New scintillation detectors based on oxide single crystal films for biological microtomography

Scintillation characteristics of the Lu3Al5O12-based single crystal films, grown on the Y3Al5O12 (YAG) substrate by liquid phase epitaxy, were explored and improved for the application in biological microtomography as X-ray image screens. To achieve a high spatial resolution, the film must be of about 1 μm thickness, a large effective atomic number Zeff being necessary for a sufficient absorption in the X-ray range. The Lu3Al5O12:Ce3+ garnet (Zeff≈60) is a proper heavy material for such films. However, a stable growth of this film on the YAG substrate is hampered by the lattice mismatch between the film and substrate. This mismatch was duly reduced with the use of specially chosen isoelectronic impurities which simultaneously enhance the light yield of the film, and the overlap of its luminescence spectrum with the spectral sensitivity of the photoreceiver (CCD camera).