Rare earth magnets, multilayer magnets, and motors

Abstract

The present invention provides rare earth magnets, laminated magnets, and motors with good prismatic properties. [Solution] A rare earth magnet containing rare earth elements, wherein when the first plane, which is the orientation plane of the rare earth magnet, is measured by X-ray diffraction, the average shift amount of the position of the strongest peak, which is the peak with the highest intensity, is 0.50 degrees or less, and when each of the first interval positions, which include the position of the first plane and are separated from each other by 0.5 mm in the orientation direction from the first plane, is measured by X-ray diffraction, the difference between the maximum and minimum values ​​of the position of the strongest peak at each of the measured first interval positions is 0.20 degrees or less.

Description

Technical Field

[0001] The present invention relates to rare earth magnets, laminated magnets, and motors.

Background Art

[0002] Rare earth magnets containing rare earth elements may be arranged on the rotor constituting the motor. As such rare earth magnets, Patent Document 1 discloses a rare earth magnet provided with a resistance layer containing rare earth elements, iron, and oxygen on its surface. Further, Patent Document 2 discloses a rare earth magnet having a dividing layer formed to extend in a direction orthogonal to the orientation direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Each of the rare earth magnets disclosed in Patent Documents 1 and 2 aims to reduce eddy current loss by providing a resistance layer or a dividing layer. However, improvement in the rectangularity of the rare earth magnet itself excluding such a configuration has still been desired.

[0005] The present invention has been made to solve at least a part of the above - described problems, and an object thereof is to provide a rare earth magnet having good rectangularity.

Means for Solving the Problems

[0006] The present invention has been made to solve at least a part of the above - described problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a rare earth magnet is provided. This rare earth magnet is a rare earth magnet containing a rare earth element, wherein when the first plane, which is the orientation plane of the rare earth magnet, is measured by X-ray diffraction, the average shift amount of the position of the strongest peak, which is the peak with the highest intensity, is 0.50 degrees or less.

[0008] With this configuration, the average shift in the position of the strongest peak when the first plane is measured by X-ray diffraction is 0.50 degrees or less, resulting in relatively small distortion in the first plane. In this case, the occurrence of knick in the second quadrant of the hysteresis loop is suppressed, and therefore, this configuration makes it possible to provide a rare earth magnet with good prismatic properties.

[0009] (2) In the rare earth magnet according to the above embodiment, when each of the first interval positions, which include the position of the first surface and are separated from each other by 0.5 mm in the orientation direction from the first surface, is measured by X-ray diffraction, the difference between the maximum and minimum values ​​of the strongest peak positions at each of the measured first interval positions may be 0.20 degrees or less. With this configuration, the difference between the maximum and minimum values ​​of the strongest peaks at each of the first interval positions is 0.20 degrees or less, so the difference in strain at each of the first interval positions in the rare earth magnet is relatively small. Therefore, with this configuration, it is possible to provide a rare earth magnet with even better prismatic properties.

[0010] (3) In the rare earth magnet according to the above embodiment, when each of the second spacing positions, which include the position of the second surface which is perpendicular to the first surface and are separated from each other by 0.5 mm in a direction perpendicular to the orientation direction from the second surface, is measured by X-ray diffraction, the difference between the maximum and minimum values ​​of the strongest peak positions at each of the measured second spacing positions may be 0.20 degrees or less. With this configuration, the difference between the maximum and minimum values ​​of the strongest peaks at each of the second interval positions is 0.20 degrees or less, so the difference in strain at each of the second interval positions in the rare earth magnet is relatively small. Therefore, with this configuration, it is possible to provide a rare earth magnet with even better prismatic properties.

[0011] (4) According to another embodiment of the present invention, a laminated magnet is provided. This laminated magnet comprises any of the rare earth magnets described in (1) to (3) above and a plurality of insulating layers, wherein the rare earth magnets and the insulating layers are alternately laminated. Rare-earth magnets tend to have low eddy current losses. Furthermore, the insulating layer exhibits almost no change in resistance with temperature, thus reducing eddy current losses over a wide temperature range. Therefore, this configuration, with alternating layers of such rare-earth magnets and insulating layers, provides a laminated magnet capable of reducing eddy current losses in high-temperature environments.

