Wide range temperature dependence of reflection high-energy electron diffraction rocking curve from a Si(111)7×7 surface
Wide range temperature dependence of reflection high-energy electron diffraction rocking curve from a Si(111)7×7 surface
复制标题
Si(111)7×7表面反射高能电子衍射摇摆曲线的宽范围温度依赖性
DOI：
10.1116/1.582285
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Y. Shigeta
中科院分区：
文献类型：
--
作者：
Y. Fukaya;K. Nakamura;Y. Shigeta
为了确定Si晶体表面层的德拜参数，我们在293-1073 K的温度范围内测量了Si（111）-7 7表面的反射高能电子衍射（RHEED）摇摆曲线。从考虑热漫散射的RHEED强度的动力学计算分析，与Brommer等人使用从头算分子动力学方案[Phys. Rev. Lett. 68，1355（1992）]，最佳德拜温度估计为420 K，这比体硅的德拜温度（505-658 K）低得多。由于德拜温度被认为是在几个表面层的平均值，差异意味着表面原子的振动振幅比体原子大。
In order to determine the Debye parameter for the surface layer of Si crystal, we have measured the rocking curves of reflection high-energy electron diffraction (RHEED) from a Si(111)-7×7 surface at temperatures extending over a wide range, 293–1073 K. From the analysis of the dynamical calculation of RHEED intensity taking account of the thermal diffuse scattering, the adatoms and rest atoms largely shifted upward compared with the atomic positions derived by Brommer et al. using ab initio molecular-dynamics scheme [Phys. Rev. Lett. 68, 1355 (1992)] and the optimum Debye temperature has been estimated at 420 K, which is much lower than that of bulk Si (505–658 K). Since the Debye temperature is considered to be an averaged value in a few surface layers, the difference means that the vibrational amplitude of surface atom is large compared to bulk atom.