Study of As―Se―Te glasses by neutron-, X-ray diffraction and optical spectroscopic methods
Study of As―Se―Te glasses by neutron-, X-ray diffraction and optical spectroscopic methods
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DOI：
10.1016/j.jnoncrysol.2011.12.076
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发表时间：
2012-02
影响因子：
3.5
通讯作者：
M. Fábián;E. Sváb;V. Pamukchieva;A. Szekeres;P. Petrik;S. Vogel;U. Ruett
中科院分区：
文献类型：
--
作者：
M. Fábián;E. Sváb;V. Pamukchieva;A. Szekeres;P. Petrik;S. Vogel;U. Ruett
用中子和高能x射线衍射方法研究了非晶态As40Se(60−x)Tex（x=10和15）和as40se60玻璃的原子结构。采用反向蒙特卡罗（RMC）仿真技术对两个数据集同时建模。RMC模拟揭示了一个由As(Se, Te)3金字塔组成的玻璃状网络，其中Te原子取代了Se原子。As-Se相关函数在2.4Å处有一个强烈而尖锐的第一个峰，在3.7和5.6Å处有两个宽而不那么强烈的峰，分别与As-Se键的第1、第2和第3相邻距离有关。它们是所研究玻璃杯中存在短序和中序的证据。ΘTe-As-Teand ΘSe-As-Sebond分布的相似性表明Te原子在结构形成中的作用与Se原子相似。FTIR光谱分析显示，玻璃中存在Se-H、As-O、Se-O和Te-O杂质键，这些杂质键有助于增强玻璃在可见光光谱范围内的吸收。通过椭偏数据分析，确定了所研究玻璃的光学常数和能参量。这些参数的组成变化可以用化学键的形成和带电缺陷密度的变化来解释。
The atomic structures of amorphous As40Se(60−x)Tex(x=10 and 15) and As40Se60glasses have been investigated by neutron and high energy X-ray diffraction methods. The two datasets were modeled simultaneously by reverse Monte Carlo (RMC) simulation technique. The RMC simulations revealed a glassy network built-up from As(Se, Te)3pyramids in which Te atoms substitute Se atoms. The As―Se correlation function shows a strong and sharp first peak at 2.4Å and two broad and much less intense peaks at 3.7 and 5.6Å, related to 1st, 2nd and 3rd neighbor distances of the As―Se bonds, respectively. They are an evidence for existence of short and medium ordering in the studied glasses. The similarity of ΘTe―As―Teand ΘSe―As―Sebond distributions suggests that Te atoms have a similar role in the structure formation as Se atoms. The FTIR spectra analysis revealed impurity bonds of Se―H, As―O, Se―O, and Te―O in the glasses which contributed to enhanced absorption in visible spectral range. From the ellipsometric data analysis the optical constants and the energetic parameters of the studied glasses were established. The compositional variation of these parameters is explained in terms of chemical bonds formation and change in the density of charged defects.