title: Towards atomic resolution in sodium titanate nanotubes using near-edge X-ray-absorption fine-structure spectromicroscopy combined with multichannel multiple-scattering calculations.
abstract: Recent advances in near-edge X-ray-absorption fine-structure spectroscopy coupled with transmission X-ray microscopy (NEXAFS-TXM) allow large-area mapping investigations of individual nano-objects with spectral resolution up to E/ΔE = 10(4) and spatial resolution approaching 10 nm. While the state-of-the-art spatial resolution of X-ray microscopy is limited by nanostructuring process constrains of the objective zone plate, we show here that it is possible to overcome this through close coupling with high-level theoretical modelling. Taking the example of isolated bundles of hydrothermally prepared sodium titanate nanotubes ((Na,H)TiNTs) we are able to unravel the complex nanoscale structure from the NEXAFS-TXM data using multichannel multiple-scattering calculations, to the extent of being able to associate specific spectral features in the O K-edge and Ti L-edge with oxygen atoms in distinct sites within the lattice. These can even be distinguished from the contribution of different hydroxyl groups to the electronic structure of the (Na,H)TiNTs.
authors.affiliation: ChIPS, University of Mons, B-7000, Mons, Belgium.
authors.forename: Carla
authors.initials: C
authors.lastname: Bittencourt
authors.forename: Peter
authors.initials: P
authors.lastname: Krüger
authors.forename: Maureen J
authors.initials: MJ
authors.lastname: Lagos
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Ke
authors.forename: Gustaaf
authors.initials: G
authors.lastname: Van Tendeloo
authors.forename: Chris
authors.initials: C
authors.lastname: Ewels
authors.forename: Polona
authors.initials: P
authors.lastname: Umek
authors.forename: Peter
authors.initials: P
authors.lastname: Guttmann