L10 type feni ordered alloy, permanent magnet, and method for producing l10 type feni ordered alloy

Abstract

The present invention provides L10 type FeNi ordered alloy 5 that has a L10 type ordered structure and includes a transition metal element 2 of group 6 or group 7. Thus, the coercive force of L10 type FeNi ordered alloy 5 can be further increased.

Description

L10 type FeNi ordered alloy, permanent magnet, and method for producing L10 type FeNi ordered alloy CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2024-107632, filed on July 3, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to L1 ０ L1 having a regular structure of type ０ FeNi (iron-nickel) ordered alloy (hereinafter also referred to as FeNi superlattice), permanent magnet and L1 ０ This invention relates to a method for producing an ordered FeNi alloy of this type.

[0003] In recent years, the electrification of mobility, including automobiles, has been promoted, and FeNi ordered alloys have been developed as materials for permanent magnets used in electric motors. For example, Patent Document 1 discloses a method for producing high-quality FeNi superlattices. This method uses a nitriding-denitriding method in which an FeNi alloy is first nitrided to obtain a nitride containing Fe and Ni (hereinafter referred to as FeNi nitride) by a nitriding process, and then nitrogen is removed from the nitride by a denitriding process. In addition, high-quality FeNi superlattices are produced by doping with light elements. The light elements used are C (carbon), B (boron), and N (nitrogen), and the doping with light elements achieves both high saturation magnetization and high coercivity.

[0004] Patent No. 6733700

[0005] L1 ０ Compared to neodymium magnets, FeNi ordered alloys exhibit less deterioration in magnetic properties due to heat, and are therefore expected to prevent deterioration in the performance of electric motors due to heat. However, their small magnetic anisotropy energy results in a small coercive force, and the desired coercive force cannot be obtained, particularly at room temperature. Therefore, further improvement in coercive force is essential for magnetization, but the method of doping a light element by interstitial doping into the lattice, as in Patent Document 1, does not provide the L1 ０ However, the amount of doping in the FeNi ordered alloy is limited, and there is a limit to the improvement in coercivity.

[0006] The present disclosure provides an L1 that can obtain a higher coercive force. ０ FeNi ordered alloy, permanent magnet and L1 ０ The present invention aims to provide a method for producing an ordered FeNi alloy of this type.

[0007] L1 according to one aspect of the present disclosure ０ The ordered FeNi alloy of the L1 type ０ It has an ordered structure of the type and contains a transition metal element of Group 6 or 7.

[0008] Thus, L1 containing a transition metal element of Group 6 or Group 7 ０ By forming an FeNi ordered alloy, a higher coercive force can be obtained. ０ If a permanent magnet is manufactured using an FeNi ordered alloy of this type as the magnetic material, the permanent magnet can have a higher coercive force.

[0009] L1 according to another aspect of the present disclosure ０ A method for producing an FeNi ordered alloy of this type includes: generating FeNi containing a transition metal element of Group 6 or Group 7; nitriding the FeNi to form an FeNi nitride containing the transition metal element of Group 6 or Group 7; and performing a denitriding process to remove nitrogen from the FeNi nitride to produce an L1 FeNi nitride containing the transition metal element of Group 6 or Group 7. ０ and forming an ordered FeNi alloy of the type.

[0010] In this way, after forming FeNi containing a transition metal element of Group 6 or Group 7, a nitriding treatment to form FeNi nitride and a denitriding treatment to remove nitrogen are performed, thereby obtaining L1 containing a transition metal element of Group 6 or Group 7. ０ This allows the formation of an L1 type FeNi ordered alloy, which provides a higher coercive force. ０ It is possible to produce ordered FeNi alloys of this type.

[0011] L1 ０FIG. 1 is a schematic diagram showing the lattice structure of an FeNi ordered structure. FIG. 2 is a cross-sectional view illustrating the states before a nitriding process, after a nitriding process, and after a denitriding process. FIG. 3 is a schematic diagram showing the lattice structure of FeNiN. FIG. 4 is a flowchart showing a manufacturing process of an FeNi superlattice. FIG. 5 is cross-sectional TEM images of all elements, Mn, Fe, and Ni obtained by a transmission electron microscope (TEM) before a nitriding process, after a nitriding process, and after a denitriding process. FIG. 6 is a diagram showing the results of extracting an energy spectrum by energy dispersive X-ray fluorescence spectroscopy (EDXRF) before a nitriding process. FIG. 7 is a table showing the analysis results of each element and the total of all elements before a nitriding process. FIG. 8 is a diagram showing the results of extracting an energy spectrum by EDXRF after a nitriding process. FIG. 9 is a table showing the analysis results of each element and the total of all elements after a nitriding process. FIG. 10 is a diagram showing the results of extracting an energy spectrum by EDXRF after a denitriding process. FIG. 11 is a table showing the analysis results of each element and the total of all elements after a denitriding process. FIG. 12 is a diagram showing the results of measuring magnetic properties. FIG. 13 is a diagram showing the change in coercivity with temperature when Mn is included and when it is not included.

