Surface Structure of Bi(111) from Helium Atom Scattering Measurements. Inelastic Close-Coupling Formalism.
Surface Structure of Bi(111) from Helium Atom Scattering Measurements. Inelastic Close-Coupling Formalism.
复制标题
DOI：
10.1021/acs.jpcc.5b05010
复制
发表时间：
2015-07-30
期刊：
影响因子：
--
通讯作者：
Ernst WE
中科院分区：
文献类型：
--
作者：
Kraus P;Tamtögl A;Mayrhofer-Reinhartshuber M;Apolloner F;Gösweiner C;Miret-Artés S;Ernst WE
利用弹性和非弹性紧耦合(CC)计算，通过对几个实验衍射图的拟合，提取了关于波纹幅度和表面振动原子位移的信息。为了模拟He原子与所研究的Bi(111)表面之间的三维相互作用，假定了波纹Morse势。用两种不同的计算方法得到了沿两个对称方向的三个表面温度下的理论衍射强度。第一类包括求解弹性CC(ECC)和用整体德拜-沃勒(DW)因子衰减相应的衍射光强。第二种方法是在么正理论中，只需解非弹性CC(ICC)方程，其中不需要包含DW因子。虽然两种方法得到的峰间波纹值的预测值相似，但ICC方法得到的值的方差要好得多。此外，更广泛的计算更适合于模拟温度诱导的信号不对称性，并且使得第二个衍射峰的德拜温度的包含是徒劳的。
Elastic and inelastic close-coupling (CC) calculations have been used to extract information about the corrugation amplitude and the surface vibrational atomic displacement by fitting to several experimental diffraction patterns. To model the three-dimensional interaction between the He atom and the Bi(111) surface under investigation, a corrugated Morse potential has been assumed. Two different types of calculations are used to obtain theoretical diffraction intensities at three surface temperatures along the two symmetry directions. Type one consists of solving the elastic CC (eCC) and attenuating the corresponding diffraction intensities by a global Debye–Waller (DW) factor. The second one, within a unitary theory, is derived from merely solving the inelastic CC (iCC) equations, where no DW factor is necessary to include. While both methods arrive at similar predictions for the peak-to-peak corrugation value, the variance of the value obtained by the iCC method is much better. Furthermore, the more extensive calculation is better suited to model the temperature induced signal asymmetries and renders the inclusion for a second Debye temperature for the diffraction peaks futile.