[0012] (5) According to another embodiment of the present invention, a motor is provided, wherein any of the rare earth magnets described in (1) to (3) above is arranged on the rotor of this motor. This configuration allows for the placement of rare-earth magnets with good prismatic properties in the rotor, thus providing a motor with excellent rotational efficiency.

[0013] Furthermore, the present invention can be realized in various forms, for example, as a rare earth magnet, a laminated magnet, and a motor in which these are arranged on a rotor, or as a device equipped with any of the rare earth magnet, the laminated magnet, and the motor. [Brief explanation of the drawing]

[0014] [Figure 1] This is an explanatory diagram schematically showing a rare earth magnet according to the first embodiment. [Figure 2] This is an explanatory diagram of the first interval position. [Figure 3] This is an explanatory diagram of the second interval position. [Figure 4] This is an explanatory diagram showing the results of evaluation tests of rare earth magnets with various parameters. [Figure 5] This is a schematic explanatory diagram showing a stacked magnet as a second embodiment of the present invention. [Figure 6]It is a cross-sectional view of a motor as a third embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0015] <First Embodiment> FIG. 1 is an explanatory diagram schematically showing a rare earth magnet 1 as a first embodiment of the present invention. In FIG. 1, XYZ axes orthogonal to each other are shown. The rectangular parallelepiped-shaped rare earth magnet 1 shown in FIG. 1 is defined by a side Sx along the X-axis direction, a side Sy along the Y-axis direction, and a side Sz along the Z-axis direction. The orientation direction of the rare earth magnet 1 is the +X-axis direction. Among the six surfaces constituting the rare earth magnet 1, the surface defined by the side Sy and the side Sz and facing the +X-axis direction side is defined as the first surface S1. The first surface S1 can also be said to be an orientation surface facing the orientation direction. Further, among the six surfaces constituting the rare earth magnet 1, the surface defined by the side Sx and the side Sz and facing the side in the Y-axis direction (a direction orthogonal to the orientation direction) is defined as the second surface S2.

[0016] The rare earth magnet 1 contains a rare earth element. Examples of the rare earth element include one or more selected from the group consisting of neodymium (Nd), praseodymium (Pr), terbium (Tb), dysprosium (Dy), samarium (Sm), yttrium (Y), scandium (Sc), lanthanum (La), cerium (Ce), europium (Eu), gadolinium (Gd), holmium (Ho), ytterbium (Yb), and lutetium (Lu). Among these, as the rare earth element, it is preferable to contain one or more of Nd, Pr, Dy, and Tb, and more preferably to contain Nd as the main component. Note that containing Nd as the main component means that the content (mass %) of Nd is the largest among the rare earth elements. The rare earth magnet 1 may contain a transition metal element and boron in addition to the rare earth element. Such a magnet is also referred to as an R-T-B-based magnet.

[0017] The rare earth magnet 1 satisfies at least one or more of the following conditions (1) to (3). Condition (1): When the first surface S1, which is the orientation surface among the rare earth magnets 1, is measured by X-ray diffraction, the average shift amount of the position of the strongest peak, which is the peak with the highest intensity, is 0.50 degrees or less. Condition (2): When each of the first interval positions P1 (described later), which includes the position of the first surface S1 and is separated from the first surface S1 at intervals of 0.5 mm in the orientation direction (the +X-axis direction in FIG. 1), is measured by X-ray diffraction, the difference between the maximum value and the minimum value among the positions of the strongest peaks at each of the measured first interval positions P1 is 0.20 degrees or less. Condition (3): When each of the second interval positions P2 (described later), which includes the position of the second surface S2 that is orthogonal to the first surface S1 and is separated from the second surface S2 at intervals of 0.5 mm in a direction orthogonal to the orientation direction (the +X-axis direction in FIG. 1), is measured by X-ray diffraction, the difference between the maximum value and the minimum value among the positions of the strongest peaks at each of the measured second interval positions P2 is 0.20 degrees or less.

