Magnetic film, member with magnetic film, actuator, and sensor

Abstract

The invention provides a magnetic film capable of obtaining high coercive force in a magnetic film having a thickness of dozens to hundreds of microns, a magnetic film-equipped member having the magnetic film, an actuator, and a sensor. A magnetic film comprising: a rare earth element containing Sm or Nd as an essential element; and a transition metal element including Co or Fe. The magnetic film has a main magnetic layer containing a plurality of crystal particles, the crystal particles have columnar particles in which a first length (Lc) in the thickness direction of the main magnetic layer is longer than a second length (La) in the direction perpendicular to the thickness direction, and a first average value (Lc1) of the lengths in the thickness direction of the crystal particles is 10 [mu] m or more.

Description

Technical Field

[0001] This disclosure relates to magnetic membranes, components with magnetic membranes, actuators, and sensors. Background Technology

[0002] With the continuous pursuit of miniaturization in various electronic devices, the development of small devices such as micro motors or micro actuators to be incorporated into these devices is also ongoing. The size and performance of these devices largely depend on the size and magnetic properties of the permanent magnets used in them. Sintered magnets have very high magnetic properties, but due to the deterioration of the surface layer during processing, it is difficult to process them into shapes with a thickness of less than 200 μm required for small device applications while maintaining their properties.

[0003] On the other hand, although high-performance permanent magnets that can be formed by sputtering have been developed, it is difficult to manufacture permanent magnets with a thickness of more than 10 μm due to the low film formation rate. Therefore, it is difficult to achieve high-performance permanent magnet films with a thickness of 10–200 μm. From the perspective of miniaturization and high performance of devices, there has been a continuous pursuit of realizing magnets with this size range.

[0004] Patent document 1 discloses a magnetic film in which a hard magnetic material containing SmCo5 with a thickness of 1 to 200 μm is formed on the main surface of the magnetic yoke containing soft magnetic material.

[0005] However, due to their shape, thin magnets suffer from a large demagnetizing field generated by the magnetization of the permanent magnet, making them prone to demagnetization. When magnetization occurs with poles appearing along the thickness direction, the magnetic reluctance of the magnetic path through the interior of the magnet becomes extremely small compared to the magnetic reluctance of the path from the N pole surface through the space outside the magnet back to the S pole; therefore, the demagnetizing coefficient is close to 1. The ease of demagnetization depends on the magnitude of the coercivity at the operating temperature of the permanent magnet, the magnitude of the demagnetizing field, and the magnitude of the external magnetic field applied in the opposite direction to the magnetization direction. However, the magnet disclosed in Patent Document 1 still has room for improvement in this regard. The aim is to obtain a magnetic film with high coercivity even in magnets with a thickness of tens to hundreds of micrometers.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2022 / 045260 Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] This disclosure was made in view of this actual situation, and its purpose is to provide a magnetic film with high coercivity obtained in a magnetic film with a thickness of tens to hundreds of micrometers, a component with a magnetic film having the magnetic film, an actuator and a sensor.

[0011] Technical solutions for solving technical problems

[0012] To achieve the above objectives, one aspect of this disclosure provides a magnetic film having:

[0013] Rare earth elements, which contain Sm or Nd as essential elements; and

[0014] Transition metal elements, including Co or Fe,

[0015] The magnetic film is a hard magnetic material.

[0016] The magnetic film has a main magnetic layer containing multiple crystalline particles.

[0017] The crystalline particles are columnar particles with a first length (Lc) along the thickness direction of the main magnetic layer that is longer than a second length (La) along a direction perpendicular to the thickness direction.

[0018] The first average value (Lc1) of the length of the crystalline particles along the thickness direction is 10 μm or more.

[0019] Generally speaking, thin permanent magnets are easier to demagnetize. The ease of demagnetization depends on the coercivity of the permanent magnet at its operating temperature, the magnitude of the demagnetizing field, and the magnitude of the external magnetic field applied in the opposite direction to the magnetization direction. The smaller the coercivity and the larger the demagnetizing field, the easier it is to demagnetize. The magnitude of the demagnetizing field depends on the shape of the permanent magnet; the thinner the permanent magnet is in the magnetization direction, the larger the demagnetizing field (the easier it is to demagnetize). That is, the shorter the distance between the magnetic poles (the thinner it is), the stronger the internal demagnetizing field (the easier it is to demagnetize).

[0020] In a magnetic film according to one aspect of this disclosure, columnar particles having a first length (Lc) along the thickness direction of the main magnetic layer longer than a second length (La) along a direction perpendicular to the thickness direction, and the first average value (Lc1) of the length of the crystalline particles along the thickness direction is 10 μm or more.

[0021] That is, in this magnetic film, the crystalline particles are shaped to elongate along the direction of the easy magnetization axis of the crystal. Therefore, the influence of magnetostatic interactions when adjacent particles experience magnetization reversal can be reduced. The demagnetizing field per unit of crystalline particle can be reduced; in other words, the demagnetizing field observed locally (hereinafter sometimes referred to as the local demagnetizing field) can be increased, thereby improving the coercivity of the magnetic film. In summary, since the crystalline particles are elongated in the thickness direction, the local demagnetizing field is reduced, and the coercivity of the magnet (magnetic film) is increased. Furthermore, although crystalline particles that are elongated in the thickness direction are known to exist in sputtered films, etc., sputtered films with a length of 10 μm or more are difficult to manufacture; therefore, it is not easy to manufacture crystalline particles with a first length (Lc) of 10 μm or more along the thickness direction.

[0022] Preferably, the rate of reduction of the proportion of rare earth elements at the grain boundaries between adjacent crystalline grains relative to the proportion of rare earth elements inside the crystalline grains (e.g., at a distance of 50 nm or more from the grain boundary) is preferably 3% or more, and also preferably 3% or more and 80% or less, or 3% or more and 70% or less. That is, (R amount within the grain - R amount at the grain boundary) / (R amount within the grain) is preferably 3% or more, and also preferably 3% or more and 80% or less, or 3% or more and 70% or less. It is believed that due to the compositional changes at the grain boundaries, the grain boundaries may become amorphous or contain amorphous microcrystals, generating gaps with anisotropic magnetic fields. That is, it is believed that because the movement of the magnetic walls is pinned between adjacent crystalline grains by grain boundaries with low rare earth elements such as Sm, the propagation of magnetization reversal is hindered, thus further increasing the coercivity.

[0023] Preferably, the first average value (Lc1) is 1.1 times or more, or even 2.0 times or more, relative to the second average value (La2) of the second length (La) of the crystalline particles. That is, Lc1 / La2 is preferably 1.1 or more, and even more preferably 2.0 or more. When it is in this range, the ratio of particle length in the thickness direction becomes larger, and the local demagnetizing field becomes smaller.

[0024] The columnar particles can also be through-type particles whose first length (Lc) is equal to the thickness of the main magnetic layer. Through-type particles with the largest particle length in the thickness direction result in a greater reduction in the local demagnetizing field.

