Effects of Codoping With Divalent Cations on Performance of YAG:Ce,C Scintillator

Growth technologies of oxide crystals in W/Mo crucibles have been developed as a low-cost alternative to conventional processes involving Ir crucibles. Carbon-containing atmosphere needed to protect crucibles from oxidation leads to the introduction of carbon into the crystal lattice and creation of carbon-related defects, which affect the scintillation performance. Meanwhile, a search for fast scintillators for the new generation of positron-emission tomographs and high-energy physics experiments at colliders is under way. Codoping with divalent cations has become an efficient way to suppress long components of scintillation decay in Ce-doped scintillators. This work addresses Y
₃
Al
₅
O
₁₂
(YAG) crystals codoped with carbon, cerium activator, and divalent cations. Optical and scintillation properties of YAG:Ce,C,
$\text{A}^{2+}$
crystals (A = Ca
$^{2+}$
, Mg
$^{2+}$
, Ba
$^{2+}$
, Sr
$^{2+}$
) are systematically studied. Among all the studied garnet compounds, YAG:Ce,C,Ca
$^{2+}$
crystals demonstrated the fastest scintillation decay times, which are promising for the mentioned applications. Mechanisms of scintillation process in the studied materials are discussed. The Ce
$^{3+}$
/Ca
$^{2+}$
ratio in YAG:Ce,C,Ca
$^{2+}$
was optimized to minimize slow components in scintillation decay.