What is barium fluoride and what is its use?

What is barium fluoride and what is its use?

Chinese name barium fluoride
Chinese alias
English name Barium fluoride
English alias barium(2+), difluoride;
CAS number 7787-32-8
Molecular formula BaF2
Molecular weight 175.32400

Physical and chemical properties:
Appearance traits colorless and odorless crystals
Refractive index 1.4741
Flash point 2260ºC
Storage conditions: The warehouse is ventilated, low temperature and dry, and stored and transported separately from food
Melting point 1354ºC
Density 4.89
Boiling point 2260ºC

Uses of barium fluoride:
Electric welding flux component, optical glass, production of infrared light-transmitting film.