Impedance of nanocomposite SiO2(Si)&FexOy(Fe) thin films containing Si and Fe nanoinclusions

Abstract

In this study, electrical properties at alternating current of the nanocomposite films containing silicon and iron inclusions in amorphous SiO x matrix are presented. The composite SiO 2 (Si)&Fe x O y (Fe) films were obtained using the ion-plasma co-sputtering of Si and Fe targets in oxygen containing atmosphere (Ar + O 2 ) followed by temperature annealing. It was revealed the predominance of the inductive contribution over the capacitive one in the reactive part of the admittance (impedance) at low frequencies (f < 1 MHz) both after annealing in air and nitrogen atmosphere. The frequency dependences of the admittance after heat treatment in air have the minima that shift to the region of high frequencies with increasing the annealing temperature. In the case of low- frequency dependence, the phase shift angle passes into the region of positive values, which indicates the predominance of the inductive contribution to the admittance at these frequencies. The dependence of the conductivity real part at the alternating current frequency does not change significantly up to ~20 kHz. Starting from the frequency higher than ~20 KHz and up to ~1 MHz, the exponent in the frequency dependence of the conductivity lies within the limits m ~ 0.49…0.52.