[0018] When determining Condition (1), first, 10 positions on the first surface S1 are randomly measured by X-ray diffraction (XRD), and the position of the strongest peak at each position is specified. At this time, XRD is measured at a step of 0.02° with an output of a voltage of 40 kV or more and a current value of 40 mA or more. Next, the shift amount of the position of the strongest peak at each position on the first surface S1 is obtained by specifying the reference position of the strongest peak as a comparison reference using the ICDD database and calculating the difference between the reference position and the position of the strongest peak at each position on the first surface S1. Then, after calculating the average value of the shift amounts of the positions of the strongest peaks at each position as the average shift amount, Condition (1) is determined using the average shift amount.

[0019] Figure 2 is an explanatory diagram of the first spacing position P1. As described above, the first spacing position P1 includes the position of the first surface S1 and is located 0.5 mm apart from each other in the orientation direction (the +X axis direction in Figure 3) from the first surface S1. Figure 2 shows five examples of the first spacing position P1. Of the five first spacing positions P1, the first spacing position P1 closest to the orientation direction is the position of the first surface S1. When determining condition (2), first, each of the first spacing positions P1 (including the position of the first surface S1) is measured by X-ray diffraction to identify the position of the strongest peak at each position. Specifically, each of the first spacing positions P1 measured by X-ray diffraction refers to the first surface S1 and the cross-section when the rare earth magnet 1 is cut in the YZ plane at a position 0.5 mm apart from the first surface S1. Next, the maximum and minimum values ​​of the strongest peaks at each of the measured first spacing positions P1 are identified. Then, after calculating the difference between the maximum and minimum values, the condition (2) is determined using that difference.

[0020] Figure 3 is an explanatory diagram of the second spacing position P2. As described above, the second spacing position P2 includes the position of the second surface S2 and is located 0.5 mm apart from the second surface S2 in a direction perpendicular to the orientation direction (the +X axis direction in Figure 3) (the Y axis direction in Figure 3). Figure 3 shows five examples of the second spacing position P2. Of the five second spacing positions P2, the one closest to the -Y axis direction is the position of the second surface S2. When determining condition (3), as when determining condition (2), first, each of the second spacing positions P2 (including the position of the second surface S2) is measured by X-ray diffraction to identify the position of the strongest peak at each position. Specifically, each of the second spacing positions P2 measured by X-ray diffraction is the second surface S2 and the cross-section when the rare earth magnet 1 is cut in the XZ plane at a position 0.5 mm apart from the second surface S2. Next, the maximum and minimum values ​​of the strongest peaks at each of the measured second interval positions P2 are identified. Then, the difference between the maximum and minimum values ​​is calculated, and this difference is used to determine condition (3).

[0021] Figure 4 shows, in table form, the results of evaluation tests conducted on rare earth magnets (Examples 1-15 and Comparative Examples 1-5) with different parameters related to the strongest peak. Of the examples and comparative examples shown in the table in Figure 4, Examples 1-15 correspond to the first embodiment of the present invention, which is rare earth magnet 1.

[0022] Examples 1-15 and Comparative Examples 1-5 were prepared according to the following steps (1)-(6).

[0023] (Process 1) SC alloy preparation process A raw material alloy (strip-cast alloy (SC alloy)) containing rare earth elements, transition metal elements, and boron is prepared. Examples of transition metal elements include one or more selected from the group consisting of iron (Fe), cobalt (Co), and nickel (Ni).

[0024] (Step 2) Hydrogen decomposition process In a hydrogen atmosphere, hydrogen is absorbed into the SC alloy at a predetermined temperature and time, causing the grain boundaries (rare earth-rich phase) and the inside of the grains of the SC alloy to become brittle. The hydrogen decomposition process is carried out under conditions where the predetermined temperature is 150-200 degrees Celsius and the predetermined time is 1-3 hours.

[0025] (Step 3) Coarse grinding step, first lubricant addition step The SC alloy powder, which has undergone a hydrogenation process, is coarsely ground (coarse grinding process). At this time, it is preferable to add a lubricant to the SC alloy powder (first lubricant addition process). This process is preferably carried out under an inert atmosphere (such as a nitrogen atmosphere or an argon atmosphere).

