CeF3 and CeF3:Tb3+ nanocrystals were successfully synthesized by the ultrasound assisted ionic liquid(IL) method at room temperature. X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), selected area electron diffraction(SAED), high-resolution transmission electron micrographs(HRTEM) and photoluminescence(PL) spectra were employed to characterize the nanocrystals. The results of XRD indicated that the obtained samples crystallized well with a hexagonal phase crystal structure. SEM and TEM images demonstrated that the obtained CeF3:Tb3+ nanocrystals had a discoid shape in the presence of ultrasound and IL, whereas only granular nanoparticles were obtained by magnetic stirring. The possible formation mechanisms of the crystal growth were proposed. The PL spectra of the CeF3:Tb3+ nanodisks exhibited a strong green emission when excited at 254 nm. Furthermore, the photoluminescence intensity of CeF3:Tb3+ of the discoid particles was largely improved compared with that of the granular nanoparticles.
The Eu3+–Y3+ double-doped Zr O2(8YSZ:Eu3+) phosphors with different doping concentrations of Eu3+ were synthesized by hydrothermal method. The dependences of the intensities of visible emission, decay lifetimes and crystal structures on Eu3+ doping concentration were investigated. The optimal doping concentration of Eu3+ in 8YSZ:Eu3+ nanophosphors was determined. The morphology and crystal structure of the resulting phosphors were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectra. The fluorescence properties of the resulting phosphors were investigated by photoluminescence spectra and decay curve. In this paper, 3 mol.% Eu3+ ions in 8YSZ:Eu3+ phosphors was the optimal doping concentration. When doping concentration was 3 mol.%, the nanophosphor had a pure tetragonal phase structure, the emission intensity was intense and decay lifetime was long, furthermore this system could be used to indicate the extent of phase transformation of thermal barrier coatings.
