Electrophysical properties of the polycrystalline BiFe$_{0.95}$Co$_{0.05}$O$_{3}$

Semiconductor BiFe$_{0.95}$Co$_{0.05}$O$_{3}$ thin-film compounds were obtained by a flare technique. The surface morphology of the films and the effect of electronic doping by replacing trivalent iron with cobalt ions on the structural, optical, magnetic, and kinetic properties in the temperature range 77–600 K in magnetic fields up to 12 kOe are studied. The existence of two relaxation channels in the impedance spectrum at frequencies of 0.1–1000 kHz has been established. The negative magnetoresistance in the anomalous magnetization region and the maximum magnetoimpedance in the vicinity of the surface phase transition has been found. Using the Hall effect measurements, carrier types prevailing in the magnetoresistance and magnetoimpedance effects has been found. The magnetization anomalies are explained using the model of superparamagnetic clusters and the magnetoresistance is attributed to the scattering of carriers by the spin fluctuations.