Study on the new functionality of glasses induced by R^+/Cu^+ and R^+/Ag^+ ion-exchange

为了开发常规玻璃制备工艺所不能获得的功能玻璃，采用离子交换技术将Na_2O-Al_2O_3-SiO_2系氧化物玻璃中的Na~+离子置换为Ag~+或Na~+~+离子，并讨论了离子交换引起的结构变化对玻璃性能的影响。X射线光电子能谱(XPS)结果表明，由Cu2+/Na+离子交换引入的Cu2+离子仍为单价离子，而EXAFS法测定的氧配位数则由Cu2+离子的典型配位数增加到4。因此，Cu2+/Na+离子交换玻璃的高电导率和极低的玻璃化转变温度归因于这种结构变化导致了Cu2+离子的氧配位数的增加。另一方面，在Ag~+/Na~+离子交换的情况下，通过测量^&lt；29&gt；Si MAS核磁共振谱和^&lt；27&gt；Al MAS核磁共振谱，没有发现明显的结构变化。但随着离子交换的进行，红外光谱和拉曼光谱的峰位置向长波方向移动，表明引入的Ag+离子首先占据了非桥氧中心，当这些中心被完全占据后，又占据了Al~(2+)&lt；3+&gt；离子附近的电荷补偿位。在此基础上，提出了用无桥氧玻璃进行Ag~(++)/Na~(++)离子交换可得到导电性极高的玻璃。

In order to develop functional glasses which are not obtainable by an ordinary glass preparation process, Na^+ ions in oxide glasses of Na_2O-Al_2O_3-SiO_2 system were replaced by Ag^+ or Na^+ ions by ion-exchange technique and the properties of the resulting glasses were discussed in relation to structural alteration induced by the ion-exchange. The Cu^+ ion introduced by Cu^+/Na^+ ion-exchange was turned out to remain mono-valent by XPS measurement, but its oxygen coordination number determined by EXAFS measurement increased from 2, which is typical of cuprous ion, to 4 which is typical of cupric ion. Thus, the high electrical couductivity and extremely low glass transition temperature of Cu^+/Na^+ ion-exchanged glasses were attributed to this structural change leading to the increase in oxygen coordination number of Cu^+ ion. In the case of Ag^+/Na^+ ion-exchange, on the other hand, no remarkable structural change was recognized by the measurement of neither ^<29>Si MAS NMR spectra and ^<27>Al MAS NMR spectra. However, the peak position of vibration spectrum obtained by IR and Raman spectroscopy shifted toward the longer wavelength side as the ion-exchange advanced, suggesting that the introduced Ag^+ ions occupy non-bridging oxygen site first, and then occupy the charge compensating site near four-fold Al^<3+> ion after the former sites were fully occupied. Based on these considerations, it was concluded that a glass of very high electrical conductivity is obtainable by Ag^+/Na^+ ion-exchange for a glass free from non-bridging oxygen.