论文标题
关于无定形硅的第一个尖峰峰的起源和结构
On the origin and the structure of the first sharp diffraction peak of amorphous silicon
论文作者
论文摘要
在2 Angstrom $^{ - 1} $附近的无定形硅（$ {\ it a} $ -SI）的第一个尖锐衍射峰（FSDP）的结构被特别强调衍射曲线的位置，强度和宽度。通过研究$ {\ it a} $ - si的许多连续随机网络（CRN）模型，可以证明FSDP的位置和强度主要由15埃15埃符号长度的无定形网络中的径向原子相关性确定。对不同径向壳的贡献的贝壳分析表明，对FSDP的关键贡献源自网络中的第二和第四个径向壳，并伴随着第一壳的背景贡献，以及遥远径向壳的小残留校正。数值计算的结果是通过对波形空间中结构因子中峰与实际空间中降低的成对相关函数降低的现象学讨论的补充。得出了非晶网络中Si原子的平均邻次距离之间的近似功能关系，得出了数值计算证实的。
The structure of the first sharp diffraction peak (FSDP) of amorphous silicon (${\it a}$-Si) near 2 Angstrom$^{-1}$ is addressed with particular emphasis on the position, intensity, and width of the diffraction curve. By studying a number of continuous random network (CRN) models of ${\it a}$-Si, it is shown that the position and the intensity of the FSDP are primarily determined by radial atomic correlations in the amorphous network on the length scale of 15 Angstroms. A shell-by-shell analysis of the contribution from different radial shells reveals that the key contributions to the FSDP originate from the second and fourth radial shells in the network, which are accompanied by a background contribution from the first shell and small residual corrections from the distant radial shells. The results from numerical calculations are complemented by a phenomenological discussion of the relationship between the peaks in the structure factor in the wavevector space and the reduced pair-correlation function in the real space. An approximate functional relation between the position of the FSDP and the average second-neighbor distance of Si atoms in the amorphous network is derived, which is corroborated by numerical calculations.
