Summary: | 博士 === 國立中山大學 === 材料與光電科學學系研究所 === 100 === The phase transformation of anodized Ti film has been studied. Although X-ray diffraction detected only the amorphous TiO2 phase, transmission electron microscopy analysis showed that TiO nanocrystallites less than 10 nm in size were also present, which was further supported by x-ray photoelectron spectroscopy analysis. Anatase was found to appear gradually by annealing the as-anodized specimen in air at 500–550 oC, which was accompanied by a simultaneous disappearance of TiO nanocrystallites. In contrast, only rutile is formed by annealing the Ti film at the same temperatures. The results indicate that TiO can induce the formation of anatase, which is explained by the close similarity between their structures. (Chapter 1)
Anatase phase of TiO2 has been shown to have very good biocompability. It was frequently observed on Ti surfaces after anodizing and thermal annealing treatments. In this report the mechanisms of the Ti to TiO and the TiO to anatase phase transitions in anodizing and annealing treatments of Ti have been studied by transmission electron microscopy. Ti thin films of two strong textures were first grown on the (001)NaCl substrates. In addition to amorphous TiO2, the anodization treatment caused the formation of TiO with an orientation relationship of (11-20)Ti // (220)TiO with Ti. The subsequent thermal annealing treatment caused the TiO to anatase transition with an orientation relationship of {200}TiO //{200}A. Pure anatase film was prepared by this method. (Chapter 2)
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