In-situ imaging of the nucleation and growth of epitaxial anatase TiO2(001) films on SrTiO3(001) |
| |
| Authors: | Y. Du D.J. Kim T.C. Kaspar S.E. Chamberlin I. Lyubinetsky S.A. Chambers |
| |
| Affiliation: | 1. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, USA;2. Fundamental & Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA;3. Department of Physics and Laboratory for Surface Studies, University of Wisconsin — Milwaukee, Milwaukee, WI 53211, USA |
| |
| Abstract: | The growth of TiO2 anatase films on Nb‐doped SrTiO3(001) molecular beam epitaxy has been studied in-situ by scanning tunneling microscopy. We show that the initial growth follows the Stranski–Krastanov mode, where islands form on top of a wetting layer consisting of two monolayers (ML) of TiO2. The epitaxial islands subsequently nucleate and coalesce into large commonly oriented crystallites. The reconstruction observed by reflection high-energy electron diffraction (RHEED) is shown to result from the coexistence of individual (4 × 1) and (1 × 4) reconstructions present on different crystallite surfaces. The anatase grows in units of bilayers, resulting in a step height of 2 ML (~ 0.5 nm). This result explains the fact that the measured period of the RHEED specular-beam intensity oscillations corresponds to the time required for deposition of 2 ML. Ar ion sputtering and UHV annealing results in a transformation to coexisting (4 × 1) and (1 × 4) reconstructed terraces on individual crystallites, as commonly observed by ex-situ STM studies. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
