【摘要】 本文讨论了在硼硅酸盐玻璃系统中引入二价 Ba2 + 、Pb2 + 和四价 Ti4+ 后 ,由于 Pb2 + 和Ti4+ 配位结构的变化 ,引起 Pb2 + 、Ti4+ 场强及其与 O2 -离子间距的变化 ,对 Li+ /Na+ 离子交换产生影响 ,从而改变折射率差值 (ΔN )和折射率分布 .更多还原

【Abstract】 In this paper,it is discussed the effects of Ba 2+ 、Pb 2+ and Ti 4+ ions on exchanging Na + for Li + in borosiliate glasses.Because of the high polarizability of Pb 2+ 、Pb 2+ ions in eight fold coordination have deformed,this cause the high field strength and the distance between O 2- and Pb 2+ dwindled.In glasses,Ti 4+ ions can act both as network formers and network modifiers.The concentration of the [TiO 4] tetrahedra decreased and that of the [TiO 6] octahedra increased with increasing alkali metal oxide content.Especially when B 2O 3 and Al 2O 3 lie in this glass,this caused the lower field strength of Ti 4+ then that of Pb 2+ ,but the field strength is still higher than that of Ba 2+ ,hence the coulombic forces between Na + and Li + ions have been degraded.Furthermore the ionic mobilities of Li + improved.So they can influence the exchange of Na + for Li +.One can control and alter radial gradient index profile and increase the refractive index difference by introducing high field strength ions Pb 2+ and Ti 4+ in borosiliate glasses system.更多还原