Eu concentration dependence of photoluminescence and scintillation properties on Eu-doped Y3Al5O12 single crystals

(Eux,Y1-x)3Al5O12 (x = 0.005, 0.01, 0.05, 0.10, 0.15, and 0.20) single crystals were prepared by the floating-zone method. We investigated their photoluminescence (PL) and scintillation properties including PL excitation/ emission contour spectra, PL quantum yields, PL decay times, X-ray-induced scintillation spectra, scintillation decay times, and pulse-height spectra under gamma-ray irradiation from 137Cs (662 keV). The PL and scintillation spectra exhibited some emission lines at visible wavelength due to the 4f-4f transitions of Eu3+ ions, and the PL and scintillation decay times resulted several milliseconds. Among all the samples, (Eu0.1,Y0.9)3Al5O12 and (Eu0.15,Y0.85)3Al5O12 single crystals showed the highest PL quantum yield. On the other hand, (Eu0.01, Y0.99)3Al5O12 single crystal showed the highest light yield. The light yield of the sample was estimated to be 36,000 photons/MeV from the pulse height spectrum.