CN-122029620-A - Magnetic film, component with magnetic film, actuator, and sensor

Abstract

The invention provides a magnetic film with high coercive force obtained from a magnetic film with a thickness of tens to hundreds of micrometers, a component with the magnetic film, an actuator and a sensor. A magnetic film has a rare earth element containing Sm or Nd as an essential element, and a transition metal element containing Co or Fe. The magnetic film has a main magnetic layer containing a plurality of crystal particles, the crystal particles have 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 (Lc 1) of the lengths of the crystal particles along the thickness direction is 10 [ mu ] m or more.

Inventors

• Large scale Schlan
• Fujiwara Ryoshimoto
• FUJIKAWA YOSHINORI
• Futian future
• Otsuru Masashi

Assignees

• TDK株式会社

Dates

Publication Date

20260512

Application Date

20241011

Priority Date

20231013

Claims (15)

1. 1. A magnetic body film, wherein, The magnetic film has: a rare earth element containing Sm or Nd as an essential element, and A transition metal element comprising Co or Fe, The magnetic film is a hard magnetic material, The magnetic film has a main magnetic layer containing a plurality of crystal particles, The crystal particles have 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, The first average value Lc1 of the length of the crystal grains in the thickness direction is 10[ mu ] m or more.
2. 2. The magnetic film according to claim 1, wherein, A reduction rate of a ratio indicating a reduction in the atomic number proportion of the rare earth element at the grain boundaries where the crystal grains are adjacent to each other with respect to the atomic number proportion of the rare earth element inside the crystal grains is 3% or more.
3. 3. The magnetic film according to claim 2, wherein, The reduction rate is 3% to 80%.
4. 4. The magnetic film according to claim 1, wherein, The first average Lc1 is 1.1 times or more the second average La2 of the second length La of the crystal grains.
5. 5. The magnetic film according to claim 1, wherein, The columnar particles have penetrating particles having the first length Lc equal to the thickness of the main magnetic layer.
6. 6. The magnetic film according to claim 1, wherein, When the rare earth element is denoted as R and the transition metal element is denoted as T, The main magnetic layer has any one of RT 5 、R 2 T 17 、RT 12 、R 2 T 17 N 3 .
7. 7. The magnetic film according to claim 1, wherein, The main magnetic layer has any one of SmCo 5 、Sm 2 Co 17 、SmFe 12 、NdFe 12 、Sm 2 Fe 17 N 3 .
8. 8. The magnetic film according to claim 1, wherein, And a secondary magnetic layer in contact with the primary magnetic layer.
9. 9. The magnetic film according to claim 8, wherein, The atomic number ratio of the rare earth element contained in the secondary magnetic layer is different from the atomic number ratio of the rare earth element contained in the primary magnetic layer.
10. 10. The magnetic film according to claim 1, wherein, The magnetic film further has a nitrogen element.
11. 11. The magnetic film according to any one of claim 1 to 10, wherein, The thickness of the main magnetic layer is 10-300 mu m.
12. 12. A member with a magnetic film, wherein, The member with a magnetic film includes: The magnetic film according to any one of claims 1 to 10, and a base member having the magnetic film formed on a surface thereof.
13. 13. The magnetic substance film-equipped member according to claim 12, wherein, The surface of the base member has the same transition metal element as the transition metal element contained in the main magnetic layer.
14. 14. An actuator, wherein, The actuator includes the magnetic film according to any one of claims 1 to 10.
15. 15. A sensor, wherein, The sensor includes the magnetic film according to any one of claims 1 to 10.

Description

Magnetic film, component with magnetic film, actuator, and sensor Technical Field The present disclosure relates to a magnetic film, a component with a magnetic film, an actuator, and a sensor. Background In the background of the continuous pursuit of miniaturization of various electronic devices, development of miniature devices such as miniature motors and miniature actuators incorporated in these devices is also advancing. The size and performance of these devices is largely dependent on the size and magnetic characteristics of the permanent magnets used in the device. The sintered magnet has very high magnetic characteristics, but it is difficult to process the sintered magnet into a shape having a thickness of 200 μm or less required for small-sized device applications, while maintaining the characteristics thereof, due to the influence of deterioration of the surface layer with processing. 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 having a thickness of 10 μm or more due to the influence of low film formation rate. Therefore, it is difficult to realize a high-performance permanent magnet film having a thickness of 10 to 200 μm, and from the viewpoint of downsizing and high performance of the device, it has been demanded to realize a magnet having such a size range. Patent document 1 discloses a magnet film in which a hard magnetic material containing SmCo 5 is formed on a main surface of a yoke portion including a soft magnetic material, the hard magnetic material having a thickness of 1 to 200 μm. However, such a magnet having a small thickness has a problem that a demagnetizing field generated by magnetization of the permanent magnet is large and easy to demagnetize due to its shape. When the magnet is magnetized so that the magnetic pole appears in the thickness direction, the magnetic resistance of the magnetic circuit passing through the inside of the magnet becomes extremely small compared with the magnetic resistance of the magnetic circuit passing through the space outside the magnet from the N pole surface and returning to the S pole, and therefore the demagnetizing factor approaches 1. The degree of ease of demagnetization depends on the magnitude of coercive force at the use temperature of the permanent magnet, the magnitude of demagnetizing field, and the magnitude of external magnetic field applied in the direction opposite to the magnetization direction, but the magnet disclosed in patent document 1 has room for improvement in this point. A magnet film having a high coercive force even in a magnet having a thickness of several tens to several hundreds micrometers is desired. Prior art literature Patent literature Patent document 1 International publication No. 2022/045260 Disclosure of Invention Technical problem to be solved by the invention The present disclosure has been made in view of such a practical situation, and an object thereof is to provide a magnetic film, a member with a magnetic film having the magnetic film, an actuator, and a sensor, which obtain a high coercive force in a magnetic film having a thickness of several tens to several hundreds micrometers. Technical scheme for solving technical problems In order to achieve the above object, an aspect of the present disclosure provides a magnetic film, which has: a rare earth element containing Sm or Nd as an essential element, and A transition metal element comprising Co or Fe, The magnetic film is a hard magnetic material, The magnetic film has a main magnetic layer containing a plurality of crystal particles, The crystal particles have 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, The first average value (Lc 1) of the length of the crystal grains in the thickness direction is 10 [ mu ] m or more. In general, a permanent magnet having a thin thickness is easily demagnetized. The ease of demagnetization depends on the magnitude of the coercivity of the permanent magnet at the temperature of use, the magnitude of the demagnetizing field, and the magnitude of the external magnetic field applied in the opposite direction of the magnetization direction. The smaller the coercive force, the larger the magnitude of demagnetizing field, and the easier the demagnetization. The magnitude of the demagnetizing field depends on the shape of the permanent magnet, and the thinner the thickness of the permanent magnet in the magnetization direction, the larger the demagnetizing field (the easier it is to demagnetize). That is, the shorter (thinner) the distance between the magnetic poles is, the higher the strength of the demagnetizing field generated inside is (the easier it is to demagnetize). In the magnetic film according to one aspect of the present disclosure, the m