The disclosure is directed to wireless power systems that include a ferromagnetic core formed of nanocrystalline material disposed on a ferrite. The wireless power systems can have reduced saturation and/or lossiness.

A coil component includes an insulator part, a coil that is embedded in the insulator part and includes a plurality of coil conductor layers electrically connected together, and outer electrodes disposed on surfaces of the insulator part. The coil is electrically connected to the outer electrodes through extended portions. The extended portions each include a plurality of stacked land conductor layers that are electrically connected together through via conductors. Of the via conductors, adjacent via conductors in a stacking direction have centers that do not coincide when viewed in plan in the stacking direction.

A multilayer coil component includes a multilayer body formed by stacking a plurality of insulating layers on top of one another and that has a coil built thereinto, and a first outer electrode and a second outer electrode that are electrically connected to the coil. The coil is formed by electrically connecting a plurality of coil conductors to one another. A first main surface of the multilayer body is a mounting surface. A stacking direction of the multilayer body and an axial direction of the coil are parallel to the mounting surface. The insulating layers between the coil conductors are composed of a material containing at least one out of a magnetic material and a non-magnetic material. A content percentage of the non-magnetic material in the insulating layers changes in a direction from a first end surface toward a second end surface of the multilayer body.

Mn—Zn ferrite particles according to the present invention contain 44-60% by mass of Fe, 10-16% by mass of Mn and 1-11% by mass of Zn. The ferrite particles are single crystal bodies having an average particle diameter of 1-2,000 nm, and have polyhedral particle shapes, while having an average sphericity of 0.85 or more but less than 0.95.

Methods of forming spinel ferrite nanoparticles containing a chromium-substituted copper ferrite as well as properties (e.g. particle size, crystallite size, pore size, surface area) of these spinel ferrite nanoparticles are described. Methods of preventing or reducing microbe growth on a surface by applying these spinel ferrite nanoparticles onto the surface in the form of a suspension or an antimicrobial product are also described.

Methods of forming spinel ferrite nanoparticles containing a chromium-substituted copper ferrite as well as properties (e.g. particle size, crystallite size, pore size, surface area) of these spinel ferrite nanoparticles are described. Methods of preventing or reducing microbe growth on a surface by applying these spinel ferrite nanoparticles onto the surface in the form of a suspension or an antimicrobial product are also described.

Composite materials containing ferrite particles and ferromagnetic metallic particles are described for high capacity, low loss, high frequency inductor applications. The materials allow exceptional performance at frequencies from 10 kHz to above 500 MHz.

A magnetic particle includes a magnetic metal particle having a plurality of phases. The plurality of phases include an Fe-based phase and an Fe.sub.3O.sub.4 phase. An area ratio of the Fe.sub.3O.sub.4 phase in which the Fe.sub.3O.sub.4 phase occupies in the plurality of phases is less than 50%.

Disclosed are a ferrite green sheet comprising a pattern formed in a top surface of the ferrite green sheet, a sintered ferrite sheet, a ferrite composite sheet comprising the same, and a conductive loop antenna module. The pattern comprises a plurality of grooves, each groove has a width W and a rounded shape bottom having a radius of curvature of R, wherein a ratio of W to R (W:R) is in the range of 1:0.1 to 1:0.5.

Provided is a ferrite sintered magnet including: magnetoplumbite type ferrite crystal grains; and a two-grain boundary interposed between the ferrite crystal grains. The two-grain boundary contains Ca and La, and an atomic ratio Ca/La at the two-grain boundary is 0.3 to 3.0.