Synthesis of Lu₂O₃:Eu³⁺ luminescent ceramic powder embedded in SiO₂ matrix

In the present work, the effect of SiO2 was analyzed in different molar ratios (Lu : Si = 4 : 1, 6 : 1, 8 : 1, 10 : 1 and 1 : 0), in order to prepare SiO₂ embedded Lu₂O₃:Eu³⁺ sol-gel luminescent powders, from a modified PVP-containing solution. The crystalized SiO₂ embedded Lu₂O₃:Eu³⁺ powders were characterized by Fourier transform infrared spectroscopy revealing the presence of high intensity bands associated with siloxanes groups at 700° C, which could indicate a cross-linked Si-O groups to Lu₂O₃:Eu³⁺. X-ray diffraction results showed that cubic phase was present in the powder heat treated at 500° C and remained up to 700° C. The powders SiO₂ embedded Lu₂O₃:Eu³⁺ powders in molar ratio Lu:Si 4 : 1 and 10 : 1 masked the crystallinity of glass ceramic. The SiO₂ effect on the morphology of the glass ceramic systems was monitored by scanning electron microscopy observations, from these results homogenous particles were obtained for Lu:Si 6 : 1 and 8 : 1 systems. Photoluminescence studies showed that adding silica to the ceramic systems increases the typical emission to around λ_em = 611 nm.