Franklin, GillianBedzyk, M. J.Woicik, J. C.Liu, ChienPatel, J. R.Golovchenko, Jene2016-11-171995Franklin, G. E., M. J. Bedzyk, J. C. Woicik, Chien Liu, J. R. Patel, and J. A. Golovchenko. 1995. Order-to-Disorder Phase-Transition Study of Pb on Ge(111). Physical Review B 51, no. 4: 2440–2445. doi:10.1103/physrevb.51.2440.0163-1829http://nrs.harvard.edu/urn-3:HUL.InstRepos:29406268X-ray standing-wave (111) and (111¯) measurements have been performed on the room-temperature and high-temperature phases of a Pb layer on Ge(111). At room temperature, our results support a four-atom–unit-cell surface structure. On passing into the high-temperature phase, we find that there is an increase in the Fourier coefficient along the surface [112¯] direction for the Pb density distribution. Our model, which requires a 0.6-Å in-plane thermal vibration amplitude, is similar to one previously proposed by Hwang and Golovchenko and disagrees with a strictly two-dimensional-liquid interpretation.en-USJournal Article2016-11-1710.1103/PhysRevB.51.2440