Temperature dependence of photo- and radioluminescence of (Gd, Y)3Al5O12:Ce3+ mixed oxide garnet ceramics

In the present study properties of garnet scintillation ceramics of general composition (Gd, Y)
₃
Al
₅
O
₁₂
:Ce
³⁺
have been investigated in a wide temperature range, from 80 to 570K. Measurements of the luminescence intensity and decay time temperature dependencies have been performed under X-ray and photo excitation. It is shown that luminescence intensity rises during heating up to room temperature and then starts falling due to thermal ionization of electrons from Ce
³
+ excited states to the conduction band. Values of activation energy of the thermal ionization process have been obtained from decay time measurements. Processes responsible for the rise of luminescence intensity are considered.