Preparation and Enhancement of Luminescent Intensity of New Rare Earth Molybdate Nala(Moo4)(2): Eu3+ Phosphors

Novel red-emitting rare earth molybdate phosphors NaLa(MoO4)(2): Eu3+ have been successfully synthesized by sol-gel method assisted by microwave. The as-synthesized samples were characterized by means of Fourier transform infrared spectroscopy, X-ray diffraction and Fluorescence spectrophotometer, respectively. The results show that the target product NaLa(MoO4)(2): Eu3+ have been synthesized by calcining precursor at 800 degrees C. The obtained samples belong to tetragonal Scheelite-structure and I4(1)/a space group. The excitation spectrum of NaLa(MoO4)(2): Eu3+ has a broad band in the range of 250-350 nm and the main peak is at 301 nm. The broad band can be ascribed to the charge transfer band of Mo-O and Eu-O. The sharp lines in 350-500 nm range are due to 4f-4f transitions of Eu3+. The emission spectrum contains a series of narrow peaks, with the main peak at 616 nm originated from the electric dipole transition of D-5(0) -> F-7(2) of Eu3+. The appropriate doping amount of Bi3+ and flux NH4F can enhance luminescent intensity of the sample effectively.