Abstract: A sintered ferrite magnet having a basic composition represented by the general formula: A1?x?y+aCax+bRy+cFe2n?zCoz+dO19 (atomic ratio), wherein a, b, c and d represent the amounts of an A element, Ca, an R element and Co added in the pulverization step of an oxide magnet material, which are numerals meeting the conditions of 0.03?x?0.4, 0.1?y?0.6, 0?z?0.4, 4?n?10, x+y<1, 0.03?x+b?0.4, 0.1?y+c?0.6, 0.1?z+d?0.4, 0.50?[(1?x?y+a)/(1?y+a+b)]?0.97, 1.1?(y+c)/(z+d)?1.8, 1.0?(y+c)/x?20, and 0.1?x/(z+d)?1.2.

Abstract: An oxide magnetic material according to the present invention is represented by the formula: (1?x)CaO.(x/2)R2O3.(n?y/2)Fe2O3.yMO, where R is at least one element selected from the group consisting of La, Nd and Pr and always includes La, M is at least one element selected from the group consisting of Co, Zn, Ni and Mn and always includes Co, and the mole fractions x, y and n satisfy 0.4?x?0.6, 0.2?y?0.35, 4?n?6, and 1.4?x/y?2.5. The oxide magnetic material includes a ferrite having a hexagonal M-type magnetoplumbite structure as a main phase.

Abstract: An oxide magnetic material according to the present invention is represented by the formula: (1?x)CaO.(x/2)R2O3.(n?y/2)Fe2O3.yMO, where R is at least one element selected from the group consisting of La, Nd and Pr and always includes La, M is at least one element selected from the group consisting of Co, Zn, Ni and Mn and always includes Co, and the mole fractions x, y and n satisfy 0.4?x?0.6, 0.2?y?0.35, 4?n?6, and 1.4?x/y?2.5. The oxide magnetic material includes a ferrite having a hexagonal M-type magnetoplumbite structure as a main phase.

Abstract: A rare-earth sintered magnet includes 12.0 at % to 15.0 at % of rare-earth element(s), which is at least one element selected from the group consisting of Nd, Pr, Gd, Tb, Dy and Ho and at least 50% of which is Nd and/or Pr; 5.5 at % to 8.5 at % of boron (B); a predetermined percentage of additive metal A; and iron (Fe) and inevitably contained impurities as the balance. The predetermined percentage of additive metal A includes at least one of 0.005 at % to 0.30 at % of silver (Ag), 0.005 at % to 0.40 at % of nickel (Ni), and 0.005 at % to 0.20 at % of gold (Au).

Abstract: A method of making a material alloy for an R-T-Q based rare-earth magnet according to the present invention includes the steps of: preparing a melt of an R-T-Q based rare-earth alloy, where R is rare-earth elements, T is a transition metal element, Q is at least one element selected from the group consisting of B, C, N, Al, Si and P, and the rare-earth elements R include at least one element RL selected from the group consisting of Nd, Pr, Y, La, Ce, Pr, Sm, Eu, Gd, Er, Tm, Yb and Lu and at least one element RH selected from the group consisting of Dy, Tb and Ho; cooling the melt of the alloy to a temperature of 700° C. to 1,000° C. as first cooling process, thereby making a solidified alloy; maintaining the solidified alloy at a temperature within the range of 700° C. to 900° C. for 15 seconds to 600 seconds; and cooling the solidified alloy to a temperature of 400° C. or less as a second cooling process.

Abstract: An inventive method of making a rare-earth alloy powder is used to produce a rare-earth sintered magnet, whose main phase has a composition R2T14A (where R is one of the rare-earth elements including Y; T is Fe with or without a non-Fe transition metal; and A is boron with or without carbon).

