Order-to-disorder phase-transition study of Pb on Ge(111)

G. E. Franklin; M. J. Bedzyk; J. C. Woicik; Chien Liu; J. R. Patel; J. A. Golovchenko

doi:10.1103/PhysRevB.51.2440

Order-to-disorder phase-transition study of Pb on Ge(111)

G. E. Franklin, M. J. Bedzyk, J. C. Woicik, Chien Liu, J. R. Patel, and J. A. Golovchenko

Phys. Rev. B 51, 2440 – Published 15 January 1995

Abstract

X-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.

Received 14 July 1994

DOI:https://doi.org/10.1103/PhysRevB.51.2440

Authors & Affiliations

G. E. Franklin

Department of Physics, Harvard University, Cambridge, Massachusetts 02138

M. J. Bedzyk

Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439

J. C. Woicik