Sintered porous glasses hosting luminescent species of different nature: Eu3+ ions and Tb3+-doped Ba2TiSi2O8 glass-ceramic powder

Abstract We report on the employment of a nano-porous Vycor-type glass as host for two luminescent substances of very different physical and chemical nature, which share the same porous space. Firstly, BTS:Tb3+ glass-ceramic nano-powders were infiltrated in the porous structure and secondly Eu3+ ions from a nitrate aqueous solution were included afterwards. Upon sintering, the porous silica matrix collapses, embedding both luminescent species. We focused on the micro and nano-structure of the sintered glasses. Upon sintering a europium silicate phase crystallizes as monocrystalline hexagonal nano-rods, which coexist with amorphous round particles below 100 nm enriched in Eu and Si. Both kinds of particles are embedded in a cristobalite matrix. The interesting microstructure is reported for the first time. The sintering heating rate influences the microstructure after the sintering. The microstructure was investigated by a last generation TEM microscope with aberration correction, EDXS and an exhaustive electron diffraction analysis. The inclusion of BTS:Tb3+ is only limited, and thus, the its role in the optical properties of the final material is negligible. Luminescence upon UV excitation shows the characteristic emission peaks of Eu3+. This work highlights the possibility of combining several luminescent materials inside a silica matrix.