Crystallization Process of Amorphous SrB4O7：Eu2+ under High Pressure and High Temperature

The crystallization process of amorphous SrB4O7 under high pressure were studied by using X-ray diffraction and Eu2+ emission spectra. X-ray diffraction results show that under the pressure of 5.0 GPa, at 200 ℃ there exists a few small diffraction peaks with very low intensity, indicating trace crystallization. At 600 ℃, however, the crystallization process basically completes, it becomes a mixture of two phases, one is an orthorhombic SrB4O7 and the other cubic SrB4O7; as the temperature increasing to 1 000 ℃, the sample crystallizes to single phase SrB4O7 with a structure the same as the powder crystal sample's prepared under atmosphere. The above results were further confirmed by Eu2+ emission spectra obsenations: the intensity of Eu2+ emission peak at 370nm increased obviously with the crystallinity of the sample.