Barium

Aside from the sulfate, other compounds of barium find only niche applications. 

  • Barium oxide is used in a coating for the electrodes of fluorescent lamps, which facilitates the release of electrons.
  • Barium carbonate is used in glassmaking. Being a heavy element, barium increases the refractive index and luster of the glass. 
  • Barium, typically as barium nitrate, is added to fireworks to impart them a green color The species responsible for the brilliant green is barium monochloride; in the absence of chlorine a yellow or "apple" green is produced instead.
  • Barium peroxide can be used as a catalyst to start an aluminothermic reaction when welding rail tracks together. It can also be used in green tracer ammunition and as a bleaching agent.
  • Barium titanate is a promising electroceramic
  • Barium fluoride is used for optics in infrared applications because of its wide transparency range of 0.15–12 micrometers.
  • YBCO was the first high-temperature superconductor that could be cooled by liquid nitrogen, as its transition temperature of 93 K exceeded the boiling point of nitrogen (77 K).