Compositionally Disordered Doped with Cerium Crystalline Garnet Type Materials for Brighter and Faster Scintillations

Abstract

Ce-doped tetracationic garnets (Gd, M)3Al2Ga3O12(M = Y, Lu) form a family of new multipurpose promising scintillation materials. The aim of this work was to evaluate the scintillation yield in the materials of quaternary garnets activated by cerium ions with partial isovalent substitution of the matrix-forming gadolinium ions by yttrium or lutetium ions.Materials were obtained in the form of polycrystalline ceramic samples, and the best results were shown by samples obtained from the raw materials produced by the coprecipitation method. It was found that ceramics obtained from coprecipitated raw materials ensure a uniform distribution of activator ions in the multi-cationic matrices, which enables the high light yield and fast scintillation kinetics of the scintillation. It was demonstrated that the superstoichiometric content of lutetium/gadolinium in the material is an effective method to suppress phosphorescence accompanied scintillation. For ceramics with the composition (Gd, Lu)3Al2Ga3O12 , a scintillation yield of more than 50.000 ph/MeV was achieved. The scintillation kinetics was measured to be close to the kinetics with a decay constant of 50 ns.In terms of the set of the parameters, the developed scintillation materials are close to the recently developed alkali halide materials LaBr3:Ce, GdBr3:Ce. Moreover, they have high mechanical hardness, are characterized by the absence of hygroscopicity, and are better adapted to the manufacture of pixel detectors used in modern devices for medical diagnostics.

Structural and Optical Properties of High Entropy (La,Lu,Y,Gd,Ce)AlO3 Perovskite Thin Films

“…[23,26] The disorder can also give rise to additional thermalization channels that allow for increased transfer efficiency. [28] It has been argued that a compositionally disordered but isovalent cation sublattice could retain anion spatial symmetry with long-range order, which can lead to improved scintillation properties. [29] Entropy-stabilized oxides (ESOs) allow the design of compositional disorder of a sublattice and have been seen to exhibit a range of desired properties.…”

“…[ 22 , 23 ] On the other hand, the disorder has been shown to dramatically increase light yield with relatively lower afterglow while maintaining a high effective atomic number. [ 23 , 26 , 27 , 28 ] The structural disorder in these materials arises from the cation competition in occupancy of the same lattice location. [ 28 ] As a result, the differences in atomic radii can lead to large distortion in the lattice that may potentially modify the conduction zone and result in an increased conversion efficiency.…”

“…[ 23 , 26 , 27 , 28 ] The structural disorder in these materials arises from the cation competition in occupancy of the same lattice location. [ 28 ] As a result, the differences in atomic radii can lead to large distortion in the lattice that may potentially modify the conduction zone and result in an increased conversion efficiency. [ 23 , 26 ] The disorder can also give rise to additional thermalization channels that allow for increased transfer efficiency.…”

“…[ 23 , 26 ] The disorder can also give rise to additional thermalization channels that allow for increased transfer efficiency. [ 28 ] It has been argued that a compositionally disordered but isovalent cation sublattice could retain anion spatial symmetry with long‐range order, which can lead to improved scintillation properties. [ 29 ]…”