Oxidation and reduction of copper oxide thin films

Oxygen diffusion induced phenomena in copper oxide thin films have been studied by a combination of the 16O(α, α)16O oxygen resonance technique and the transmission electron microscopy (TEM), which provides a method for studing the kinetics of nucleation and growth of the Cu2O phase in the CuO matrix. A discontinuous morphology of grain growth of Cu2O is found in the CuO matrix during reduction. The migration of the Cu2O-CuO phase boundary is induced by oxygen diffusion along the moving phase boundary. A metastable phase Cu4O3 can be formed by ion milling the CuO film with high current density. The refractory metals (Zr and Ti) and reducing ambients can significantly enhance the reduction rate of CuO films. The kinetics study of the reduction and oxidation of copper oxides shows that the two processes are asymmetrical and the latter is faster.