[0026] (Step 4) Fine grinding step, second lubricant addition step The SC alloy powder after the coarse grinding process is finely ground to a predetermined average particle size D50 (fine grinding process). At this time, a lubricant may be added to the finely ground SC alloy powder to improve its fluidity (second lubricant addition process). This process is preferably carried out under an inert atmosphere (nitrogen atmosphere, argon atmosphere, etc.). The fine grinding process is carried out with a predetermined average particle size D50 of 2.0 μm to 4.5 μm.

[0027] (Step 5) Powder filling process, orientation process, molding process The SC alloy powder, after the fine grinding process, is filled into a mold. This process is preferably carried out under an inert atmosphere (such as a nitrogen or argon atmosphere). The mold used has multiple molding spaces of a predetermined thickness. Each molding space is separated, for example, by multiple partition plates. After filling the mold with powder, a magnetic field is applied in a predetermined direction to align the orientation of the SC alloy powder. Then, the SC alloy powder filled in the mold is pressurized to form an SC alloy molded body. In this way, an SC alloy molded body having a predetermined degree of orientation (for example, an average degree of orientation of 90% or more) and a predetermined thickness (for example, a thickness of 1.2 mm to 2.5 mm) can be obtained without performing a cutting process.

[0028] (Step 6) Mold removal process, firing process The molded body is removed from the mold (mold removal process). The molded body is fired at a predetermined firing temperature for a predetermined time (firing process). This firing is preferably carried out in a vacuum. Prior to this firing, heating at a temperature lower than the firing temperature may be performed for dehydrogenation. The firing process is carried out under conditions where the predetermined firing temperature is 950 degrees and the predetermined time is 0.5 to 4.0 hours.

[0029] In the manufacturing of rare earth magnets by the above-described steps (1) to (6), it is preferable to reduce the processing load and processing resistance, and to relieve stress by heat treatment so that no distortion remains, from the viewpoint of reducing the amount of strain. In Examples 1 to 15, the processing (polishing after firing) conditions were set to a feed rate of 1 / 10 or less, a processing speed of 1 / 10 or less, and abrasive grain roughness of 0.5 μm or less. In addition, the heat treatment involved holding at 500 to 550 degrees for 30 minutes, then holding at 800 to 850 degrees for 30 minutes, and then cooling to 500 degrees at -8 degrees / minute. On the other hand, in Comparative Examples 1 to 5, the feed rate and processing speed were not set to 1 / 10 or less, and no heat treatment was performed, and normal processing (polishing) was carried out.

[0030] Let's return to the explanation of Figure 4. In the "Magnet Shape" section of the table in Figure 4, "X," "Y," and "Z" represent the lengths of sides Sx, Sy, and Sz in Figure 1, respectively, and the unit is mm.

[0031] In Figure 4, the "average shift amount" on "Face 1" is the difference between the position of the strongest peak at each of the 10 randomly measured locations on Face 1 S1 and the reference position of the strongest peak. The shift amount is calculated for each position, and then the average of these 10 shift amounts is obtained, with the unit being degrees (° / 2θ). The "average shift amount" is the criterion for determining condition (1), and condition (1) is met if it is less than 0.50° / 2θ.

[0032] In the table in Figure 4, the "Number of Measurement Positions" under "First Interval Position" refers to the number of first interval positions P1 measured by X-ray diffraction. For example, in Example 1, the "Number of Measurement Positions" is 8. In detail, in Example 1, "X" is 4 mm, and the first interval positions P1 are located at 0.5 mm intervals, including the position of the first surface S1. Therefore, in addition to the position of the first surface S1, measurements can be performed at 8 (= 4 mm / 0.5 mm) first interval positions P1. However, the first interval position P1 furthest to the -X axis (the surface of the rectangular rare-earth magnet 1 facing the first surface S1) will not be measured. In other words, the first interval position P1 furthest from the first surface S1 will be excluded from the measurement. In the table in Figure 4, the "maximum difference" at the "first interval position" is the difference between the maximum and minimum values ​​of the strongest peak positions at each of the first interval positions P1 measured by X-ray diffraction, and the unit is degrees (° / 2θ). Here, the "maximum difference" is the criterion for determining condition (2), and condition (2) is satisfied if it is 0.20° / 2θ or less.

