Abstract
Here, we report our results referring to the preparation of Ce doped Y sub(2.22)MgGa sub(2)Al sub(2)SiO sub(12), Y sub(1.93)MgAl sub(4)SiO sub(12) and Y sub(2.22)Gd sub(0.75)Ga sub(2)Al sub(3)O sub( 12) using solid state reaction at high temperature. Several complementary methods (i.e. powder x-ray diffraction (XRPD), energy dispersive analysis of X-rays (EDX), scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR)) were studied to examine the effects of the synthesis procedure on the morphology and structure. XRD analyses revealed that all compounds include yttrium aluminate phase with garnet structure. Cathodoluminescence (CL), radioluminescence (RL) and photoluminescence (PL) measurements were carried out for clarification of relationship between host lattice defects and the spectral luminescence emissions. Luminescence emission of phosphors is peaked at 530 nm assigned to 5d-4f transitions of the dopant Ce super(3+) ions with a broad emission band in 400-700 nm range. Under electron irradiation, the emission spectrum of Ce doped (YGd) sub(3)Ga sub(2)Al sub(3)O sub(12) is well defined and has a characteristic fairly narrow and sharp emission band peaking at 312 nm and 624 nm corresponding to transition of super(6)P sub(7/2) arrow right super(8)S sub(7/2) and super(6)G sub(J) arrow right super(6)P sub(J) (Gd super(3+)), respectively. We suggest some of phosphors might be excellent phototherapy phosphor materials under electron excitation.