Epitaxial growth of gadolinium and lutetium-based aluminum perovskite thin films for X-ray micro-imaging applications

Abstract : Our work is related to the liquid phase epitaxy-based development of new scintillating screens for high-resolution X-ray imaging. We successfully grew undoped and Tb, Eu and Ce-doped GdAlO₃ as well as Gd_xLu_1−xAlO₃ single crystalline films on YAlO₃ substrates. We studied crystallization conditions as a function of melt composition, growth temperature and lattice mismatch between the film and the substrate. The film composition was measured by using an electron microprobe and the morphology of the film surface was studied by scanning electron microscopy. X-Ray diffraction was used to characterize the crystal structure and the mismatch between the film and the substrate. In addition, the light yield of the Eu³⁺-doped films, as well as the obtained spatial resolution show that Gd_xLu_1−xAlO₃ may advantageously compete with existing thin film scintillators in particular energy ranges.