To clarify the existence of cation vacancies in Ce-doped Gd 3 Al 2 Ga 3 O 12 (Ce:GAGG) scintillators, we performed gamma-ray-induced positron annihilation lifetime spectroscopy (GiPALS). GiPALS spectra of GAGG and Ce:GAGG comprised two exponential decay components due to positron annihilation at bulk and defect states. By an analogy with Ce:Y 3 Al 5 O 12 , the defect-related component was attributed to Al/Ga–O divacancy complexes. This component was weaker for Ce,Mg:GAGG, which correlated with the suppression of electron traps responsible for phosphorescence. O vacancies were charge compensators for Al/Ga vacancies. The lifetime of the defect-related component was changed by Mg co-doping. This was explained by the formation of vacancy clusters.

中文翻译：

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通过γ射线诱导的正电子lifetime没寿命光谱可视化Ce：Gd 3 Al 2 Ga 3 O 12闪烁体中的阳离子空位

为了弄清Ce掺杂的Gd 3 Al 2 Ga 3 O 12（Ce：GAGG）闪烁体中阳离子空位的存在，我们进行了伽马射线诱导的正电子lifetime灭寿命光谱（GiPALS）。GAGG和Ce：GAGG的GiPALS光谱包含两个指数衰减分量，这是由于在体态和缺陷态下正电子an没所致。与Ce：Y 3 Al 5 O 12类似，缺陷相关成分归因于Al / Ga-O空位复合物。对于Ce，Mg：GAGG，该成分较弱，这与抑制负责磷光的电子陷阱有关。O空位是Al / Ga空位的电荷补偿器。与缺陷有关的成分的寿命通过Mg共掺杂而改变。这可以通过空缺集群的形成来解释。