Reactive processes of nickel oxide on oxidic substrates as observed by scanning force microscopy

Abstract

High-temperature diffusion/reaction processes of nickel oxide (NiO) have been studied on oxidic surfaces. Nickel was sputtered on silicon dioxide (SiO2, quartz) and on yttrium stabilized zircon dioxide (YSZ). The metallic films with layer-thicknesses of 200-800 nm possessing well-defined steps and shapes, subsequently were annealed in air. On quartz, the thermal anneal at 500 °C led to the formation of nickel olivine. Thermal anneal on YSZ at 500 °C led to the formation of NiO. Further treatment at 1200 °C caused the development of a sigmoid profile at the former step of the NiO film. The evolution of the topological changes with annealing time is not completely understood, but surface diffusion of NiO must play an essential role.