Composite Materials A composite material responsive to mechanical and/or electrical stress comprises at least one substantially non-conductive binder and at least a first electrically conductive filler. The conductivity of the composite material in an unstressed state is related to the conductivity of the at least one substantially non-conductive binder and in a stressed state to the conductivity resulting from the presence of the at least first electrically conductive filler in the composition. The first electrically conductive filler is comprised of magnetite particles in a particle size distribution, and the at least one binder may include an oil, a gel, a wax a gel-wax, gel-ink or mixtures thereof.

The present disclosure relates to a soft magnetic composite with a two-dimensional magnetic moment and a high working frequency band, and a preparation method therefor. According to an embodiment, the soft magnetic composite with a two-dimensional magnetic moment may comprise: an insulating matrix; and two-dimensional magnetic moment micropowder dispersed in the insulating matrix, wherein inside the two-dimensional magnetic moment micropowder, a magnetic moment is distributed in a specific two-dimensional plane. The soft magnetic composite with a two-dimensional magnetic moment of the present disclosure has a higher cut-off frequency than existing materials, and therefore can be widely applied in the field of high frequency microwave application

Described herein is a nanocrystalline ferrite having the formula Ni.sub.1-x-y M.sub.yCo.sub.xFe.sub.2+zO.sub.4, wherein M is at least one of Zn, Mg, Cu, or Mn, x is 0.01 to 0.8, y is 0.01 to 0.8, and z is −0.5 to 0.5, and wherein the nanocrystalline ferrite has an average grain size of 5 to 100 nm. A method of forming the nanocrystalline ferrite can comprise high energy ball milling.

A method and apparatus for automatically repairing structure cracks. The method may include mixing a filler material with ferromagnetic dust to create a filler material mixture. The method may also include storing each filler material mixture in a filler material reservoir. The method may also include creating an array of magnetic coils in the structure, where the array of magnetic coils creates a magnetic path through the structure. The apparatus may include a structure. The structure may include a plurality of filler material reservoirs, wherein each filler material reservoir stores a filler material mixture. The structure may also include an array of magnetic coils inside the structure.

The present application relates to compositions and methods of making flexible composite materials that are capable of moving, on a micro- or macro-scale, in response to an applied magnetic field and localized heat from a heat source. The present disclosure further provides systems and methods of using the flexible composite material as an actuator for performing a mode of actuation. In one embodiment, the flexible composite material forms a wireless actuator that, when irradiated with light, is capable of micro- and macro-scale motion acting through the interplay of optically absorptive elements and low-Curie temperature magnetic particles.

Provided is a thermoplastic resin composition, including (a) 100 parts by weight of a thermoplastic resin including 80-100% by weight of a base resin and 0-20% by weight of a reinforcing resin; (b) 2-60 parts by weight of linear carbon fibers having an average diameter of 1-15 μm; (c) 1-5 parts by weight of carbon nanofibrils having a BET specific surface area of 200-400 m.sup.2/g; (d) 1-15 parts by weight of carbon nanoplates; and (e) 1-25 parts by weight of metal powder, a method of preparing the thermoplastic resin composition, and an injection-molded article manufactured using the thermoplastic resin composition. The thermoplastic resin composition has excellent mechanical properties, e.g., impact strength, and also excellent conductivity, heat resistance, and electromagnetic wave shielding capacity, particularly high shielding efficiency against high-frequency electromagnetic waves, and thus can be used as automobile, electric, and electronic parts, and as a substitute for aluminum alloys and magnesium alloys.

In an aspect, a Co.sub.2Z ferrite has the formula: (Ba.sub.1−xSr.sub.x).sub.3Co.sub.2+yM.sub.yFe.sub.24−2y−zO.sub.41. M is at least one of Mo, Ir, or Ru. The variable x can be 0 to 0.8, or 0.1 to 0.8. The variable y can be 0 to 0.8, or 0.01 to 0.8. The variable z can be −2 to 2. The Co.sub.2Z ferrite can have an average grain size of 5 to 100 nanometers, or 30 to 80, or 10 to 40 nanometers as measured using at least one of transmission electron microscopy, field emission scanning electron microscopy, or x-ray diffraction.

A magnetic powder is obtained by removing a dispersion medium from a magnetic fluid that includes magnetic particles, a dispersant and the dispersion medium. A magnetic powder composition includes the magnetic powder and a resin material, and a magnetic powder composition molded body is obtained therefrom. A method of producing a magnetic powder includes removing a dispersion medium from a magnetic fluid containing magnetic particles, a dispersant and the dispersion medium, and powdering a solid component obtained by removing the dispersion medium. A method of producing a magnetic powder composition and a method of producing a magnetic powder composition molded product are also provided.

The present invention provides a powdered ferrite having high dispersibility in a resin and high electromagnetic shielding characteristics. The powdered ferrite comprises platy ferrite particles having a spinel crystal structure. The powdered ferrite comprises at least 50 number % platy ferrite particles each having at least one protrusion on a surface of the particle, and the protrusion has a shape selected from the group consisting of a rectangular pyramid, a truncated rectangular pyramid, an elongated rectangular pyramid, and combinations thereof.

An object of the present invention is to provide ferrite particles having a high saturation magnetisation, and being excellent in the dispersibility in a resin, a solvent or a resin composition, a resin composition including the ferrite particles, and a resin film composed of the resin composition. The ferrite particles are a single crystalline body having an average particle size of 1 to 2000 nm, and Mn-based ferrite particles having a spherical shape, and have a saturation magnetisation of 45 to 95 Am.sup.2/kg. The resin composition includes the ferrite particles as a filler. The resin film is composed of the resin composition.