Europium oxide is mostly used in phosphors. Eu3 is used as an activator of red phosphor and Eu2 as a blue phosphor. Now Y2O rammed S: Eu3 is the best phosphor for luminescent efficiency, coating stability and recovery cost. In addition, it is widely used to improve luminescence efficiency and contrast. Europium oxide has also been used in stimulated emission phosphors of new X-ray medical diagnostic systems in recent years. Europium oxide can also be used to make coloured lenses and optical filters, magnetic bubble storage devices, control materials, shielding materials and structural materials of atomic reactors.