物理化学学报 >> 2003, Vol. 19 >> Issue (11): 1054-1058.doi: 10.3866/PKU.WHXB20031114

研究论文 上一篇    下一篇

Cl/GaAs(111)表面近边X射线吸收精细结构的多重散射研究

沈少来;唐景昌;曹松;汪雷   

  1. 浙江大学物理系, 浙江大学硅材料科学国家重点实验室,杭州　310027
  • 收稿日期:2003-04-15 修回日期:2003-07-14 发布日期:2003-11-15
  • 通讯作者: 沈少来 E-mail:ascoaco@zju.edu.cn

Theoretical Studies of Near Edge X-rays Absorption Fine Structure for Cl Adsorbed on GaAs(111) Surface

Shen Shao-Lai;Tang Jing-Chang;Cao Song;Wang Lei   

  1. 1Department of Physics, 2State Key Laboratory for Silicon Material Science, Zhejiang University, Hangzhou　310027
  • Received:2003-04-15 Revised:2003-07-14 Published:2003-11-15
  • Contact: Shen Shao-Lai E-mail:ascoaco@zju.edu.cn

PDF

3149

赞

摘要： 利用多重散射团簇方法（MSC）计算了Cl/GaAs(111)吸附表面的Cl原子k边X射线吸收精细结构谱（NEXAFS）.阐明了NEXAFS谱中各个弱结构的物理起源.根据模型计算的结果与实验比较,求得吸附在顶位的氯原子和最近邻的镓原子的键长为（0.213±0.005）nm.这个结果在0.005 nm的误差范围内将广延X射线吸收精细结构（EXFAS）实验谱的Fourier变换结果（0.217 nm）和Slab模型计算的结果（0.208 nm）合理地联系起来.此外,MSC计算求得衬底表面层Ga－As键长为（0.235±0.005）nm,证实Cl吸附引起GaAs(111)表面驰豫.

关键词: 近边X射线吸收精细结构（NEXAFS）, Cl/GaAs(111)吸附表面, 多重散射团簇方法（MSC）

Abstract: The multiple scattering cluster (MSC) method has been employed to calculate the chlorine 1s near edge X-ray absorption fine structure (NEXAFS) of the Cl adsorbed on GaAs(111) surface. A series of specially designed clusters have been used to mimic the Cl/GaAs(111) geometry for finding the local geometrical structures of the system. The physical origin of the peaks in NEXAFS spectra has been revealed. MSC calculation shows that the Cl atom is adsorbed on the top site, the Cl－Ga bond length is (0.213±0.005) nm and the Ga－As bond length in surface layer is (0.235±0.005) nm. The comparison between above results and those of EXAFS experiment and the Slab model calculation has been made and discussed.

Key words: Near edge X-ray absorption fine structure (NEXAFS), Cl/GaAs(111) surface, Multiple-scattering cluster method(MSC)