title: Clusterization modes of Ti on TiO2(1 1 0)-1 × 1 due to stablization by catalytic suboxide formation.
abstract: The electronic states of individual clusters formed from Ti deposition on a TiO(2)(1 1 0)-1 × 1 surface were measured using scanning tunneling spectroscopy (STS). The results of scanning tunneling microscopy (STM) suggests that as the amount of deposited Ti increased, at a critical height of 1.4 nm, the cluster growth changes from vertical oxide formation to lateral growth. Based on the STS spectra, the relation between the band-gap and cluster size was revealed. In the first oxide-formation mode, the band gaps decreased smoothly in response to the increase of the cluster size, while a band-gap-free (metallic) phase appears when the clusters are thicker than ∼1.4 nm. This result indicates that Ti adatoms initially diffuse on the oxide surface and are stabilized by oxygen atoms from the substrate to form a suboxide interfacial layer. This catalytic suboxide formation promotes the vertical granular growth of the deposited Ti atoms.
authors.affiliation: Faculty of Engineering Science, Yokohama National University, Tokiwadai 79-5, Hodogaya-ku, Yokohama 240-8501, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Shindo
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Manaka
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Shudo