Investigation of the effect of oxygen partial pressure on the phase composition of copper oxide nanoparticles by vacuum arc synthesis

Copper oxide nanoparticles were obtained in the plasma of a low-pressure arc discharge. The effect of the partial pressure of oxygen (10 – 40%) on the physical properties of the deposited nanoparticles has been studied. X-ray diffraction analysis shows that the cubic structure of Cu$_2$O changes to monoclinic CuO with increasing O$_2$ pressure. The results of Raman spectroscopy further confirmed the phase variations of copper-based oxide nanoparticles. X-ray photoelectron spectroscopy confirmed the change in the binding energy in the oxidation state of nanoparticles. The optical band gap of the deposited Cu$_{2}$O is 2.12 eV, while that of CuO is 1.79 – 1.82 eV.