Flexible room-temperature multiferroic thin film with multifield tunable coupling properties

Abstract

Flexible multiferroic materials that exhibit unique properties are considered as a promising solution for electronic applications in wearable products and implantable systems. In this work, we present a high quality and large-area multiferroic (1-x)BiTi(1-y)/2FeyMg(1-y)/2O3-(x)CaTiO3(BTFM-CTO) thin films grown on mica substrate by employing the sol-gel method, while the respective ferroelectric and magnetic effects are characterized at room temperature. Compared with the flat state, the in-plane ferroelectric domains of the BTFM-CTO thin films were switched under the application of a bending radius of 9 mm. This result indicates that the applied bending strain can switch the in-plane ferroelectric domain patterns by the manifestation of the respective flexoelectricity effect, whereas the external in-plane magnetic field can also switch the ferroelectric domain patterns. Thus, it is demonstrated that the flexible BTFM-CTO thin film can achieve multifield control ferroelectric polarization properties. Our work opens new paths for the developing novel flexible multiferroic devices via mechanical bending for various applications.