碳纳米管束中的正电子理论  

Analysis of positron annihilation lifetime in single-walled carbon nanotube bundles

作　　者：陈祥磊[1] 郗传英[1] 叶邦角[1] 翁惠民[1] 

机构地区：[1]中国科学技术大学近代物理系,合肥230026

出　　处：《物理学报》2007年第11期6695-6700,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10475072;10675115)资助的课题.~~

摘　　要：采用中性原子叠加模型和有限差分方法(SNA-FD)计算了大范围内不同管径的单壁碳纳米管束中的正电子情况,发现对于单壁碳纳米管束,正电子的主要湮没区域,湮没对象和正电子寿命随碳纳米管管径的不同而发生规律性变化.计算得到管径范围在0.8—1.6nm的碳纳米管束的正电子寿命范围为332—470ps,与实验测得的394ps符合较好.　Superposed-neutral-atom model and the finite-difference method（SNA-FD）is used to calculate the positron annihilation lifetime in single-walled carbon nanotube bundles with different diameters in a large range.We find that in single-walled carbon nanotube bundles,the main area where positron annihilation takes place,the main object that positron annihilates with,as well as the positron annihilation lifetime change regularly as the diameter of single-walled carbon nanotube bundles changes.The positron annihilation lifetime in single-walled carbon nanotube bundles with diameter between 0.8—1.6nm is calculated to be 332—470ps.It agrees well with the experimental result of 394ps.

关 键 词：局域密度近似 单壁碳纳米管 正电子寿命 

分 类 号：O481[理学—固体物理]