New types of composite scintillators based on the single crystalline films and crystals of Gd3(Al,Ga)5O12:Ce mixed garnets

This work presents the results of creation of novel composite scintillators based on the Gd3Al5-xGaxO12:Ce (x = 1.16-2.67) single crystalline films (SCF), grown by the LPE method onto Gd3Al2.5Ga2.5O12:Ce single crystal (SC) substrates. The scintillation properties of film/crystal epitaxial structures were investigated under alpha-particle and gamma-quantum excitations. Under alpha-particle excitation, the light yield of mentioned SCF scintillators is significantly less than that in their substrates due to the influence of Pb2+ flux contamination and formation of Pb2+-Ce4+ centers. Meanwhile, these SCF scintillators under alpha-excitation possess significantly faster decay kinetics than that of their substrates under gamma-excitation. Therefore, the Gd3Al5-xGaxO12:Ce SCFs (x = 1.16-2.67)/Gd(3)Al(2.5)G(2)(.5)O(12): Ce SC epitaxial structures can be used as composite scintillators for simultaneous registration of the components of mixed ionizing fluxes, specifically for detection of alpha-particles (SCF) and gamma-quanta (substrate). The separation of the response from the SCF and substrate parts of composite scintillators under alpha-particle (Am-241) and gamma-quantum (Cs-132) excitations occurs at large t(gamma)/t(alpha) = 1.7-4.2 ratio.