Hwang, Ing-ShouhGolovchenko, Jene2016-11-181993Hwang, Ing-Shouh, and Jene A. Golovchenko. 1993. Tunneling Microscope Observation of a Structural Surface Phase Transition: Structure, Fluctuations, and Local Effects. Physical Review Letters 71, no. 2: 255–258. doi:10.1103/physrevlett.71.255.0031-9007http://nrs.harvard.edu/urn-3:HUL.InstRepos:29407029We study a reversible phase transition of one monolayer of Pb on a Ge(111) surface with a tunneling microscope over a temperature range from below to above the transition (∼175 °C). The controversial high temperature phase is actually a simple Pb-terminated 1×1 structure. Below the transition temperature, Pb atoms are displaced from their T1 positions and form trimers with √3 × √3 periodicity. A fluctuating structure with patches of trimers can be resolved slightly above the transition temperature. The important effects of boundaries and domain size on the phase transformation are discussed.en-USJournal Article2016-11-1810.1103/PhysRevLett.71.255