On the Quenching Mechanism of Ce, Tb Luminescence and Scintillation in Compositionally Disordered (Gd, Y, Yb)3Al2Ga3O12 Garnet Ceramics

Two series of (Gd, Y, Yb)3Al2Ga3O12 quintuple compounds with a garnet structure and solely doped Ce Tb were prepared in the form ceramics by sintering oxygen at 1600 °C for two hours studied interaction activator ions ytterbium entering matrix. It was shown that photoluminescence scintillation Ce3+ are completely suppressed, predominantly tunneling ionization through charge transfer state (CTS) Ce4+-Yb2+ ions. The Tb3+ is quenched presence ytterbium, but not due to poor resonance conditions intraconfiguration transitions CTS single Yb3+ visible range both Ce3+- Tb3+-doped samples intensely as well, which indicates strong competition from activators Gd substrate.