掺杂TiO_2的ZnO压敏电阻正电子寿命谱研究

Study of Positron Lifetime Spectrum in ZnO Varistor Doped with TiO_2

利用正电子湮灭技术(PAS)和扫描电子显微镜(SEM),分析了掺杂TiO2的ZnO压敏电阻的晶界缺陷,以及不同降温速率对晶界特性的影响。实验结果表明,向样品中掺杂TiO2或者快速冷却样品,都能使得样品晶界处Zn空位团尺寸变大,浓度减小。

Positron annihilation lifetime spectra of TiO2 doped ZnO varistor were measured in order to study the defects formed by doping and influenced by different cooling rates. Morphologies of the materials were observed in SEM （Scanning electron microscopy ） to determine the defects and to compare with the results obtained in positron annihilation. It is found that the vacancy defect concentration is decreased and the scale of vacancy defect is increased both in the TiO2-doped sample and in the sample which cools faster.