The effect of surface structure on the growth of ceramic thin films

Thin-films of yttria-stabilized zirconia (YSZ) and Y2O3(cubic structure) have been grown on annealed substrates of (0001) and (101formula prasented0) AI2O3(α-AI2O3corundum structure) by pulsed-laser deposition. These model systems demonstrate the effect that surface structure, such as surface steps and facets, can have on ceramic thin-hlm growth. The near-(0001) Al2O3surface facets into a terrace-and-step morphology where the terraces correspond to the (0001) surface. YSZ grew on, or near, surface steps on the nominally (0001) surface such that it was preferentially aligned with the (110) YSZ plane parallel to the (112 formula prasented 0) AI2O3plane. On the large (0001) terraces, the grains grew so that the (110) YSZ plane was aligned parallel to the (101 formula prasented 0) AI2O3plane. The (101 formula prasented 0) AI2O3surface facets into a hill-and-valley structure that corresponds to the (101 formula prasented 2) and [101 formula prasented 1 formula prasented] planes. Growth of Y2O3onto this surfaceagain produced two different orientations. For growth which occurred on the (101 formula prasented 1 formula prasented) facet, grains of Y2O3where aligned with the (111) Y2O3plane parallel to the (0001) Al2O3plane, while for the growth on the (101 formula prasented 2) facet the (001) Y2O3plane was parallel to the (12 formula prasented 10) Al2O3plane. © 1997 Taylor & Francis Group, LLC.