The Effect of Variations in SIntering Temperature on the Structure of Electrically Active Interfaces in Zinc Oxide Varistors

摘要

The non linear electrical properties of zinc oxide based varistors are controlled by propcesses occurring at grain boundaries. In this study a series of zinc oxide based materials containing 0.5mol percent Bi_2O_3 and 0.5mol percent MnO were prepared using a range of sintering temperatures between 950 deg C and 1300 deg C and the electrical effects of built in fields and resistive barriers in the materials' microstructures were analysed using remote electron beam induced current (RECBIC) imaging. This technique involves probing adjacent grains with electrodes guided by a micromanipulator and using the collected current to form an image. Quantitative line-scans across typical conductive mode features were also carried out.