanding the orientational epitaxies observed in low‐energy electron diffraction (LEED) measurements of monolayer O₂ deposited on graphite. Superlattices for the δ, δ’, ζ₁, and ζ₂ phases were found that give excellent agreement with experiment for the epitaxial orientations and the departure of the unit cell from centered rectangular. It is concluded that the lateral variations in the admolecule–substrate interaction are responsible for the epitaxy and the departure of the unit cell from centered rectangular. The structure and epitaxial orientations of O₂ clusters of size 1≤N≤16, deposited on graphite, are also investigated.