[0033] In the table in Figure 4, the "Number of Measurement Positions" under "Second Interval Position" refers to the number of second interval positions P2 measured by X-ray diffraction. For example, in Example 1, the "Number of Measurement Positions" is 24. In detail, in Example 1, "Y" is 12 mm, and the second interval positions P2 are located at 0.5 mm intervals, including the position of the second surface S2. Therefore, in addition to the position of the second surface S2, measurements can be performed at 24 (= 12 mm / 0.5 mm) second interval positions P2. However, the second interval position P2 furthest to the +Y axis (the surface of the rectangular rare-earth magnet 1 facing the second surface S2) will not be measured. In other words, the second interval position P2 furthest from the second surface S2 will be excluded from the measurement. In the table in Figure 4, the "maximum difference" at the "second spacing position" is the difference between the maximum and minimum values ​​of the strongest peak positions at each of the second spacing positions P2 measured by X-ray diffraction, and the unit is degrees (° / 2θ). Here, the "maximum difference" is the criterion for determining condition (3), and condition (3) is satisfied if it is 0.20° / 2θ or less.

[0034] In the "Evaluation Results" section of Figure 4, "Rectangularity" represents the degree to which the demagnetization curve of rare earth magnet 1 is rectangular. "Rectangularity" was evaluated as "C" if it was 90% or less, "B" if it was greater than 90% but 93% or less, and "A" if it was greater than 93%.

[0035] In the table in Figure 4, the "Coercivity Distribution" in the "Evaluation Results" column represents the distribution of coercivity in rare-earth magnet 1. The "Coercivity Distribution" was evaluated as follows: "C" if the variation was 5% or more, "B" if the variation was 3% or more but less than 5%, and "A" if the variation was less than 3%.

[0036] In the table in Figure 4, the "Br distribution" in the "Evaluation Results" column represents the distribution of remanent magnetic flux density in rare-earth magnet 1. Similar to the "Coercivity Distribution" mentioned above, the "Br distribution" was evaluated as follows: "C" if the variation was 5% or more, "B" if the variation was 3% or more but less than 5%, and "A" if the variation was less than 3%.

[0037] In the "Evaluation Results," the "Angular Shape," "Coercivity Distribution," and "Br Distribution" were all measured using a vibrating sample magnetometer (VSM) or a pulsed BH tracer. When measuring "Angular Shape," the 15mm × 5mm × 35mm examples and comparative examples were used instead of the sizes specified by "X," "Y," and "Z" in the "Magnet Shape" section. If a 7mm × 7mm × 7mm measurement sample is available, it is preferable to use that size sample. If a 7mm × 7mm × 7mm measurement sample is not available, it is preferable to use a measurement sample that is as close as possible to 7mm × 7mm × 7mm from the sizes between 5mm × 5mm × 5mm and 7mm × 7mm × 7mm, rather than using a 15mm × 5mm × 35mm measurement sample. The measurement samples referred to here are each of Examples 1 to 15 and Comparative Examples 1 to 5 used for measurement.

[0038] Comparative Examples 1-5 all failed to meet conditions (1)-(3). In all of Comparative Examples 1-5, the "squareness" was "C", the "coercivity distribution" was "C", and the "Br distribution" was "B".

[0039] Examples 1-4 all met only condition (1). In all of Examples 1-4, the "squareness" was "B", the "coercivity distribution" was "B", and the "Br distribution" was "B". In other words, compared to Comparative Examples 1-5, Examples 1-5 had the same evaluation of "Br distribution" among the "evaluation results", but the evaluations of "squareness" and "coercivity distribution" were improved.

[0040] Examples 5-7 all satisfied conditions (1)-(3). In all of Examples 5-7, the "rectangular shape" was "A", the "coercivity distribution" was "B", and the "Br distribution" was "B". In other words, compared to Examples 1-4, Examples 5-7 had equivalent evaluations of "coercivity distribution" and "Br distribution" among the "evaluation results", but the evaluation of "rectangular shape" was improved.

