Preparation of High-purity Barium Hydrogenfluoride for Fluoride-Optical Fiber

Abstract

Barium hydrogenfluoride (BaHF₃) as raw material for zirconium (IV) fluoride-optical fiber was purified by solvent extraction, sublimation and fluorination with hydrofluoric acid. Barium acetate was the best starting material for the preparation of high-purity BaHF₃. Trace impurities of iron, cobalt, nickel and copper in the BaHF₃ and oxygen in the zirconium (IV) fluoride glass containg BaHF₃ were determined by neutron activation analysis and charged particle activation analysis, respectively. It was found that the amounts of hydrofluoric acid and oxygen in the prepared BaHF₃ affect the transmission loss in the fluoride-optical fiber. The analytical results for hydrofluoric acid, transition elements and oxygen in the prepared BaHF₃ showed that the solvent extraction, the sublimation and the fluorination by hydrofluoric acid are the best methods for the preparation of high-purity BaHF₃ for a low-loss zirconium (IV) fluoride-optical fiber.