Structural and resistive properties of Pt/BiFeO3 /La0.5Sr0.5CoO3 heterostructure for storage application

BiFeO 3 has promissing application in non-volatile ferroelectric memory, but the dominant mechanism has not been unified. Here, Pt/BiFeO 3 (100 nm)/La 0.5 Sr 0.5 CoO 3 (Pt/BFO/LSCO) heterostructures have been fabricated on (001) SrTiO 3 (STO) single crystal substrates by off -axis magnetron sputtering. Both XRD and TEM analyses confirm that the (001) oriented BFO/LSCO heterostructures have been epitaxially grown on STO. In addition, XRD, TEM along with XPS analyses further indicate that the BFO film (001) presents epitaxial perovskite structure. On the basis of electric field regulation of Pt/BFO and BFO/LSCO interface barrier, the switching interface state is controlled by charge filling and trapping in interface potential well, which is responsible for I -V resistance and G -V hysteretic curve. Based on the fitting results of the conduction mechanism of I -V characteristic curve, it proves that the space charges limiting current play a dominant role, and the filling and trapping of interface traps are considered as the main resistance mechanisms. Moreover, ultraviolet irradiation can modulate the I -V resistance curve but does not change its conduction mechanism. This work provides experimental data for the practical application of integrated BFO resistive memories.