Scintillation and Luminescent Properties of Cerium Doped Lutetium Aluminum Garnet (Ce:LuAG) Powders and Transparent Ceramics

Transparent cerium doped lutetium aluminum garnet (Ce:LuAG) ceramic scintillantors with different Ce³⁺ concentrations were densified successfully from synthetical nanosized Ce:LuAG powders using co-precipitation method. It was found that the 0.5 mol% Ce: LuAG ceramic exhibited the highest luminescent emission intensity under synchrotron radiation excitation which could be divided into two components centered at 505 and 540 nm under low temperature (50-150 K) conditions originated from the 5d¹ excited level (¹D) to the 4f ground state of Ce³⁺ ( ²F 5 / 2; ²F 7 / 2). The quantum efficiency (QE) of the optimized Ce:LuAG ceramic could reach 66.3% under UV excitation of 345 nm. Typical absorption at 170 nm related to possible Lu Al³⁺ antisite defect (AD) was observed both in Ce³⁺ doped and undoped LuAG ceramics which formed electron traps disturbing the energy transfer from host lattice to Ce³⁺ centers, leading to a slow decay component of 109.4 ns in the 0.5 mol% Ce:LuAG transparent ceramic under ¹³⁷Cs (662 keV) irradiation.