[0012] Embodiments of the present disclosure will be described in detail below. However, the embodiments described below are examples for embodying the technical ideas of the present disclosure, and the present disclosure is not limited to the following. In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. Furthermore, a numerical range indicated using "to" indicates a range that includes the numerical values ​​written before and after "to" as the minimum and maximum values, respectively. Furthermore, in the following embodiments, parts that are identical or equivalent to each other will be described using the same reference numerals.

[0013] <L1 ０ L1 type FeNi ordered alloy according to this embodiment ０ The FeNi ordered alloy of this type is used, for example, as a magnetic powder or magnetic material, and by manufacturing a sintered magnet or a bonded magnet with this FeNi ordered alloy as the main phase, it can be made into a permanent magnet. ０ The type FeNi ordered alloy is L1 ０It has an ordered structure of the type L1 and contains a transition metal element of Group 6 or 7 that does not exhibit ferromagnetism at room temperature. ０ The ordered alloy of this type means that the degree of order is 0.1 or more, and preferably 0.5 or more. The upper limit of the degree of order may be 1 or less. ０ The degree of order of the FeNi ordered alloy of this type is actually measured to be 0.6 to 0.7 or more.

[0014] The degree of ordering S indicates the degree of ordering in the FeNi superlattice. ０ The ordered structure of the type is based on a face-centered cubic lattice, and has a lattice structure as shown in Figure 1. Metal A and metal B in the figure represent Fe and Ni, and either Fe or Ni can be metal A or metal B. In this figure, the uppermost layer in the stacked structure of the (001) plane of the face-centered cubic lattice is the I site, and the intermediate layer located between the uppermost layer and the lowermost layer is the II site. In this case, if the ratio of metal A existing in the I site is x and the ratio of metal B existing in the I site is 1-x, then the ratio of metal A and metal B existing in the I site is A. ｘ B １－ｘ Similarly, if the ratio of metal B present at the II site is x and the ratio of metal A present at the II site is 1-x, then the ratio of metal A and metal B present at the II site is A １－ｘ B ｘ Here, x satisfies 0.5≦x≦1. In this case, the degree of order S is defined as S=2x−1.

[0015] The degree of order is L1 shown in the following formula 1. ０ The degree of order S in an FeNi ordered alloy of this type can be estimated by the following equation.

[0016] Here, in Equation 1, "I ｓｕｐ " is the L1 observed in the XRD pattern that can be observed by powder X-ray diffraction (XRD) method. ０ is the integrated intensity of the diffraction peaks (hereinafter referred to as superlattice diffraction peaks) specific to the ordered alloy of the I type. ｆｕｎｄ " is an FeNi alloy and L1 ０The "(I)" is the integrated intensity of the diffraction peak (hereinafter referred to as the fundamental diffraction peak) that appears in both the FeNi ordered alloy and the I ｓｕｐ / I ｆｕｎｄ ) ｏｂｓ " is the ratio of the integrated intensity of the superlattice diffraction peak to the integrated intensity of the fundamental diffraction peak in the X-ray diffraction pattern measured in each example and comparative example. ｓｕｐ / I ｆｕｎｄ ) ｃａｌ " is the ratio of the integrated intensity of the superlattice diffraction peak to the integrated intensity of the fundamental diffraction peak of an FeNi ordered alloy with an order degree of 1 estimated from Rietveld simulation. Then, as shown in Equation 1, the square root of these two ratios is calculated as the order degree S. As the XRD device used here, a general one such as SmartLab manufactured by Rigaku Corporation can be used, but the order degree S can be estimated with high accuracy by using Fe-kβ rays as X-rays.

[0017] L1 ０ The lower limit of the content of the transition metal element of Group 6 or 7 in the FeNi ordered alloy of the L1 type can be, for example, 0.3 at% or more, and preferably 0.5 at% or more. ０ The upper limit of the content of the transition metal element of Group 6 or Group 7 in the FeNi ordered alloy of this type is, for example, 1.19 at% or less, and preferably 1 at% or less. It has been confirmed through experiments that the upper limit of the content of the transition metal element of Group 6 or Group 7 shows the same tendency even if the transition metal element to be contained is different, and if the content is too high, undesirable phenomena may occur. Specifically, although increasing the content contributes to improving the coercive force, it also leads to the deterioration of L1. ０In this case, a phenomenon occurred in which the ordered FeNi alloy could not be ordered or subphases appeared. In other words, a trade-off phenomenon occurs with the improvement in coercivity. Therefore, it is preferable to determine the upper limit of the content of the transition metal element from Group 6 or Group 7 in order to set both within an appropriate range. Experiments have shown that a content of 1.19 at% or less, preferably 1 at% or less, can achieve high coercivity while suppressing the phenomenon of the ordering being unable to be ordered or the appearance of subphases. On the other hand, the lower limit of the content of the transition metal element from Group 6 or Group 7 can be set arbitrarily depending on the required coercivity. However, a content of at least 0.3 at% or more, preferably 0.5 at% or more, can increase the coercivity compared to when no transition metal element from Group 6 or Group 7 is contained.