[0025] When rare earth elements are denoted as R and transition metal elements as T, the main magnetic layer can also have RT5 and R2T. 17 RT 12 R2T 17 Any of N3. Additionally, the main magnetic layer can also be SmCo5 or Sm2Co. 17 、SmFe 12 NdFe 12 Sm2Fe 17Any of N3. Magnetic films may also contain nitrogen.

[0026] The magnetic film can also have a secondary magnetic layer in contact with the primary magnetic layer. The atomic ratio of rare earth elements in the secondary magnetic layer can also differ from that in the primary magnetic layer. For example, when rare earth elements are denoted as R and transition metal elements as T, the primary magnetic layer could be composed of RT5, and the secondary magnetic layer could be composed of, for example, Sm2Co. 17 Wait for R2T 17 It may be composed of Sm2Co7, R2T7, etc.

[0027] The thickness of the main magnetic layer is preferably 10 μm or more, but can also be 20 μm or more, 30 μm or more, 50 μm or more, or 10 to 300 μm.

[0028] One aspect of this disclosure provides a component with a magnetic film, comprising: a magnetic film as described in any of the preceding claims; and a substrate component on which the magnetic film is formed. A secondary magnetic layer may also be located between the substrate component and the primary magnetic layer and stacked thereon, for example, it may be composed of Sm2Co. 17 Wait for R2T 17 The structure can be configured as follows. Alternatively, the secondary magnetic layer can be stacked on the surface of the main magnetic layer opposite to the substrate component; in this case, it can be composed of Sm2Co7, R2T7, or similar materials. Furthermore, the secondary magnetic layer can also be stacked at two locations: between the substrate component and the main magnetic layer, and on the surface of the main magnetic layer opposite to the substrate component.

[0029] The surface of the substrate component may also have the same transition metal element as that contained in the main magnetic layer.

[0030] One aspect of this disclosure provides an actuator having a magnetic membrane as described in any of the above claims.

[0031] One aspect of this disclosure is to provide a sensor having a magnetic membrane as described in any of the preceding claims. Attached Figure Description

[0032] Figure 1 This is a schematic cross-sectional view of a magnetic film according to one embodiment of the present disclosure.

[0033] Figure 2A It means Figure 1 A cross-sectional view of a portion of the manufacturing process of the magnetic film shown.

[0034] Figure 2B It means Figure 2A A cross-sectional view of the subsequent process in the manufacturing process of the magnetic film shown.

[0035] Figure 2C It means Figure 2B A cross-sectional view of the subsequent process in the manufacturing process of the magnetic film shown.

[0036] Figure 3A It has Figure 1 A schematic cross-sectional view of an example of a magnetic membrane electric motor.

[0037] Figure 3B It has Figure 1 A schematic cross-sectional view of an example of a linear actuator for a magnetic membrane.

[0038] Figure 3C It has Figure 1 A schematic cross-sectional view of an example of a magnetic membrane sensor shown.

[0039] Figure 4 This is a cross-sectional SEM image of a magnetic film according to an embodiment of the present disclosure.

[0040] Figure 5 yes Figure 4 The STEM image shown is of the area near the grain boundary of the V region.

[0041] Figure 6 It means along with Figure 5 A graph showing the concentration distribution of rare earth elements at the measurement point of the imaginary line perpendicular to the grain boundary.

[0042] Figure 7A It is a cross-sectional SEM image of a magnetic film formed on the surface of a substrate component with a concave curved surface.

[0043] Figure 7B It is a cross-sectional SEM image of a magnetic film formed on the surface of a substrate component with a convex curved surface.

[0044] Figure 8 This is a cross-sectional SEM image of a magnetic film according to an embodiment of the present disclosure.

[0045] Explanation of reference numerals in the attached figures

[0046] 1, 1a, 1b Substrate (base component)

[0047] 1α surface

[0048] 1A Motor Rotor (Base Component)

[0049] 1B Actuator substrate (base component)

[0050] 1C Detection substrate (substrate component)

[0051] 10 Magnetic membrane

[0052] 10A, 10B, 10C magnetic films

[0053] 20 Main magnetic layers

[0054] 22 Crystalline particles

[0055] 22a Columnar particles

[0056] 22a1 Through-type particles

[0057] 22a2 Non-penetrating particles

[0058] 22b Non-columnar particles

[0059] 23 Grain boundary

[0060] 30a and 30b secondary magnetic layers

[0061] 40A motor Detailed Implementation

[0062] The following description is based on the implementation method.

[0063] Magnetic membrane 10

[0064] like Figure 1 As shown, the magnetic film 10 of this embodiment is formed on the surface of the substrate 1, which serves as the base component, and has at least a main magnetic layer 20, and may also have secondary magnetic layers 30a and 30b as needed. The secondary magnetic layer 30a is stacked between the substrate 1 and the main magnetic layer 20, and another secondary magnetic layer 30b is stacked on the surface of the main magnetic layer 20 located on the side opposite to the substrate 1. In the magnetic film 10 of this embodiment, the main magnetic layer 20 mainly constitutes the permanent magnet film.

[0065] The magnetic film 10, which includes at least the main magnetic layer 20, is a hard magnetic material. It is a magnetic film containing rare earth elements (Sm or Nd as essential elements), transition metal elements (Co or Fe), and, if necessary, nitrogen. The rare earth element R can also be Sc, Y, or a lanthanide element. The transition metal T does not contain rare earth elements. The transition metal T can also be an iron group element. The main magnetic layer 20 and the secondary magnetic layers 30a and 30b, formed as needed, preferably contain the same elements, but can also contain different elements. For example, Li, K, Cl, Mo, Ta, and Nb can be included as different elements.

[0066] When rare earth elements are denoted as R and transition metal elements as T, the main magnetic layer 20 can also have RT5 and R2T. 17 RT 12 R2T 17 Any of N3. For example, the main magnetic layer 20 is preferably made of SmCo5 or Sm2Co. 17、SmFe 12 NdFe 12 Sm2Fe 17 Any of the following compositions in N3. The secondary magnetic layers 30a and 30b are preferably composed of rare earth elements in a different atomic ratio than those in the main magnetic layer 20. For example, if the main magnetic layer 20 is composed of SmCo5, it is preferable that the secondary magnetic layer 30b is composed of a composition with a higher rare earth element content than the main magnetic layer 20 (e.g., Sm2Co7), and the secondary magnetic layer 30a is composed of a composition with a lower rare earth element content than the main magnetic layer 20 (e.g., Sm2Co7). 17 It is composed of [a certain structure]. In addition, the surface of the substrate component preferably has the same transition metal element as the transition metal element contained in the main magnetic layer 20.

[0067] Preferably, there are no intervention layers made of non-magnetic materials such as oxide layers, resin layers, or adhesive layers that are observable with a specific resolution of 0.5 to 4 nm between the substrate 1 and the secondary magnetic layer 30a, between the secondary magnetic layer 30a and the main magnetic layer 20, and between the main magnetic layer 20 and the secondary magnetic layer 30b. However, there may be intervention layers that are thin with a specific resolution of 0.5 to 4 nm. In addition, a protective layer made of non-magnetic materials such as oxide layers, resin layers, or adhesive layers may be formed on the surface of the secondary magnetic layer 30b, or on the surface of the main magnetic layer 20 when the secondary magnetic layer 30b is not present.

