LaF3 nanowires with high aspect ratios have been prepared via a low-temperature solvothermal method using LaCl3 and KF or NH4F as starting materials in absolute alcohol at 160 ℃ for 12 h. XRD pattern and TEM images s...LaF3 nanowires with high aspect ratios have been prepared via a low-temperature solvothermal method using LaCl3 and KF or NH4F as starting materials in absolute alcohol at 160 ℃ for 12 h. XRD pattern and TEM images show that the products are hexagonal structure with diameter of 80 nm and length up to 8 μm. The lanthanum sources played most important roles, reaction temperature and time also played important roles in the morphology control of final LaF3 products. The optimal conditions for ideal LaF3 nanowire are at a reaction temperature of 160 ℃ and reaction time for 14 h using LaCl3 and NH4F as starting materials. A possible formation mechanism for LaF3 nanowires is proposed.展开更多
The europium-doped LaF3 nanoparticles were prepared by refluxing method in glycerol/water mixture and characterized with X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), UV-vis diffuse ...The europium-doped LaF3 nanoparticles were prepared by refluxing method in glycerol/water mixture and characterized with X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), UV-vis diffuse reflectance spectrum, and photoluminescence spectra.The results of XRD indicated that the obtained LaF3:Eu^3+ nanoparticles were well crystallized with a hexagonal structure.The FE-SEM image illustrated that the LaF3:Eu^3+ nanoparticles were spherical with an average size around 30 nm.Under irradiation of UV light, the emission spectrum of LaF3:Eu^3+ nanoparticles exhibited the characteristic line emissions arising from the 5D0→7FJ(J=1, 2, 3, 4) transitions of the Eu3+ ions, with the dominating emission centered at 590 nm.In addition, the emissions from the 5D1 level could be clearly observed due to the low phonon energies(-350 cm^-1) of LaF3 matrix.The optimum doping concentration for LaF3:Eu3+ nanoparticles was determined to be 20mol.%.展开更多
文摘LaF3 nanowires with high aspect ratios have been prepared via a low-temperature solvothermal method using LaCl3 and KF or NH4F as starting materials in absolute alcohol at 160 ℃ for 12 h. XRD pattern and TEM images show that the products are hexagonal structure with diameter of 80 nm and length up to 8 μm. The lanthanum sources played most important roles, reaction temperature and time also played important roles in the morphology control of final LaF3 products. The optimal conditions for ideal LaF3 nanowire are at a reaction temperature of 160 ℃ and reaction time for 14 h using LaCl3 and NH4F as starting materials. A possible formation mechanism for LaF3 nanowires is proposed.
基金supported by the Natural Science Foundation of Henan Province (082300440130, 2008A180039, 2007150049)Startup Fund for Doctoral Program of Zhoukou Normal University
文摘The europium-doped LaF3 nanoparticles were prepared by refluxing method in glycerol/water mixture and characterized with X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), UV-vis diffuse reflectance spectrum, and photoluminescence spectra.The results of XRD indicated that the obtained LaF3:Eu^3+ nanoparticles were well crystallized with a hexagonal structure.The FE-SEM image illustrated that the LaF3:Eu^3+ nanoparticles were spherical with an average size around 30 nm.Under irradiation of UV light, the emission spectrum of LaF3:Eu^3+ nanoparticles exhibited the characteristic line emissions arising from the 5D0→7FJ(J=1, 2, 3, 4) transitions of the Eu3+ ions, with the dominating emission centered at 590 nm.In addition, the emissions from the 5D1 level could be clearly observed due to the low phonon energies(-350 cm^-1) of LaF3 matrix.The optimum doping concentration for LaF3:Eu3+ nanoparticles was determined to be 20mol.%.