Photoluminescence, and scintillation/thermoluminescence yields of several Ce3+ and Eu2+ activated borates

Powder samples of the berates YBO(3):Ce(3+) GdBO(3):Ce(3+), Li(6)Y(BO(3))(3):Ce(3+), LaB(3)O(6):Ce(3+,) GdB(3)O(6):Ce(3+), LaMgB(5)O(10):Ce(3+), YMgB(5)O(10):Ce(3+), CaLaB(7)O(13):Ce(3+), CaLaB(7)O(13):Eu(2+), Ca(4)YO(BO(3))(3):Ce(3+) and CaY-OBO(3):Eu were studied. The photoluminescence properties of Ce(3+) in these compounds are discussed and some of them are reported for the first time. The scintillation light yield of the orthoborates: YBO(3):Ce(3+), GdBO(3):Ce(3+) ScBO(3):Ce(3+) and YAl(3)B(4)O(12):Ce(3+) is of the order of 10,000 pho/MeV. The light yield due to Ce(3+) in the other berates is an order of magnitude lower. In LaB(3)O(6):Ce(3+) and LaMgB(5)O(10):Ce(3+) a broad emission band, attributed to self-trapped exciton (STE) emission. is observed under X-ray excitation. The STE light yield of LaB(3)O(6):Ce(3+) (0.05%) is 8000 pho/MeV and it is quenched at higher Ce concentrations. Thermoluminescence measurements show that none of these materials has a potential to be utilized as a thermal neutron storage phosphor, (C) 2000 Elsevier Science B.V. All rights reserved.