Bismuth ferrite (BiFeO3) thin films were prepared by a spin-coating method. Crystal structure and optical properties of the BiFeO3 films were evaluated using X-ray diffraction. The lattice constants, crystallite size, and energy gap of BiFeO3 films depended on the concentration of the BiFeO3 precursor solution. BiFeO3/CH3NH3PbI3 photovoltaic devices were fabricated to investigate photovoltaic p...

Bismuth ferrite, BiFeO3, is an important multiferroic material that has attracted remarkable attention for potential applications in functional devices. While thin films of BiFeO3 are attractive for applications in nanoelectronics, bulk polycrystalline BiFeO3 has great potential as a lead-free and/or high-temperature actuator material. However, the actuation mechanisms in bulk BiFeO3 are still ...

Ferroelectric domain structures of epitaxial BiFeO3 thin films on miscut 001 SrTiO3 substrates have been studied by transmission electron microscopy. BiFeO3 on 0.8° miscut substrates are composed of both 109° and 71° domains; in contrast, only 71° stripe domains are observed in BiFeO3 on 4° miscut 001 SrTiO3 substrates. The domain width in BiFeO3 on 4° miscut substrates increases as film thickn...

Voltage-modulated magnetism in magnetic/BiFeO3 heterostructures can be driven by a combination of the intrinsic ferroelectric-antiferromagnetic coupling in BiFeO3 and the antiferromagnetic-ferromagnetic exchange interaction across the heterointerface. However, ferroelectric BiFeO3 film is also ferroelastic, thus it is possible to generate voltage-induced strain in BiFeO3 that could be applied o...

BiFeO3 thin films have drawn much attention due to its potential applications for novel magnetoelectric devices and fundamental physics in magnetoelectric coupling. However, the structural evolution of BiFeO3 films with thickness remains controversial. Here we use an optical second-harmonic generation technique to explore the phase-related symmetry evolution of BiFeO3 thin films with the variat...

We explore BiFeO3 under tensile strain using first-principles calculations. We find that the actual structures are more complex than what had been previously thought, and that there is a strong shear deformation type structural instability which modifies the properties. Specifically, we find that normal tensile strain leads to structural instabilities with a large induced shear deformation in (...

BiFeO3 based MIM structures with Ti-implanted Pt bottom electrodes and Au top electrodes have been fabricated on Sapphire substrates. The resulting metal-insulator-metal (MIM) structures show bipolar resistive switching without an electroforming process. It is evidenced that during the BiFeO3 thin film growth Ti diffuses into the BiFeO3 layer. The diffused Ti effectively traps and releases oxyg...

A (001)-epitaxial-BiFeO3/CoFe2O4 bilayer was grown by self-assembly on SrTiO3 (100) substrates by just coating a mixture precursor solution. The thickness ratio of the bilayer could be controlled by adjusting the composition ratio. For example, a BiFeOx:CoFe2Ox = 4:1 (namely Bi4CoFe6Ox) mixture solution could make a total thickness of 110 nm divided into 85-nm-thick BiFeO3 and 25-nm-thick CoFe2...

Crystal and electronic structures of ~380 nm BiFeO3 film grown on LaAlO3 substrate are comprehensively studied using advanced transmission electron microscopy (TEM) technique combined with first-principles theory. Cross-sectional TEM images reveal the BiFeO3 film consists of two zones with different crystal structures. While zone II turns out to have rhombohedral BiFeO3, the crystal structure o...

Self-assembled epitaxial BiFeO3-MgO and BiFeO3-MgAl2O4 nanocomposite thin films were grown on SrTiO3 substrates by pulsed laser deposition. A two-phase columnar structure was observed for BiFeO3-MgO codeposition within a small window of growth parameters, in which the pillars consisted of a magnetic spinel phase (Mg,Fe)3O4 within a BiFeO3 matrix, similar to the growth of BiFeO3-MgFe2O4 nanocomp...