ZnO压敏材料的PAT研究

A Positron Annihilation Study of the Zinc Oxide Varistor

ZnO压敏材料自60年代问世以来发展迅速,应用越来越广泛,市场对材料性能也不断提出新的要求.如何从实验中研究出性能优良、价格低廉的实用材料和器件一直成为该领域科技人员努力的目标,其技术突破的关键又在于寻找合适的掺杂配方和烧结工艺.本文试图用正电子湮没寿命方法研究材料性能与掺杂量及烧结工艺之间的内在联系,探讨不同条件下微观结构的变化,以期寻求一种优化掺杂和工艺的新方法.从结果来看,这种研究方法是有意义的.

The positron lifetime spectra of the zinc oxide varistor are studied. The relationship between the positron annihilation parameters and the amount of the MnO2 doping and the sinteringtem perature is discussed. Experimental results show that, at the same sintering temperature, parameters 1 and T2 reach a minimum and intensity I2 reaches a maximum with an increase of the doping. This means that there exists a limited ability of the Mn ion to restrain the growth of grains. The effect of the sintering temperature on the structure of material can also be seen from the variation of annihilation parameters.