The doping effects of La^3＋, Gd^3＋ and Lu^3＋ on the crystal structure and luminescence properties of （Yo96-x LnxCe0.04）3Al5O12（Ln = Gd, La, Lu） phosphors were studied. The X-ray diffraction patterns presented that with the inerease of the doping concentrations of La^3＋ and Gd^3＋ ions, the d-value of （Y0.96-xLnxCe0.04）3Al5O12 （Ln = Gd, La） inereased and the larger the doping ion, the stronger the effect would be. The doping amount causing phase transition in （Y0.96-xLnxCe0.04）3Al5O12 decreased with the inerease of the ionic radii of the doping lanthanide ions （La^3＋： 0.106 nm, Gd^3＋： 0. 094 nm, Lu^3＋ ： 0.083 nm）. The bigger doping ion of Gd^3＋ made the emission of （Y0.96-xGdxCe0.04）3Al5O12 move to red spectral region, but the smaller one of Lu^3＋ made it blue.
Lanthanum hydroxide nanorods with a diameter of 10-20 nm and length up to 100-200 nm were synthesized through a direct reaction of La(NO3)3 and KOH under hydrothermal microemulsion conditions.X-ray diffraction（XRD） and scanning electron microscope（SEM） were employed for the characterization of the structure,compositions and morphology of the obtained products.The results showed that the molar ratio of water to the surfactant CTAB,concentration of La(NO3)3,reactant temperature and reactant time all could affect the morphology and size of the lanthanum hydroxide nanorods.
