Tunable structural transition and multiferroic properties of the composite thin films through the structural transition of magnetic layer

The Bi0.9Er0.1Fe0.96Mn0.02Co0.02O3/Co1-xMnxFe2O4 (BEFMCO/CMxFO) thin films have been deposited by sol-gel method. Structural distortion is observed in the BEFMCO with the appearance of trigonal-R-3m: H in the CMxFO. The enhanced multiferroic properties, well electrically writable and ferroelectric switching properties are obtained in BEFMCO/CMxFO thin films. The investigation indicates that the structural transformation of the CMxFO influences the structure and multiferroic properties of BEFMCO and the interfacial effects between BEFMCO and CMxFO layers. This transformation and Mn-doping cause the change of carriers, which solves the problem that the magnetic layer exacerbates the ferroelectric properties. It promotes to form the weak local electric field, which causes the weak interface effect, and brings out the weak resistive switching in the BEFMCO/CMxFO thin films. Therefore, it is believed that the BEFMCO/CMxFO films can offer a potentially tunable structural transformation of composite films for practical applications.