H01F1/113

Ferrite sintered magnet, ferrite particles, bonded magnet, motor, and generator

Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R.sub.1-xA.sub.xFe.sub.m-yCo.sub.y, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B.sub.2O.sub.3.
0.2≤x≤0.8  (1)
0.1≤y≤0.65  (2)
3≤m<14  (3)

Ferrite sintered magnet, ferrite particles, bonded magnet, motor, and generator

Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R.sub.1-xA.sub.xFe.sub.m-yCo.sub.y, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B.sub.2O.sub.3.
0.2≤x≤0.8  (1)
0.1≤y≤0.65  (2)
3≤m<14  (3)

MAGNETIC POWDER FOR RADIO WAVE ABSORBER AND MANUFACTURING METHOD THEREFOR, RADIO WAVE ABSORBER, RADIO WAVE ABSORBING ARTICLE, AND RADIO WAVE ABSORBING COMPOSITION
20230360828 · 2023-11-09 · ·

The magnetic powder for a radio wave absorber is a powder of a hexagonal ferrite having a composition represented by Formula 1, a region B is present on the particle surface of the powder, and Expression 2: 0.3≤content of A atom in region B/content of Al atom in region B≤23.0 and Expression 3: 1.2≤total of content of A atom and content of Al atom in region B/total of content of A atom and content of Al atom in entire powder≤2.5 are satisfied. The region B is a region that is observed as a bright region having a long side diameter of 0.1 μm to 0.6 μm in an image subjected to binarization processing. A represents one or more kinds of atoms (A atom) selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 0.10≤x≤5.00.


AFe.sub.(12-x)Al.sub.xO.sub.19  (Formula 1)

Rare earth magnet precursor or rare earth magnet molded body having roughened structure on surface and method for manufacturing same

Provided are a rare earth magnet precursor having a roughened structure on a surface or a rare earth magnet molded body having a roughened structure on a surface, and a method for manufacturing the same. In the rare earth magnet precursor or the rare earth magnet molded body, recesses and protrusions are formed on the surface having the roughened structure, and the recesses and protrusions satisfy at least one of the following (a) to (c): (a) an arithmetic mean height (Sa) (ISO 25178) from 5 to 300 μm, (b) a maximum height (Sz) (ISO 25178) from 50 to 1500 μm, and (c) a developed interfacial area ratio (Sdr) (ISO 25178) from 0.3 to 12.

Ferrite particles for bonded magnets, resin composition for bonded magnets, and molded product using the same

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.

Ferrite particles for bonded magnets, resin composition for bonded magnets, and molded product using the same

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.

Ferrite particles for bonded magnets, resin composition for bonded magnets, and molded product using the same

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.

(CO)POLYMER MATRIX COMPOSITES COMPRISING THERMALLY-CONDUCTIVE PARTICLES AND MAGNETIC PARTICLES AND METHODS OF MAKING THE SAME

(Co)polymer matrix composites including a porous (co)polymeric network; a multiplicity of thermally-conductive particles and a multiplicity of magnetic particles distributed within the (co)polymeric network structure; wherein the thermally-conductive particles, magnetic particles and optional magnetic particles are present in a range from 15 to 99 weight percent, based on the total weight of the particles and the (co)polymer (excluding the solvent). Methods of making and using the (co)polymer matrix composites are also disclosed. The (co)polymer matrix composites are useful, for example, as heat dissipating or heat absorbing thermal interface materials that also provide magnetic properties useful, for example, in flux field directional materials or shielding from electromagnetic interference.

Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

The magnetic tape includes a non-magnetic support; and a magnetic layer, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference L.sub.99.9−L.sub.0.1 between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 or more and 0.40 or less.

Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

The magnetic tape includes a non-magnetic support; and a magnetic layer, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference L.sub.99.9−L.sub.0.1 between a value L.sub.99.9 of a cumulative distribution function of 99.9% and a value L.sub.0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 or more and 0.40 or less.