Formation of Cu_x clusters in Cu/ZnO nanocomposites studied by IR spectroscopy

摘要

prepared by radio frequency co-sputtering technique. The composite films were annealed at different temperatures in argon atmosphere for 2 hrs. Transmission electron microscopy and x-ray diffraction studies revealed the formation of partially oxidized Cu nanoparticles in ZnO matrix. The size of the Cu nanoparticles depended strongly on the annealing temperature. Infrared spectroscopy study revealed that the nanoparticles consist of an elemental Cu core surrounded by the oxidized copper shell. The elemental core consists of Cu_x clusters. IR spectroscopy and DFT calculation were used to identify the Cu clusters.