Special effects of YbF3 on the structural changes for fluorophosphate glass

From Raman and IR spectra, obvious differences of the glass structure were observed in non-Yb3+-doped and Yb3+-doped fluorophosphate glasses. Results showed that Yb3+ ions can induce, in a better glass, polymerization and network uniformity. Compared with the monophosphate-mastered Yb3+-free glass, Yb3+-doped glass has a pyrophosphate environment. The main building blocks in Yb3+-doped samples are metaphosphate groups, pyrophosphate groups (P2(O,F)7,PO3F), Al[F6]+Al[O,F]6 and F3Al-O-AlF3 while those of the Yb3+-free glasses are monophosphate groups P(O,F)4, little pyrophosphate groups, Al[F4]+Al[F6]+Al[O,F]4+Al[O,F]6 and F3Al-O-AlF3. The DSC analysis also showed a slight increase in crystallization stability.