Epitaxial growth of nano-texturized NiO films on MgO (001) substrates by a reactive magnetron sputtering method

Abstract

Epitaxial films with nanostructures are of great significance for some special applications. In this work, nano-texturized NiO films are epitaxially grown on MgO (001) substrates by a reactive magnetron sputtering method. The evolution in morphology is studied as a function of deposition time, and the influences of substrate temperature, oxygen partial pressure, and the substrate treatment before deposition of NiO on the formation of nano-texturized NiO films are explored. It is found that the non-symmetrically epitaxial growth of nano-texturized NiO films can be linked with the surface damages of MgO (001) substrate, which leads to the coalescence of adjacent NiO grains preferentially occurs along the direction of 〈100〉 and 〈010〉, but they do not coalesce simultaneously following the other directions. In addition, the optical property of nano-texturized NiO films is studied using the Cauchy model.