title: Structure of the Ba-induced Si(111)- (3 x 2) reconstruction.
abstract: The Ba/Si(111) surface, previously known as a 3 x 1 phase, is found to have a 3 x 2 periodicity and a semiconducting band gap. The substrate reconstructs into the honeycomb chain-channel (HCC) structure with Ba atoms in the channel, as in the alkali-metal-induced Si(111)-(3 x 1). However, the metal coverage is determined to be 1/6 monolayers, half the alkali-metal coverage. We propose that the structure and the metal coverage determined for the Ba adsorbate is universal for other alkaline-earth-metal adsorbates. With the alkali-metal-induced 3 x 1 case, our results lead to a rule that one donated electron per 3 x 1 surface unit is necessary to stabilize the HCC reconstruction of Si.
authors.affiliation: Materials Evaluation Center, Korea Research Institute of Standards and Science, Taejon 305-600, Korea. glee@kriss.re.kr
authors.forename: G
authors.initials: G
authors.lastname: Lee
authors.forename: S
authors.initials: S
authors.lastname: Hong
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: D
authors.initials: D
authors.lastname: Shin
authors.forename: J Y
authors.initials: JY
authors.lastname: Koo
authors.forename: H I
authors.initials: HI
authors.lastname: Lee
authors.forename: D W
authors.initials: DW
authors.lastname: Moon