BaF2替代BaO 对钡镓锗酸盐玻璃光学性质的影响

在摩尔分数组成x(BaO),r(Ga2O),r(GeO2)为0．20，0．15,0．65的玻璃中，分别以摩尔分数0．05，0．10．0．15和0．20的BaF2替代BaO,研究了氟化物对玻璃折射率和光吸收性质的影响。结果表明，在玻璃中加入氟化物．玻璃折射率和色散降低，玻璃的紫外吸收边向短波侧迁移，而红外吸收边无明显变化。不含氟化物的氧化物玻璃中含有大量的OH基．这些OH基在2．24μm、2．97μm和4．23μm附近引起光吸收．在含氟化物的玻璃中，2．24μm的吸收峰消失，而2．97μm和4．23μm附近的吸收大大减弱。讨论了各OH基吸收峰的起源，利用计算机技术对2．97μm附近的OH基吸收峰进行了高斯峰分离。玻璃在2．24μm的弱吸收可能来自H2O分子的一个伸缩模和两个振动模的结合(p 2ρ)．4．23μm吸收带是由与非桥O形成强氢键的OH基(T-OH…O^--T)伸缩振动引起，而中心位于2．7～3．2μm的OH吸收带为受不同程度氢键影响的OH基伸缩振动吸收．这些吸收带叠加导致OH吸收带出现非对称性加宽，吸收中心随玻璃中OH含量不同发生移动。

Effect of BaF2/BaO Substitution on the Optical Properties of Barium GalloGermanate Glass

The refractive index and optical absorption of glass were studied when the BaO was substituted by 0.05, 0.10, 0.15,0.20 (mole fraction) BaF2 respectively in glass 0.20BaO-0.15Ga2O3-0.65GeO2 (mole fraction). The results show that, when fluoride was introduced into glass, the refractive index and dispersion of glass decrease, and the ultraviolet absorption edge shifts to shorter wavelength, but the IR absorption edge doesn't move obviously. The glass without fluoride contains a great deal of OH group that cause optical absorption band at 2.24 μm, 2.97 μm and 4.23 μm. In the glasses containing fluoride, the 2.24 μm absorption band disappears; while the 2.97 μm absorption band and the 4.23 μm absorption band weaken obviously. The origin of every OH absorption band was also discussed and Gaussian separations of the 2.97 μm absorption band of OH group were carried out. The weak peak at about 2.24 μm maybe come from the combination of a stretching mode and two shaking modes of H2O molecular (ν+2ρ); the absorption band at 4.23 μm is caused by the stretching vibrations of the OH groups forming strong hydrogen bond with non-bridge oxygen's (T-OH…O--T); the OH absorption band at about 2.7～3.2 μm can be attributed to the overlapping of stretching bands for the OH groups influenced by various species of hydrogen bond, which causes the asymmetric broadening of absorption band and the shifting of absorption center with OH group content.