[0068] The thickness of the protective layer is not particularly limited, but from the viewpoint of maximizing the utilization of magnetic flux from the main magnetic layer 20 toward the surface of the magnetic film 10, a thinner layer is preferable. From the viewpoint of further increasing the surface magnetic flux density, the lower limit of the thickness of the main magnetic layer 20 is preferably 10 μm or more, 20 μm or more, 30 μm or more, or 50 μm or more. The upper limit of the thickness is not particularly limited, but from the viewpoint of miniaturizing the device mounting the magnetic film 10, it can also be 350 μm or less, 300 μm or less, or 200 μm or less.

[0069] The thicknesses of the secondary magnetic layers 30a and 30b are preferably smaller than the thickness of the primary magnetic layer 20. For example, the thickness of the secondary magnetic layer 30a may be less than 1 / 2, 1 / 4, or 1 / 8 of the thickness of the primary magnetic layer 20. The thickness of the secondary magnetic layer 30b may also be less than 1 / 2, 1 / 3, or 1 / 4 of the thickness of the secondary magnetic layer 30a. The thicknesses of these layers 20, 30a, and 30b can, for example, be... Figure 4 The average value of measurement points at multiple locations in the cross-sectional SEM image shown is used for measurement.

[0070] In the following description, the main magnetic layer 20 contains SmCo5 as the main phase, and the secondary magnetic layer 30a contains Sm2Co. 17 The following explanation uses Sm2Co7 as the main phase in the secondary magnetic layer 30b as an example.

[0071] SmCo5 has a CaCu5-type crystal structure and is an alloy with Sm and Co as the main components. The main components refer to the Sm and Co content, which must be at least 80 mol%. The ratio of Sm atoms to Co atoms in SmCo5 can deviate from the stoichiometric ratio. For example, if various elements are added to improve magnetic properties, the ratio of Sm atoms to Co atoms in SmCo5 may not always be stoichiometric. Therefore, as long as SmCo5 has a CaCu5-type crystal structure, the ratio of Sm atoms to Co atoms can deviate from the stoichiometric ratio.

[0072] In the specification of this application, "as the main phase" refers to the phase with the largest area proportion in a cross-section substantially perpendicular to the surface of the magnetic film 10. For example, the main magnetic layer 20 may also have a phase different from SmCo5, such as other crystalline phases and grain boundary phases. Regarding the proportion of SmCo5 in the SmCo5 film, for example, the area proportion may be 70% or more, 80% or more, 90% or more, or 95% or more. As a heterogeneous phase, for example, a Sm-rich phase with a higher Sm content than SmCo5 can be cited.

[0073] The crystal orientation [00L] of SmCo5 is oriented along the thickness direction of the main magnetic layer 20, that is, perpendicular to the film surface. L is any natural number. Regardless of the value of L, it refers to the same direction. For example, L is 2. The orientation of the SmCo5 crystal orientation [00L] along the thickness direction of the main magnetic layer 20 means that the degree of orientation is 50% or more. This degree of orientation is based on the vector-corrected Lotgering method, which represents the proportion of the sum of diffraction peaks based on the crystal orientation [00L] composition relative to the sum of diffraction peaks based on the crystal plane (hkl) of SmCo5. From the viewpoint of further improving the surface magnetic flux density of the magnetic film 10, the degree of orientation is preferably 90% or more, more preferably 95% or more. In addition, SmCo5 has a Curie point of 700°C or more, and therefore has excellent thermal stability.

[0074] Sm2Co 17 With Th2Zn 17 This type of crystal structure is an alloy with Sm and Co as the main components. The main components refer to the content of Sm and Co being 80 mol% or higher. (Sm₂Co) 17 The ratio of Sm atoms to Co atoms in Sm2Co can also deviate from the stoichiometric ratio. For example, if various elements are added to improve magnetic properties, etc., then Sm2Co... 17The ratio of Sm atoms to Co atoms in Sm₂Co is not always a stoichiometric ratio. Therefore, as long as Sm₂Co 17 With Th2Zn 17 In a crystal structure of this type, the ratio of Sm atoms to Co atoms can also deviate from the stoichiometric ratio.

[0075] The secondary magnetic layer 30a can also have properties similar to Sm2Co. 17 Different phases, such as other crystalline phases and grain boundary phases. Regarding Sm2Co... 17 Sm2Co in the membrane 17 In terms of proportion, for example, the area ratio on a cross section approximately perpendicular to the surface of the magnetic film 10 can be 70% or more, 80% or more, 90% or more, or 95% or more.

[0076] The ratio of Sm atoms to Co atoms in the secondary magnetic layer 30b can be greater than 0.28 and less than 0.51. The secondary magnetic layer 30b can be Sm2Co7, SmCo3, or SmCo2. The secondary magnetic layer 30b can also have multiple crystalline phases and grain boundary phases.

[0077] Crystallized particles 22

[0078] In this embodiment, such as Figure 1 As shown, the magnetic layer 20 has a plurality of crystalline particles 22. In this embodiment, the crystalline particles 22 have at least one columnar particle 22a, and may also have non-columnar particles 22b. The columnar particle 22a may be a through-type particle 22a1 or a non-through-type particle 22a2.

[0079] Columnar particles 22a, for example, can be passed through Figure 4 The cross-sectional SEM image shown is observed and is defined as: along Figure 1 The crystalline particles shown have a first length Lc in the thickness direction of the main magnetic layer 20 that is longer than a second length La in the direction perpendicular to the thickness direction. Within the columnar particles 22a, crystalline particles that penetrate from the lower surface to the upper surface along the thickness direction of the main magnetic layer 20 are defined as penetrating particles 22a1, and non-penetrating columnar particles 22a are defined as non-penetrating particles 22a2. Additionally, along... Figure 1 Crystalline particles with a first length Lc in the thickness direction of the main magnetic layer 20, which is the same as or shorter than a second length La in the direction perpendicular to the thickness direction, are defined as non-columnar particles 22b.

[0080] In this embodiment, in a cross-sectional SEM image of the magnetic film 10, for example, within the observation range of more than 100 crystalline particles 22, the first average value Lc1 of the first length Lc of the crystalline particles 22 along the thickness direction of the main magnetic layer 20 is 10 μm or more. Furthermore, the ratio (Lc1 / La2) of the first average value Lc1 relative to the second average value La2 of the second length La of the crystalline particles 22 observed within the same observation range is not particularly limited, but is preferably 0.5 or more, 1.1 or more, or 2.0 or more. That is, by making Lc1 / La2 a predetermined value or more, the ratio in the thickness direction with respect to particle length increases, and the demagnetizing effect is considered to be greater. As a result, the coercivity of the magnetic film 10 can be improved.

[0081] Since Lc1 / La2 is likely to be above a specified value, which easily improves the coercivity of the magnetic film 10, the through-type particles 22a1 preferably contain 10% or more, more preferably 30% or more in terms of the number of particles.