[0041] Examples 8-12, like Examples 5-7, all satisfied conditions (1)-(3). On the other hand, in all Examples 8-12, the "squareness" was "A", the "coercivity distribution" was "A", and the "Br distribution" was "B". In other words, compared to Examples 5-7, Examples 8-12 had equivalent evaluations for "squareness" and "Br distribution" among the "evaluation results", but the evaluation of "coercivity distribution" was improved. In Examples 8-12, the "average shift amount" was in the range of 0.22-0.27° / 2θ, and the "maximum difference" at the "second spacing position" was in the range of 0.07-0.14° / 2θ. On the other hand, in Examples 5-7, the "average shift amount" was in the range of 0.32-0.35° / 2θ, and the "maximum difference" at the "second spacing position" was in the range of 0.14-0.20° / 2θ. In other words, it is presumed that these "evaluation results" were obtained in Examples 8 to 12 because both the "average shift amount" and the "maximum difference" in the "second interval position" were smaller compared to Examples 5 to 7.

[0042] Examples 13-15, like Examples 5-12, all satisfied conditions (1)-(3). On the other hand, in all Examples 13-15, the "squareness" was "A", the "coercivity distribution" was "A", and the "Br distribution" was "A". In other words, compared to Examples 8-12, Examples 13-15 had equivalent evaluations of "squareness" and "coercivity distribution" in the "evaluation results", but the evaluation of "Br distribution" was improved. In Examples 13-15, the "average shift amount" was in the range of 0.10-0.22° / 2θ, and the "maximum difference" at the "second spacing position" was 0.03° / 2θ. On the other hand, in Examples 8-12, the "average shift amount" was in the range of 0.22-0.27° / 2θ, and the "maximum difference" at the "second spacing position" was in the range of 0.07-0.14° / 2θ. In other words, it is presumed that these "evaluation results" were obtained in Examples 13 to 15 because both the "average shift amount" and the "maximum difference" in the "second interval position" were smaller compared to Examples 8 to 12.

[0043] The rare earth magnet 1 of the embodiment described above satisfies at least one of the above-mentioned conditions (1) to (3).

[0044] When the rare-earth magnet 1 satisfies condition (1), the average shift in the position of the strongest peak when the first surface S1 is measured by X-ray diffraction is 0.50 degrees or less, so the distortion in the first surface S1 is relatively small. In this case, since the occurrence of knicks is suppressed in the second quadrant of the hysteresis loop, the rare-earth magnet 1 that satisfies condition (1) has good prismatic properties.

[0045] When the rare earth magnet 1 satisfies condition (2), the difference between the maximum and minimum values ​​of the strongest peak positions at each of the first interval positions P1 is 0.20 degrees or less, so the difference in strain at each of the first interval positions P1 in that rare earth magnet is relatively small. Furthermore, such a rare earth magnet 1 also has good prismatic properties.

[0046] When the rare earth magnet 1 satisfies condition (3), the difference between the maximum and minimum values ​​of the strongest peak positions at each second spacing position P2 is 0.20 degrees or less, so the difference in strain at each second spacing position P2 in that rare earth magnet 1 is relatively small. And such a rare earth magnet 1 also has good angularity. Furthermore, a comparison of Examples 5-7 and Examples 1-4 in Figure 4 shows that satisfying conditions (2) and (3) in addition to condition (1) improves "angularity". Furthermore, a comparison of Examples 5-7, Examples 8-12 and Examples 13-15 in Figure 4 shows that when conditions (1)-(3) are satisfied and both the "average shift amount" and the "maximum difference" at the "second spacing position" are small, the "coercivity distribution" and "Br distribution" improve.

[0047] <Second Embodiment> Figure 5 is a schematic diagram illustrating a laminated magnet 2 as a second embodiment of the present invention. The laminated magnet 2 comprises a plurality of rare earth magnets 1 and a plurality of insulating layers IN. As shown in Figure 5, in the laminated magnet 2, the rare earth magnets 1 and insulating layers IN are stacked alternately. The rare earth magnets 1 referred to here are the same as the rare earth magnets 1 described in the first embodiment. In Figure 5, the orientation direction of the magnetic field of each rare earth magnet 1 is the +X axis direction.

[0048] The insulating layer IN is mainly composed of inorganic crystals. Preferably, the inorganic crystals are non-magnetic crystalline particles. "Mainly composed of inorganic crystals" means that the inorganic crystal content in the insulating layer IN is 50% by mass or more. The composition of the insulating layer IN can be analyzed by the following method: The presence of inorganic crystals is determined by micro-X-ray analysis or XRD analysis, and the inorganic crystal content is calculated by combining this with compositional analysis using EPMA (Electron Probe Micro Analyser).

