摘要
采用分子动力学模拟的方法研究了CaO-Al_2O_3-SiO_2系玻璃的微观结构,发现Ca/Al=1/2时CaO-Al_2O_3-SiO_2系玻璃(网硅酸盐体系)并不像传统理论认为的那样是一个完整的三维网络,而是存在一定量的非桥氧,从而从理论上进一步证实了Stebins等人的实验结果.同时也发现不同的Ca/Al比对Si和Al键接方式产生重要影响,在Ca/Al>1/2时,Al比Si容易成为网络的中间体,其首先插入网络体中间;在Ca/Al<1/2时,Si比Al容易成为网络中间体.虽然在能量上Al—O—Si占有扰势,但当Ca/Al从大于1/2变化到小于1/2时,仍有部分Al—O—Si转变成Al—O—Al和Si—O—Si,丰富了Al自回避规则的内容.
The microstructure of CaO-Al2O3-SiO2 （CAS）glass system is studied by molecular dynamics method. When Ca/Al equals to 1/2,which is called tectosilicate glass system, CAS is not a totally full network as conventional theories, but with some Non-Bridging Oxygen（NBO）. The theoretical result proves Stebins＇ s experimental conclusion. The result also reveals that when the ratio of Ca/Al is greater than 1/2 Al is preferred inserting in polymerized network to the end of polymerized network, when the ratio of Ca/Al is less than 1/2, the situationis is contrary. The ＂aluminium avoidance＂ principle believes that Al--O--Al linkages are energetically less favorable than Al--O--Si linkages in CAS glass system. However when the ratio of Ca/Al alters down across 1/2,there are some Al--O--Si linkages change to Al--O---Al and Si--O--Si linkages.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第9期4795-4802,共8页
Acta Physica Sinica
基金
广东省自然科学基金(批准号:021289)资助的课题.~~
