Oxygen Packing Fraction and the Structure of Silicon and Germanium Oxide Glasses
Oxygen Packing Fraction and the Structure of Silicon and Germanium Oxide Glasses
复制标题
硅和氧化锗玻璃的氧填充率和结构
DOI：
10.1021/acs.jpcb.7b09357
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发表时间：
2017-11-30
影响因子：
3.3
通讯作者：
Tse, John S.
中科院分区：
文献类型：
--
作者：
Du, XiangPo;Tse, John S.
用Bader原子分子理论，利用第一性原理分子动力学计算得到的玻璃结构，研究了高压下固体和液体氧化物玻璃中氧体积分数与拓扑有序度之间的关系。结果表明，由AIM理论得到的原子体积比(O/Si和O/Ge)不随压力变化。这一发现是由于压缩下电子拓扑结构的不断变化所致。与晶体固体不同，玻璃中的Si-O和Ge-O配位没有明显的转变压力；相反，这种变化在很大的压力范围内是渐进和连续的。因此，将唯一的Si-O或Ge-O配位数与玻璃在给定压力下的性质联系起来是困难的。
The recently proposed relationship between the oxygen volume fraction and topological ordering in solid and liquid oxide glasses at high pressure is examined with Bader's atoms-in-molecules (AIM) theory using glass structures generated from first principles molecular dynamics calculations. It is shown that the atomic (O/Si and O/Ge) volume ratio derived from AIM theory is not constant with pressure. This finding is due to the continuous change in the electron topology under compression. Unlike crystalline solids, there is no distinctive transition pressure for Si-O and Ge-O coordination in a glass; instead, the changes are gradual and continuous over a broad pressure range. Therefore, relating a unique Si-O or Ge-O coordination number to the properties of the glass at a given pressure is difficult.