Measurement of the micro mechanical properties of sol-gel TiO2 films

Abstract

The interest in the use of sol-gel derived films in tribological applications during recent years has increased the interest in the mechanical properties of these films. In this study we compare conventional film processing, firing in a tube furnace, with an alternative method, ion bombardment with medium energy hydrogen ions. In order to understand the behaviour of sol-gel derived titanium dioxide (TiO2) films deposited on glass, we have employed a number of different mechanical testing techniques. An ultra micro indentation system has been employed to measure the hardness and elastic modulus. This technique has been complemented by a bi-axial bending technique in order to fully determine the mechanical properties of the thin films. The results from the bi-axial bending technique have been analyzed using a finite element method in order to determine the stress distribution during the bi-axial loading and therefore to correct for non-uniform sample support. The films have been analyzed using RBS, XRD and AFM in order to examine the structure of the films. A comparison of the behaviour of the sol-gel TiO2 to PVD deposited aluminium and copper films has also been carried out.