light rare-earth-doped titanium dioxide nano-Preparation and Properties of Materials

Title: light rare-earth-doped titanium dioxide nano-Preparation and Properties of Materials
　　Author: Liu Guojing
　　Degree-granting units: Northwestern University
　　Keywords: nanocrystalline;; rare-earth doped;; sol - gel technology;; energy transfer;; lattice
　　Summary:
　　Sol - gel method (sol-gel) and hydrothermal method, with tetrabutyl titanate as precursor prepared Eu3 ion-doped TiO2 nanocrystalline thin films and light, scanning electron microscopy (SEM), EDS spectrum, Photoluminescence spectra of the sample morphology, composition and performance were characterized to study the annealing temperature, rare-earth ion Neodymium Magnets doped Eu3 mole fraction, the amount of ethanol solvent, alkali on luminescence properties and luminescence mechanism of analysis.
　　Sol - gel prepared by rare-earth-doped TiO2 nanocrystalline Eu3 samples, doping uniformity, particles of about 30-80nm; EDS spectrum analysis can be obtained from the Ti: O atomic number ratio is not stoichiometric TiO2 meet a : 2, Eu3 ions are likely to replace the Ti4 ions, while the formation of oxygen vacancies, indicating that the Eu3 rare earth ions into the TiO2 lattice. Samples of the main emission peak at 614nm (5D0 → 7F2) at the strongest light, and in the 595nm (5D0 → 7F1) at the emergence of magnetic dipole transitions belonging to the emission peak, while the 578nm (5D0 → 7F0), 652nm (5D0 → 7F3), 700nm (5D0 → 7F4) also appeared in the emission peak. Preparation of Eu3: TiO2 nanocrystals component, annealing temperature, the amount of alcohol in different solvents, catalysts are not at the same time, the intensity of emission spectra will be different. When the Eu3 ions, Ce3 ion co-doped, the realization of the Eu2 ions blue emission. Preparation of light-emitting layer plating film in each film are its 500 ℃ annealing, crystal film obtained good results, http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets   but there is 578nm (5D0 → 7F0) of the emission peak. λex = 464nm, 414nm, 395nm, 382nm, 272nm as the excitation wavelength of the excitation light from emission spectra of thin films, obtained λex = 395nm emission peak when the 614nm (5D0 → 7F2) at the highest luminous efficiency. Al3 900 ℃ annealing to join the Eu3: TiO2 thin films to achieve a light-emitting Eu2 ions blue emission, demonstrated that in the high-temperature environment, Al3 to restore Eu2 Eu3 ions.
　　Prepared by hydrothermal method and light-emitting nano-crystalline thin films, the reaction temperature, Al3 all of the samples affect the intensity of the emission spectrum. NaOH solution to change the light-emitting crystal structure of TiO2 matrix, enhancing the absorption of the sample in the UV region.
　　Degree Year: 2010