Formation of Noncoil-Like Inductance in Nanocomposites $(Fe_{0.45}Co_{0.45}Zr_{0.10})_{x}(Al_2O_3)_{1-x}$ Manufactured by Ion-Beam Sputtering of Complex Targets in $Ar+O_2$ Atmosphere

This paper investigates the inductive contribution to AC conductance in the granular nanocomposites $(Fe_{0.45}Co_{0.45}Zr_{0.10})_{x}(Al_2O_3)_{1-x}$. The initial nanocomposites studied were manufactured in $Ar+O_2$ atmosphere by ion-beam sputtering of the target containing $Fe_{0.45}Co_{0.45}Zr_{0.10}$ and alumina stripes and then subjected to the annealing procedure in air over the temperature range 373 K < $T_{a}$ < 873 K. These samples, before and after annealing, were studied using the temperature 77 K < $T_{p}$ < 300 K and frequency 50 Hz < f < 1 MHz dependences of a real part of the admittance σ(T, f). Analysis of the observed σ (f, $T_{p}$) dependences for x < 0.5 demonstrated that in the studied samples the equivalent circuits with the capacitive and noncoil-like inductive contributions can be accomplished. Just in this case, the capacitive properties of RLC circuit with the phase angle - 90° ≤ $\Theta_{L}$ < 0° are exhibited at low frequencies and the inductive properties with 0° ≤ $\Theta_{H}$ < 90° become apparent at high frequencies. A value of the critical frequency $f_{R}$, where $\Theta_{H}$ changes sign, depends on the metallic phase concentration x, measuring temperature $T_{p}$, and annealing temperature $T_{a}$.