[0049] From the viewpoint of reducing eddy current loss, the insulating layer IN preferably contains one or more inorganic crystals selected from the group consisting of CaF2, BaF2, SrF2, MgF2, Al2O3, ZrO2, Dy2O3, Tb2O3, Nd2O3, TbF3, DyF3, LiF, SiO2, BN, ZrB2, Si3N4, TiB2, Pr2O3, and SiC.

[0050] The insulating layer IN is made of inorganic crystals, specifically fluorides from Group 2A of the periodic table, from the viewpoint of reducing eddy current losses. It is preferable that the insulating layer IN contains at least one of the following as a Group 2A fluoride of the periodic table: CaF2, BaF2, SrF2, and MgF2. Among these, it is particularly preferable that the insulating layer IN contains CaF2.

[0051] In Figure 5, each insulating layer IN is positioned along the XZ plane and aligned with the orientation direction of each magnetic field of the rare earth magnet 1 (the +X axis direction in Figure 5). When a laminated magnet 2, which consists of the rare earth magnet 1 and the insulating layer IN stacked as shown in Figure 5, is used as a motor magnet or the like, the insulating layer IN is positioned approximately parallel to the direction in which the magnetic flux generated in the stator passes through the rare earth magnet 1 (the X axis direction in Figure 5), thus effectively reducing eddy current losses. Note that each insulating layer IN may be positioned along the YZ plane or along the XY plane with respect to the orientation direction of each magnetic field of the rare earth magnet 1 (the +X axis direction in Figure 5).

[0052] Rare earth magnets 1 tend to have low eddy current losses. Furthermore, the insulating layer IN, which is mainly composed of inorganic crystals, shows almost no change in resistance from room temperature to 150°C, thus reducing eddy current losses over a wide temperature range. Therefore, a laminated magnet 2 in which such rare earth magnets 1 and insulating layer IN are alternately stacked is a laminated magnet 2 that can reduce eddy current losses generated internally in high-temperature environments. In the case of a laminated magnet 2 equipped with such an insulating layer IN mainly composed of inorganic crystals, it is preferable to relieve stress by heat treatment at around 800°C to prevent residual strain.

[0053] <Third Embodiment> Figure 6 is a cross-sectional view of a motor 3 as a third embodiment of the present invention. The motor 3 comprises a stator 31 and a rotor 33 arranged inside the stator 31. A laminated magnet 2 is arranged on the rotor 33, and a winding (not shown) is arranged on the stator 31. The laminated magnet 2 referred to here is the same as the laminated magnet 2 described in the second embodiment. That is, the rare earth magnet 1 described in the first embodiment is arranged on the rotor 33. The motor 3 is an inner rotor type with the magnet arranged on the inside (rotating shaft side) and the winding arranged on the outside. The motor 3 is not limited to an inner rotor type. For example, the motor 3 may be an outer rotor type with the winding arranged on the inside (rotating shaft side) and the magnet arranged on the outside.

[0054] The rotor 33 comprises a rotating shaft 34, a rotating core 35, and multiple laminated magnets 2. The rotating core 35 is formed by laminating electromagnetic steel sheets. A shaft hole 37 is formed in the center of the rotating core 35. The rotating shaft 34 is inserted into the shaft hole 37. Multiple magnet holes 39 are formed in the rotating core 35 at intervals in the circumferential direction. A laminated magnet 2 is inserted into each magnet hole 39. Therefore, the motor 3 shown in Figure 6 is a motor with excellent rotational efficiency because the rotor 33 is equipped with rare earth magnets 1 that have good prismatic properties.

[0055] <Modified form of this embodiment> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit, for example, the following modifications are also possible.

[0056] In the first embodiment described above, the examples shown in Table 4 of Figure 4 were Examples 1 to 4 which satisfied only condition (1), and Examples 5 to 15 which satisfied conditions (1) to (3), but are not limited thereto. Embodiments of the present invention do not need to satisfy all of conditions (1) to (3). In particular, embodiments of the present invention may satisfy conditions (1) and (2) but not condition (3), and may satisfy conditions (1) and (3) but not condition (2).