[0082] like Figure 1 As shown, the main magnetic layer 20 has grain boundaries 23 between columnar particles 22a and between columnar particles 22a and non-columnar particles 22b. The thickness of the grain boundaries 23 is, for example, as shown in the figure. Figure 5 The image shown is not particularly limited, for example, it is below 20nm, preferably 0.5 to 10.0nm, or preferably 2.0 to 7.0nm.

[0083] In this embodiment, for example, such as Figure 6 As shown, the reduction rate of the proportion of rare earth elements at the grain boundary 23 relative to the proportion of rare earth elements (e.g., Sm) inside the crystalline grain 22a is 3% or more. That is, (R amount inside the grain - R amount at the grain boundary) / (R amount inside the grain) is preferably 3% or more, and also preferably 3% or more and 80% or less, or 3% or more and 70% or less. Furthermore, the interior of the crystalline grain 22a refers, for example, to a location 50 nm or more away from the grain boundary 23 in a direction perpendicular to the long side of the grain boundary 23.

[0084] It is believed that due to the compositional changes of grain boundaries 23, the grain boundaries may become amorphous or contain microcrystals containing amorphous material, resulting in gaps in anisotropic magnetic fields. That is, it is believed that because the movement of the magnetic walls is pinned between adjacent crystalline grains 22 by grain boundaries with low rare earth elements such as Sm, the propagation of magnetization reversal is hindered, thus further increasing the coercivity.

[0085] Method for manufacturing magnetic films

[0086] Next, the manufacturing method of the magnetic film 10 will be described.

[0087] First, a substrate 1 is prepared as the base component. The substrate 1 is not particularly limited, but in order to form the magnetic film 10 on the surface of the substrate 1, at least one surface of the substrate 1 must have a transition metal element that is the same as the transition metal element contained in the main magnetic layer 20. Examples of materials for the substrate 1 include Co, Fe, Ni, Mo, Ta, Nb, FeCo, CoCr, and CoCrMo. When the transition metal element contained in the main magnetic layer 20 is Co or Fe, the surface of the substrate 1 preferably has a Co layer or an Fe layer. Alternatively, the substrate 1 may also be a Co substrate or an Fe substrate.

[0088] When using a Co substrate as substrate 1, a metallic Co plate is preferred. The purity of Co in the Co substrate can be 99% by mass or more, or 99.998% by mass or more. Other substrates may also be present beneath the Co substrate. The thickness of the Co substrate is not particularly limited and can be appropriately selected according to the application, for example, it can be 0.01 to 2 mm.

[0089] Next, the method for fabricating the magnetic film 10 on the surface of the substrate 1 will be described in detail. As an example, the case where a Co substrate is used as the substrate 1 will be explained. First, as Figure 2A As shown, substrate 1, which is made of Co substrate, is prepared.

[0090] The surface 1α of the substrate 1 is preferably roughened. For example, the arithmetic mean surface roughness Ra of the surface of the substrate 1 (e.g., JIS B 0601) is preferably 0.5 μm or more, more preferably 5.1 μm or more. Furthermore, there is no particular limitation on the upper limit of the arithmetic mean surface roughness Ra of the substrate; for example, it can be 50 μm or less, or 29 μm or less. The surface roughness can be measured using known methods. Additionally, the surface roughness of the substrate 1 can be controlled using known methods, such as sandpaper-based methods or sandblasting, tumbling, electrolytic polishing, and surface processing methods that combine photolithography and etching (wet etching or dry etching, micro-blasting, etc.) to form desired patterns (checkerboard patterns, etc.). In this case, when processing with sandpaper, it is preferable to process in a random direction.

[0091] Next, as Figure 2B As shown, an SmCo2 film 10a is formed on the surface of substrate 1. The SmCo2 film 10a is preferably manufactured, for example, by a molten salt impregnation method or a method using a molten salt impregnation method. First, a reaction solution containing an Sm source and molten salt is prepared for substrate 1.

[0092] In preparing the reaction solution, firstly, a specified inorganic salt is dehydrated by drying it. Examples of inorganic salts include KCl (potassium chloride), LiCl (lithium chloride), and NaCl (sodium chloride). One type of inorganic salt can be used, or two or more can be used in combination. The dehydrated inorganic salt is then heated to a specified temperature to melt it (molten salt). The melting temperature of the inorganic salt can be appropriately determined according to the type of inorganic salt used; for example, 400°C or higher is preferred, 500°C or higher is more preferred, and 600°C or higher is even more preferred.

[0093] An Sm source is added to the molten salt (the molten inorganic salt) to obtain a reaction solution. Examples of Sm sources include metallic Sm and Sm alloys; one or more Sm sources can be used. When the total number of moles of Sm source and inorganic salt in the reaction solution is set to 100 mol%, the proportion of Sm source in the reaction solution is preferably, for example, 0.2 mol% or more and 6 mol% or less.

[0094] Next, by bringing the above-mentioned reaction solution into contact with the surface of substrate 1, the Sm source in the molten salt reacts and diffuses on the surface of substrate 1, forming a magnetic coating containing Sm on the surface of substrate 1. This process is called the reaction diffusion process.

[0095] In the reactive diffusion process, a plate-shaped Co substrate 1 is simply immersed in the reaction solution at a specified temperature for a specified time to form a magnetic coating containing Sm on both sides of the substrate 1. However, if the substrate 1 is directly immersed in the reaction solution, a magnetic coating containing Sm will also form in areas where a magnetic coating is not required, resulting in a lower yield. Therefore, an inert film can also be used to cover areas where a magnetic coating is not required to suppress reactive diffusion.

[0096] For example, it is preferable to form a mask of a high-melting-point material in the unwanted areas. Examples of high-melting-point materials include W, Ta, Nb, Mo, or alloys containing at least one of these elements. The mask of the high-melting-point material can be formed, for example, by a vapor deposition method. After forming the mask of the high-melting-point material on the outer peripheral surface and the end surface, the substrate 1 is immersed in the reaction solution, thereby allowing the Sm source to react and diffuse only in the desired areas of the substrate 1, and enabling the formation of a magnetic coating containing Sm.

[0097] In the reactive diffusion process, the temperature of the reaction solution is maintained at a temperature that allows the inorganic salt to remain in a molten state. From the viewpoint of efficiently forming a magnetic coating, the temperature of the reaction solution is preferably 500°C or higher and 900°C or lower, more preferably 650°C or higher and 800°C or lower. Furthermore, the reaction time can be appropriately set according to the reaction temperature or the proportion of Sm source in the reaction solution to form a magnetic coating of the desired thickness. For example, the reaction time can also be set to 1 hour or more and 60 hours or less.

