Synthesis and photoluminescence of Eu³⁺- or Tb ³⁺-doped Mg₂SiO₄ nanoparticles prepared by a combined novel approach

Tb³⁺- or Eu³⁺-doped magnesium silicate phosphors were prepared for the first time by using a novel approach, combined sol-gel-microwave heating. X-ray diffraction (XRD), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and photoluminescence analyses were used to characterize the phosphors. XRD confirmed a forsterite lattice of Mg₂SiO₄ for the phosphors. TEM observation indicated that the phosphors have a spherical-like shape with little aggregation and the particle size is about 50 nm, and the small size is favorable to the potential application in field emission displays. The luminescent colors of Mg₂SiO₄:Tb³⁺ and Mg₂SiO ₄:Eu³⁺ phosphors are green and red respectively, furthermore the luminescent intensities of them are relatively higher than the traditional Zn₂SiO₄:Tb³⁺ and Zn ₂SiO₄:Eu³⁺ phosphors. In addition, Eu ³⁺ ion emissions as a structural probe suggest that the rare earth ions replace the Mg²⁺ ions in the site of M2 (C _s) in the forsterite lattice of Mg₂SiO₄.