It is mainly used to make magnetic bubble material for computer, which makes magnetic bubble memory have the characteristics of high speed, large capacity, small volume and multi-function. It is used to make permanent magnetic materials, optical glass, ceramic colorants, laser materials, catalysts, chemical additives and so on. It is used to prepare rare earth upconversion luminescent materials, radio ceramics and magnetic bubble materials. It is also an additive for optical glass and quartz glass fibers.