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

摘要

Transparent cerium doped lutetium aluminum garnet (Ce:LuAG) ceramic scintillantors with different Ce$^{3 +}$ 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 $5{hbox{d}}^{1}$ excited level ($^{1}$ D) to the 4f ground state of Ce$^{3 +}$ ($^{2}$F$_{5 / 2};$ $^{2}$ F$_{7 / 2}$ ). 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$_{rm Al}^{3 +}$ antisite defect (AD) was observed both in Ce$^{3 +}$ doped and undoped LuAG ceramics which formed electron traps disturbing the energy transfer from host lattice to Ce$^{3 +}$ centers, leading to a slow decay component of 109.4 ns in the 0.5 mol% Ce:LuAG transparent ceramic under $^{137}$Cs (662 keV) irradiation.