Direct fabrication of single-phase multiferroic BiFe0.95Co0.05O3 films on polyimide substrates for flexible memory

Abstract

• Low-temperature prepared BiFe 0.95 Co 0.05 O 3 films exhibited excellent characteristics. • A solution-based seeded photocatalytic precursor method has been developed. • The physical mechanism of the low-temperature prepared films is explained. Multiferroic memory exhibits unusual physical properties due to the electrical writing and magnetic reading of data to achieve low power consumption and efficient data processing. The flexibility of the multiferroic memory can realize its application in portable and wearable smart electronic products. The main challenge of integrating multiferroic oxides onto flexible substrates is to lower their processing temperature below the degradation temperature of plastic substrates. In this paper, the bendable inorganic BiFe 0.95 Co 0.05 O 3 polycrystalline thin films were prepared directly on flexible polyimide substrates with Pt electrode at only 350 ℃ by solution-based seeded photocatalytic precursor method. The flexible multiferroic element could bend safely to a small bending radius of 3 mm and exhibited excellent ferroelectricity, ferromagnetic, and magnetoelectric coupling characteristics at room temperature. Its remanent polarization was as high as 36 μC/cm 2 , remanent magnetization up to 4110 A/m, and magnetoelectric coupling coefficient up to 0.0135 V/A. The polarization did not deteriorate significantly during 10 3 bending-release cycles, 10 7 fatigue cycles, and 10 4 s data retention.These results prove the concept of integrating single-phase multiferroic thin films and flexible plastic substrates with low temperature by seeded photocatalytic precursor method and demonstrate the application potential of single-phase multiferroic films prepared at low temperature in the next generation of flexible multiferroic memory.