LUMINESCENCE PROPERTIES OF GDA1O(3)CE POWDERS - DEPENDENCE ON REDUCTION CONDITIONS

The influence of the preparation method on the luminescence efficiency of GdAlO3(GAP):Ce crystalline powders has been studied. Due to the se gregation coefficient of Ce3+ in GAP, there is always a second absorpt ion band in the UV, next to the 4f-5d absorption of Ce3+ in these crys talline powders. This absorption band ranges up to 400 mn, i.e. the ar ea where the Ce3+ emission transition is situated and this absorption will therefore hamper the efficiency of the Ce3+ emission, independent of the excitation source. However, GAP:Ce crystalline powders can be used to study the scintillator characteristics of this material becaus e the conversion and transfer processes are not necessarily influenced .