Nucleation controlled surface oxidation epitaxy of thermally grown NiO on (0 0 1) Ni for coated conductor applications assisted by Mo or Mn microalloying

Abstract

High temperature oxidation of cube textured (1 0 0)Ni and (1 0 0)Ni–0.1wt%(Mo or Mn) was carried out in a wide temperature regime between 900 and 1400 °C in air. Special attention was paid to avoid pre-oxidation at lower temperatures, thus favouring nucleation controlled surface oxidation epitaxy (SOE) as opposed to SOE achieved by competitive grain growth. Consequently, cube textured epitaxial NiO layers, under 1 μm in thickness, have been grown on pure Ni in a much wider working window than previously published. Furthermore, thin cube textured NiO layers have been grown on Ni–0.1%Mo tape in a still wider working window of ∼200 °C between 1150 and 1350 °C. Preliminary results on Ni–0.1wt%Mn show a similar trend. An in-plane orientation of <5° and out of plane orientation approaching 2° was obtained. Single crystal like transparent NiO films were grown under optimal conditions.