Influence of the external field and temperature on the temporal evolution of the leakage current in the BiFeO$_3$/TiO$_2$(Nt)Ti film structure

The behavior of leakage currents of the BiFeO$_3$/TiO$_2$(Nt) film structure has been studiedTi (BFOT) obtained by atomic layer deposition of bismuth ferrite on a substrate of pre-prepared titanium dioxide nanotubes, depending on the exposure time and the magnitude of the electric voltage in the temperature range of 28–250$^\circ$C. Electrically inhomogeneous states with a volume charge arise in the BFOT structure, which leads to hysteresis of the VAC. Hysteresis and heterogeneity depend on the relaxation time. The time dependence of the leakage currents revealed features in the form of a tendency to form a maximum in the temperature range $\sim$28–200$^\circ$C. At a temperature of $T$ = 250$^\circ$C, the maximum is stabilized on a time dependence and grows monotonously with an increase in the applied voltage. For this structure, the characteristic time $t$ = 0.5 s for dependencies $I(t)$ is determined due to the capture and release of carriers from defective levels.