Changes in dewetting behavior of SiO<inf>2</inf> films on TiO<inf>2</inf> substrates due to film thickness and crucible choice

The TiO2/SiO2 materials system has had renewed interest in recent years due to its photoelectric and photocatalytic properties, and serves as an ideal model system for liquid-phase sintering studies (LPS). In this study, glass SiO2 films of three different nanoscale thicknesses were deposited onto (001) rutile TiO2 substrates. The resulting dewet patterns of the glass were found to change depending on the initial film thickness when subjected to identical annealing conditions. In addition, changing the crucible type from Pt to Al2O3, caused films of the same thickness to undergo different convection mechanisms and thus developing very different surface patterns. It is proposed that Marangoni convection drove pattern formation when a Pt crucible was used, while the Rayleigh instability was responsible for dewetting when an Al 2O3 crucible was used. © 2011 Springer Science+Business Media, LLC.