用正电子寿命谱研究GeSe_x硫系玻璃的自由体积  

The Free-Volume of GeSe_x Chalcogenide Glass Studied by Positron Lifetime Spectroscopy

作　　者：王柱[1] 田丰收[1] 皮道显 陶海征[2] 

机构地区：[1]武汉大学物理科学与技术学院,湖北武汉430072 [2]武汉理工大学硅酸盐建筑材料国家重点实验室,湖北武汉430070

出　　处：《武汉大学学报（理学版）》2015年第2期174-178,共5页Journal of Wuhan University:Natural Science Edition

基　　金：国家自然科学基金资助项目(11275142)

摘　　要：采用正电子寿命谱和拉曼散射研究了不同组分配比的Ge Sex(x=6,7,8,9)硫系玻璃的微结构.正电子寿命结果显示在x=8时,其平均正电子寿命具有最小值.拉曼光谱结果研究表明,这种硫系玻璃样品主要由[Ge Se4]四面体和Seμ链的结构单元构成.以上的实验结果用级配理论得到了合理的解释,这两种结构单元配比关系的变化导致硫系玻璃样品中的自由体积变化,从而导致正电子平均寿命减小.研究发现Ge Se8具有最小的自由体积,即具有最稳定的结构.In this study,positron lifetime and Raman scattering spectroscopy are used for studying the micro-structure in Ge Sex（ x = 6,7,8,9） chalcogenide glasses samples with differences of Se content. The positron lifetime results indicate that the average positron lifetime has a minimum value at x = 8,which means the minimum free-volume. The Raman scattering results show that the chalcogenide glass samples mainly consist of [Ge Se4]tetrahedral and Seμchain units. These two kinds of results was properly explained by the aggregate grading theory. The proportion of two kinds unit leads to the porosity decrease,corresponding to the decrease of the average positron lifetime. In the sample of this study,Ge Se8 has the smallest free volume,i. e. has the most stable structure.

关 键 词：硫系玻璃 正电子寿命 自由体积 拉曼散射 级配理论 

分 类 号：O474[理学—半导体物理]