[0018] L1 ０ The FeNi ordered alloy of the type L1 may be in the form of a film or may be composed of particles 10 as shown in FIG. 5 described later. ０ The ordered FeNi alloy of the L1 type ０ When the particle is composed of particles 10 having an ordered structure of type L1, the transition metal element of group 6 or group 7 may be present throughout the particle, may be segregated inside the particle 10, or may be segregated on the particle surface. When present throughout the particle, it may be present uniformly or non-uniformly. Furthermore, it may be present inside the particle 10 and segregated on the particle surface. When segregated on the particle surface, it may be segregated over the entire surface or only part of the surface. ０ Similarly, when the FeNi ordered alloy is in the form of a film, the transition metal element of Group 6 or Group 7 may be present throughout the interior of the film or may be segregated on the surface. The transition metal element may be present uniformly or unevenly inside or on the surface of the film, or may be present inside the film and segregated on the surface, or may be segregated over the entire surface or only partially.

[0019] L1 ０The ratio of the at% of Fe to the total at% of Fe and Ni in the FeNi ordered alloy of this type may be 0.4 to 0.6, preferably 0.45 to 0.55, and more preferably 0.48 to 0.52. The at% of Fe and Ni can be measured by measuring the number of moles of each element using inductively coupled plasma (ICP) optical emission spectroscopy or EDXRF using an electron microscope.

[0020] <L1 ０ Manufacturing method of type FeNi ordered alloy> L1 of this embodiment ０ The method for producing an FeNi ordered alloy of this type includes a step of producing FeNi containing a transition metal element of Group 6 or Group 7 that does not exhibit ferromagnetism at room temperature. In this production step, it is sufficient to produce FeNi doped with a transition metal element of Group 6 or Group 7. ０ The method for producing an FeNi ordered alloy of this type includes a nitriding step for forming FeNi nitrides containing transition metal elements of Group 6 or Group 7. The FeNi used in the nitriding step contains transition metal elements of Group 6 or Group 7 obtained in the previous generating step, and by nitriding it in the nitriding step, FeNi nitrides containing transition metal elements of Group 6 or Group 7 can be obtained. Furthermore, the L1 of this embodiment ０ The method for producing the FeNi ordered alloy includes a denitrification step of removing nitrogen from FeNi nitride containing a transition metal element of Group 6 or Group 7. By passing through this denitrification step, it is possible to obtain an L1 alloy containing a transition metal element of Group 6 or Group 7. ０ The L1 type FeNi ordered alloy can be produced. ０ The FeNi ordered alloy is, for example, a film-like alloy made up of countless particles 10, and can be made into powder by dividing it into particles 10. ０ The FeNi ordered alloy of this type is used as a magnetic powder and a magnetic material, and can be made into a permanent magnet by manufacturing a sintered magnet or a bonded magnet. The production process, nitriding process, and denitriding process will be explained below using an example.

[0021] [Production Step] In the production step, FeNi containing a transition metal element of Group 6 or Group 7 is produced. The form of doping of the transition metal element of Group 6 or Group 7 into FeNi is arbitrary, but it is preferable that the element is doped at a uniform density in FeNi. Here, as shown in State 1 in FIG. 2, SiO ２ A flat glass substrate 1 made of the above is prepared, and FeNi3 doped with a transition metal element 2 of Group 6 or 7 is formed on the flat surface of the glass substrate 1.

[0022] FeNi3 may be configured with a disordered structure. The disordered structure here may be a structure in which the atomic arrangement is random and does not have regularity, so-called random FeNi, or a structure in which the L1 ０ It is also acceptable that no peak of the ordered structure of the type is observed. The FeNi3 is formed as a thin film, for example, 45 to 50 nm thick, with a laminated structure in which Ni films of a few tenths of a nanometer to a few nanometers and Fe films of a few tenths of a nanometer to a few nanometers are repeatedly and alternately stacked. Then, doping with a Group 6 or Group 7 transition metal element 2 is performed at least either after the formation of the Ni film and before the formation of the Fe film, or before the formation of the Fe film and after the formation of the Ni film. For example, a thin film of a Group 6 or Group 7 transition metal element 2 is formed. Examples of the Group 6 transition metal element 2 include Cr (chromium), Mo (molybdenum), and W (tungsten). Examples of the Group 7 transition metal element 2 include Mn (manganese), Tc (technetium), and Re (rhenium).

