Preparation And Luminescence Properties Of Spheric La2o3 : Eu Nanocrystals

The spheric La2O3:Eu nanocrystals were prepared using NH3 center dot H2O-NH4HCO3 mixture as precipitant. The material was characterized by FTIR, XRD and TEM techniques. The luminescence properties of Eu3+ in spheric La2O3 were measured by three dimension spectra, emission and excitation spectra. The results indicate that the La2O3:Eu nanocrystals are in hexagonal phase by annealing at 800 degrees C, the crystal size is about 30 nm. The maximum emission and excitation wavelength were determined by three dimensional spectroscopy to be at 591 nm and 394 nm, 7 respectively. In emission spectrum the band at 591 nm and 612 nm are corresponding to D-5(0)-F-7(1) and D-5(0)-F-7(2) transition of Eu3+ ions. With increasing in annealing temperature the differences of intensity of the two transitions are increased. This phenomenon shows that the luminescence intensity of La2O3:Eu nanocrystals can be tuned by changing annealing temperature.