氟锆酸盐光纤玻璃中的析晶和分相现象

Phase separation and crystallization in fluorozirconate glasses

氟化物光纤玻璃中的夹杂物,分相颗粒和微晶颗粒等缺陷,造成光纤的散射损失,影响了实际制备工作.本文利用大视场光学显微镜,X射线衍射,透射电子显微镜和差热分析,研究了ZBLA氟化物玻璃中的分相和析晶现象,观察到了以成核生长机理进行的分相颗粒,析晶颗粒的成分是β-BaF_2·ZrF_4和α-BaF_2·2ZrF_4,通过DTA分析确定了这些相的析晶活化能.

Optical waveguide fluoride glasses face a number of difficult problems despite their potential for ultra-low loss. One of the most serious is scattering loss from defects such as inclusions, phase separation particles and crystallites. By means of a Leitz optical microscope, X-ray diffraction, transmission electron microscope (TEM) and differential thermal analysis (DTA), we have investigated the phase separation and crystallization phenomena in ZrF4-BaF2-LaFs-AlF3 fluoride glasses. Phase separated particles, which formed via the nucleation and growth mechanism, were observed in the glass. The crystallites in the glass are confirmed to be beta-BaF2·ZrF4 and alpha-BaF2·2ZrF4. The activation energies of crystallization of these phases were determined by DTA.