Flexible and self-standing inorganic-organic hybrid films of silica coated Fe3O4 nanoparticles and polyvinylidene fluoride (PVDF) polymer with significant magneto-dielectric coupling have been prepared at low temperature by a simple solvent casting method. PVDF films with two different concentrations of silica coated Fe3O4 (4.76 and 9.09 wt%) have been developed and well characterized using different techniques like XRD, TEM and IR. The thin film coating of silica on Fe3O4 could be detected by IR and TEM. The ferroelectric, magnetic and magneto-capacitive measurements at room temperature confirm the multiferroic nature of the composite films with significant magneto-electric coupling between Fe3O4 and PVDF.

Inorganic–organic multiferroic hybrid films of Fe3O4 and PVDF with significant magneto-dielectric coupling

Barium titanate (BaTiO3) nanowires have gained considerable research interest due to their lead-free composition and strong energy conversion efficiency. However, most research has focused on free-standing BaTiO3 nanowires, which are hard to apply for sensing and energy harvesting. Here, a novel method for the growth of vertically aligned BaTiO3 nanowire arrays on a conductive substrate is developed, and their electromechanical coupling behavior is directly evaluated to yield the strain coupling coefficient. The preparation of vertically aligned BaTiO3 nanowire arrays is based on a two-step hydrothermal reaction by first growing oriented rutile TiO2 nanowire arrays and then converting them to BaTiO3 while simultaneously retaining their morphology. A refined piezoelectric force microscopy (PFM) testing method is applied to demonstrate the piezoelectric behavior of BaTiO3 nanowires in the longitude direction. The piezoelectric response (d33 = 43 ± 2 pm/V) of the BaTiO3 nanowires is measured to demonstrate t...

Vertically Aligned Arrays of BaTiO3 Nanowires

Multiferroic materials exhibiting magnetism and ferroelectricity are promising multifunctional materials, especially for spin electronic applications. The magnetoelectric effect was observed in man...

White-Light-Controlled Magnetic and Ferroelectric Properties in Multiferroic BiFeO3 Square Nanosheets

Wave propagation characteristics in magneto-electro-elastic nanoshells using nonlocal strain gradient theory

A facile surface hydroxylation treatment to modify the surface of nickel nanoparticles dispersed in ferroelectric polyvinylidene fluoride (PVDF) is reported. A remarkable increase in the amount of polar β phase of PVDF has been observed upon dispersion of nickel nanoparticles in the PVDF matrix. The leakage current reduces drastically in the composite with surface-modified nickel nanoparticles. This improvement has been observed with concurrent enhancement of electrical polarization in the surface-modified nickel–PVDF composite. However, the magnetic moment of the modified composite is found to be slightly lower than that of the unmodified composite. Most importantly, the composite with surface-modified nickel exhibits magnetodielectric coupling significantly higher than that of the unmodified composite. The magnetodielectric coupling appears to be facilitated by surface hydroxyl groups on nickel. These results establish the potential of facile surface functionlization of nanoparticles toward the design o...

Improvement of Magnetodielectric Coupling by Surface Functionalization of Nickel Nanoparticles in Ni and Polyvinylidene Fluoride Nanohybrids

The development of methods to economically synthesize single wire structured multiferroic systems with room temperature spin–charge coupling is expected to be important for building next-generation multifunctional devices with ultralow power consumption. We demonstrate the fabrication of a single nanowire multiferroic system, a new geometry, exhibiting room temperature magnetodielectric coupling. A coaxial nanotube/nanowire heterostructure of barium titanate (BaTiO3, BTO) and cobalt (Co) has been synthesized using a template-assisted method. Room temperature ferromagnetism and ferroelectricity were exhibited by this coaxial system, indicating the coexistence of more than one ferroic interaction in this composite system.

Xaiobo Zhan

Papers

Hybrid Multiferroic Nanostructure with Magnetic−Dielectric Coupling