Financial support by the FCI (Fund of the Chemical Industry) is gratefully acknowledged. We thank Prof. Manfred Martin (RWTH Aachen, Germany) for stimulating discussions.
Nanocarving of Titania as a Diffusion-Driven Morphological Instability†
Article first published online: 30 JAN 2008
Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Functional Materials
Volume 18, Issue 3, pages 422–431, February 11, 2008
How to Cite
Lee, D.-K. and Janek, J. (2008), Nanocarving of Titania as a Diffusion-Driven Morphological Instability. Adv. Funct. Mater., 18: 422–431. doi: 10.1002/adfm.200601189
- Issue published online: 12 FEB 2008
- Article first published online: 30 JAN 2008
- Manuscript Revised: 13 APR 2007
- Manuscript Received: 12 DEC 2006
- Inorganic Nanostructures;
- Surface Modification;
Under strongly reducing conditions at high temperatures titania develops a specific surface morphology, comprising a regular array of fibers with a diameter in the sub-micrometer range. By a chemical diffusion experiment in a defined oxygen potential gradient it is shown that this surface structuring is caused by a diffusion-driven morphological instability of an advancing reaction front (surface). The kinetics of the process is analyzed in terms of linear transport equations. The conditions for the occurrence of the surface instability are discussed and the required materials properties are analyzed. The observed surface structuring is not restricted to titania, rather it has to occur in all nonstoichiometric compounds with predominant cation mobility.