Unique photoluminescence in SiO ₂:;Sm prepared by sol-gel process

SiO ₂:Sm powders prepared by the sol-gel process were structurally characterized by thermogravimetric-differential scanning calorimetry (TG-DSC), Fourier transform infrared (FTIR) spectraoscopy and ²⁹Si magic angle spinning nuclear magnetic resonance(MAS-NMR). The peaks near 960 cm ^-1 in FTIR results are assigned to the deformation vibration of Si-O-Sm linkages, and the samarium ion has been incorporated into the framework of SiO ₂ as validated by ²⁹Si MAS-NMR. Blue-green and red photoluminescence (PL) emission in structural disordered SiO ₂:Sm powders was observed at room temperature with excitation at 380 nm. Study on the luminescence spectra of SiO ₂:Sm powders with different doping concentrations of Sm ³⁺ indicates that the generation of the special PL band is related to the formation of Si-O-Sm linkages.