[0023] For example, random FeNi3 containing a group 6 or 7 transition metal element 2 can be produced by forming a Ni film, a Mn film, and an Fe film in this order on the flat surface of a glass substrate 1. Each film can be formed, for example, by sputtering. The thickness of each film can be determined based on the composition ratio, i.e., content, of Fe, Ni, and the group 6 or 7 transition metal element 2. For example, if the group 6 or 7 transition metal element 2 is 1 at % and the remainder is equal parts Fe and Ni, i.e., 49.5 at %, each film can be formed to a thickness corresponding to that ratio. The number of repetitions when repeatedly forming each film, the thickness of each film, and the total film thickness can be arbitrary as long as the composition ratio is maintained, and the thicknesses of each film can also be different. However, a larger number of repetitions is preferable because the group 6 or 7 transition metal element 2 is uniformly doped into FeNi.

[0024] [Nitriding Step] In the nitriding step, FeNi3 containing a Group 6 or Group 7 transition metal element 2 is nitrided to obtain FeNi nitride 4. The nitriding method is not particularly limited as long as it produces FeNi nitride 4 containing a Group 6 or Group 7 transition metal element 2, but examples include gas nitriding using ammonia gas or nitrogen, plasma nitriding, and nitriding using a metal amide. Specifically, the FeNi3 containing a Group 6 or Group 7 transition metal element 2 produced through the above-described production step is heat-treated under an ammonia gas flow to perform the nitriding step. The flow rate of the ammonia gas in the nitriding step can be 0.1 to 10 liters / min, preferably 0.5 to 5 liters / min, per gram of FeNi3 containing a Group 6 or Group 7 transition metal element 2. The heat treatment temperature can be, for example, 300 to 500°C, preferably 310 to 475°C, and more preferably 330 to 450°C. The heat treatment time can be, for example, 5 to 50 hours, and preferably 10 to 20 hours.

[0025] The FeNi nitrides obtained in the nitriding step include FeNiN, Fe ２ Ni ２ N, etc., and L1 ０In order to obtain an ordered FeNi alloy of this type, it is preferable that the proportion of FeNiN is large. For example, when FeNi3 containing a group 6 or 7 transition metal element 2 formed on a glass substrate 1 is subjected to a nitriding process, FeNi nitride 4 composed mainly of FeNiN is formed, as shown in state 2 in Figure 2. This FeNi nitride 4 contains the group 6 or 7 transition metal element 2. Because FeNi3 expands upon nitriding, the volume of FeNi nitride 4 becomes larger than that of FeNi.

[0026] FeNiN has a crystal structure as shown in Figure 3 and can be identified from the XRD diffraction pattern. The FeNi nitride 4 does not need to be completely nitrided, and some unnitrided FeNi 3 may remain. The proportion of the nitrided portion in the FeNi nitride 4 may be 50 at% or more of the total including FeNi and the group 6 or 7 transition metal element 2, but is preferably 80 at% or more, and more preferably 90 at% or more. The proportion of the nitrided portion in the FeNi nitride 4 and the proportion of FeNiN in the nitrided portion can be calculated by analyzing the XRD diffraction pattern using the reference intensity ratio (RIR) method.

[0027] The ratio of the at% of Fe to the total at% of Fe and Ni in the FeNi nitride 4 obtained in the nitriding step may be 0.4 to 0.6, preferably 0.45 to 0.55, and more preferably 0.48 to 0.52. The at% of Fe and Ni can also be measured by measuring the number of moles of each element by ICP emission spectroscopy or EDS using an electron microscope.

[0028] The lower limit of the content of the Group 6 or Group 7 transition metal element 2 contained in the FeNi nitride 4 obtained in the nitriding step can be, for example, 0.3 at% or more, and preferably 0.5 at% or more. The upper limit of the content of the Group 6 or Group 7 transition metal element 2 contained in the FeNi nitride 4 can be, for example, 1.19 at% or less, and preferably 1.0 at% or less. The at% of the Group 6 or Group 7 transition metal element 2 can also be measured by measuring the number of moles using ICP emission spectroscopy or EDS using an electron microscope.

[0029] When the FeNi nitride 4 is formed by nitriding FeNi3 formed on the glass substrate 1, it is obtained as a thin film expanded more than FeNi3, but it may also be composed of particles 10. When the FeNi nitride 4 is composed of particles 10, the Group 6 or Group 7 transition metal element 2 may be present throughout the particle, or may be segregated inside the particle. The Group 6 or Group 7 transition metal element 2 may also be segregated on the particle surface. When present throughout the particle, it may be present uniformly or non-uniformly. The element may also be present inside the particle 10 and segregated on the particle surface. When segregated on the particle surface, it may be segregated over the entire surface or on a portion of the surface. For example, it may be segregated more at the interface with the glass substrate 1 than in other portions. Similarly, when it is a thin film, the Group 6 or Group 7 transition metal element 2 may be present throughout the film or may be segregated on the surface. Furthermore, they may be present uniformly inside or on the surface of the film, or may be present unevenly. Furthermore, they may be present inside the film and segregated on the surface, or they may be segregated over the entire surface or only part of the surface.

