Barium Dinickelite, BaO.2NiO₂

Barium Dinickelite, BaO.2NiO₂, is obtained by heating an intimate mixture of barium oxide and nickel sesquioxide in the electric furnace. It forms a greenish-brown crystalline powder of density 4.8 at 20° C., and hardness 4 on Mohs' scale. It is decomposed by water, and is readily attacked by anhydrous hydrochloric and hydrofluoric acid, chlorine, bromine, and sulphur, but not by oxygen. Neutral oxidising agents, for example potassium nitrate, are without action upon it.