HDEHP assisted solvothermal synthesis of monodispersed REPO4(RE=La-Lu, Y) nanocrystals and their photoluminescence properties
Coordination polymer submicrospheres were successfully synthesized by solvothermal method using organophosphate (HDEHP) and Y(NO3)3 without any additional ligand and surfactant under mild conditions. Upon calcination of the obtained precursor produced stable tetragonal phase (t-)YPO4 submicrospheres. XRD, SEM and HRTEM were used to characterize the precursor and calcined samples. The results showed that t-YPO4 submicrospheres were obtained by thermal decomposition of the precursor, and there was no other phase transition in the process. FTIR and TG-DTA confirmed that the precursor was coordination polymers formed by HDEHP and Y3+, and the growth process of the spherical precursor was proposed. Furthermore, various REPO4 (RE=La-Lu, except radioactive Pm) spherical particles and Eu3+ doped YPO4 phosphor were synthesized under similar conditions. The luminescent properties of YPO4:Eu phosphor were also studied in detail.