Scintillation properties of Lu3Al5O12:Ce single-crystalline films

The possibility of obtaining scintillators for X-ray detectors by liquid-phase epitaxy of Lu3Al5O12:Ce single-crystalline films (SCF) on Y3Al5O12 substrates is studied. Optical, luminescent and scintillation characteristics of Lu3Al5O12:Ce SCF doped by isoelectronic La, Y, Sc impurities are analyzed. The possibility of crystallization of Lu3Al5O12:Ce SCF on Y3Al5O12 substrates by means of matching of lattice parameters of these garnets due to the occupation of Al3+ octa-sites by Lu3+ ions is proved. Lu3Al5O12:Ce-based SCF containing Gd3+, Tb3+, and Eu3+ dopants were investigated with the aim of matching the emission spectra with the spectral sensitivity of radiation detectors like CCD cameras. The maximum light yield, exceeding that of analogs based on Y3Al5O12:Ce SCIF by a factor of 1.1-1.5, is found in Lu3Al5O12:Ce3+-, Lu3Al5O12:Ce,Y,La- and Lu3Al5O12:Ce,Tb-SCF. An increase of the effective atomic number Z(eff) and density rho up to the values of 60.6 and 7.35 g/cm(3), respectively, allows to raise the efficiency of X-ray absorption in comparison with Y3Al5O12:Ce3+-SCF by a factor of 2.5-8 and to reach a spatial resolution not <0.75-1.0 mum for a SCF thickness of 1.0-2.0 mum. (C) 2002 Elsevier Science B.V. All rights reserved.