Crystal growth and scintillation properties of Ce and Sr co-doped (Gd,Y)F₃ single crystals

In this study, (Gd_1-xY_x)F₃ (x=0.2, 0.4, 0.5 0.6 and 0.8) crystals were grown by the μ-PD method. Neither visible inclusions nor cracks were observed in (Gd_1-xY_x)F ₃ (x=0.4, 0.5 and 0.6) crystals. Lattice constants increase linearly as the Y³ concentration decreases. Using (Gd_1-xY _x)F₃ as a host material, the Sr0.5% Ce1%, 3%, 5% and 7% co-doped Gd_0.5Y_0.5F₃ single crystal was prepared. In this crystal, Ce³-perturbed luminescence at 380 nm is observed with 31.8 ns photoluminescence decay time. Under X-ray excitation rather high radioluminescence intensity of this band was obtained exceeding that of BGO scintillator. The energy transfer in the sequence of regular Ce ³→ (Gd³)_n→ perturbed Ce³ sites was evidenced though observation of decay time shortening of the regular Ce³ and Gd³ centers and intensity change between Gd ³ and Ce³-perturbed emission.