Tunable Nanostructures and Crystal Structures in Titanium Oxide Films
1 Division of Materials Characterization, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110012, India
2 Technische Universität Darmstadt, Darmstadt, D-64287, Germany
Nanoscale Research Letters 2008, 4:54-62 doi:10.1007/s11671-008-9202-9Published: 18 November 2008
Controllable nanostructures in spin coated titanium oxide (TiO2) films have been achieved by a very simple means, through change of post deposition annealing temperature. Electron beam imaging and reciprocal space analysis revealed as-deposited TiO2films to be characterized by a dominant anatase phase which converts to the rutile form at 600 °C and reverts to the anatase modification at 1,200 °C. The phase changes are also accompanied by changes in the film microstructure: from regular nanoparticles (as-deposited) to nanowires (600 °C) and finally to dendrite like shapes at 1,200 °C. Photoluminescence studies, Raman spectral results, and X-ray diffraction data also furnish evidence in support of the observed solid state phase transformations in TiO2.