氧化物纳米陶瓷中氧离子扩散激活能和电导率

The Diffusion Activation Energy and Electric Conductivity of Oxygen Ion of Oxide Nano-ceramic

建立了氧化物纳米陶瓷中离子导电的模型,研究了系统中离子扩散激活能随温度、粒径、表面张力系数等的变化规律.在此基础上,确定离子电导率与温度和粒径、表面张力系数的关系.以ZrO2∶16%Y为例,探讨了线度、温度对电导率的影响.结果表明:原子振动使颗粒受的机械压力变化,降低了离子扩散的能量势垒,离子定向扩散是氧化物纳米陶瓷中离子导电的机制.离子扩散激活能随温度升高而减小,随粒径增大而增大;离子电导率随温度升高而增大,随粒径增大而减小.理论值与文献给出的实验资料相符.

The model of ion electric conductivity is founded. Then the variation of diffusion activation energy with temperature, the grain size, and surface tension is studied and gets the relation. The example of ZrO2 ： 16%Y gives the affection of temperature and grain size on the electric conductivity. The result is followed. The reason of oxide ceramic conductivity is that the variation of mechanical force on grain decreases the potential harrier and made the ion conductivity. The diffusion activation energy decreases with the increasing temperature and grows with the grain size, which is contrary to the electric conductivity. The result of the paper is considered with the experiment.