Two- and Three-Layered Composite Scintillators Based on the Ce³⁺-Doped GAGG and TbAG Garnets for the Simultaneous Registration of Various Types of Ionizing Radiation

This work presents our most recent results in the development of composite scintillators using the liquid phase epitaxy growth method based on the single crystalline films and single crystals of garnet compounds for the radiation monitoring of different components of mixed ionization radiation fluxes. Such composite scintillators present two- and three-layered epitaxial structures consisting of two single crystalline films of Ce3+-doped garnets, namely, Gd3Al5–xGaxO12:Ce garnet with a Ga content of x = 1.75–2.25 as a first film layer and Tb3Al5O12:Ce garnet as a second film layer. As substrates, Gd3Al5–xGaxO12:Ce single crystals with fixed Ga concentrations x = 2.3, 2.5, and 3.0 were used. For the estimation of scintillation properties of the respective epitaxial structures (pulse height spectra, light yield, and scintillation decay kinetics), we have used three types of ionizing radiation: α-particles (239Pu), β-particles (90Sr + 90Y), and γ-quanta (137Cs).