[0098] The magnetic coating formed on the surface of substrate 1 during the reactive diffusion process is Sm2Co. 17 The magnetic coating after the reactive diffusion process preferably contains Sm2Co7, SmCo3, SmCo2, Sm5Co2, Sm3Co, and Sm as the main phase, and particularly preferably contains SmCo2 as the main phase. SmCo2 is an alloy of Sm and Co with a MgCu2-type crystal structure. As long as the main phase SmCo2 has a MgCu2-type crystal structure, the ratio of Sm atoms to Co atoms in SmCo2 can deviate slightly from the stoichiometry. For example, when additive elements are added to improve magnetic properties, the ratio of Sm atoms to Co atoms may sometimes deviate slightly from the stoichiometry.

[0099] In addition to the main phase, the magnetic coating may also contain Sm-rich phases and grain boundary phases, such as Sm-rich phases with a higher Sm ratio than SmCo2. Regarding the SmCo2 content in the magnetic coating, for example, the area ratio on a cross-section substantially perpendicular to the surface of the magnetic film 10 may be 50% or more, preferably 70% or more, and more preferably 90% or more.

[0100] In addition, after the reaction diffusion process, the substrate 1 with the magnetic coating can be cleaned using organic solvents such as ethanol or pure water.

[0101] Next, the substrate 1 with the magnetic coating containing SmCo2 is heated at a specified temperature for a specified time (heating process). The heating rate in the heating process is not particularly limited, and can be, for example, 0.1 to 100°C / second. The holding temperature is preferably 800°C or higher and 1200°C or lower. The holding time is not limited and can be 1 to 10 hours. In this heating process, the reaction between SmCo2 and Co on the surface of the substrate 1 further proceeds, through the surface of the substrate 1 composed of Co and the magnetic coating 10a composed of SmCo2, such as... Figure 2C As shown, Sm2Co is generated 17 The system comprises a secondary magnetic layer 30a composed of layers and a primary magnetic layer 20 composed of SmCo5 layers. Additionally, a secondary magnetic layer 30b is formed on the surface of the primary magnetic layer 20.

[0102] The heating rate during the heating process is not particularly limited, but is preferably 1°C / min or more and 20°C / min or less. The holding temperature (reached temperature) is preferably 800°C or more and 1200°C or less, more preferably 850°C or more and 1150°C or less, and even more preferably 900°C or more and 1100°C or less. The holding time at the above holding temperature is preferably 2 hours or more and 48 hours or less. Furthermore, the cooling rate after heating is preferably 5°C / min or more, more preferably 10°C / min or more, and even more preferably 20°C / min or more.

[0103] There are no particular restrictions on the atmosphere used in the heating process, but from the viewpoint of suppressing the oxidation of the SmCo5 layer, an inert gas atmosphere is preferred. For example, Ar gas and N2 gas can be used as the inert gas.

[0104] Furthermore, in this embodiment, after the heating process, the temperature is lowered to a specified temperature and then maintained at the specified temperature for a specified time (low-temperature annealing process). Through this low-temperature annealing process, Co element diffuses from the Co in the substrate 1 through the grain boundaries of SmCo5 crystals to the grain boundaries, and the two-grain grain boundaries between SmCo5 crystal grains are modulated. That is, it is believed that an amorphous phase or a mixed phase of amorphous phase and microcrystalline phase richer in transition metal (Co) than the crystal grains 22 of the main phase will be formed at the two-grain grain boundaries 23.

[0105] The holding temperature in the low-temperature annealing process is preferably 550°C or higher and 700°C or lower, more preferably 550°C or higher and 600°C or lower. The holding time in the low-temperature annealing process is preferably 2 hours or higher and 8 hours or lower. In particular, in annealing at 600°C or lower, the coarsening of the crystalline particles 22 of the main phase, such as SmCo5, or the decomposition of the main phase does not occur. Instead, the diffusion of elements (Co) from the substrate 1 through the two-grain boundaries 23 occurs. It is believed that this results in the formation of two-grain boundaries 23 with a thickness of several nanometers, which are amorphous or a mixture of amorphous and microcrystalline phases. The reason for this may not be clear, but an anisotropic magnetic field gap is generated at the interface between the crystalline particles 22 of the main phase and the two-grain boundaries 23, producing a pinning effect on the magnetic walls. As a result, the coercivity may be improved.

[0106] The multilayer magnetic film 10 can be manufactured through the above-described processes (reaction diffusion process, heating process, and low-temperature annealing process). In the magnetic film 10, Sm2Co... 17 Layer 1 and SmCo5 layer are sequentially formed on the surface of substrate 1 to obtain a multilayer structure. When a mask of high melting point material is formed on the surface of substrate 1, the mask of high melting point material can be removed after the heating process, or the mask of high melting point material can be left behind.

[0107] Furthermore, when using an Fe substrate as substrate 1, by performing a heating process in an Ar atmosphere, Fe elements diffuse from the Fe substrate toward the SmFe2 magnetic film, enabling the SmFe2 magnetic film to transform into Sm2Fe. 17 Magnetic membrane.

[0108] Furthermore, when using an Fe substrate as the substrate 1, the magnetic film 10 can be nitrided by heating in a nitrogen atmosphere after the heating process and before the low-temperature annealing process. Specific examples of the nitrogen atmosphere include ammonia, a mixture of ammonia and hydrogen, nitrogen, or a mixture of nitrogen and hydrogen. When using ammonia, the magnetic film can be nitrided in a short time. The flow rate of the gas can be appropriately selected according to the type of gas and the amount of sample, and can be 10 mL / min or more, 50 mL / min or more, or 200 mL / min or more. The heating temperature is preferably 300°C or more and 600°C or less, and the heating time is preferably 1 to 60 hours. By applying the above conditions to the Sm2Fe... 17 By nitriding the magnetic film 10, a magnetic material with high magnetic properties can be obtained from Sm2Fe. 17 10 is a magnetic film composed of N3.

[0109] The above-described method for manufacturing the magnetic film 10 is applicable not only to flat substrates 1, but also to the formation of the magnetic film 10 on the surface of substrate components with various curved surfaces. Furthermore, it is also applicable to the formation of the magnetic film 10 on the inner surface of cylindrical substrate components.

[0110] Summary of this implementation method

[0111] Generally speaking, thin permanent magnets are easier to demagnetize. The ease of demagnetization depends on the magnitude of the coercivity at the operating temperature of the permanent magnet, the magnitude of the demagnetizing field, and the magnitude of the external magnetic field applied in the opposite direction to the magnetization direction. The smaller the coercivity and the larger the demagnetizing field, the easier it is to demagnetize. The thinner the permanent magnet is in the magnetization direction, the larger the demagnetizing field (the easier it is to demagnetize). That is, the shorter the distance between the magnetic poles (the thinner it is), the stronger the internal demagnetizing field (the easier it is to demagnetize).

[0112] In the magnetic film 10 of this embodiment, at least one columnar particle 22a is present within the observation range of the SEM cross-section. The first length Lc of the columnar particle 22a along the thickness direction of the main magnetic layer 20 is longer than the second length La along the direction perpendicular to the thickness direction. Furthermore, the first average value (Lc1) of the length of the crystalline particles 22 along the thickness direction is 10 μm or more. More preferably, within the observation range of the SEM cross-section where more than 100 crystalline particles 22 are observed, the columnar particle 22a is preferably observed to be more than 1 / 5, more than 2 / 5, or more than 1 / 2.

