Short, intermediate and mesoscopic range order in sulfur-rich binary glasses
Short, intermediate and mesoscopic range order in sulfur-rich binary glasses
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DOI：
10.1016/j.jnoncrysol.2005.11.002
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发表时间：
2006
影响因子：
3.5
通讯作者：
E. Bychkov;M. Miloshova;D. Price;C. Benmore;A. Lorriaux
中科院分区：
文献类型：
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作者：
E. Bychkov;M. Miloshova;D. Price;C. Benmore;A. Lorriaux
利用脉冲中子和高能X射线衍射、小角中子散射、拉曼光谱和差示扫描量热法研究了富硫AsSx（x 1.5）和GeSx（x 2）玻璃在短、中、介观尺度上的结构变化。两个系统中发现了两个结构区域。(1)在化学计量（As2S3和GeS2）和"饱和"（AsS2.3和GeS2.7）组成之间，过量的硫原子形成硫二聚体和/或短链，取代角共享AsS3/2和GeS4/2单元中的桥接硫。(2)高于[As]<30.5at. %时的"饱和"成分且[Ge]<27at. %，硫环和较长的硫链（特别是在AsSx体系中）出现在玻璃网络中。玻璃变成相分离的20 - 50埃的域，推测富含硫环。较长的链Sn是不稳定的，并且在几天到几个月的老化中结晶成c-S8，这取决于组成。
Pulsed neutron and high-energy X-ray diffraction, small-angle neutron scattering, Raman spectroscopy and DSC were used to study structural changes on the short, intermediate and mesoscopic range scale for sulfur-rich AsSx(x⩾1.5) and GeSx(x⩾2) glasses. Two structural regions were found in the both systems. (1) Between stoichiometric (As2S3and GeS2) and ‘saturated’ (AsS2.3and GeS2.7) compositions, excessive sulfur atoms form sulfur dimers and/or short chains, replacing bridging sulfur in corner-sharing AsS3/2and GeS4/2units. (2) Above the ‘saturated’ compositions at [As]<30.5at.% and [Ge]<27at.%, sulfur rings and longer sulfur chains (especially in the AsSxsystem) appear in the glass network. The glasses become phase separated with the domains of 20–50Å, presumably enriched with sulfur rings. The longer chains Snare not stable and crystallize to c-S8on ageing of a few days to several months, depending on composition.