A probe element for separation and sensing of analytes of interest controlled by temperature is provided. The probe element includes at least one magnetic crystal and one or more types of capping agents. The capping agent can have stabilizing and or anchoring functions. The magnetic crystal produces a stable magnetic field at the temperature of interest for sensing or separation. The stable magnetic field can be controlled by temperature and the probe can be integrated in a sensing and or separation device and process.

Discrete, individualized carbon nanotubes having targeted, or selective, oxidation levels and/or content on the interior and exterior of the tube walls are claimed. Such carbon nanotubes can have little to no inner tube surface oxidation, or differing amounts and/or types of oxidation between the tubes' inner and outer surfaces. These new discrete carbon nanotubes are useful in electromagnetic and radio frequency shielding applications, especially where the shielding is essentially constant over a relatively wide range of frequencies. Additives such as plasticizers, can be used in compounding and formulation of elastomeric, thermoplastic and thermoset composite for improvement of mechanical, electrical and thermal properties.

Described embodiments include a system, method, and apparatus. The apparatus includes a magnetic substrate at least partially covered by a first negative-permittivity layer comprising a first plasmonic outer surface. The apparatus includes a plasmonic nanoparticle having a magnetic element at least partially covered by a second negative-permittivity layer comprising a second plasmonic outer surface. The apparatus includes a dielectric-filled gap between the first plasmonic outer surface and the second outer surface. The first plasmonic outer surface, the dielectric-filled gap, and the second plasmonic outer surface are configured to support one or more mutually coupled plasmonic excitations.

Provided are methods of producing cobalt nanoparticles (Co NPs). The methods include combining a cobalt salt, a capping agent, and a reducing agent, under Co NP synthesis conditions including a temperature selected to produce cobalt nanoparticles of a pre-selected diameter, where the temperature and pre-selected diameter are inversely related. In certain aspects, the methods further include producing hollow gold nano spheres (HGNs) using the cobalt nanoparticles as scaffolds. Also provided are cobalt nanoparticles and hollow gold nano spheres (HGNs) produced according to the present methods. Kits that find use in practicing the methods of the present disclosure are also provided.

Superparamagnetic nanocomposites are provided. In an embodiment, a superparamagnetic nanocomposite comprises a superparamagnetic core comprising a first, soft superparamagnetic ferrite and a superparamagnetic shell comprising a second, soft superparamagnetic ferrite, the shell formed over the core, wherein the first and second soft superparamagnetic ferrites are different compounds and have different magnetocrystalline anisotropies.

A method for fabricating a thermal composite includes pouring a mixture including a plurality of magnetically susceptible particles and a thermosetting polymer into a mold, placing the mold containing the mixture in a chamber including a plurality of magnet arrays, and heating the mold containing the mixture in the chamber for a time and at a temperature sufficient to cure the thermosetting polymer. At least one of the plurality of magnet arrays includes a Halbach array.

Disclosed herein are iron oxide nanoparticles prepared through high-temperature thermal decomposition of an Fe.sup.3+ precursor and an M.sup.+ or M.sup.2+ (M=Li, Na, K, Mg, and Ca) precursor in an oxygen atmosphere. The iron oxide nanoparticles are nanoparticles, in which an alkali metal or alkali earth metal is doped into an Fe vacancy site of -Fe.sub.2O.sub.3, and generate explosive heat even in a biocompatible low AC magnetic field. Through both in vitro and in vivo tests, it was proven that cancer cells could be killed by performing low-frequency hyperthermia using the iron oxide nanoparticles set forth above.

Systems for screening and health monitoring of materials are provided. The system can include a material embedded with magneto-electric nanoparticles (MENs), a laser configured to direct incident laser light waves at a target area of the material, an optical filter disposed between the laser and the material, and an analyzer configured to detect the laser light reflected from the material.

Disclosed herein is a permanent magnet comprising: a plurality of aligned iron nitride nanoparticles wherein the iron nitride nanoparticles include -Fe.sub.16N.sub.2 phase domains; wherein a ratio of integrated intensities of an -Fe.sub.16N.sub.2 (004) x-ray diffraction peak to an --Fe.sub.16N.sub.2 (202) x-ray diffraction peak for the aligned iron nitride nanoparticles is greater than at least 7%, wherein the diffraction vector is parallel to alignment direction, and wherein the iron nitride nanoparticles exhibit a squareness measured parallel to the alignment direction that is greater than a squareness measured perpendicular to the alignment direction.

A virtual adhesion method is provided. The virtual adhesion method includes increasing a magnetic characteristic of an initial structure, supporting the initial structure on a surface of a substrate, generating a magnetic field directed such that the initial structure is forced toward the surface of the substrate and forming an encapsulation, which is bound to exposed portions of the surface, around the initial structure.