POSITRON LIFETIME SPECTRA AND SCANNING ELECTRON MICROSCOPE INVESTIGATIONS DURING THE CRYSTAL-LIZATION PROCESS OF AMORPHOUS IONIC CONDUCTOR B2O3-0.7Li2O-0.7LiCl-xAl2O3
非晶离子导体B2O3-0.7Li2O-0.7LiCl-xAl2O3晶化过程的正电子湮没寿命谱和扫描电子显微镜研究

The traditional pressed powder-samples spoil seriously the accuracy and reproduci-bility in measurement of positron lifetime spectra and scanning electron microscopy. This paper has overcome the above difficulties by preparing large amorphous disk-samples, and obtained new result of positron lifetime spectra and scanning electron microscopy during the crystallization process.According to our experiements on amorphous ionic conductor B2O3-0.7Li2O-0.7LiCl-xA12O3, we find that the mean lifetime of positron at room temparature is not affected by content Nariation of A12O3, mean lifetime of positron decreases greatly after full crystallization. Moreover, during the beginning of the crystallization process mean lifetime of positron of sample of x=0.15 exhibits a notable anomalous enhancement, which occurs within the same temperature range while the anomalous enhancement of ionic conductivity appears.