Temperature and frequency dependences of real part of impedance in the FeCoZr-doped PZT nanogranular composites

The study of carrier transport in granular nanocomposite films consisting of ferromagnetic Fe45Co45Zr10 alloy nanoparticles embedded in a low-conductive Pb81Sr4(Na5Bi5)15(Zr57.5Ti42.5)O3 matrix has been performed. Real part of the impedance of the nanocomposites was studied as a function of composition, temperature and frequency, for the samples with 25 ≤ x ≤ 80 at.%, deposited by ion-beam sputtering in Ar + O2 gas mixture at the oxygen pressures of $P_{O_2 } $ = 2.4·10−3 and 3.7·10−3 Pa. It has been proved that approaching the threshold concentration, x C in the FeCoZr alloy resulted in the transition from high-ohmic to low-ohmic state with the x increase, without the change of hopping mechanism of carrier transport.