SOFT INCOMMENSURATE RECONSTRUCTION ON PB/SI(111) - STRUCTURE, STRESS MODULATION, AND PHASE-TRANSITION

We resolve the atomic structure of the one-monolayer incommensurate (IC) reconstruction of Pb on Si(111) using a tunneling microscope. The local structure of this surface consists of two types of Pb trimers and a quasi-1×1 region, while on larger (>10 Å) scales the trimers are assembled into alternating domains discommensurate with the substrate. One feature of this surface is the sensitivity of the domain morphology to surface-stress inhomogeneities. This sensitivity dramatically alters the temperature at which the IC phase transforms locally to a 1×1 phase. © 1995 The American Physical Society.