Abstract: The objectives of the present invention are to provide a stable and simple method for producing a rare earth metal-based permanent magnet having on the surface thereof a corrosion-resistant film containing fine zinc particles dispersed therein, a corrosion-resistant rare earth metal-based permanent magnet produced by the method, a dip spin coating method being suitable for forming a coating film on thin type work pieces having various shapes, and a method for forming a coating film on a work piece.

Abstract: A method of making a magnetically anisotropic magnet powder according to the present invention includes the steps of preparing a master alloy by cooling a rare-earth-iron-boron based molten alloy and subjecting the master alloy to an HDDR process. The step of preparing the master alloy includes the step of forming a solidified alloy layer, including a plurality of R2Fe14B-type crystals (where R is at least one element selected from the group consisting of the rare-earth elements and yttrium) in which rare-earth-rich phases are dispersed, by cooling the molten alloy through contact with a cooling member.

Abstract: To avoid various problems caused by remnant magnetization and produce an anisotropic bonded magnet at a reduced cost, a method for producing an anisotropic bonded magnet by feeding a magnetic powder (such as an HDDR powder) into the cavity of a press machine and compacting it is provided. A weak magnetic field is created as a static magnetic field in a space including the cavity by using a magnetic member that is steadily magnetized. The magnetic powder being transported into the cavity is aligned parallel to the direction of the weak magnetic field. Next, the magnetic powder is compressed in the cavity, thereby obtaining a compact.

Abstract: There is provided a magnetic field generator for MRI 10 applicable to a variety of magnetic field generators, and capable of preventing separation of permanent magnets 20 which constitute permanent magnet groups 14a, 14b. The magnetic field generator for MRI 10 includes a pair of permanent magnet groups 14a, 14b. The pair of permanent magnet groups 14a, 14b each including a plurality of permanent magnets 20 bonded to each other, are opposed to each other with a space in between. The permanent magnet groups 14a, 14b have projections 18 projecting more outward than the area of contact with respective pole pieces 16a, 16b. A flange-shaped member 34 is attached to each outer circumferential surface of the pole pieces 16a, 16b, covering a space-facing surface 18a of the projection 18.

Abstract: An anisotropic bonded magnet is produced at a low cost by avoiding various problems caused by remanence. Also, the unit weight and density of a compact is increased by filling even a cavity, having no easily feedable shape, with a magnet powder just as intended. An anisotropic bonded magnet is produced by feeding the cavity of a press machine with a magnetic powder (e.g., an HDDR powder) and compacting it. After the magnetic powder has been positioned outside of the cavity, an oscillating magnetic field (e.g., an alternating magnetic field) is created in a space including the cavity. The magnetic powder is transported into the cavity while being aligned parallel to the oscillating direction of the oscillating magnetic field. Thereafter, the magnetic powder is compressed within the cavity to make a compact for an anisotropic bonded magnet.

Abstract: The objectives of the present invention are to provide a stable and simple method for producing a rare earth metal-based permanent magnet having on the surface thereof a corrosion-resistant film containing fine zinc particles dispersed therein, a corrosion-resistant rare earth metal-based permanent magnet produced by the method, a dip spin coating method being suitable for forming a coating film on thin type work pieces having various shapes, and a method for forming a coating film on a work piece.

Abstract: The step of preparing a rapidly solidified alloy by rapidly quenching a melt of an R-T-B-C based rare-earth alloy (where R is at least one of the rare-earth elements including Y, T is a transition metal including iron as its main ingredient, B is boron, and C is carbon) and the step of thermally treating and crystallizing the rapidly solidified alloy are included. The step of thermally treating results in producing a first compound phase with an R2Fe14B type crystal structure and a second compound phase having a diffraction peak at a site with an interplanar spacing d of 0.295 nm to 0.300 nm (i.e., where 2?=30 degrees). An intensity ratio of the diffraction peak of the second compound phase to that of R2Fe14B type crystals representing a (410) plane is at least 10%. The present invention provides an R-T-B-C based rare-earth alloy magnetic material, including carbon (C) as an indispensable element but exhibiting excellent magnetic properties, and makes it possible to recycle rare-earth magnets.

