Objects are to provide a ferrite powder having a residual magnetization and a coercive force larger than those of spherical hard ferrite particle, and magnetic permeability μ″ is maximum in a specific frequency range, a manufacturing method thereof, a resin compound containing the ferrite powder, and a molded product made from the resin compound. To achieve the objects, a hexagonal plate shaped ferrite powder containing 7.8 to 9 wt % of Sr, 61 to 65 wt % of Fe, and 0.1 to 0.65 wt % of Mg, a manufacturing method thereof, a resin compound containing the hexagonal plate shaped ferrite powder, and a molded product made from the resin compound are employed.

Two or more high permeability magnetodielectric slabs in combination with electrical coils wound on each slab form a compact antenna that radiates electromagnetic signals efficiently in the omnidirectional pattern.

The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nm.sup.3 or less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ε-iron oxide powder, and a ratio (PSD.sub.5μm-PSDmag/PSD.sub.10μm-PSDbc) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape.

An electromagnetic wave absorbing particle has a composition, which is represented by Formula 1 of Sr.sub.1-xR.sub.xFe.sub.y-2zM.sub.2zO.sub.a and contains M-type hexaferrite as a main phase. In Formula 1, R is one or more substances selected from among Ba, Ca, and La, M is one or more substances selected from among Co, Ti, and Zr, 0<x≤0.8, 8≤y≤14, 0<z≤1.5, and a is equal to 19.

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.

Two or more high permeability magnetodielectric slabs in combination with electrical coils wound on each slab form a compact antenna that radiates electromagnetic signals efficiently in the omnidirectional pattern.

A radio wave absorber including a magnetic powder and a binder, in which the magnetic powder is a powder of a hexagonal ferrite in which a ratio (σs/β) of a saturation magnetization as to a half-width β of a diffraction peak on a (107) plane is 240 emu.Math.g.sup.−1.Math.degree.sup.−1 or more, where the half-width β is determined by X-ray diffraction analysis.

A magnetic particle-containing composition contains magnetic particles having a plurality of peak tops in a particle size distribution curve showing a volume-based frequency distribution, a resin, and a solvent.

A grain-oriented M-type hexagonal ferrite has the formula MeFe.sub.12O.sub.19, and a dopant effective to provide planar magnetic anisotropy and magnetization in a c-plane, or a cone anisotropy, in the hexagonal crystallographic structure wherein Me is Sr.sup.+, Ba.sup.2+ or Pb.sup.2+, and wherein greater than 30%, preferably greater than 80%, of c-axes of the ferrite grains are aligned perpendicular to the c-plane.

In an aspect, a ferrite composition can comprise a SbCo—M-type ferrite having the formula: Me.sub.1-xSb.sub.xCo.sub.y+xM′.sub.yFe.sub.12-x-2yO.sub.19, wherein Me is at least one of Sr, Pb, or Ba; M′ is at least one of Ti, Zr, Ru, or Ir; x is 0.001 to 0.3; and y is 0.8 to 1.3. In another aspect, a method of making the ferrite composition comprises mixing ferrite precursor compounds comprising Me, Fe, Sb, Co, and M; and sintering the ferrite precursor compounds in an oxygen atmosphere to form the SbCo—M-type ferrite. In yet another aspect, a composite comprises the ferrite composition and a polymer. In still another aspect, an article comprises the ferrite composition.