摘要
LaF_3:Yb^(3 +),Er^(3 +) nanoparticles were successfully synthesized using solvothermal treatment,and LaF_3:Yb^(3 +),Er^(3 +) /SiO_2 core /shell nanoparticles were also prepared with reverse microemulsion technique.The crystal structure,morphology and photoluminescence properties of as-prepared core /shell nanoparticles were investigated by X-ray diffraction,transmission electron microscopy and fluorescence spectrophotometer.The results showed that LaF_3:Yb^(3 +),Er^(3 +) nanoparticles are of hexagonal structure and SiO_2 shell is amorphous.The size of LaF_3:Yb^(3 +),Er^(3 +) nanoparticles is 13 nm and the LaF_3:Yb^(3 +),Er^(3 +) /SiO_2 nanoparticles present clearly a core /shell structure with 12 nm shell thickness.The solubility of LaF_3:Yb^(3 +),Er^(3 +) nanocrystals in water and the biocompatibility are both improved by the SiO_2 shell.The upconversion luminescence spectra suggested that the SiO_2 shell has small effect on the upconversion luminescence properties of the LaF_3:Yb^(3 +),Er^(3 +) nanocrystals.The core /shell structure LaF_3:Yb^(3 +),Er^(3 +) /SiO_2 nanoparticles are expected to be used in biological applications.
LaF^3＋ Yb^3＋ , Er^3＋ nanoparticles were successfully synthesized using solvothermal treatment, and LaF^3＋ Yb^3＋ , Er^3＋/SiO2 core/shell nanoparticles were also prepared with reverse microemulsion technique. The crystal structure, morphology and photoluminescence properties of as-prepared core/shell nanoparticles were in- vestigated by X-ray diffraction, transmission electron microscopy and fluorescence spectrophotometer. The re- sults showed thatLaF^3＋ Yb^3＋ , Er^3＋ nanoparticles are of hexagonal structure and SiO2 shell is amorphous. The size ofLaF^3＋ Yb^3＋ , Er^3＋. nanoparticles is 13 nm and the LaF^3＋ Yb^3＋ , Er^3＋/SiO2 nanoparticles present clearly a core/shell structure with 12 nm shell thickness. The solubility of LaF^3＋ Yb^3＋ , Er^3＋ nanocrystals in water and the biocompatibility are both improved by the SiO2 shell. The upconversion luminescence spectra suggested that the SiO~ shell has small effect on the upconversion luminescence properties of the LaF^3＋ Yb^3＋ , Er^3＋ nanocrys- tals. The core/shell structure LaF^3＋ Yb^3＋ , Er^3＋ /SiO2. nanopartlcles are expected to be used in biological appli- cations.
