Concentration effect on the scintillation properties of sol-gel derived LuBO3 doped with Eu3+ and Tb3+

Lu1-xEuxBO3 and Lu1-xTbxBO3 powders have been prepared by a sol-gel process with 0 < x < 0.15 for Eu3+ and 0 < x < 0.05 for Tb3+. The purity of powders has been verified by X-ray diffraction and the results confirm that all the materials have the vaterite type even if the calcination has been performed at 800 degrees C. Furthermore, the solid solution for LuBO3 vaterite is observed up to x = 0.15 and x = 0.05 for europium and terbium ions respectively. So doping with Eu3+ or Tb3+ ions does not affect the structure. These materials have also been analyzed by Fourier transform infrared spectroscopy. The morphology of the powders has been studied by scanning electron microscopy and shows a very nice morphology with small spherical particles with narrow size distribution. Optical properties have then been studied to confirm the effective substitution of Eu3+ or Tb3+ for Lu3+ ions and to determine the materials scintillation performances. The optima, in term of scintillation yield, are obtained for Eu3+ and Tb3+ concentration of x = 0.05 in both cases. The afterglows have also been measured and confirm the potentiality of these materials as scintillators. (c) 2005 Elsevier B.V. All rights reserved.