LiNbO_3/SiO_2凝胶玻璃的非等温结晶动力学研究

Study on Nonisothermal Crystallization Kinetics of LiNbO 3/SiO 2 Gel Glass

利用差热分析和Ｘ衍射分析对ＬｉＮｂＯ３／ＳｉＯ２凝胶玻璃的非等温结晶动力学进行了研究。利用修正的ＪＭＡ方程直线计算了ＬｉＮｂＯ３和石英的析晶活化能、磷石英的相变活化能和频率因子，根据峰形指数计算了Ａｖｒａｍｉ结晶指数。ＬｉＮｂＯ３的结晶活化能为１４２ｋＪ／ｍｏｌ，ＬｉＮｂＯ３和石英晶体的生长过程受表面或界面控制。最后对凝胶玻璃的析晶难易和稳定性进行了分析。

The nonisothermal crystallization kinetics of LiNbO 3/SiO 2 Gel glass was investigated by XRD and DTA. By using Johnson Mehl Avrami equation, the activation energies、 avrami factors for precipitation of LiNbO 3、 quart and tridymite crystals were evaluated and the crystallization mechanism were analyzed. The results indicated that the growth of LiNbO 3、 quart and tridymite crystals were one dimensional process, controlled by the crystal glass interface reaction The average value of activation energies of LiNbO 3 crystal is 142 kJ/mol By using kinetics factor of crystallization, the stability of LiNbO 3/SiO 2 Gel glass was studied。