Dielectric properties of free-substrate synthesized Cu₂O nanopyramids and CuO nanoflakes

Abstract In this work, Cu 2 O nanopyramids and CuO nanoflakes are synthesized using simple co-precipitation and hydrothermal methods, respectively. The XRD and Rietveld refinement results show that the synthesized samples are pure single phases of cubic Cu 2 O and monoclinic CuO. The field emission scanning electron microscope (FE-SEM) is used to figure out the size, shape and surface morphology of the materials. The alternating current (AC) conductivity ( σ ac ) of the Cu 2 O and CuO nanostructures was investigated and explained in the framework of the correlated barrier hopping model. Maxwell–Wagner model was applied to explain the behavior of the dielectric constant as a function of frequency. The impedance spectra show that the grain boundaries play an important role in the dielectric relaxation processes. The obtained Cole-Cole diagrams were explained using the Maxwell- Wagner capacitor model.