[0030] In the nitriding step, the FeNi alloy contains a transition metal element 2 of Group 6 or Group 7. ０ An ordered FeNi alloy of the type L1 containing a transition metal element of Group 6 or Group 7 may also be used. ０ In addition to the present embodiment, the L1 type FeNi ordered alloy is also produced by a known method. ０It can be produced by adding a predetermined amount of a transition metal element 2 of Group 6 or Group 7 to an FeNi ordered alloy of the L1 type, as needed. ０ It can also be produced by mixing an FeNi ordered alloy of this type with a transition metal element 2 of Group 6 or 7, followed by heat treatment.

[0031] [Denitriding Step] In the denitriding step, the FeNi nitride 4 containing the Group 6 or Group 7 transition metal element 2 obtained in the above-mentioned nitriding step is denitrified to obtain L1 containing the Group 6 or Group 7 transition metal element 2. ０ As shown in state 3 of FIG. 2, the L1 ０ The FeNi ordered alloy 5 is obtained in a state containing a transition metal element 2 of Group 6 or Group 7. When the FeNi nitride 4 is in the form of a thin film, the L1 containing the transition metal element 2 of Group 6 or Group 7 obtained by the denitrification treatment is ０ The FeNi ordered alloy 5 is also visually recognized as a thin film, but may be separated into particles 10.

[0032] Specifically, the FeNi nitride 4 containing a Group 6 or 7 transition metal element 2 obtained in the nitriding step can be subjected to a denitriding treatment by heat treating it in a hydrogen atmosphere. The flow rate of hydrogen in the denitriding treatment can be set to 0.01 to 10 liters / min, and preferably 0.1 to 5 liters / min, per gram of the FeNi nitride 4 containing a Group 6 or 7 transition metal element 2. The heat treatment temperature can be, for example, 100 to 400°C, and preferably 200 to 350°C. The heat treatment time can be, for example, 1 to 24 hours, and preferably 2 to 10 hours.

[0033] Based on the manufacturing method of each of the above-described embodiments, L1 containing a transition metal element 2 of Group 6 or Group 7 that does not exhibit ferromagnetism at room temperature is produced. ０ In Example 1, Mn was used as the Group 7 transition metal element, and in Example 2, Cr was used as the Group 6 transition metal element. As a comparative example, an L1 alloy containing neither Group 6 nor Group 7 transition metal elements was also produced. ０The FeNi ordered alloy 5 was also produced. Specifically, the L1 alloy containing the Group 6 or Group 7 transition metal element 2 of Examples 1 and 2 was produced according to the flow chart of the production process shown in FIG. ０ In addition, an L1 FeNi ordered alloy 5 containing no Group 6 or Group 7 transition metal element 2 of Comparative Example 1 was produced by the same production process. ０ An FeNi ordered alloy 5 of the type was produced.

[0034] In Examples 1 and 2, a thin film of FeNi3 containing a Group 6 or Group 7 transition metal element 2 was formed on a glass substrate 1 to a thickness of 45 to 50 nm in step S1. The content of each element was 1 at % for the Group 6 or Group 7 transition metal element 2, and 49.5 at % for Fe and Ni. In Comparative Example 1, a thin film of FeNi3 not containing a Group 6 or Group 7 transition metal element 2 was formed on a glass substrate 1, and the contents of Fe and Ni were both 50 at %. Then, by performing the above-described nitriding process and denitriding process as the nitriding process and denitriding process shown in steps S2 and S3, a thin film of FeNi3 containing a Group 6 or Group 7 transition metal element 2 was formed on a glass substrate 1 as shown in step S4 in Examples 1 and 2. ０ Similarly, as Comparative Example 1, an L1 FeNi ordered alloy containing no transition metal element 2 of Group 6 or 7 was produced. ０ An FeNi ordered alloy 5 of the type was produced.

[0035] 5 shows cross-sectional TEM images taken with a transmission electron microscope before the nitriding step, after the nitriding step, and after the denitriding step for Example 1, showing a cross-sectional TEM image of all elements and a cross-sectional TEM image in which only Mn, Fe, and Ni are extracted. In the cross-sectional TEM images, the black area at the bottom indicates the glass substrate 1. In the cross-sectional TEM images, the white area indicates FeNi3 or FeNi nitride 4 containing a group 6 or group 7 transition metal element 2, or L1 after the denitriding treatment. ０The cross-sectional TEM image shows a FeNi ordered alloy 5 of the type. The upper black portion in the cross-sectional TEM image is a carbon film 6 formed as a surface cap layer for creating the cross-sectional TEM image. The carbon film 6 is formed each time a cross-sectional TEM image is obtained. In the cross-sectional TEM image in which Mn, Fe, and Ni are extracted, the dots scattered at positions corresponding to FeNi3, FeNi nitride 4, or FeNi ordered alloy 5 indicate each element.

