Abstract: According to one embodiment, a permanent magnet is provided with a sintered body having a composition represented by R(FepMqCurCo1-p-q-r)zOw (where, R is at least one element selected from rare-earth elements, M is at least one element selected from Ti, Zr and Hf, and p, q, r, z and w are numbers satisfying 0.25?p?0.6, 0.005?q?0.1, 0.01?r?0.1, 4?z?9 and 0.005?w?0.6 in terms of atomic ratio). The sintered body has therein aggregates of oxides containing the element R dispersed substantially uniformly.

Abstract: According to one embodiment, a control device detects a field current in a rotary electrical machine, estimates a rate of rotation of a rotor of the machine based on the detected current, obtains a field voltage in the machine based on a difference between the estimated rate of rotation and a target rate of rotation, and controls the switching of an inverter based on the field voltage such that the rate of rotation follows the target rate of rotation. A permanent magnet using the machine is an R—Co permanent magnet containing 25 to 40 at % iron. The control device performs field-weakening control by increasing and decreasing the field voltage based on a negative-field current in accordance with the rate of rotation by a material of the permanent magnet.

Abstract: A high-performance permanent magnet is provided. The magnet is expressed by a composition formula: RpFeqMrCutCo100-p-q-r-t. The magnet includes a sintered body including: a plurality of crystal grains each having a Th2Zn17 crystal phase; and a plurality of grain boundaries between the crystal grains. If an oxide phase of the R element is defined by a continuous region that is disposed in the sintered body and contains the R element and oxygen having a concentration of 85 atomic percent or more, a ratio of the number of the oxide phases in the grain boundaries to the number of the crystal grains is 1.1 or less.

Abstract: According to embodiments, an electric machine includes a shaft, a rotor core, and a plurality of permanent magnets. The shaft rotates about an axis thereof. The rotor core is fixed to the shaft. The plurality of permanent magnets are provided in the rotor core, and include at least a first permanent magnet and a second permanent magnet. The first permanent magnet has an intrinsic coercive force of 1200 [kA/m] or more. The second permanent magnet has an intrinsic coercive force of 800 [kA/m] or more, a residual magnetization substantially the same as or larger than that of the first permanent magnet, and a recoil permeability smaller than that of the first permanent magnet.

Abstract: A permanent magnet is expressed by a composition formula: RpFeqMrCutCo100-p-q-r-t. The magnet includes: a crystal grain including a matrix; and a grain boundary phase. The matrix has cell phase having a Th2Zn17 crystal phase, a cell wall phase dividing the cell phase, and a plurality of Cu high-concentration phases. An area ratio of Cu high-concentration phases to the matrix is not less than 0.2% nor more than 5.0%. In a 3 ?m radius circle centered at a center of gravity of at least one of the Cu high-concentration phases, an average number of other Cu high-concentration phases is not less than 3 nor more than 15.

Abstract: An magnetic material is a magnetic material expressed by a composition formula 1: (R1-xYx)aMbTc, which includes a main phase consisting of a ThMn12 type crystal phase. 30 atomic percent or more of the element M in the composition formula 1 is Fe.

Abstract: An magnetic material is a magnetic material expressed by a composition formula: (R1-xYx)aMbTcAd, which includes a main phase consisting of a ThMn12 type crystal phase. 30 atomic percent or more of the element M in the composition formula is Fe.

Abstract: A high-performance permanent magnet is provided. A permanent magnet expressed by a composition formula: RpFeqMrCutCo100-p-q-r-t-. The magnet comprises a metal structure including a cell phase having a Th2Zn17 crystal phase, and a Cu-rich phase provided to divide the cell phase and having a Cu concentration higher than that of the Th2Zn17 crystal phase. An Fe concentration of the Th2Zn17 crystal phase is not less than 30 atomic % nor more than 45 atomic %. An average length of the Cu-rich phase is not less than 30 nm nor more than 250 nm.

Abstract: A high-performance permanent magnet is provided. A permanent magnet expressed by a composition formula: (R1-xAx)pFeqMrCutCo100-p-r-t. The magnet comprises a metal structure including a plurality of crystal grains which constitutes a main phase having a Th2Zn17 crystal phase, An Fe concentration of each of the crystal grains is 28 atomic % or more. A concentration difference of the element A among the crystal grains is not less than 0.2 atomic % nor more than 3.0 atomic %.

Abstract: According to one embodiment, a control device detects a field current in a rotary electrical machine, estimates a rate of rotation of a rotor of the machine based on the detected current, obtains a field voltage in the machine based on a difference between the estimated rate of rotation and a target rate of rotation, and controls the switching of an inverter based on the field voltage such that the rate of rotation follows the target rate of rotation. A permanent magnet using the machine is an R—Co permanent magnet containing 25 to 40 at % iron. The control device performs field-weakening control by increasing and decreasing the field voltage based on a negative-field current in accordance with the rate of rotation by a material of the permanent magnet.

Abstract: A permanent magnet of an embodiment includes: a composition represented by a composition formula: R(FepMqCurCo1-p-q-r)z, where R is at least one element selected from rare-earth elements, M is at least one element selected from Zr, Ti, and Hf, and relations of 0.3?p?0.4, 0.01?q?0.05, 0.01?r?0.1, and 7?z?8.5 (atomic ratio) are satisfied; and a structure including a cell phase having a Th2Zn17 crystal phase, and a cell wall phase existing to surround the cell phase. An average magnetization of the cell wall phase is 0.2 T or less.

