Investigations of optical and scintillation properties of Tm3+-doped YAlO3

Abstract Pure, 0.1, 0.5 and 1 mol% Tm-doped YAP single crystalline scintillators were grown by the μ-PD method. The XRD analysis confirmed the lattice constants decrease with the Tm concentration. In the transmittance measurement, the absorption bands due to the Tm3+ 4f–4f transitions were observed at 265, 360, 485, 690 and 800 nm and they were ascribed to the transition from the 3H6 ground state to its 1I6, 1D2, 1G4, 3F3 and 3H4 excited states, respectively. Strong emission peak due to the 1I6–3F4 transition of Tm3+ appeared at 350 nm under X-ray irradiation. The photoluminescence decay time constants related to this transition were evaluated to be from 15.3 to 17.3 μs and the scintillation decay time constants under gamma-ray excitation were estimated to be from 17.5 to 18.8 μs. The Tm 1% doped crystal exhibited the highest light yield of 15, 100 ± 1500 photons/MeV when excited by 137Cs gamma-ray radiation.