[0036] As shown in this figure, before the nitriding process, Mn was uniformly distributed in the thin film of FeNi3. Furthermore, Fe and Ni were also uniformly distributed throughout the thin film of FeNi3.

[0037] In this state, the moles of each element were measured by EDXRF to determine the at%. When X-rays are emitted to the sample, the X-ray irradiation excites the element, causing it to fluoresce. Measuring the energy spectrum reveals the elements and their amounts. Figure 6 shows the results of extracting the energy spectrum, and Figure 7 shows the results of measuring the at% from the energy spectrum of the area enclosed by the dashed line in Figure 6, i.e., Mn, Fe, and Ni. Figure 6 indicates which element each spectrum represents. Ga in Figure 6 was detected as a residue because Ga ions were used for sampling before TEM analysis. Si is a constituent material of the glass substrate 1. Figure 7 also lists the element lines for Mn, Fe, and Ni as MnK, FeK, and NiK, respectively. The net count indicates the integrated intensity of the detected fluorescent X-rays from the element, and the weight percentage of the element indicates the proportion of each element relative to the sum of the integrated intensities. The weight percentage ratio of each element was converted to calculate the at% ratio. As can be seen from this result, the Mn content was 1.06 at % before the nitriding step, and Mn was introduced at approximately 1 at %.

[0038] Subsequently, when a nitriding step was carried out, N was taken into the thin film of FeNi 3, resulting in an expanded FeNi nitride 4 as shown in Fig. 5. Even in this state, Mn was present almost uniformly in the FeNi nitride 4, but more Mn was segregated at the interface with the glass substrate 1. As for Fe and Ni, although the FeNi nitride 4 was deformed due to expansion, they were still present almost uniformly.

[0039] After the nitriding step, the moles of each element were measured by EDXRF to determine the at% as in the case before the nitriding step. The notations in Figures 8 and 9 are the same as those in Figures 6 and 7, respectively. As can be seen from these results, after the nitriding step, Mn was 1.01 at%, meaning that Mn was introduced at approximately 1 at%.

[0040] Furthermore, when the denitrification step is performed, nitrogen is released and L1 ０ As shown in FIG. 5 , the FeNi ordered alloy 5 was separated into particles 10 due to the desorption of nitrogen. Even in this state, Mn was distributed roughly evenly in the FeNi ordered alloy 5, with more Mn segregating at the interface with the glass substrate 1. Furthermore, although Fe and Ni were shrunk more than in the case of the FeNi nitride 4 due to the desorption of nitrogen, they were still distributed roughly evenly.

[0041] After the denitriding step, the moles of each element were measured by EDXRF to determine the at% as in the case before the nitriding step. The notations in Figures 10 and 11 are the same as those in Figures 6 and 7, respectively. As can be seen from these results, after the denitriding step, Mn was 1.19 at%, meaning that Mn was introduced at approximately 1 at%.

[0042] Thus, Mn-doped L1 ０An FeNi ordered alloy 5 of the type 1000 was obtained. Furthermore, when Mn was used, an FeNi ordered alloy 5 was obtained in a state where more Mn was segregated at the interface with the glass substrate 1, that is, Mn was segregated throughout the particles of the FeNi ordered alloy 5, as well as on the particle surfaces. Furthermore, since the area of ​​each element extracted in the cross-sectional TEM image indicates the content of each element, the Mn content was calculated by measuring the area, and was found to be approximately 1 at %, which was the same as the doped amount. Therefore, when FeNi is doped with a transition metal element 2 of group 6 or group 7, the doping ratio is maintained even after the nitriding step and denitriding step, so that by adjusting the doping ratio in FeNi, it is possible to obtain an L1 ０ The content of the type in the FeNi ordered alloy 5 can also be adjusted.

[0043] In addition, when Mn was used, the results showed that it was more likely to segregate at the particle surface, especially at the interface with the glass substrate 1. However, in experiments, even when other Group 6 or Group 7 transition metal elements 2 were used, various segregation forms were obtained depending on the element used or the nitriding and denitriding processes. Specifically, FeNi ordered alloys 5 were obtained in which the Group 6 or Group 7 transition metal element was present throughout the particle, segregated inside the particle 10, or segregated on the particle surface. When present throughout the particle, the element may be present uniformly or unevenly. In some cases, the element may be present inside the particle 10 and segregated on the particle surface, and in some cases, the element may be segregated over the entire surface or only partially on the surface. In either case, the L1 doped with the Group 6 or Group 7 transition metal element 2 was ０ The alloy was an FeNi ordered alloy 5 of the type, and good magnetic properties were obtained. This will be explained below.

