Relationship between Crystal Structure and Luminescence Properties of (Y0.96 - x Lnx Ce0.04)3 Al5 O12 (Ln = Gd, La, Lu) Phosphors

The doping effects of La3+, Gd3+ and Lu3+ on the crystal structure and luminescence properties of (Y0.96 - x Lnx Ce0.04)3 Al5 O12 (Ln = Gd, La, Lu) Phosphors were studied. The X-ray diffraction patterns presented that with the increase of the doping concentrations of La3+ and Gd3+ ions, the d-value of (Y0.96 - x Lnx Ce0.04)3 Al5 O12 (Ln = Gd, La, Lu) increased and the larger the doping ion, the stronger the effect would be. The doping amount causing phase transition in (Y0.96 - x Lnx Ce0.04)3 Al5O12 decreased with the increase of the ionic radii of the doping lanthanide ions (La3+ : 0.106 nm, Gd3+ : 0.094 nm, Lu3+ : 0.083 nm). The bigger doping ion of Gd3+ made the emission of (Y0.96 - x Gdx Ce0.04)3 Al5O12 move to red spectral region, but the smaller one of Lu3+ made it blue.