TiO_2薄膜结构及氧敏性研究

Study on TiO_2 Oxygen Sensitive Thin Films

利用溶胶-凝胶技术制备了TiO2氧敏薄膜,通过氧化物掺杂和贵金属的表面修饰,在空气气氛下烧结氧敏薄膜.结果表明:600℃～800℃下处理的薄膜是以金红石为主晶相及少量锐钛矿的混合晶型,随着温度升高锐钛矿减少,900℃时锐钛矿相的峰基本消失;800℃下处理的薄膜灵敏度明显高于600℃和900℃下处理的薄膜灵敏度.W,Ce氧化物掺杂促进TiO2薄膜微量氧化还原,增加催化反应活性,使薄膜的氧气灵敏度有明显提高;以Pd对W-TiO2薄膜进行表面修饰,使薄膜的阻温特性得到了明显提高.

This paper dealt with the preparation of the oxide-doped TiO2 thin films and the Pd-modified TiO2 thin films by using the sol-gel method. The oxide sensitive film was sintered in air. The main crystalline phase of the TiO2 films sintered at 600 degrees C similar to 800 degrees C is rutile, together with some anatase which decreases when temperature goes up and even disappeares at 900 degrees C. The oxygen sensitivity of the film sintered at 800 degrees C is obviously higher than that of the film sitered at 600 degrees C and 900 degrees C. The oxygen sensitivity is obviously enhanced because the complex crystalline phase and the doping of W, Ce oxides accelerates the micro oxidation-reduction reaction of the film, and the resistance-temperature characteristics, especially the response speed, are evidently improved by means of the surface modification with the noble metal Pd.