[0044] L1 containing the Group 6 or Group 7 transition metal element 2 in Examples 1 and 2 prepared as described above ０ The FeNi ordered alloy 5 and the L1 alloy in Comparative Example 1 which does not contain the transition metal element 2 of Group 6 or Group 7 ０The magnetic properties were investigated for the FeNi ordered alloy 5. Fig. 12 shows the hysteresis curves at room temperature, e.g., 27°C, and the intercept of the hysteresis curve on the X axis represents the coercive force Hc [Oe].

[0045] As shown in this figure, the coercive force Hc of Comparative Example 1 was 1022 [Oe], the coercive force Hc of Example 2 was 1395 [Oe], and the coercive force Hc of Example 1 was the largest at 1621 [Oe]. In other words, it was confirmed that in both Examples 1 and 2, the coercive force Hc was higher than that of Comparative Example 1, and both were able to achieve high values ​​close to or above 1400 [Oe]. In this way, it was confirmed that the L1 containing a Group 6 or Group 7 transition metal element 2 ０ By forming the FeNi ordered alloy 5, a high coercive force Hc can be obtained even at room temperature. ０ The FeNi ordered alloy 5 can be used as a magnetic material, and if a permanent magnet is manufactured by making it into a sintered magnet or a bonded magnet, it becomes possible to obtain a permanent magnet having a higher coercive force Hc.

[0046] Furthermore, when the temperature change in coercivity Hc was investigated for Comparative Example 1 and Example 1, the characteristics shown in Figure 13 were obtained. Specifically, the coercivity Hc measured at room temperature was designated room temperature coercivity Hc1, and the coercivity Hc when the temperature was raised from room temperature was designated high temperature coercivity Hc2. The ratio of the high temperature coercivity Hc2 to the room temperature coercivity Hc1 was measured and plotted for each temperature. Specifically, the coercivity Hc was calculated based on the following formula. Since the coercivity Hc at a temperature of 300 [K] is the room temperature coercivity Hc1, the ratio is 100%. (Formula 2) Hc (%) = (Hc2 / Hc1) x 100

[0047] As shown in this figure, in the temperature range below 500 [K], both Comparative Example 1 and Example 1 have equivalent coercive forces Hc. In this temperature range, both Comparative Example 1 and Example 1 show similar rates of decrease in coercive force Hc. However, around 600 [K], the ratio of high-temperature coercive force Hc2 to room-temperature coercive force Hc1 begins to decrease in Comparative Example 1 more than in Example 1, and the rate of decrease increases with increasing temperature. The temperature at which the ratio of high-temperature coercive force Hc2 to room-temperature coercive force Hc1 becomes 90% was estimated to be 608 [K] for Comparative Example 1 and 654 [K] for Example 1. In other words, compared to Comparative Example 1, the temperature at which the ratio of high-temperature coercive force Hc2 to room-temperature coercive force Hc1 becomes 90% was nearly 50 [K] higher in Example 1. This indicates that Example 1 exhibits little decrease in coercive force Hc with increasing temperature and has excellent magnetic properties against heat, that is, the FeNi superlattice structure is maintained and the stability of the FeNi superlattice is improved.

[0048] Here, the temperature change of the coercive force Hc was investigated for Example 1 using Mn as the Group 7 transition metal element, but even when other Group 7 transition metal elements or Group 6 transition metal elements were used, the degree of decrease in coercive force Hc with increasing temperature was less than that of Comparative Example 1. In other words, the L1 containing Group 6 or Group 7 transition metal element 2 ０ By using an FeNi ordered alloy 5 of the L1 type, ０ The heat resistance of the ordered structure was improved. However, when Mn was used in particular, the degree of decrease in coercive force Hc with increasing temperature was small, and it can be said that the use of Mn makes it possible to obtain higher heat resistance.

[0049] As described above, L1 containing a transition metal element 2 of Group 6 or Group 7 ０ By forming the FeNi ordered alloy 5, a higher coercive force Hc can be obtained, and if a permanent magnet is manufactured using the alloy as a magnetic material, the permanent magnet can have a higher coercive force Hc. ０ By making the alloy into an FeNi ordered alloy 5, and in particular by making it contain Mn, it becomes possible to improve the heat resistance.

[0050] Furthermore, since the material has high heat resistance even at temperatures above 600 [K], i.e., above 300 [°C], it is possible to set the molding temperature for magnetization at a high temperature of 300 [°C] or above, making magnetization easier.

