Promising single crystal host for bulk scintillators: luminescence and energy migration in (Gd,Y)AlO3

Abstract

The optical and photoluminescent characteristics of the heavy perovskite (Gd_0.40,Y_0.60)AlO₃ single crystal were evaluated. Typical Gd³⁺ transitions were observed in the absorption spectrum. The photoluminescent kinetics and temperature dependence of the Gd³⁺ emission line at 312 nm were examined in order to study the energy migration within the Gd³⁺ sublattice. In comparison to multicomponent (Gd,Y)₃(Ga,Al)₅O₁₂ garnet, the migration in (Gd_0.40,Y_0.60)AlO₃ was demonstrated to be more rapid and more efficient at lower temperatures. The radioluminescent spectrum demonstrated the existence of accidental impurities, namely Ce³⁺, Fe³⁺ and Cr³⁺, within the primary material, which were subsequently verified through the observation of their distinctive kinetic properties. In excitation spectra within the VUV-UV range at room temperature the band-to-band transition is situated at about 180 nm, in which also an efficient excitation of Ce³⁺ emission occurs. Such a host paves the way to economic industrial production of heavy aluminum perovskite-based single crystal scintillators.