Resistive Switching and the Local Electric Field in Bi0.85-xPr0.15RExFe0.97Mn0.03O3/CuFe2O4 (RE = Sr, Dy) Bilayered Thin Films.

Bilayer Bi0.85-xPr0.15RExFe0.97Mn0.03O3/CuFe2O4 (BPRExFMO/CuFO, RE = Sr, Dy) thin films were prepared on FTO/glass substrates by the chemical solution deposition method. The structure transition does not appear after ion doping, which is confirmed by XRD and its refined results. The samples remain in the trigonal R3c:H structure in the BFO phase and in the tetragonal I41/amd structure in the CuFO phase. The asymmetric character of leakage current density curves and resistive switching effects have been explored. And the ion substitution impacts on the resistive switching effects may be due to the existence of local fields. Under the applied electric field, carries are accumulated and arranged directionally at the interface between the BFO and CuFO layers to form the local electric field. Such local field is affected by ion dopants, and the field compensates or weakens the applied electrical field. The reinforced or weakened resistive behavior is dependent on the direction of the local field and the injection of electrons. The polarization switching currents of the BPFMO/CuFO, BPSFMO/CuFO, and BPDFMO/CuFO samples, whose distribution fields are proportional to the local electrical fields, are 0.0070, 0.0049, and 0.0074 A under the positive applied field, respectively. And the remanent polarization is increased to 74.4, 73.5, and 84.3 μC/cm2 of the doped samples, respectively.