Dramatic Effect of Temperature on Metal-oxide Nanostructures: Oxidation of Cu Films by In situ UHV-TEM

Abstract

We investigated the temperature effect on the Cu2O morphology by oxidizing Cu(100) thin films at the temperature ranging from 350°C to 1000°C. We demonstrated that dramatically different morphologies of oxide nanostructures can be achieved by modifying the oxidation temperature. Quasi-one-dimensional Cu2O structures with aspect ratios as large as 40:1 were formed at the oxidation temperature of 600°C. The in situ observation data on the elongation of Cu2O islands agree with the energetic calculations based on the balance between surface and interface energies and the elastic stress relaxation in the three dimensional islands.