Synthesis of Sr2CeO4 phosphor by mechanical milling and reactive sintering

Sr2CeO4 phosphor was synthesized by mechanical milling and reactive sintering in this work. The solid state reaction of SrCO3 and CeO2 (2:1) started at about 850 degreesC and completed at 1000 degreesC for about 4 h. Two types of formation mechanism of Sr2CeO4 were proposed. When the starting powder mixture was fired above 1000 degreesC, the unstable intermediate phase SrCeO3 was developed, which then reacted with SrCO3 to form the final product Sr2CeO4, however, SrCO3 and CeO2 converted directly to Sr2CeO4 at a lower temperature. The XRD results showed the crystal structure of Sr2CeO4 was orthorhombic. The emission spectra displayed a broad band with maximum at about 465 nm. The mechanical milling of starting power mixture and the sintering temperature had no effect on this emission spectra.