Polarization manipulation via orientation control in polycrystalline BiFeO₃ thin films on biaxially textured, flexible metallic tapes

(111)-, (101)-, and (001)-oriented polycrystalline BiFeO₃ films were fabricated on rolling-assisted biaxially textured substrates (RABiTS) with appropriate engineering of heteroepitaxially grown buffer multilayers on RABiTS. The crystallographic orientation and polarization direction were confirmed using X-ray diffraction and piezoresponse force microscopy (PFM), respectively. All the films exhibited excellent piezoelectric properties. Switching spectroscopy PFM demonstrated that the switching polarization in (111)-oriented polycrystalline BiFeO₃ films is higher than that in (101)- or (001)-oriented films. These BiFeO₃ films on low-cost, flexible, biaxially textured metallic tapes with controllable orientation and polarization are attractive for application in flexible piezoelectric devices.