6570
Langmuir 2006, 22, 6570-6577
Low-Temperature Preparation of Anatase Thin Films on Tantalum Scott E. Johnson, Matthew W. P. Burgoon, Qi Wang, and J. M. White* Department of Chemistry and Biochemistry, Center for Materials Chemistry, UniVersity of Texas at Austin, Austin, Texas 78712 ReceiVed February 24, 2006. In Final Form: May 15, 2006 Titanium dioxide thin films were grown on oxidized Ta surfaces using a cyclic layer-by-layer wet chemistry method: successive-ionic-layer-adsorption-and-reaction (SILAR). Film thicknesses varied monotonically and approximately linearly with the number of cycles. As-grown (AG) films were amorphous and rougher (16.2 nm root-mean-square (rms)) than the Ta substrate (10.2 nm rms). After hydrothermal annealing (AN) at a remarkably low temperature of 393 K, the films exhibited anatase crystallites (10 nm dimensions) and reduced roughness (11.8 nm rms). The atomic composition of both AG and AN films was consistent with that of TiO2 containing no more than 4 atom % carbon. A small Si impurity (