[0057] In the first embodiment described above, the second spacing positions P2 were positions separated by 0.5 mm in the Y-axis direction, with the direction perpendicular to the orientation direction (+X-axis direction) being the Y-axis direction, but are not limited to this. The second spacing positions P2 may also be positions separated by 0.5 mm in the Z-axis direction, with the direction perpendicular to the orientation direction (+X-axis direction) being the Z-axis direction. In this embodiment as well, condition (3) is satisfied if the difference between the maximum and minimum values ​​of the strongest peak positions at each of the second spacing positions P2 is 0.20 degrees or less.

[0058] In the second embodiment described above, the insulating layer IN was mainly composed of inorganic crystals, but is not limited to this. The insulating layer IN may be mainly composed of any material as long as it has insulating properties.

[0059] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0060] The present invention can also be realized in the following forms. [Application Example 1] A rare earth magnet containing rare earth elements, A rare earth magnet characterized in that, when the first orientation surface of the rare earth magnet is measured by X-ray diffraction, the average shift amount of the position of the strongest peak, which is the peak with the highest intensity, is 0.50 degrees or less. [Application Example 2] The rare earth magnet described in Application Example 1, A rare earth magnet characterized in that, when each of the first interval positions, which include the position of the first surface and are separated from each other by 0.5 mm in the orientation direction from the first surface, is measured by X-ray diffraction, the difference between the maximum and minimum values ​​of the strongest peak positions at each of the measured first interval positions is 0.20 degrees or less. [Application Example 3] A rare earth magnet as described in Application Example 1 or Application Example 2, A rare earth magnet characterized in that, when each of the second spacing positions, which include the position of a second surface that is perpendicular to the first surface and are separated from each other by 0.5 mm in a direction perpendicular to the orientation direction from the second surface, is measured by X-ray diffraction, the difference between the maximum and minimum values ​​of the strongest peak positions at each of the measured second spacing positions is 0.20 degrees or less. [Application Example 4] It is a stacked magnet, Multiple rare earth magnets as described in any one of the application examples 1 to 3, It comprises multiple insulating layers, A laminated magnet characterized in that the rare earth magnet and the insulating layer are stacked alternately. [Application Example 5] It is a motor, A motor characterized in that a rare earth magnet described in any one of Application Examples 1 to 3 is arranged in the rotor. [Explanation of symbols]

[0061] 1…Rare earth magnets 2…Stacked magnets 3…motor 31…Stata 33...Rota 34…Rotation axis 35…Rotating iron core 37…Axial hole 39…Magnetic hole IN...insulating layer P1…1st interval position P2…Second interval position S1...Side 1 S2...Side 2 Sx...side Sy... Sz...side

Claims

1. A rare earth magnet containing rare earth elements, A rare earth magnet characterized in that, when the first plane, which is the orientation plane of the rare earth magnet, is measured by X-ray diffraction, the average shift amount of the position of the strongest peak, which is the peak with the highest intensity, is 0.50 degrees or less.

2. A rare earth magnet according to claim 1, A rare earth magnet characterized in that, when each of the first interval positions, which include the position of the first surface and are separated from each other by 0.5 mm in the orientation direction from the first surface, is measured by X-ray diffraction, the difference between the maximum and minimum values ​​of the strongest peak positions at each of the measured first interval positions is 0.20 degrees or less.

3. A rare earth magnet according to claim 2, A rare earth magnet characterized in that, when each of the second spacing positions, which include the position of a second surface that is perpendicular to the first surface and are separated from each other by 0.5 mm in a direction perpendicular to the orientation direction from the second surface, is measured by X-ray diffraction, the difference between the maximum and minimum values ​​of the strongest peak positions at each of the measured second spacing positions is 0.20 degrees or less.

4. It is a stacked magnet, A plurality of rare earth magnets according to any one of claims 1 to 3, It comprises multiple insulating layers, A laminated magnet characterized in that the rare earth magnet and the insulating layer are stacked alternately.

5. It is a motor, A motor characterized in that a rare earth magnet according to any one of claims 1 to 3 is arranged in the rotor.

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