La2Hf2O7:Ti4+ ceramic scintillator for x-ray imaging

Transparent ceramic scintillators of La2Hf2O7:Ti4+ were developed by a novel combustion synthesis method. The optical transmittance for a 1.0-mm-thick specimen is about 60% of the incident light, and the x-ray stopping power is also quiet high. The broad emission band centered at 475 nm originates from the oxide-Ti4+ charge-transfer transitions, which renders fast decay time on the order of 10 mu s. The highest relative light output has reached about 1.5 times that of Bi4Ge3O12 (BGO) single crystal when excited by 120 kV x-rays.