Real-time Monitoring of Nanosponge Titania Formation During Oxidation of Monolayer Ti and Multilayered Ti/Metal Thin Films
Y.H. Yeo, H.H. Lau, A.S. Zuruzi, S.X. Wu, Z. Chen
Nanyang Polytechnic, SG
Keywords: nanoporous, real-time monitoring, titania
Abstract:Nanoporous titanium oxides have extremely wide applications ranging from chemical sensing to solar energy. We have recently shown that oxidation of titanium thin films in hydrogen peroxide results in the formation of highly porous nanosponge titanium dioxide (NST). This low-temperature method allows the integration of nanosponge titanium dioxide into transparent and flexible transparent substrates for chemical sensing applications [1-3]. For practical implementation in industry, methods of monitoring real-time oxidation of titanium film need to be developed. Previously, we have proposed an electrical-based method of monitoring the oxidation process . In this contribution, we present a novel optical monitoring technique during the oxidation process. The method is optical based and provides real-time data of the oxidation process. It is expected to be easily integrated in manufacturing lines as well. Using this technique, we are able to monitor the oxidation of monolayer titanium films with thickness ranging from 5 to 100 nm. To demonstrate the accuracy of the technique, we used it to determine the activation energy for the oxidation of Ti in hydrogen peroxide solution. The activation energy was found to be 0.36 eV, which is close to reported values obtained using other techniques. Furthermore, using this technique, we are able to differentiate the oxidation of various layers in multilayer Ti/Pt films. This technique is a potentially useful tool to study the oxidation properties of various Ti-based alloys as well as Ti/Metal multilayers. References  A. S. Zuruzi, N. C. MacDonald, Advanced Functional Materials 2005, 15, 396.  A. S. Zuruzi, A. Kolmakov, N. C. MacDonald, M. Moskovits, Applied Physics Letters 2006, 88, 102904.  A. S. Zuruzi, N. C. MacDonald, M. Moskovits, A. Kolmakov, Angewandte Chemie International Edition 2007, 46, 4298.  D.M. DeRosa, A. S. Zuruzi, N. C. MacDonald, Advanced Engineering Materials, 2006, 77.