[0113] That is, in the magnetic film 10 of this embodiment, the crystalline particles 22 are made into a shape that elongates in the direction of the easy magnetization axis of the crystal. Therefore, the influence of the magnetostatic interaction when adjacent particles 22 undergo magnetization reversal can be minimized. As a result, the local demagnetizing field can be reduced, and the coercivity of the magnetic film 10 can be improved. In summary, since the crystalline particles 22 are elongated in the thickness direction, the local demagnetizing field is reduced, and the coercivity of the magnet (magnetic film) is improved. Furthermore, although crystalline particles 22a that are elongated in the thickness direction are known to exist in sputtered films and the like, sputtered films with a thickness of 10 μm or more are difficult to manufacture.

[0114] Furthermore, in this embodiment, the columnar particles 22a have through-type particles 22a1 with a first length Lc equal to the thickness of the main magnetic layer 10. Since the main magnetic layer 20 has through-type particles 22a1 with the largest particle length in the thickness direction, the reduction effect of the demagnetizing field in the magnetic film 10 is greater. As a result, the coercivity of the magnetic film 10 is further improved.

[0115] Furthermore, in this embodiment, the magnetic film 10 is magnetized to function as a magnetic film, and the surface magnetic flux density of the magnetic film is preferably 5 mT or more, more preferably 7 mT or more, and even more preferably 10 mT or more. The surface magnetic flux density of the magnetic film can be measured by scanning the surface of the magnetic film 10, which functions as a magnetic film, with a Hall element probe and converting the output voltage into magnetic flux density, etc.

[0116] In this embodiment, the secondary magnetic film 30a or the substrate 1 can also function as a magnetic yoke for the main magnetic layer 20, which functions as a magnet film. In other words, the surface magnetic flux density of the magnetic film 10 can be increased.

[0117] Furthermore, this disclosure is not limited to the above-described embodiments, and various modifications can be made within the scope of this disclosure.

[0118] For example, the surface shape of the substrate (component with magnetic film) 1 having a magnetic film 10 on its surface in this embodiment is not limited to... Figure 1 The planar shape shown. For example, as... Figure 7A As shown, the magnetic film 10 can be formed on the surface of a substrate 1a with a concave surface, or on the surface of a substrate 1b with a convex surface. In either case, a main magnetic layer 20 with elongated columnar particles 22a in the film thickness direction perpendicular to the concave or convex surface can be formed. That is, a main magnetic layer 20 with elongated columnar particles 22a in a direction substantially perpendicular to the tangent of the curved surface of the substrate 1 can be formed.

[0119] Furthermore, the magnetic film 10 of this embodiment, when magnetized to become a magnet film 10A, can also be used in an actuator. For example, it can also be formed on... Figure 3A The surface of the rotor 1A of the electric motor 40A shown. The magnet film 10A can also be configured to be opposite the coil 42A at a specified distance.

[0120] Alternatively, the magnetic film 10 of this embodiment can be magnetized to become a magnet film 10B. For example, it can also be formed in a manner that is opposite to the coil 42B at a predetermined distance. Figure 3B The linear actuator 40B shown is on the actuator substrate 1B.

[0121] Alternatively, the magnetic film 10 of this embodiment can be magnetized to become a magnet film 10C. For example, it can also be formed in a manner that is opposite to the magnetic sensor 42C at a predetermined distance. Figure 3C The position sensor 40C shown is on the detection substrate 1C.

[0122] Example

[0123] The present disclosure will now be described with reference to more detailed embodiments, but the present disclosure is not limited to these embodiments.

[0124] Example 1

[0125] (Preparation of the substrate)

[0126] Prepare multiple flat Co substrates (20×20×1mm) as base components. To ensure a uniform surface condition across the multiple Co substrates, pre-grind the surfaces of the substrates with sandpaper in the order of #320, #1200, and #4000 for 60 seconds each.

[0127] Next, the pre-grinded surface of the substrate underwent surface processing, resulting in numerous grinding marks. As shown in samples 1-9 of Table 1A, the surface processing was achieved using sandpaper with grits of #80, 120, 150, 320, 800, 1200, 2000, and 4000, and was performed for a total of 30 or 300 seconds using a precision surface grinder. For sample 3, sandpaper was not used; instead, surface processing was performed by sandblasting. Furthermore, to randomize the orientation of the grinding marks, the sample orientation was changed every 10 seconds. The Co substrates that underwent surface roughening and other surface processing were then cleaned with acetone.

[0128] After surface processing of the substrate, the surface roughness (arithmetic mean roughness) is measured at 10 randomly selected points and averaged to determine the surface roughness Ra of the substrate. Furthermore, the surface roughness measurement is performed using a laser microscope (Olympus Corporation: OLS4000).

[0129] (Reaction diffusion process)

[0130] LiCl was dried and dehydrated. The dehydrated LiCl was then heated to 700°C in a Mo metal container using an external heater until it melted. Sm metal powder was added to the molten LiCl as an Sm source. The Sm source was added at a molar ratio of LiCl:Sm = 100.0:2.5. Next, the substrate was immersed in the molten LiCl. The substrate was pre-cleaned with acetone. The reaction diffusion temperature was 700°C, and the reaction diffusion time was 9 hours. Through the reaction diffusion process, a laminate with an SmCo2 film formed on the substrate was obtained.

[0131] (Heating process)

[0132] The resulting laminate was heated to 1050°C at a rate of 0.15°C / second. The laminate was then held at 1050°C for 24 hours. The heating atmosphere was Ar gas.

[0133] (Low-temperature annealing process)

[0134] The laminate was cooled to 600°C and held for 3 hours for low-temperature annealing. The cooling rate was 20°C / second, and the atmosphere was Ar gas. Afterward, the laminate was allowed to cool without applying a magnetic field, resulting in a flat SmCo magnet. The cooling rate after the low-temperature annealing was 20°C / second. X-ray diffraction and energy-dispersive X-ray diffraction analysis confirmed that the structure of the obtained SmCo magnet consisted of Sm2Co layers sequentially formed on a Co substrate. 17 The structure of membranes, SmCo5 membranes and Sm2Co7 membranes.

[0135] (Measurement of the thickness of magnetic films)

[0136] The obtained SmCo-based magnetic film was coated with resin. A portion of the resin was ground to expose a cross-section of the SmCo-based magnetic film. The exposed cross-section was observed using a scanning electron microscope (Hitachi High Technology Co., Ltd., trade name SU5000), and the thickness of the main magnetic layer 20 composed of SmCo5 was used as the film thickness for length measurement. The magnification was adjusted to include the entire film being measured within the field of view.

[0137] (Cross-section view)

[0138] For a surface ground approximately parallel to the thickness direction of the magnetic film, SEM images were acquired along the surface direction with a field of view of 1 mm or more to observe the cross-section along the thickness direction of the magnetic film. The magnification at this time was 500x. A portion of the cross-sectional SEM image of sample number 4 from Tables 1A and 1B is shown below. Figure 4 In addition, Figure 4 A portion of the scanning transmission electron microscope (STEM) image of the two grain boundaries in the V region shown is presented. Figure 5 A portion of the cross-sectional SEM image of specimen number 9 is shown below. Figure 8 .

