Multiferroic consequence of porous (BiFeO3)x–(BiCro3)12x composite thin films by novel sol–gel method

Abstract

In this work, we have presented a spin-coating method to produce thin films started with pure BiCrO3 (BCO) and ended up with BiFeO3 (BFO) by increasing x values in the (BiFeO3)x–(BiCrO3)1-x composites. All the produced thin films have been crystallized at the annealing temperatures of 400 °C for 0.5 h. The XRD and EDAX spectrums give insight that the two crystal phases related to BCO and BFO stayed together within the thin film matrices. SEM analysis showed that the prepared composite had macroporous morphology with interconnected pores and its width (size) decreased with increasing x values. The strong correlations are observed among the microstructure, dielectric, ferroelectric, ferromagnetic properties and Fe concentration. Among all composites, the composition of 0.75 shows an attractive magnetization, polarization, switching and improved dielectric behaviors at room temperature. Significant increase in the multiferroic characteristics of 0.75 composition is due to arise of lower leakage current by causing reduction in oxygen vacancy density, and enhancement of super-exchange magnetic interaction between Fe3? and Cr3? at BFO/BCO interface layers. Our result shows that the thin layer on Pt (111)/Ti/SiO2/Si substrate possesses simultaneously improved ferroelectric and ferromagnetic properties which make an inaccessible potential application for nonvolatile ferroelectric memories.