一种改进的运动学低能电子衍射和数据平均方法及其在Cu(001)1×1表面上的应用  

AN IMPROVED KLEED/CMTA METHOD AND ITS APPLICATION ON Cu(001)1×1 SURFACE

作　　者：贾金峰[1] 李燕芳 赵汝光[1] 杨威生[1] 

机构地区：[1]北京大学物理系,北京100871

出　　处：《物理学报》1992年第5期819-826,共8页Acta Physica Sinica

摘　　要：本文对现有的运动学低能电子衍射(KLEED)和数据平均方法(CMTA)进行了全面的分析与评述,指出这一方法有很好的应用前景,并对已有的方法进行了重大的改进,建立了一整套实用的KLEED和CMTA表面分析新方法,在Cu(001)1×1表面上的应用使这一新方法得到充分的验证。结果表明:KLEED和CMTA方法是一种简单、有效、可靠的表面结构分析方法,且具有很高的表面灵敏度。In this paper, we investigate the method of kinematic low energy electron diffraction (KLEED) and constant momentum transfer averaging (CMTA). Through a thorough review, we point out that the method has great potential in surface structure determination although it had not been used properly in che past years. This method has been improved greatly in the present work. Firstly, with our own experiment, we demonstrate that the effect of multiple scattering can be eliminated in large part by averaging only a few I-S curves taken with different suitably selected diffraction geometry. Secondly, we show that in KLEED calculation, the constant scattering factor approximation is quite convenient and reasonable for surfaces consisting of same kind of atoms. Thirdly, this work introduces a peak broadening factor to reflect the thermal effect upon the I-V curves which had been neglected in some KLEED calculations. Finally, nonstructural parameters, such as inner potential, mean free path, peak broadening factor and attenuation factor, are optimized to give the best agreement between the calculated and experiment results. Application on Cu(001)1×1 surface indicates that the improved KLEED/CMTA method for surface analyses is simple, reliable and powerful.

关 键 词：铜 单晶 表面结构 KLEED CMTA 

分 类 号：O484.5[理学—固体物理]