It was recalled that the efficiency of scintillator materials was decreased by processes associated with electrons or holes trapped at point defects. It therefore followed that minimizing the concentration of the defects responsible for trapped electrons/holes would increase the scintillator efficiency. It had been proposed that annealing or doping oxide scintillators with aliovalent ions could change the concentration of point defects. Here, the defect structures corresponding to ZrO2 doping in a series of rare-earth aluminate perovskites were predicted. From these calculations, the mechanism leading to the decrease in O vacancy concentration (the predominant electron trap in rare-earth aluminate AlO3) was predicted.

Defect Structure of ZrO2-Doped Rare Earth Perovskite Scintillators. C.R.Stanek, M.R.Levy, K.J.McClellan, B.P.Uberuaga, R.W.Grimes: Physica Status Solidi B, 2005, 242[13], R113-5