The present invention relates to ferrite particles for bonded magnets and a resin composition for bonded magnets which can provide a bonded magnet molded product capable of realizing a high magnetic force and a complicated multipolar waveform owing to such a feature that the ferrite particles are readily and highly oriented against an external magnetic field in a flowing resin upon injection molding, as well as a bonded magnet molded product obtained by injection-molding the above composition. According to the present invention, there are provided ferrite particles for bonded magnets which have a crystallite size of not less than 500 nm as measured in an oriented state by XRD, and an average particle diameter of not less than 1.30 μm as measured by Fisher method; a resin composition for bonded magnets; and a molded product obtained by injection-molding the composition.

According to the present invention, there are provided ferrite particles for bonded magnets and a resin composition for bonded magnets which are capable of producing a bonded magnet molded product having a good tensile elongation and exhibiting excellent magnetic properties, as well as a bonded magnet molded product such as a rotor which is obtained by using the resin composition. The present invention relates to ferrite particles for bonded magnets having a bulk density of not less than 0.5 g/cm.sup.3 and less than 0.6 g/cm.sup.3 and a degree of compaction of not less than 65%, a resin composition for bonded magnets using the ferrite particles, and a molded product obtained by using the ferrite particles and the resin composition.

The present invention relates to a method of producing permanent magnets free of rare-earth metals. Specifically the type of magnets produced by the present invention are rare-earth free magnets based on iron. More specifically, the magnets of the present invention are of the class hexaferrites. The present invention further relates to magnets produced by the method of the invention, which are highly aligned magnets with improved magnetic properties compared to commercially available analogues.

The present invention relates to a method of producing permanent magnets free of rare-earth metals. Specifically the type of magnets produced by the present invention are rare-earth free magnets based on iron. More specifically, the magnets of the present invention are of the class hexaferrites. The present invention further relates to magnets produced by the method of the invention, which are highly aligned magnets with improved magnetic properties compared to commercially available analogues.

[Solving Means] A method of producing a magnetic powder includes: coating a surface of each of silica-coated precursor particles with at least one type of coating agent of a metal chloride or a sulfate; and firing the precursor particles coated with the coating agent.

[Solving Means] A method of producing a magnetic powder includes: coating a surface of each of silica-coated precursor particles with at least one type of coating agent of a metal chloride or a sulfate; and firing the precursor particles coated with the coating agent.

A cobalt ferrite magnetic powder includes magnetic particles that have a uniaxial crystal magnetic anisotropy and contain cobalt ferrite. A peak top 2θ of a (3, 1, 1) plane determined by powder X-ray diffractometry using a CoKα ray is 41.3° or more and 41.5° or less. Some Cos contained in the magnetic particles are substituted with at least one selected from the group consisting of Zn, Ge, and a transition metal element other than Fe.

Disclosed are a particle of a 13-iron oxyhydroxide-based compound represented by Formula (1), in which an average equivalent circle diameter of primary particles is 5 nm to 30 nm, and a coefficient of variation of equivalent circle diameters of the primary particles is 10% to 30% [In Formula (1), A represents at least one kind of metal element other than Fe, and a represents a number that satisfies a relationship of 0≤a<1.], and applications thereof.
β-A.sub.aFe.sub.1-aOOH   (1)

Disclosed are a particle of a 13-iron oxyhydroxide-based compound represented by Formula (1), in which an average equivalent circle diameter of primary particles is 5 nm to 30 nm, and a coefficient of variation of equivalent circle diameters of the primary particles is 10% to 30% [In Formula (1), A represents at least one kind of metal element other than Fe, and a represents a number that satisfies a relationship of 0≤a<1.], and applications thereof.
β-A.sub.aFe.sub.1-aOOH   (1)

Provided is a powder of a β-iron oxyhydroxide-based compound that is a group of particles of a β-iron oxyhydroxide-based compound represented by Formula (1) below; in which a surface of the particles of the β-iron oxyhydroxide-based compound is modified with a surface modifier; in which, in a case where the powder is dispersed in water to be made into a sol, a zeta potential of the powder is equal to or higher than +5 mV at pH 10; and
β-A.sub.aFe.sub.1-aOOH  (1)
in which, in Formula (1), A represents at least one metallic element other than Fe, and a represents a number that satisfies a relationship of 0≤a<1.