ソーダ万灰ガラス基板上に形成したゾルーゲルTiO_2-SiO_2薄膜のアルカリパッシベイションメカニズム Alkali Passivation Mechanism of Sol-Gel Derived TiO_2-SiO_2 Films Coated on Soda-Lime-Silica Glass Substrates

Alkali passivation mechanism of sol-gel derived TiO_2-SiO_2 glass films with different TiO_2 contents coated on a soda-lime-silica glass substrate has been studied by SIMS and XPS analyses, and compared with the results of a sol-gel derived pure SiO_2 film. An increase in TiO_2 content in the TiO_2-SiO_2 film increased the sodium concentration in the film, which was induced by sodium migration from the glass substrate during the heat-treatment. It was also found that the chemical state of sodium ions in the TiO_2-SiO_2 films was different from the state of those either in the glass substrate or in the sol-gel derived pure SiO_2 film. It is thus concluded that the TiO_2-SiO_2 films serve not as a barrier but as an effective getter of alkli ions and thereby effectively improve the weathering resistance of the glass substrate.