A STRUCTURAL BASIS FOR IONIC-DIFFUSION IN OXIDE GLASSES
A STRUCTURAL BASIS FOR IONIC-DIFFUSION IN OXIDE GLASSES
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DOI：
10.1080/01418619108204878
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发表时间：
1991-11-01
期刊：
影响因子：
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通讯作者：
DOBSON, BR
中科院分区：
文献类型：
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作者：
GREAVES, GN;GURMAN, SJ;DOBSON, BR
讨论了用X射线吸收精细结构(XAFS)和魔角旋转核磁共振(MASMRI)测定的碱性硅酸盐中阳离子的环境之间的关系。两者都与玻璃结构的修正随机网络一致，在该网络中，修饰剂形成了渗入网络的通道。认为决定玻璃化转变过程中桥氧原子和非桥氧原子分布的机制与促进玻璃中低温离子迁移的机制是相同的。特别是，XAFS和MAS核磁共振的结果可以用来预测离子迁移的活化能和电导率的大小。碱性二硅酸盐的这些参数与直接由输运性质测得的值符合得很好。
The relationships between the environments of cations in alkali silicates measured by X-ray absorption fine structure (XAFS) and magic angle spinning nuclear magnetic resonance (MASNMR) are considered. Both are consistent with the modified random network for glass structure in which modifiers form channels percolating through the network. It is proposed that the mechanisms determining the distribution of bridging and non-bridging oxygen atoms at the glass transition are the same as those that promote ionic transport at lower temperatures in the glass. In particular the results of XAFS and MASNMR can be used to predict the activation energy for ionic transport and the magnitude of the electrical conductivity. Values of these parameters for alkali disilicates are in good agreement with those measured directly from transport properties.