Complex oxide nanocrystals with a spinel structure show their remarkable optical, electronic, mechanical, thermal, and magnetic properties. In this study, we present a simple yet versatile strategy to grow selfassembled epitaxial CoFe2O4 nanocrystals with well-controlled size (less than 10 nm) and single orientation. CoFe2O4 nanocrystals were fabricated via phase separation in a BiFeO3–CoF2O4 u...

Highly textured BiFeO3(001) films were formed on L10-FePt(001) bottom electrodes on glass substrates by sputtering at reduced temperature of 400°C. Good electric polarization 2Pr = 80 and 95 μC/cm2, comparable to that of the reported epitaxial films, and coercivity Ec = 415 and 435 kV/cm are achieved in the samples with 20-nm- and 30-nm-thick electrodes. The BiFeO3(001) films show different deg...

We have determined the full magnetic dispersion relations of multiferroic BiFeO3. In particular, two excitation gaps originating from magnetic anisotropies have been clearly observed. The direct observation of the gaps enables us to accurately determine the Dzyaloshinskii-Moriya (DM) interaction and the single ion anisotropy. The DM interaction supports a sizable magnetoelectric coupling in thi...

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...

There is a growing activity in the search of novel single-phase multiferroics that could finally provide distinctive magnetoelectric responses at room temperature, for they would enable a range of potentially disruptive technologies, making use of the ability of controlling polarization with a magnetic field or magnetism with an electric one (for example, voltage-tunable spintronic devices, unc...

Multiferroic (MF) materials exhibit a highly coupled, spontaneous ferroelectric polarization and magnetization. Coupling between electrical and magnetic properties in multiferroic materials makes them a promising material for the design of multifunctional device applications, but also because of the interesting physics found in this class of materials. The role or absence of phonon softening in...

To date, electric fields have been widely used to control the magnetic properties of BiFeO3-based antiferromagnet/ferromagnet heterostructures through application of an exchange bias. To extend the applicability of exchange bias, however, an alternative mechanism to electric fields is required. Here, we report the photo-control of exchange bias in BiFeO3/La2/3Sr1/3MnO3 thin films on an SrTiO3 s...

Magnetic, dielectric and calorimetric studies on 0.9BiFeO3-0.1BaTiO3 indicate strong magnetoelectric coupling. XRD studies reveal a very remarkable change in the rhombohedral distortion angle and a significant shift in the atomic positions at the magnetic Tc due to an isostructural phase transition. The calculated polarization using Rietveld refined atomic positions scales linearly with magneti...

Two-dimensional (2D) magnets have broad application prospects in the spintronics, but how to effectively control them with a small electric field is still an issue. Here we propose that 2D can be efficiently controlled multiferroic heterostructure composed of magnetic material and perovskite oxide ferroelectric (POF) whose dielectric polarization easily flipped under field. We illustrate feasib...

Bismuth ferrite (BiFeO3) nanocomposites were synthesized using a novel nano-agitator bead milling method followed by calcination. oxide and iron nanoparticles mixed in stoichiometric ratio milled for 3 h calcined at 650 °C air. X-ray diffraction with Rietveld refinement, scanning electron microscopy, transmission microscopy techniques used to elucidate the structure of BiFeO3. The particle diam...