Ali F, Chadwick A V, Greaves G N, Jermy M C, Ngai K L, Smith M E
Chemical Laboratory, University of Kent, Canterbury, UK.
Solid State Nucl Magn Reson. 1995 Oct;5(1):133-43. doi: 10.1016/0926-2040(95)00033-m.
Results from 29Si, 23Na and 7Li magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy, 7Li NMR relaxation and electrical conductivity in a series of [Li(1-x).Nax]2O.2SiO2 (disilicate) glasses are used to investigate the mixed-alkali effect. From the 29Si NMR spectra there is relatively little change of the network with alkali composition. 23Na and 7Li NMR linewidths and shifts change continuously as a function of composition, indicating that the alkali ions are intimately and uniformly mixed rather than separated into lithium and sodium-rich domains. The activation energy from electrical conductivity shows a distinct maximum at the central composition (x = 0.5), whereas the local activation energy for lithium motion determined from NMR shows only a smaller but monotonic increase as the lithium-content decreases.
通过对一系列[Li(1 - x)·Nax]2O·2SiO2（二硅酸盐）玻璃进行29Si、23Na和7Li魔角旋转核磁共振（NMR）光谱分析、7Li NMR弛豫和电导率测量，来研究混合碱效应。从29Si NMR光谱来看，网络结构随碱金属组成的变化相对较小。23Na和7Li NMR线宽及位移随组成连续变化，这表明碱金属离子紧密且均匀地混合，而非分离成富锂和富钠区域。电导率的活化能在中心组成（x = 0.5）处呈现出明显的最大值，而由NMR测定的锂运动的局部活化能仅随着锂含量的降低呈现出较小但单调的增加。
