title: The growth of sulfur adlayers on Au(100).
abstract: We have studied the growth of S layers adsorbed on Au(100) with low-energy electron diffraction (LEED), X-ray photoemission spectra (XPS), and scanning tunneling microscope (STM). Three phases of S/Au(100)-(2 × 2), trimer, and c(2 × 4)-are identified; the latter two are not previously reported. A dose of S2 at 300 K transformed Au(100)-(5 × 20) initially into the (2 × 2) phase and formed the c(2 × 4) phase at a saturation coverage. The STM results show that monolayer Au islands formed during the initial S dose and remained throughout the growth, resulting in a rough c(2 × 4) surface. We show that a highly ordered c(2 × 4) phase can be obtained with a flat (2 × 2) phase as an intermediate step during growth. Based on the evolution of XPS and STM images with varied S2 dose, the components of S 2p are assigned and structural models for the various S/Au(100) phases are proposed. In the (2 × 2) phase, one S atom resides on a four-fold hollow site in each (2 × 2) unit cell, corresponding to a S coverage of 0.25 ML; in the trimer phase, three S atoms form a trimer residing on a four-fold hollow site in each (2 × 2) unit cell, corresponding to a S coverage of 0.75 ML; in the c(2 × 4) phase, there are five S atoms in each primitive unit cell of c(2 × 4); three of them form a trimer residing on a four-fold hollow site, and the other two form a dimer located on the top of the trimer, corresponding to a nominal S coverage of 1.25 ML. With the proposed structural models, the growth of S on Au(100) at 300 K is described in detail.
authors: Department of Physics, National Central University, Taoyuan 32001, Taiwan.
authors: Yue
authors: Y
authors: Jiang
authors: Department of Physics, National Central University, Taoyuan 32001, Taiwan.
authors: Xihui
authors: X
authors: Liang
authors: Department of Physics, National Central University, Taoyuan 32001, Taiwan.
authors: Shendong
authors: S
authors: Ren
authors: Department of Physics, National Central University, Taoyuan 32001, Taiwan.
authors: Chi-Lu
authors: CL
authors: Chen
authors: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
authors: Liang-Jen
authors: LJ
authors: Fan
authors: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
authors: Yaw-Wen
authors: YW
authors: Yang
authors: Department of Physics, University of New Hampshire, Durham, New Hampshire 03824, USA.
authors: Jian-Ming
authors: JM
authors: Tang
authors: Department of Physics, National Central University, Taoyuan 32001, Taiwan.
authors: Dah-An
authors: DA
authors: Luh