Abstract: A press machine 10 includes a die 12 with a through hole 12a that defines a cavity, a first press surface 14a and a second press surface 16a for pressing a magnetic powder 18 loaded in the cavity, and magnetic field generating means for applying an aligning magnetic field to the magnetic powder 18 in the cavity. At least one of the first and second press surfaces 14a and 16a has a region made of a material having a Vickers hardness that is higher than 200 but equal to or lower than 450. In pressing the powder under the aligning magnetic field, the press machine 10 minimizes the disturbance in the orientation of the powder.

Abstract: [Problems] To provide a method for producing a rare earth metal-based permanent magnet having on the surface thereof a copper plating film by using a novel plating solution for use in a copper electroplating treatment capable of forming a copper plating film having excellent adhesiveness on the surface of a rare earth metal-based permanent magnet. [Means for Resolution] The method for producing a rare earth metal-based permanent magnet having a copper plating film on the surface thereof according to the invention is characterized in that it comprises forming a copper plating film on the surface of a rare earth metal-based permanent magnet by means of a copper electroplating treatment by using a plating solution having its pH adjusted to a range from 9.0 to 11.5 and containing at least the following three components: (1) Cu2+ ions, (2) a chelating agent having a chelate stability constant of 10.0 or higher for Cu2+ ions, and (3) a chelating agent having a chelate stability constant of 16.

Abstract: An iron-based rare earth alloy magnet has a composition represented by the general formula: (Fe1-mTm)100-x-y-zQxRyMz, where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; R is at least one rare earth element substantially excluding La and Ce; and M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti. In this formula, the mole fractions x, y, z and m meet the inequalities of: 10 at %<x?20 at %; 6 at %?y<10 at %; 0.1 at %?z?12 at %; and 0?m?0.5, respectively.

Abstract: An anisotropic thin-film rare-earth permanent magnet endowed with high magnetic characteristics by rendering a vapor-phase-grown thin film anisotropic in the layering direction. The atomic laminate units are formed by laminating a monoatomic layer of a rare earth element on a substrate of a non-magnetic material having, a flat smoothness and then by laminating an atomic laminate of a transition metal element having a plurality of monoatomic layers of a transition metal element, so that the atomic laminate units of a characteristic construction are laminated in a plurality of layers. As a result, each atomic laminate of the transition metal element has an easy magnetizable axis in the laminate direction of the monoatomic layers and which are sandwiched between a monoatomic layer of a rare-earth element so that an inverse magnetic domain is suppressed to establish a strong coercive force.

Abstract: An R—Fe—B based thin film magnet including an R—Fe—B based alloy which contains 28 to 45 percent by mass of R element (where R represents at least one type of rare-earth lanthanide elements) and which is physically formed into a film, wherein the R—Fe—B based alloy has a composite texture composed of R2Fe14B crystals having a crystal grain diameter of 0.5 to 30 ?m and R-element-rich grain boundary phases present at boundaries between the crystals. The magnetization characteristics of the thin film magnet are improved. The R—Fe—B based thin film magnet can be prepared by heating to 700° C. to 1,200° C. during physical film formation or/and the following heat treatment, so as to grow crystal grains and form R-element-rich grain boundary phases.

Abstract: A nanocomposite magnet has a composition represented by (Fe1-mTm)100-x-y-z-nQxRyTizMn, where T is at least one of Co and Ni, Q is at least one of B and C, R is at least one rare earth element that always includes at least one of Nd and Pr and optionally includes Dy and/or Tb, and M is at least one element selected from the group consisting of Al, Si, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb. The mole fractions x, y, z, m and n satisfy 10 at %<x?20 at %, 6 at %?y<10 at %, 0.5 at %?z?12 at %, 0?m?0.5 and 0 at %?n?10 at %, respectively. The nanocomposite magnet has an oxygen content of at most about 1,500 ppm by mass.