Observation of a metastable state in monolayers of carbon tetrafluoride on graphite

We find that the two-peak diffraction patterns seen in slightly incommensurate monolayers of CF4 adsorbed on graphite are metastable; the peak at the commensurate position shrinks, while the incommensurate peak grows, with time or with temperature cycling. Similar behavior is seen with ZYX and single-crystal exfoliated graphite substrates. Thus, there is no striped phase in this system, but rather a metastable coexistence of commensurate and incommensurate phases. © 1989 The American Physical Society.