A superconducting bulk magnet comprising a plurality of superconducting bulk materials combined, in which breakage of superconducting bulk materials is prevented and a strong magnetic field can be generated, that is, a superconducting bulk magnet comprising a plurality of superconducting bulk materials, each comprising a single-crystal formed RE.sub.1Ba.sub.2Cu.sub.3O.sub.y (RE is one or more elements selected from Y or rare earth elements, where 6.8≦y≦7.1) in which RE.sub.2BaCuO.sub.5 is dispersed and each provided with a top surface, a bottom surface, and side surfaces, combined together, in which superconducting bulk magnet, bulk material units, each comprising a superconducting bulk material and a bulk material reinforcing member arranged so as to cover a side surface of the same, are arranged facing the same direction and contacting each other to form an assembly, a side surface of the assembly is covered by an assembly side surface reinforcing member, a top surface and bottom surface of the assembly are respectively covered by an assembly top reinforcing member and an assembly bottom reinforcing member, and the assembly side surface reinforcing member, the assembly top reinforcing member, and the assembly bottom reinforcing member are joined into an integral unit, is provided.

A method of making a flexible magnetized sheet is provided. The method may comprise the steps of (1) using cold extrusion to produce a highly viscous fluid magnetizable sheet, (2) passing the sheet through a magnetic field to create an uncured magnetized sheet, and (3) curing the sheet with electron beam curing. The fluid mixture may comprise magnetizable particles with a random charge orientation and an acrylic resin. The components of the mixture are cool when passed through an extrusion die. The extruded fluid sheet allows for the sheet to be magnetized and then, instead of curing by cooling, cured by the bombardment of electrons via an electron beam (EB) generator. The method can eliminate the heat of extrusion and can allow for more freedom of orientation because the sheet does not cure until it reaches the electron beam curing station.

There is provided a radio wave absorber including a powder of a hexagonal ferrite; and a binder, in which the radio wave absorber has a squareness ratio in a range of 0.40 to 0.60.

There is provided a radio wave absorber including a powder of a hexagonal ferrite; and a binder, in which the radio wave absorber has a squareness ratio in a range of 0.40 to 0.60.

There is provided a radio wave absorber including a magnetic powder and a binder, in which a volume filling rate of the magnetic powder in the radio wave absorber is 35% by volume or less, a transmission attenuation amount is 8.0 dB or more, and a reflection attenuation amount is 8.0 dB or more.

A ferrite powder for bonded magnets capable of producing a ferrite bonded magnet having high BH.sub.max, and excellent in fluidity when converted to a compound, and having a high p-iHc value, and a method for producing the same, and a ferrite bonded magnet using the ferrite powder for bonded magnets, wherein an average particle size of particles obtained by a dry laser diffraction measurement is 5 μm or less; a specific surface area is 1.90 m.sup.2/g or more and less than 2.80 m.sup.2/g; a compression density is 3.50 g/cm.sup.3 or more and less than 3.78 g/cm.sup.3, and a compressed molding has a coercive force of 2300 Oe or more and less than 2800 Oe.

A ferrite powder for bonded magnets having a high iHc value usable even in a low temperature environment, a method for producing the same, and a bonded magnet using the ferrite powder and having high iHc value which can be used even in a low temperature environment, wherein a specific surface area is 2.20 m.sup.2/g or more and less than 3.20 m.sup.2/g; a compression density is 3.30 g/cm.sup.3 or more and less than 3.60 g/cm.sup.3, and a compressed molding has a coercive force of 3250 Oe or more and less than 3800 Oe.

A ferrite powder for bonded magnets having a high iHc value usable even in a low temperature environment, a method for producing the same, and a bonded magnet using the ferrite powder and having high iHc value which can be used even in a low temperature environment, wherein a specific surface area is 2.20 m.sup.2/g or more and less than 3.20 m.sup.2/g; a compression density is 3.30 g/cm.sup.3 or more and less than 3.60 g/cm.sup.3, and a compressed molding has a coercive force of 3250 Oe or more and less than 3800 Oe.

A production method for metal oxide particles includes: obtaining precursor particles of a metal oxide by performing a synthesis reaction of the precursor particles in the presence of an organic compound; and converting the obtained precursor particles into metal oxide particles by heating an aqueous solution containing the precursor particles to 300° C. or higher and pressurizing the aqueous solution at a pressure of 20 MPa or higher.

An e-type iron-based oxide magnetic particle powder has narrow particle size distribution and has a low content of fine particles which do not contribute to magnetic recording characteristics. As a result, a narrow coercive force distribution is achieved and the powder is suitable for increasing recording density of a magnetic recording medium. The powder containing substituting metal elements can be obtained by: adding an alkali to an aqueous solution containing trivalent iron ions and ions of the metals for partially substituting Fe sites to neutralize the aqueous solution to a pH of 1.5 to 2.5; then adding a hydroxycarboxylic acid; further adding the alkali to neutralize the aqueous solution to a pH of 8.0 to 9.0; washing with water a precipitation of an iron oxyhydroxide containing the substituting metal elements produced; and coating the iron oxyhydroxide containing the substituting metal elements with a silicon oxide and heating the resultant.