A study on the conduction path in undoped polycrystalline diamond films

The conduction path in as-grown undoped diamond films deposited by chemical vapor deposition has been investigated by employing impedance spectroscopy, electroplating and electroetching. The thickness- and direction-dependencies of electrical resistivity did not agree with the previously known surface conduction model. The Cu electroplating and Ag electroetching results showed that the current path followed the grain boundaries within the diamond films. The Cu electroplating of diamond film with an insulating surface layer also showed that the grain boundaries within the films were the main conduction path in undoped polycrystalline films.     

高纯铝箔电解腐蚀扩面机理研究进展

概述了高纯铝箔在含氯离子的溶液中电解腐蚀时外加极化电流或电位、交流电频率、电解液中的氯离子浓度、腐蚀温度、铝的立方织构等因素对蚀坑萌生和蚀坑发展动力学（包括蚀坑的密度、形状、尺寸、生长速度等）的影响机制，并总结出一些重要结论，同时也提出了有待进一步研究解决的问题。     

电容器铝箔交流腐蚀扩面机理研究

实现铝电解电容器小型化的关键是铝电极箔电解腐蚀扩面过程的人为设计。为实现这一目标,本文就目前尚不清楚的交流腐蚀扩面机制进行了系统分析研究。首先研究了高纯铝箔在水溶液中的热力学和在盐酸溶液中的动力学行为,接着详细地研究了铝在交流电的负半周所发生的变化,以及这些变化对交流正半周铝的点蚀的萌生和生长的影响,并从理论上推导出控制交流负半周腐蚀膜形成的数学关系式。在此基础上,提出了铝在交流负半周发生的四种变化,以及交流腐蚀扩面机理。根据这一机理,提出了铝箔的交流腐蚀工艺优化原则,并用实验对这一原则进行了初步验证。本论文的主要内容如下：