高介电常数TiO_2纳米晶的表面态研究

Surface State Studies of Nanocrystalline TiO_2 with High Dielectric Constant

将钛酸四丁酯和硬脂酸在熔融状态下混合均匀后置于冷水浴中 ,使其凝固成凝胶 ,通过控制烧结过程中氧气的含量 ,成功地制备出粒度均匀、介电性能好的纳米晶 Ti O2 .通过采用 X射线光电子能谱和表面光电压谱对纳米晶 Ti O2 表面状态的分析发现 ,材料表面存在大量的氧空位缺陷 ,暴露在粒子表面上的主要是一些金属 Ti4 + .纳米材料的这种表面状态对其极化性质具有重要的影响 。

An appropriate amount of stearic acid was melted at 70 ℃, into which tetrabutyl titanate was added while stirring. Then the solution was cooled in cool water to form a gel. By controlling the amount of oxygen during the calcining procedure, nanocrystalline TiO 2 powder with even grain size and good dielectric properties were obtained. The surface state was analyzed by means of X ray photoelectron spectroscopy and surface photovoltage spectroscopy. The results of experiments show that the surface structure...