Magnetoelectric nanoparticles shape modulates their electrical output

Core-shell magnetoelectric nanoparticles (MENPs) have recently gained popularity thanks to their capability in inducing a local electric polarization upon an applied magnetic field and vice versa. This work estimates the magnetoelectrical behavior, in terms of magnetoelectric coupling coefficient (αME), via finite element analysis of MENPs with different shapes under either static (DC bias) and time-variant (AC bias) external magnetic fields. With this approach, the dependence of the magnetoelectrical performance on the MENPs geometrical features can be directly derived. Results show that MENPs with a more elongated morphology exhibits a superior αME if compared with spherical nanoparticles of similar volume, under both stimulation conditions analyzed. This response is due to the presence of a larger surface area at the interface between the magnetostrictive core and piezoelectric shell, and to the MENP geometrical orientation along the direction of the magnetic field. These findings pave a new way for the design of novel high-aspect ratio magnetic nanostructures with an improved magnetoelectric behaviour.

Relationship between the Synthesis Method and the Magnetoelectric Properties of Bismuth Sodium-Potassium Titanate/Nickel Cobalt Ferrite Lead-Free Composites

In this work, the influence of the synthesis methods of piezoelectric and magnetostrictive phases on the final properties of the Bi_0.5(Na_0.8K_0.2)_0.5TiO₃-Ni_0.5Co_0.5Fe₂O₄ composites was studied. Different routes were used to individually synthesize each phase, and the composites were prepared using different fractions for each phase. Composites were sintered, and the structural, microstructural, dielectric, and magnetoelectric properties were evaluated. According to the selected synthesis method employed for each phase, different particle sizes and reactivities of the individual phases were obtained. These differences determined the suitable sintering temperature for each set of composites and were responsible for the final properties. In fact, magnetoelectric properties were modulated by the combination of composition and synthesis routes.

Emerging Developments in the Use of Electrospun Fibers and Membranes for Protective Clothing Applications

There has been increased interest to develop protective fabrics and clothing for protecting the wearer from hazards such as chemical, biological, heat, UV, pollutants etc. Protective fabrics have been conventionally developed using a wide variety of techniques. However, these conventional protective fabrics lack breathability. For example, conventional protective fabrics offer good protection against water but have limited ability in removing the water vapor and moisture. Fibers and membranes fabricated using electrospinning have demonstrated tremendous potential to develop protective fabrics and clothing. These fabrics based on electrospun fibers and membranes have the potential to provide thermal comfort to the wearer and protect the wearer from wide variety of environmental hazards. This review highlights the emerging applications of electrospinning for developing such breathable and protective fabrics.

Engineering Ceramic Fiber Nanostructures Through Polymer-Mediated Electrospinning

Electrospinning is increasingly used as a simple and straightforward technique to fabricate one-dimensional fibers from both organic and inorganic materials. These one-dimensional fibers with controlled sizes possess some unique features such as large surface area to volume ratio, high porosity, and low density. Compared to other conventional materials, these features make them attractive for applications such as energy harvesting, energy storage, super-hydrophobic membranes, and sensors. This chapter provides an overview on the synthesis of inorganic fibers through polymer-mediated electrospinning. Some of the common techniques employed by many researchers, such as solgel combined with electrospinning, emulsion electrospinning, and electrospinning combined with solid–gas reaction, to fabricate metal oxide fibers are discussed. In addition, techniques to fabricate ceramic and metal oxide fibers having different morphologies and hierarchical structures are described. Recent applications of electrospun metal oxide fibers are finally highlighted with a focus on filtration, sensors, photocatalysis, and energy.

Development of magnetoelectric CoFe2O4 /poly(vinylidene fluoride) microspheres

Magnetoelectric microspheres based on piezoelectric poly(vinylidene fluoride) (PVDF) and magnetostrictive CoFe₂O₄ (CFO), a novel morphology for polymer-based ME materials, have been developed by an electrospray process.