The oriented growth of zirconia thin films on NaCl (0Â 0Â 1) surface

Nanosized cubic and tetragonal ZrO2 were formed as thin nanocrystalline film on NaCl (1 0 0) plane by radio frequency ion beam sputtering. The microstructure and the epitaxy relationship with the NaCl (1 0 0) plane were studied by a high-resolution transmission electron microscope. The epitaxy orientation was found to be [0 0 1]Z∥[0 0 1]N, [100]Z∥[11¯0]N (group A), [0 1 1]Z∥[0 0 1]N, [1 0 0]Z∥[1 0 0]N (group B1) and [0 1 1]Z∥[0 0 1]N, [1 0 0]Z∥[0 1 0]N (group B2) between zirconia (Z) and NaCl (N). Groups B1 and B2 are the dominant type. The possible causes for the epitaxy relationship are discussed. Crystallites within the same group can merge by rotation and coalesce into a single crystal, whereas crystallites in different groups can form high-angle grain boundaries.