The (3 x 2) phase of Ba adsorption on Si(001)-2 x 1

Citation
X. Hu et al., The (3 x 2) phase of Ba adsorption on Si(001)-2 x 1, SURF SCI, 445(2-3), 2000, pp. 256-266
Citations number
59
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
SURFACE SCIENCE
ISSN journal
00396028 → ACNP
Volume
445
Issue
2-3
Year of publication
2000
Pages
256 - 266
Database
ISI
SICI code
0039-6028(20000120)445:2-3<256:T(X2PO>2.0.ZU;2-I
Abstract
The initial stages and surface structures of the (3 x 2) phase of Ba adsorp tion on an Si(100)-2 x 1 surface held at 900 degrees C have been studied by low-energy electron diffraction, Auger electron spectroscopy, and ultra-hi gh vacuum scanning tunneling microscopy (STM). At low coverages (<1/6 ML), the Ba atoms from atomic chains across the Si dimer rows by occupying valle y bridge sites, as well as on fourfold sites by replacing Si dimers and exh ibiting a local (3 x 2) phase, with the 3 x -phase along the Si dimer row d irection. Two different configurations for the (3 x 2) phase, namely, mono- and dimer-Ba models, are proposed based on the STM images. Below a coverag e of 1/6 ML, the (3 x 2) phase is formed by single Ba atoms at fourfold sit es by replacing original Si dimers. For a Ba coverage of 1/3 ML, the (3 x 2 ) phase is formed by buckled Ba dimers, as revealed by high-resolution STM images. (C) 2000 Elsevier Science B.V. All rights reserved.