A Novel Spinel Ferrite-Hexagonal Ferrite Composite for Enhanced Magneto-Electric Coupling in a Bilayer with PZT.

The magnetoelectric effect (ME) is an important strain mediated-phenomenon in a ferromagnetic-piezoelectric composite for a variety of sensors and signal processing devices. A bias magnetic field, in general, is essential to realize a strong ME coupling in most composites. Magnetic phases with (i) high magnetostriction for strong piezomagnetic coupling and (ii) large anisotropy field that acts as a built-in bias field are preferred so that miniature, ME composite-based devices can operate without the need for an external magnetic field.

Electric field tuning of a nickel zinc ferrite resonator by non-linear magnetoelectric effects.

The nature of nonlinear magnetoelectric (NLME) effect has been investigated at room-temperature in a single-crystal Zn substituted nickel ferrite. Tuning of the frequency of magnetostatic surface wave (MSSW) modes under an applied pulsed DC electric field/current has been utilized to probe the effect. The frequencies of the modes at 8-20 GHz were found to decrease by ~ 400 MHz for an applied DC power P of ~ 100 mW and the frequency shift was the same for all of the MSSW modes and linearly proportional to P.

Highly piezoelectric, biodegradable, and flexible amino acid nanofibers for medical applications.

Amino acid crystals are an attractive piezoelectric material as they have an ultrahigh piezoelectric coefficient and have an appealing safety profile for medical implant applications. Unfortunately, solvent-cast films made from glycine crystals are brittle, quickly dissolve in body fluid, and lack crystal orientation control, reducing the overall piezoelectric effect. Here, we present a material processing strategy to create biodegradable, flexible, and piezoelectric nanofibers of glycine crystals embedded inside polycaprolactone (PCL).

Structure-property correlations and scaling in the magnetic and magnetocaloric properties of GdCrOparticles.

The structure, magnetic, and magnetocaloric (MC) properties of orthorhombic nanocrystalline GdCrOwith six particle sizes: ⟨⟩ = 87, 103, 145, 224, 318, and 352 nm are reported. The particle size was tailored by annealing under different temperatures and estimated by scanning electron microscopy. With increase in ⟨⟩, Goldschmidt tolerance factor, orthorhombic strain, and out-of-plane Cr-O-Cr bond angle first decrease, reaching minimum values for ⟨⟩ = 224 nm, and then increase for sample with ⟨⟩ = 318 nm and 352 nm, thus showing a V-shaped variation.

Graphene and Poly(3,4-ethylene dioxythiophene):Poly(4-styrenesulfonate) on Nonwoven Fabric as a Room Temperature Metal and Its Application as Dry Electrodes for Electrocardiography.

Highly conductive, metal-like poly(ethylene terephthalate) (PET) nonwoven fabric was prepared by coating poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) containing dimethyl sulfoxide (DMSO) onto PET nonwoven fabric previously coated with graphene/graphite. The sheet resistance of the original nonwoven fabric decreases from >80 MΩ□ to 1.1 Ω□ after coating with 10.

Switchable 3-0 magnetoelectric nanocomposite thin film with high coupling.

A mixed precursor solution method was used to deposit 3-0 nanocomposite thin films of PbZrTiO (PZT) and CoFeO (CFO). The piezoelectric behavior of PZT and magnetostrictive behavior of CFO allow for magnetoelectric (ME) coupling through strain transfer between the respective phases. High ME coupling is desired for many applications including memory devices, magnetic field sensors, and energy harvesters.

Hierarchically structured free-standing hydrogels with liquid crystalline domains and magnetic nanoparticles as dual physical cross-linkers.

Here we report a modular strategy for preparing physically cross-linked and mechanically robust free-standing hydrogels comprising unique thermotropic liquid crystalline (LC) domains and magnetic nanoparticles both of which serve as the physical cross-linkers resulting in hydrogels that can be used as magnetically responsive soft actuators. A series of amphiphilic LC pentablock copolymers of poly(acrylic acid) (PAA), poly(5-cholesteryloxypentyl methacrylate) (PC5MA), and poly(ethylene oxide) (PEO) blocks in the sequence of PAA-PC5MA-PEO-PC5MA-PAA were prepared using reversible addition-fragmentation chain transfer polymerization. These pentablock copolymers served as macromolecular ligands to template Fe(3)O(4) magnetic nanoparticles (MNPs), which were directly anchored to the polymer chains through the coordination bonds with the carboxyl groups of PAA blocks.

Recyclable and electrically conducting carbon nanotube composite films.

Carbon nanotube (CNT) composite films possess unique electrical, mechanical and thermal properties. In particular, some research has shown that CNT-polymer composite films greatly enhance the performance of organic light-emitting diodes. Therefore, CNT composite films have been intensively fabricated and applied.

Ultrathin epitaxial superconducting niobium nitride films grown by a chemical solution technique.

Ultrathin epitaxial superconducting NbN (18 nm) films, exhibiting a superconducting transition temperature of 14 K and a critical current density as high as 5.2 MA cm(-2) at 5 K under zero magnetic field, were grown on SrTiO(3) (STO) by a chemical solution technique, polymer assisted deposition (PAD).

Strong and ductile colossal carbon tubes with walls of rectangular macropores.

We report a new type of carbon material-porous colossal carbon tubes. Compared with carbon nanotubes, colossal carbon tubes have a much bigger size, with a diameter of between 40 and 100 mum and a length in the range of centimeters. Significantly, the walls of the colossal tubes are composed of macroscopic rectangular columnar pores and exhibit an ultralow density comparable to that of carbon nanofoams.