Dielectric properties of nanocomposite (Cu)x(SiO2)(100-x) produced by ion-beam sputtering

Abstract

It has been established that in the nanocomposite Cux(SiO2)(100 x) with the metallic phase content x = 27.27 at.% the following phenomena occur: hopping conductivity, additional polarity and coilless-like inductance. Coilless-like inductance phenomenon consists in the occurrence of positive values of phase shift in the high frequency area. Activation energy of the dielectric relaxation time for copper nanoparticles of unoxidized surface is of approx. 0.0003 eV, whereas surface oxidation causes a potential barrier occurrence and activation energy increase up to approx. 0.3360 eV. Comparative analysis of results obtained for the Cux(SiO2)(100 x) material and the measurements results obtained for the nanocomposites (FeCoZr)x(Al2O3)(100 x), (FeCoZr)x(CaF2)(100 x) and (FeCoZr)x(PZT)(100 x), which containing nanoparticles of ferromagnetic alloy, has been performed. It has shown that the type of magnetic properties of metallic phase, which is ferromagnetic ones for FeCoZr and diamagnetic ones for Cu, does not affect capacitive and inductive phenomena of the nanocomposites. The phenomena are related only to the nanogranular structure of the materials and the hopping mechanism of the charge transport between the metallic phase nanoparticles.