[0139] For each crystalline grain observed in the SEM image, the lengths Lc in the film thickness direction and La in the direction perpendicular to the film thickness were measured. Their average values ​​Lc1 and La2 were calculated. The results are shown in Table 1B.

[0140] In the "Columnar Particles" column following Table 1B, "Y" indicates that more than one particle that grows in the thickness direction can be identified within the field of view, i.e., particles that satisfy Lc > La. On the other hand, "N" indicates that no particles that grow in the thickness direction were identified within the specified field of view, and all particles grow in the in-plane direction (or are non-columnar particles).

[0141] Furthermore, in the "Penetrating Particles" column following Table 1B, "Y" indicates that more than one particle with a film thickness t equal to the particle length Lc can be identified within the field of view, i.e., particles satisfying t=Lc. Moreover, it can be confirmed that these penetrating particles all satisfy Lc>La, meaning they are also columnar particles. On the other hand, "N" indicates that no columnar penetrating particles with a film thickness equal to the particle length were identified within the specified field of view. In samples numbered 1-6 and 13-17 recorded as "Y", columnar penetrating particles accounted for more than 10% of the total number of crystalline particles.

[0142] (Measurement of coercivity)

[0143] The substrate (Co substrate) was removed by grinding, leaving only the magnetic film. The coercivity HcJ of the magnetic film was then measured using a vibrating sample magnetometer (VSM).

[0144] (Composition Analysis)

[0145] A portion of the sample was processed using FIB (Focused Ion Beam) to obtain a thin film with a thickness of 100 nm. The composition of the crystalline grains and grain boundary phases of this thin film was analyzed using STEM-EDS (Scanning Transmission Electron Microscope-Energy Dispersive X-ray Spectroscopy).

[0146] Specifically, such as Figure 5 As shown, measurements were taken perpendicularly from one crystalline grain across the grain boundary phase to another, with each measurement point positioned at the grain boundary at 5 nm intervals. Compositional analysis was performed using EDS to obtain the rare earth element (Sm) concentration at the grain boundary. The compositional analysis results near the grain boundary of sample number 4 in Tables 1A and 1B are presented below. Figure 6 .

[0147] In addition, the portion 100 nm from the grain boundary was analyzed by EDS and used as the concentration (at%) of rare earth element (Sm) within the grain. The reduction rate (at%) of rare earth element (Sm) concentration at the grain boundary was calculated relative to the grain size. The reduction rate of rare earth element concentration at the grain boundary for sample number 4 in Tables 1A and 1B was calculated and the results are shown in Table 3B.

[0148] Comparative Example 1

[0149] Except that the surface processing time was changed to the processing time described in sample number 10 of Table 1A in order to adjust the surface roughness Ra of the substrate, the magnetic film was prepared in the same manner as sample number 9 of Example 1. The resulting magnetic film was evaluated in the same way as in Example 1. The results are shown in Table 1B.

[0150] Rating 1

[0151] As shown in Tables 1A and 1B, based on the results of samples 1 to 10, it can be seen that a magnetic film with high coercivity is obtained by using columnar particles that are long in the thickness direction (i.e., satisfying Lc > La) and Lc1 is 10 μm or more. Furthermore, it can be seen that the higher the Lc1 / La2 ratio, the greater the coercivity. Additionally, it can be seen that when through-type particles with Lc equal to the thickness of the magnet portion are present, the coercivity tends to increase.

[0152] The formation mechanism of columnar crystals is not yet clear, but it is believed that the valleys or slopes on the substrate surface are the starting points for crystal growth. The thickness direction of the magnetic film strongly tends to align with the C-axis of SmCo5 crystals, but the direction perpendicular to the C-axis is random. Therefore, during the growth of SmCo5 crystal particles, even when crystals in different orientations come into contact, it is not easy for one crystal to be engulfed by another. As a result, it is believed that SmCo5 crystals grow in a columnar shape along the thickness direction of the magnetic film.

[0153] Example 2

[0154] Except for changing the reaction time in the reaction diffusion process, the temperature in the heating process, or the holding time to those shown in Table 2A for sample numbers 13-18, in order to change the film thickness of the magnetic film in sample number 4 of Example 1, the magnetic film was prepared in the same manner as sample number 4. The resulting magnetic films were evaluated in the same way as those for sample number 4. The results are shown in Table 2B.

[0155] Comparative Example 2

[0156] Except for changing the temperature and holding time in the heating process of sample number 13 in Example 2 to those shown in sample number 11 as in Table 2A, the magnetic film was prepared in the same manner as that of sample number 13. The resulting magnetic film was evaluated in the same way as that of sample number 13. The results are shown in Table 2B.

[0157] Comparative Example 3

[0158] As shown in sample number 12 of Table 2A, the magnetic film was prepared in the same manner as sample number 11, except that the low-temperature annealing process was not performed on sample number 11. The resulting magnetic film was evaluated in the same way as that of sample number 11. The results are shown in Table 2B. In sample number 12, a further reduction in coercivity can be confirmed.

[0159] Rating 2

[0160] As shown in Tables 2A and 2B, based on the results of samples 11 to 18, it can be confirmed that a magnetic film with high coercivity is obtained by using columnar particles that are long in the thickness direction (i.e., satisfying Lc > La) and Lc1 is 10 μm or more. Furthermore, it can be confirmed that Lc1 / La2 is preferably 1 or more, more preferably 2 or more, which improves coercivity. Additionally, it can be confirmed that the thickness of the magnetic film is preferably 20 μm or more, 30 μm or more, or 50 μm or more, which improves coercivity, and the upper limit of the thickness is preferably 300 μm or less, which also improves coercivity.

[0161] Furthermore, by comparing sample number 11 of Comparative Example 1 with sample number 13 of Example 2, it can be confirmed that when the surface roughness of the substrate is approximately the same and the thickness of the magnetic film is approximately the same, the generation or non-generation of columnar particles can also be controlled by controlling the temperature and time of the heating process.

[0162] Example 3

[0163] Except that the temperature of the low-temperature annealing process in sample number 4 of Example 1 was changed to that shown in sample number 21 of Table 3A, the magnetic film was prepared in the same manner as sample number 4. The resulting magnetic film was evaluated in the same way as sample number 4. The results are shown in Table 3B. In addition, in sample number 21 of Example 3, the rate of decrease in the concentration (at%) of rare earth element (Sm) at the grain boundary between two grains relative to the grain size was determined in the same manner as in sample number 4. The results are shown in Table 3B.

[0164] Example 4

[0165] As shown in Table 3A for sample number 20, the magnetic film was prepared in the same manner as sample number 4, except that the low-temperature annealing process was not performed on sample number 4. The resulting magnetic film was evaluated in the same way as sample number 4. The results are shown in Table 3B.

