Abstract: An R-T-B based permanent magnet in which R is a rare earth element, T is Fe and Co, and B is boron. R at least includes Dy. The R-T-B based permanent magnet includes M, and M is at least one or more elements selected from the group consisting of Cu, Ga, Al, Mn, Zr, Ti, Cr, Ni, Nb, Ag, Hf, Ta, W, Si, Bi, and Sn. M at least includes Cu. A total content of R is 28.0 mass % to 30.2 mass %, a content of Dy is 1.0 mass % to 6.5 mass %, a content of Cu is 0.04 mass % to 0.50 mass %, a content of Co is 0.5 mass % to 3.0 mass %, and a content of B is 0.85 mass % to 0.95 mass %.

Abstract: An A R-T-B based permanent magnet, wherein R is a rare earth element, T is Fe and Co, and B is boron. R at least includes Dy and Tb. The R-T-B based permanent magnet includes M, and M is one or more elements selected from the group made of Cu, Ga, Al, Mn, Zr, Ti, Cr, Ni, Nb, Ag, Hf, Ta, W, Si, Bi, and Sn. M at least includes Cu. A total content of R is 28.05 mass % to 30.60 mass %, a content of Dy is 1.0 mass % to 6.5 mass %, a content of Cu is 0.04 mass % to 0.50 mass %, a content of Co is 0.5 mass % to 3.0 mass %, and a content of B is 0.85 mass % to 0.95 mass %. A concentration distribution of Tb decreases from an outer side towards an inner side of the R-T-B based permanent magnet.

Abstract: An R-T-B based permanent magnet in which R is a rare earth element, T is Fe and Co, and B is boron. R at least includes Dy. The R-T-B based permanent magnet includes M, and M is at least one or more elements selected from the group consisting of Cu, Ga, Al, Mn, Zr, Ti, Cr, Ni, Nb, Ag, Hf, Ta, W, Si, Bi, and Sn. M at least includes Cu. A total content of R is 28.0 mass % to 30.2 mass %, a content of Dy is 1.0 mass % to 6.5 mass %, a content of Cu is 0.04 mass % to 0.50 mass %, a content of Co is 0.5 mass % to 3.0 mass %, and a content of B is 0.85 mass % to 0.95 mass %.

Abstract: An A R-T-B based permanent magnet, wherein R is a rare earth element, T is Fe and Co, and B is boron. R at least includes Dy and Tb. The R-T-B based permanent magnet includes M, and M is one or more elements selected from the group made of Cu, Ga, Al, Mn, Zr, Ti, Cr, Ni, Nb, Ag, Hf, Ta, W, Si, Bi, and Sn. M at least includes Cu. A total content of R is 28.05 mass % to 30.60 mass %, a content of Dy is 1.0 mass % to 6.5 mass %, a content of Cu is 0.04 mass % to 0.50 mass %, a content of Co is 0.5 mass % to 3.0 mass %, and a content of B is 0.85 mass % to 0.95 mass %. A concentration distribution of Tb decreases from an outer side towards an inner side of the R-T-B based permanent magnet.

Abstract: The objects of the present invention are to provide a magnetic field molding device capable of improving yield in a production and stabilizing product quality, and a method for producing a ferrite magnet. In molding in a magnetic field, the mortar-shaped die 19 provided with a plurality of the cavities 13 is heated by the heater member 20, provided in the heater block located under the mortar-shape die 19, under control of a controller at varying temperature depending on the position of the mortar-shape die 19, to keep uniform temperature of the slurry in the cavities 13. This assures good and stable slurry dehydration properties and improves product yield.

Abstract: A method of synthesizing fine particles includes creating a subcritical or supercritical reaction environment by application of at least one of heat and pressure with a mixed medium of water and a solvent of lower critical temperature and lower critical pressure than water, so that the mixed medium comes into a supercritical state at a lower temperature and a lower pressure than those in a case of water alone; and leaving source materials under the created reaction environment as a reaction field for a predetermined time to produce fine particles.

Abstract: The objects of the present invention are to provide a magnetic field molding device capable of improving yield in a production and stabilizing product quality, and a method for producing a ferrite magnet. In molding in a magnetic field, the mortar-shaped die 19 provided with a plurality of the cavities 13 is heated by the heater member 20, provided in the heater block located under the mortar-shape die 19, under control of a controller at varying temperature depending on the position of the mortar-shape die 19, to keep uniform temperature of the slurry in the cavities 13. This assures good and stable slurry dehydration properties and improves product yield.

Abstract: There is provided a method for producing a La—Co based ferrite magnet by using a polyhydric alcohol as a dispersant, the method capable of suppressing the composition deviation.

