熔盐对Li+/Na+离子交换及折射率分布的影响

研究发现利用Li⁺/Na⁺离子交换制取径向梯度折射率(GRIN)棒透镜时,在NaNO₃熔盐中,添加NaCl,会影响Li⁺/Na⁺离子交换反应平衡,最终改变径向GRIN棒透镜的折射率分布、折射率差值及像差.并着重分析和讨论了在本实验中NaNO₃+NaCl混合熔盐对径向GRIN棒透镜中折射率分布、数值孔径及像差的影响机理.

Effects of Molten Salt Composition on Exchanging Na+ for Li+ and Refractive Index Profile

Presently the most widely used technique for fabricating radial gradient index(GRIN) rod lens is ion exchange. The ability to control and alter the shape of the index profile is an important area of research for the fabrication of gradient index materials. It is observed that radial gradient index profile produced by exchanging Na + for Li + can been controlled and altered by introducing NaCl into NaNO 3 molten salt in this paper. Because of the higher polarizability of Cl - than that of NO - 2 ions in molten salt, hence the coulombic forces between Cl - and Li + ions are stronger than the forces between NO - 2 and Li + ions, which limit the activity of Li + at the interface between glass and molten salt. Furthermore the reaction balance of ion exchange between Na + and Li + shifts toward right, which could alter the constant of balance and improved ion exchange. So radial gradient index profile can been controlled and altered by introducing NaCl into NaNO 3 molten salt.