Significant magnetic, dielectric and magnetodielectric properties of CuO nanoparticles prepared by exploding wire technique

Abstract

The CuO nanoparticles, prepared by exploding wire technique (EWT) followed by annealing in oxygen atmosphere at 900 °C, have been studied for phase purity and structure formation by employing X ray diffraction (XRD) method. Rietveld refinement and Debye-Scherrer analyses ensured the formation of monoclinic single phase of CuO nanoparticles with an average crystallite size of ~ 21 nm. Irregular shape nanoparticles in the size range of 5–30 nm were observed by Transmission Electron Microscopy. The temperature dependent (5–300 K) magnetization measurements have been performed to ascertain the magnetic properties of the prepared nanoparticles, which indicated the antiferromagnetic behavior around 230 K. The temperature dependent (10–300 K) dielectric measurements in 0 T and 1.3 T external magnetic fields demonstrated the frequency dependent dispersive behavior of CuO nanoparticles in the temperature range 100–200 K. The dielectric relaxation mechanism of CuO nanoparticles was further analyzed and found to follow the Arrhenius like behavior. Finally, we could observe that the Variable range hopping (VRH) is more precise in present case of CuO nanoparticles. Notably, the magnetodielectric response (MDR) of the order of 2.5 is also observed at 12 kHz frequency at the temperature around 150 K in the optimal magnetic field of 1.3 T. This proves to be an uncommon interesting property of prepared CuO nanoparticles and may lead to new technological applications.