[0166] Example 5

[0167] Except for changing the temperature and holding time of the low-temperature annealing process in sample number 4 of Example 1 to those shown in samples 22 and 23 of Table 3A, the magnetic film was prepared in the same manner as sample number 4. The resulting magnetic film was evaluated in the same way as that of sample number 4. The results are shown in Table 3B.

[0168] Example 6

[0169] Except that the temperature of the low-temperature annealing process in sample number 9 of Example 1 was changed to that shown in sample number 24 of Table 3A, the magnetic film was prepared in the same manner as sample number 9. The resulting magnetic films and the magnetic films of sample number 9 were evaluated in the same way as those of sample number 4. The results are shown in Table 3B.

[0170] Rating 3

[0171] As shown in Tables 3A and 3B, based on the results of samples 4, 9, and 20-24, it can be confirmed that when the reduction rate of the proportion of rare earth element (Sm) atoms at the grain boundary relative to the interior of the crystalline grain (e.g., at a distance of 100 nm from the grain boundary) is within a specified range, preferably 3% or more, the coercivity is further improved. Furthermore, it can be confirmed that when the reduction rate of the proportion of rare earth element (Sm) atoms at the grain boundary relative to the proportion of rare earth element (Sm) atoms within the crystalline grain is within a specified range, for example, 3% or more and 80% or less, or 3% or more and 70% or less, the coercivity is further improved.

[0172] [Table 1A]

[0173]

[0174] [Table 1B]

[0175]

[0176] [Table 2A]

[0177]

[0178] [Table 2B]

[0179]

[0180] [Table 3A]

[0181]

[0182] [Table 3B]

[0183]

[0184] Example 7

[0185] As shown in Table 4A, a flat Fe substrate was prepared as the base component, and the Fe substrate was prepared in the same manner as the Co substrate in Example 1. Then, a reaction diffusion process was performed in the same manner as in Example 1 to obtain a laminate with an SmFe2 film formed on the substrate. The resulting laminate was subjected to the same heating process as in Example 1.

[0186] Then, it is subjected to the same low-temperature annealing process as in Example 1.

[0187] The resulting laminate was then nitrided by heating at 500°C for 20 hours under a nitrogen atmosphere with a flow rate of 200 mL / min. Afterward, the laminate was cooled without applying a magnetic field, resulting in a flat SmFeN-based magnet. X-ray diffraction and energy-dispersive X-ray diffraction analysis confirmed that the structure of the obtained SmFeN-based magnet consisted of a sequence of SmFe3 film and Sm2Fe2 film formed on an Fe substrate. 17 Membrane and Sm2Fe 17 The structure of the N3 film. The obtained magnetic films were evaluated in the same manner as sample number 4. The results are shown in Table 4B.

[0188] Comparative Example 4

[0189] Except for adjusting the surface processing time to adjust the surface roughness Ra of the substrate, the magnetic film was fabricated in the same manner as in Example 4. The resulting magnetic film was evaluated in the same way as in Example 4. The results are shown in Table 4B.

[0190] Rating 4

[0191] As shown in Tables 4A and 4B, it can be seen that in a magnetic film containing Fe as a transition metal element, a magnetic film with high coercivity is also obtained in the same way as in Example 1 by using columnar particles that are long in the thickness direction (i.e., satisfying Lc > La) and Lc1 is 10 μm or more.

[0192] [Table 4A]

[0193]

[0194] [Table 4B]

[0195]

[0196] Example 8

[0197] Except for adding Nd to replace Sm in the reaction diffusion process, a plate-shaped NdFe magnet was obtained through the same steps as in Example 7. X-ray diffraction and energy-dispersive X-ray diffraction were used to confirm that the structure of the obtained NdFe magnet consisted of NdFe atoms formed on an Fe substrate. 12 The structure of the membrane. The obtained magnetic membrane was evaluated in the same manner as sample number 4. The results are shown in Table 5B.

[0198] Comparative Example 5

[0199] Except for adjusting the surface processing time to adjust the surface roughness Ra of the substrate, the magnetic film was fabricated in the same manner as in Example 8. The resulting magnetic film was evaluated in the same way as in Example 8. The results are shown in Table 5B.

[0200] Rating 5

[0201] As shown in Tables 5A and 5B, it can be seen that in a magnetic film containing Nd as a rare earth element and composed of NdFe-based magnets, a magnetic film with high coercivity is also obtained in the same way as in Example 1 by using columnar particles that are long in the thickness direction (i.e., satisfying Lc > La) and Lc1 is 10 μm or more.

[0202] [Table 5A]

[0203]

[0204] [Table 5B]

[0205]

Claims

1. A magnetic film, wherein, The magnetic membrane has the following characteristics: Rare earth elements, which contain Sm or Nd as essential elements; and Transition metal elements, including Co or Fe, The magnetic film is a hard magnetic material. The magnetic film has a main magnetic layer containing multiple crystalline particles. The crystalline particles are columnar particles with a first length Lc along the thickness direction of the main magnetic layer that is longer than a second length La along a direction perpendicular to the thickness direction. The first average value Lc1 of the length of the crystalline particles along the thickness direction is 10 μm or more.

2. The magnetic film according to claim 1, wherein, This indicates that the rate of decrease in the proportion of rare earth elements at the grain boundaries between adjacent crystalline particles relative to the proportion of rare earth elements inside the crystalline particles is 3% or more.

3. The magnetic film according to claim 2, wherein, The reduction rate is above 3% and below 80%.

4. The magnetic film according to claim 1, wherein, The first average value Lc1 is more than 1.1 times the second average value La2 relative to the second length La of the crystalline grain.

5. The magnetic film according to claim 1, wherein, The columnar particles are through-type particles with a first length Lc equal to the thickness of the main magnetic layer.

6. The magnetic film according to claim 1, wherein, When the rare earth element is denoted as R and the transition metal element as T, The main magnetic layer has RT5 and R2T. 17 RT 12 R2T 17 Any of N3.

7. The magnetic film according to claim 1, wherein, The main magnetic layer has SmCo5 and Sm2Co. 17 、SmFe 12 NdFe 12 Sm2Fe 17 Any of N3.

8. The magnetic film according to claim 1, wherein, It also has a secondary magnetic layer in contact with the primary magnetic layer.

9. The magnetic film according to claim 8, wherein, The proportion of rare earth elements in the secondary magnetic layer is different from that in the primary magnetic layer.

10. The magnetic film according to claim 1, wherein, The magnetic membrane also contains nitrogen.

11. The magnetic film according to any one of claims 1 to 10, wherein, The thickness of the main magnetic layer is 10–300 μm.

12. A component with a magnetic film, wherein, The component with the magnetic film has: The magnetic film according to any one of claims 1 to 10; and a substrate component having the magnetic film formed on its surface.

13. The component with a magnetic film according to claim 12, wherein, The surface of the substrate component has the same transition metal element as that contained in the main magnetic layer.

14. An actuator, wherein, The actuator comprises a magnetic film according to any one of claims 1 to 10.

15. A sensor, wherein, The sensor comprises a magnetic membrane as described in any one of claims 1 to 10.

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