The structure of calcium metaphosphate glass obtained from x-ray and neutron diffraction and reverse Monte Carlo modelling.
The structure of calcium metaphosphate glass obtained from x-ray and neutron diffraction and reverse Monte Carlo modelling.
复制标题
通过 X 射线和中子衍射以及逆蒙特卡罗建模获得的偏磷酸钙玻璃的结构。
DOI：
10.1088/0953-8984/21/3/035109
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Wetherall KM
中科院分区：
文献类型：
--
作者：
Wetherall KM
用X射线和中子衍射研究了（CaO）0.5（P2 O 5）0.5玻璃的短程结构，并用逆蒙特卡罗方法模拟了其结构。使用这种技术的组合允许六个原子间的相关性被区分和拟合，以获得一组描述玻璃结构的键长和配位数。玻璃由磷酸盐四面体的偏磷酸盐链组成，每个磷酸盐单元具有两个可用于与Ca配位的非桥接氧原子。Ca-O相关性在2.35和2.86 nm处有两个峰，代表了键长的广泛分布。总的Ca-O配位为6.9，并且与扭曲的多面体单元如加帽的八面体或加帽的三棱柱一致。发现大多数非桥氧原子与两个钙原子键合。所有这些观察结果与Hoppe的磷酸盐玻璃模型一致。此外，中程秩序被揭示为由磷酸盐链与明显伸长的Ca离子簇交织在一起，Ca-O和Ca-P相关性对X射线衍射中的第一个尖锐衍射峰有显着贡献。
The short range structure of (CaO) 0.5 (P 2 O 5) 0.5 glass has been studied using x-ray and neutron diffraction and modelled using the reverse Monte Carlo method. Using this combination of techniques has allowed six interatomic correlations to be distinguished and fitted to obtain a set of bond lengths and coordination numbers that describe the structure of the glass. The glass consists of metaphosphate chains of phosphate tetrahedra and each phosphate unit has two non-bridging oxygen atoms available for coordination with Ca. The Ca–O correlation was fitted with two peaks at 2.35 and 2.86 Å, representing a broad distribution of bond lengths. The total Ca–O coordination is 6.9 and is consistent with distorted polyhedral units such as capped octahedra or capped trigonal prisms. It is found that most non-bridging oxygen atoms are bonded to two calcium atoms. All of these observations are consistent with Hoppe's model for phosphate glasses. Furthermore, the medium range order is revealed to consist of phosphate chains intertwined with apparently elongated clusters of Ca ions, and the Ca–O and Ca–P correlations contributed significantly to the first sharp diffraction peak in x-ray diffraction.