Abstract: The objects of the present invention are to provide a magnetic field molding device, and method for producing a ferrite magnet, or the like, capable of improving yield in a production line and stabilizing product quality, and method for producing a ferrite magnet. In molding in a magnetic field, the mortar-shaped die 19 provided with a plurality of the cavities 13 is heated by the heater member 20 at a given temperature level, under the control of the controller 23. The temperature level is preferably controlled by the controller 23 at 40° C. or higher as mortar-shaped die 19 temperature T1, sensed by the sensor 22. A molding slurry can be kept at a high temperature level in the cavities 13 by heating the mortar-shaped die 19, and can have high dehydration properties and improve product yield.

Abstract: An oxide magnetic material is prepared by wet molding in a magnetic field a slurry containing a particulate oxide magnetic material, water and a polyhydric alcohol having the formula: Cn(OH)nHn+2 wherein n is from 4 to 100 as a dispersant. By improving the orientation in a magnetic field upon wet molding using water, an oxide magnetic material having a high degree of orientation, typically an anisotropic ferrite magnet, is obtained at a high rate of productivity. The method is advantageous from the environmental and economical standpoints.

Abstract: An oxide magnetic material is prepared by wet molding in a magnetic field a slurry containing a particulate oxide magnetic material, water and a polyhydric alcohol having the formula: Cn(OH)nHn+2 wherein n is from 4 to 100 as a dispersant. By improving the orientation in a magnetic field upon wet molding using water, an oxide magnetic material having a high degree of orientation, typically an anisotropic ferrite magnet, is obtained at a high rate of productivity. The method is advantageous from the environmental and economical standpoints.

Abstract: The present invention provides an oxide magnetic material, which includes a primary phase of a hexagonal ferrite containing metallic elements Ca, R, Fe and M, where M represents at least one element selected from the group including Co, Ni and Zn, and R represents at least one element selected from the group including Bi and rare earth elements including Y, with La being essentially included in R; wherein the proportions of the metallic elements Ca, R, Fe and M with respect to the total amount of the metallic elements are from 1 to 13 atomic % for Ca, from 0.05 to 10 atomic % for R, from 80 to 95 atomic % for Fe, and from 1 to 7 atomic % for M. The present invention also provides ferrite particles, a bonded magnet, a sintered magnet, a process for producing them, and a magnetic recording medium, which contain the oxide magnetic material.

Abstract: The magnetic powder and the sintered magnet of the invention contains a primary phase of a hexagonal ferrite containing A, Co or R wherein A represents Sr, Ba or Ca, and R represents at least one element which may be rare earth elements including Y, and Bi, and have at least two different Curie temperatures. wherein the two different Curie temperatures are present within a range of from 400 to 480° C., and an absolute value of a difference therebetween is 5° C. or more. As both the saturation magnetization and the magnetic anisotropy of the M type ferrite therein are increased, the magnetic powder and the wintered magnet have a high residual magnetic flux density and a high coercive force, which conventional M type ferrite magnets could not have, while having excellent temperature characteristics of coercive force.

Abstract: An object of the invention is to simultaneously increase the saturation magnetization and magnetic anisotropy of M type ferrite, thereby realizing a hexagonal ferrite magnet having a high remanence and high coercivity which could never be achieved in prior art M type hexagonal ferrite magnets. The object is attained by a hexagonal ferrite magnet comprising A, R, and Fe, wherein A represents at least one element selected from among Sr, Ba, and Ca, and R represents an element capable of assuming a valence of +3 or +4 and having an ionic radius of at least 1.00 angstrom, and n/N is up to 0.35 provided that N is the total number of crystal grains and n is the number of crystal grains having stacking faults.

Abstract: The magnetic powder and the sintered magnet of the invention contains a primary phase of a hexagonal ferrite containing A, Co or R wherein A represents Sr, Ba or Ca, and R represents at least one element which may be rare earth elements including Y, and Bi, and have at least two different Curie temperatures, wherein the two different Curie temperatures are present within a range of from 400 to 480.degree. C., and an absolute value of a difference therebetween is 5.degree. C. or more. As both the saturation magnetization and the magnetic anisotropy of the M type ferrite therein are increased, the magnetic powder and the wintered magnet have a high residual magnetic flux density and a high coercive force, which conventional M type ferrite magnets could not have, while having excellent temperature characteristics of coercive force.

Abstract: The method of the invention uses a molding slurry containing a particulate oxide magnetic material and water and having a dispersant added thereto. The dispersant is an organic compound having a hydroxyl group and a carboxyl group or a neutralized salt thereof or a lactone thereof, an organic compound having a hydroxymethylcarbonyl group, or an organic compound having an enol form hydroxyl group dissociable as an acid or a neutralized salt thereof. The organic compound has 3 to 20 carbon atoms, with the hydroxyl group being attached to at least 50% of carbon atoms other than the carbon atom forming a double bond with an oxygen atom. Citric acid or a neutralized salt thereof is also useful as the dispersant. The addition of the dispersant facilitates the wetting of the particulate oxide magnetic material with water and improves the dispersion of primary particles and a degree of orientation upon molding.