title: The adsorption of O2 on Pb films and the effect of quantum modulation: a first-principles prediction.
abstract: Using first-principles calculations based on density-functional theory, we systematically study the adsorption of O(2) molecules on ultrathin Pb(111) films ranging from 3 to 11 monolayers (MLs). It is found that no matter how thick the film is, the O(2) molecule prefers to adsorb at the threefold hcp hollow site where it lies parallel to the surface. The adsorption mechanism is discussed from the hybridization of p orbitals of O(2) and Pb. The adsorption energy of O(2) on the Pb(111) film, about several hundred meV, shows a 2 ML oscillation with the thickness. This study well confirms the modulation of the surface reactivity of Pb films induced by the quantum well states, which is compatible with the previous experimental observation.
authors.affiliation: Center for Advanced Study and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Wenhui
authors.initials: W
authors.lastname: Duan
authors.forename: Qi-Kun
authors.initials: QK
authors.lastname: Xue
authors.forename: Bing-Lin
authors.initials: BL
authors.lastname: Gu
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.forename: Xucun
authors.initials: X
authors.lastname: Ma
authors.forename: S B
authors.initials: SB
authors.lastname: Zhang