Investigation of the Magnetic-Impedance Properties of CuO Nanoparticles Obtained in a Low-Pressure Arc Discharge Plasma

CuO nanoparticles obtained in a low-pressure arc discharge plasma followed by annealing in an oxygen atmosphere at 500°C were studied by X-ray diffraction and transmission electron microscopy. The formation of irregularly shaped nanoparticles in the size range of 5–30 nm was found. The Rietveld refinement confirmed the formation of a monoclinic CuO phase with an average crystallite size of ~21 nm. The temperature dependences of the magnetization and permittivity of CuO nanoparticles have been studied. They show antiferromagnetic behavior with a Neel temperature of 230 K and frequency-dependent dispersion behavior in the temperature range of 100–200 K at an external magnetic field induction of 0–1.3 T. The dielectric relaxation mechanism is analyzed and found to follow the Arrhenius behavior. It is shown that hopping conductivity with a variable hop length more accurately describes charge transport in CuO nanoparticles. A magnetodielectric response of about 2.5 was observed at a frequency of 12 kHz at a temperature of 150 K in a magnetic field of 1.3 T.