Bi_2O_3–ZnO–B_2O_3三元系统玻璃结构与性能

Network Structures and Characteristics of Bi_2O_3–ZnO-B_2O_3 Ternary System Glasses

采用X射线吸收精细结构和红外吸收光谱分别对铋锌硼玻璃中铋离子邻近结构和硼氧网络结构进行研究,分析其结构变化对玻璃转变温度Tg和热膨胀系数α的影响。结果表明:1)铋离子以三配位([BiO3])和六配位([BiO6])两种配位状态存在;随Bi2O3含量增加,三配位铋离子的配位数上升,六配位铋离子配位数下降,同时铋离子总配位数上升。2)随Bi2O3含量增加,硼氧网络中硼氧四面体含量下降,硼氧三角体含量上升,硼氧四面体网络解聚形成硼氧三角体网络。3)上述结构因素是造成玻璃转变温度Tg下降和热膨胀系数α上升的主要原因。

The local structures of Bi3＋ ions and the B-O network structures in Bi2O3–ZnO-B2O3 ternary system glasses were investigated by X-ray absorption fine structure technique and Fourier transform infrared spectroscopy （FTIR）, respectively. The effect of structures change of the glasses on the transition temperature （Tg） and thermal expansion coefficient （α） was analyzed. The results show that Bi ions exist in the glass as two coordination states of three-coordination [BiO3] and six-coordination [BiO6]. The Bi3＋ ion coordination number of [BiO3] increases and that of [BiO6] decreases, and the Bi ion total coordination number also increases with the increase of Bi2O3 content. The decrease of [BO4] content and the increase of [BO3] can result in the dissociation of [BO4] network and the formation of [BO3] network. All of these structure changes are mainly due to the decrease of Tg and the increase of α of the glass.