Abstract: In an embodiment, a permanent magnet includes a composition represented by a composition formula: R(FepMqCur(Co1-sAs)1-p-q-r)z, where, R is at least one element selected from rare earth elements, M is at least one element selected from Ti, Zr, and Hf, A is at least one element selected from Ni, V, Cr, Mn, Al, Si, Ga, Nb, Ta, and W, 0.05?p?0.6, 0.005?q?0.1, 0.01?r?0.15, 0?s?0.2, and 4?z?9, and a two-phase structure of a Th2Zn17 crystal phase and a copper-rich phase. In a cross-section of the permanent magnet containing a crystal c axis of the Th2Zn17 crystal phase, an average distance between the copper-rich phases is 120 nm or less.

Abstract: In an embodiment, a magnet material includes a composition represented by R(FepMqCur(Co1-aAa)1-p-q-r)z, where R is at least one element selected from rare earth elements, M is at least one element selected from Ti, Zr and Hf, A is at least one element selected from Ni, V, Cr, Mn, Al, Si, Ga, Nb, Ta, and W, p is 0.05?p?0.6, q is 0.005?q?0.1, r is 0.01?r?0.15, a is 0?a?0.2, z is 4?z?9, and a structure including an intragranular phase having a Th2Zn17 crystal phase and a grain boundary phase. An average crystal grain diameter of the intragranular phase is in a range of 20 to 500 nm, and an average thickness of the grain boundary phase is smaller than a magnetic domain wall thickness.

Abstract: A permanent magnet of an embodiment includes a sintered compact, the sintered compact including: a composition expressed by RpFeqMrCusCo100-p-q-r-s, (R is at least one element selected from rare earth elements, M is at least one element selected from Zr, Ti, and Hf, 10.5?p?12.5 atomic %, 24?q?40 atomic %, 0.88?r?4.5 atomic %, and 3.5?s?10.7 atomic %); and a structure having crystal grains each composed of a main phase including a Th2Zn17 crystal phase, and a crystal grain boundary of the crystal grains. An average crystal grain diameter of the crystal grains is 50 ?m or more and 100 ?m or less, and a ratio of the crystal grains having a crystal grain diameter of 50 ?m or more is 75% or more.

Abstract: A permanent magnet is expressed by a composition formula: RpFeqMrCutCo100-p-q-r-t. The magnet comprises a metal structure including a main phase having a Th2Zn17 crystal phase and a grain boundary phase. The main phase includes a cell phase having the Th2Zn17 crystal phase and a Cu-rich phase. A section including a c-axis of the Th2Zn17 crystal phase has a first region in the crystal grain and a second region in the crystal grain, the first region is provided in the cell phase divided by the Cu-rich phase, the second region is provided within a range of not less than 50 nm nor more than 200 nm from the grain boundary phase in a direction perpendicular to an extension direction of the grain boundary phase, and a difference between a Cu concentration of the first region and a Cu concentration of the second region is 0.5 atomic percent or less.

Abstract: A permanent magnet expressed by a composition formula: RpFeqMrCutCo100-p-q-r-t. The magnet comprises: a metal structure including a main phase having a Th2Zn17 crystal phase and a grain boundary phase. The main phase includes a cell phase having the Th2Zn17 crystal phase, a Cu-rich phase having a Cu concentration higher than the cell phase, and a plurality of M-rich platelet phases extending in a direction intersecting with a c-axis of the Th2Zn17 crystal phase in a section including the c-axis and having a M element concentration higher than the cell phase. In the section, the cell phase has a 200 nm diameter or more, and a gap between the M-rich platelet phases is 80 nm or less.

Abstract: The magnet has a composition expressed by RpFeqMrCutCo100-p-q-r-t. The magnet has a metallic structure including a main phase having a Th2Zn17 crystal phase. The main phase has crystal grains. 5% or less of the crystal grains having a grain diameter equal to or smaller than 10 ?m, 40% or less of the crystal grains having crystal orientation perpendicular to (001) plane of the Th2Zn17 crystal phase in a direction deviated 30 degrees or more relative to an axis of easy magnetization.

Abstract: The embodiments provide a high-performance permanent magnet. The permanent magnet includes a sintered body having a composition expressed by a composition formula RpFeqMrCutCo100-p-q-r-t, with carbon in a range from 50 mass ppm to 1500 mass ppm. The sintered body also includes a metallic structure. The metallic structure includes a main phase having a Th2Zn17 crystal phase, and a secondary phase having a carbide phase of the M element of the composition formula. A ratio (I2/I1) of a maximum intensity I2 of a diffraction peak at an angle 2? in a range from 37.5 degrees to 38.5 degrees to a maximum intensity I1 of a diffraction peak at the angle 2? in a range from 32.5 degrees to 33.5 degrees is greater than 25 but no greater than 80 in an X-ray diffraction pattern obtained by applying an X-ray diffraction measuring method to the sintered body.

Abstract: A permanent magnet expressed by a composition formula: RpFeqMrCutCo100-p-q-r-t. The magnet comprises a metallic structure including crystal grains which constitutes a main phase having a Th2Zn17 crystal phase. An average value of Fe concentrations in the crystal grains of 20 or more is 28 atomic percent or more and an average value of R element concentrations in the crystal grains of 20 or more is 10 atomic percent or more.

Abstract: A method of manufacturing a permanent magnet comprises a solution heat treatment. The solution heat treatment includes: performing a heat treatment at a temperature TST; placing a cooling member including a first layer and a second layer on the first layer between the heater and the treatment object so that the first layer faces the treatment object; and transferring the treatment object together with the cooling member to the outside of a heating chamber, and cooling the treatment object until a temperature of the treatment object becomes a temperature lower than a temperature TST?200° C. In the step of cooling the treatment object, a cooling rate until the temperature of the treatment object becomes the temperature TST?200° C. is 5° C./s or more.