Reflection high-energy electron diffraction studies of epitaxial oxide seed-layer growth on rolling-assisted biaxially textured substrate Ni(001): The role of surface structure and chemistry

We present a study of the {100}〈100〉 biaxially textured Ni(001) surface and seed-layer growth using in situ reflection high-energy electron diffraction and Auger electron spectroscopy. Our observations are consistent with formation of a c(2 × 2) two-dimensional superstructure due to the surface segregation of sulfur contained in the metal. We show that this superstructure can have a dramatic effect on the heteroepitaxial growth of oxide seed layers. In particular, the surface superstructure promotes the (200) epitaxial oxide growth of Y₂O₃-stabilized ZrO₂, which is necessary for the development of high-J_c superconducting films for coated conductors.