title: Imaging of the hydrogen subsurface site in rutile TiO2.
abstract: From an interplay between simultaneously recorded noncontact atomic force microscopy and scanning tunneling microscopy images and simulations based on density functional theory, we reveal the location of single hydrogen species in the surface and subsurface layers of rutile TiO2. Subsurface hydrogen atoms (H(sub)) are found to reside in a stable interstitial site as subsurface OH groups detectable in scanning tunneling microscopy as a characteristic electronic state but imperceptible to atomic force microscopy. The combined atomic force microscopy, scanning tunneling microscopy, and density functional theory study demonstrates a general scheme to reveal near surface defects and interstitials in poorly conducting materials.
authors.affiliation: Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, University of Aarhus, Denmark.
authors.forename: Georg H
authors.initials: GH
authors.lastname: Enevoldsen
authors.forename: Henry P
authors.initials: HP
authors.lastname: Pinto
authors.forename: Adam S
authors.initials: AS
authors.lastname: Foster
authors.forename: Mona C R
authors.initials: MC
authors.lastname: Jensen
authors.forename: Werner A
authors.initials: WA
authors.lastname: Hofer
authors.forename: Bjørk
authors.initials: B
authors.lastname: Hammer
authors.forename: Jeppe V
authors.initials: JV
authors.lastname: Lauritsen
authors.forename: Flemming
authors.initials: F
authors.lastname: Besenbacher