Structural and compositional characterization of single crystal uranium dioxide thin films deposited on different substrates

Uranium dioxide thin films were deposited on single crystal TiO2, Al2O3, YSZ, ZnO and NdGaO3 substrates to optimize conditions for the growth of high quality single crystal films. X-ray diffraction results show that all the films have one growth direction and well defined peaks in the specular scans with the expected symmetry for each growth orientation. The UO2/Al2O3, TiO2, and ZnO films have high concentration of misfit dislocations that increase with the lattice mismatch. The UO2 film on YSZ is found to be in registry with the substrate. The film has narrow mosaic component that is imposed upon a broader component arises from the diffuse scattering due to defects in the film. Meanwhile, UO2/NdGaO3 film shows a splitting of the X-ray diffraction peaks which is attributed to the in-plane asymmetry of the orthorhombic substrate.