[0051] While the present disclosure has been described based on the above-described embodiment, it is not limited to the embodiment and encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0052] For example, in the above embodiment, the case where FeNi is formed as a thin film has been described as an example, but it may also be formed in particulate form. Furthermore, the case where each film constituting FeNi is formed by sputtering has been described as an example, but the method is not limited to sputtering. Particulate FeNi can be formed, for example, by a precipitation process in which an Fe raw material or raw material is dissolved in a strongly acidic solution to prepare a solution containing Fe and Ni, and a precipitant is introduced into the solution to obtain a precipitate containing Fe and Ni. Furthermore, although the case where a Group 6 or Group 7 transition metal element 2 is formed in film form has been described, this does not necessarily have to be formed in film form, and it may also be doped into FeNi by other methods.

[0053] The present disclosure is not limited to the above-described embodiments and can be modified as appropriate. It goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle. Furthermore, in each of the above embodiments, when numerical values ​​such as the number, value, amount, and range of the components of the embodiments are mentioned, they are not limited to the specific number unless they are specifically stated as essential or are clearly limited to a specific number in principle.

[0054] (Aspects of the present disclosure) The above-described present disclosure can be understood from the following aspects, for example. [First aspect] L1 ０L1 having an ordered structure of the type and containing a transition metal element of Group 6 or Group 7 (2) ０ [Second Aspect] The L1 type FeNi ordered alloy according to the first aspect, wherein the transition metal element of Group 6 or Group 7 is an element that does not exhibit ferromagnetism at room temperature. ０ [Third Aspect] The L1 alloy according to the first or second aspect, wherein the transition metal element of Group 6 or Group 7 is any one of Cr, Mo, W, Mn, Tc, and Re. ０ [Fourth Aspect] The L1 alloy according to the first or second aspect, wherein the transition metal element of Group 6 or Group 7 is Mn. ０ [Fifth Aspect] The L1 alloy according to any one of the first to fourth aspects, wherein the content of the transition metal element of Group 6 or Group 7 is 1.19 at % or less. ０ [Sixth Aspect] The alloy L1 according to any one of the first to fifth aspects, which is composed of particles, and the transition metal element of Group 6 or Group 7 is present inside and on the surface of the particles. ０ [Seventh Aspect] The alloy L1 according to any one of the first to sixth aspects, which is composed of particles, and the transition metal element of Group 6 or Group 7 is segregated on the surface of the particles. ０ [Eighth Aspect] An FeNi ordered alloy containing a Group 6 or Group 7 transition metal element according to any one of the first to seventh aspects. ０ A permanent magnet composed of an FeNi ordered alloy of the L1 type as the main phase. ０ L1 having a regular structure of type ０ A method for producing an FeNi ordered alloy of this type, comprising: generating FeNi (3) containing a Group 6 or Group 7 transition metal element (2); nitriding the FeNi to form an FeNi nitride (4) containing the Group 6 or Group 7 transition metal element; and performing a denitrification process to remove nitrogen from the FeNi nitride to produce an L1 alloy containing the Group 6 or Group 7 transition metal element. ０ forming an ordered FeNi alloy (5) of type L1; ０ Method for producing ordered FeNi alloys of this type.

Claims

1. L1 ０ L1 having an ordered structure of the type and containing a transition metal element of Group 6 or Group 7 (2) ０ A type of FeNi ordered alloy.

2. The L1 according to claim 1, wherein the transition metal element of Group 6 or 7 is an element that does not exhibit ferromagnetism at room temperature. ０ A type of FeNi ordered alloy.

3. The L1 according to claim 1, wherein the transition metal element of Group 6 or Group 7 is any one of Cr, Mo, W, Mn, Tc, and Re. ０ A type of FeNi ordered alloy.

4. The L1 according to claim 1, wherein the transition metal element of Group 6 or Group 7 is Mn. ０ A type of FeNi ordered alloy.

5. The L1 according to claim 1, wherein the content of the transition metal element of Group 6 or Group 7 is 1.19 at % or less. ０ A type of FeNi ordered alloy.

6. The L1 according to claim 1, which is composed of particles, and the transition metal element of Group 6 or Group 7 is present inside and on the surface of the particles. ０ A type of FeNi ordered alloy.

7. The L1 according to claim 1, which is composed of particles, and the transition metal element of Group 6 or Group 7 is segregated on the surface of the particles. ０ A type of FeNi ordered alloy.

8. L1 containing a Group 6 or 7 transition metal element according to any one of claims 1 to 7. ０ A permanent magnet composed of an FeNi ordered alloy of this type as the main phase.

9. L1 ０ L1 having a regular structure of type ０ A method for producing an FeNi ordered alloy of this type, comprising: generating FeNi (3) containing a Group 6 or Group 7 transition metal element (2); nitriding the FeNi to form an FeNi nitride (4) containing the Group 6 or Group 7 transition metal element; and performing a denitrification process to remove nitrogen from the FeNi nitride to produce an L1 alloy containing the Group 6 or Group 7 transition metal element. ０ forming an ordered FeNi alloy (5) of type L1; ０ Method for producing ordered FeNi alloys of this type.

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