CN-122003723-A - Magnetic film, component with magnetic film, actuator, and sensor

Abstract

The invention provides a magnetic film with high magnetization in a magnetic film with a thickness of tens to hundreds micrometers, a component with the magnetic film, an actuator and a sensor. The magnetic film (10) has a main magnetic layer (20) containing at least one or more crystal particles, and the concentration (T/(R+T)) of the transition metal element (T) in at least one or more crystal particles (22) relative to the total (R+T) of the rare earth element (R) and the transition metal element (T) varies along the thickness direction of the main magnetic layer (20).

Inventors

• Fujiwara Ryoshimoto
• FUJIKAWA YOSHINORI
• Futian future

Assignees

• TDK株式会社

Dates

Publication Date

20260508

Application Date

20241011

Priority Date

20231013

Claims (14)

1. 1. A magnetic film, characterized in that, 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 at least one or more crystal particles, Along the thickness direction of the main magnetic layer, the concentration of the transition metal element in the at least one or more crystal grains with respect to the total of the rare earth element and the transition metal element changes, The first concentration of the transition metal element near the surface-side end of the at least one or more crystalline particles on the surface of the magnetic film differs by a predetermined ratio or more from the second concentration of the transition metal element near the back-side end of the at least one or more crystalline particles on the back surface of the magnetic film on the opposite side of the surface.
2. 2. The magnetic film according to claim 1, wherein, The first concentration is lower than the second concentration by a predetermined ratio or more.
3. 3. The magnetic film according to claim 1, wherein, The first concentration is higher than the second concentration by a predetermined ratio or more.
4. 4. The magnetic film according to claim 1, wherein, The predetermined ratio is 0.1% or more.
5. 5. 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 .
6. 6. 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 .
7. 7. The magnetic film according to claim 1, wherein, And a secondary magnetic layer in contact with the primary magnetic layer.
8. 8. The magnetic film according to claim 7, 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.
9. 9. The magnetic film according to claim 1, wherein, And also has nitrogen element.
10. 10. The magnetic film according to any one of claim 1 to 9, wherein, The thickness of the main magnetic layer is 10-300 mu m.
11. 11. A member with a magnetic film, wherein, The member with a magnetic film includes: the magnetic film according to claim 1 to 9, and a base member on which the magnetic film is mounted.
12. 12. The magnetic substance film-equipped component according to claim 11, wherein, The surface of the base member has the same transition metal element as the transition metal element contained in the main magnetic layer.
13. 13. An actuator, wherein, The actuator includes the magnetic film according to any one of claims 1 to 9.
14. 14. A sensor, wherein, The sensor includes the magnetic film according to any one of claims 1 to 9.

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. However, a conventional high-performance magnet is a sintered magnet or a bonded magnet, and the sintered magnet has very high magnetic properties, 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 properties, 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 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 about 100 to 200 μm, and from the viewpoint of downsizing and high performance of the device, it has been desired 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. The magnetic flux that can be generated by a magnet is largely dependent on its volume, and therefore the smaller the size, the thinner the thickness, the smaller the resulting magnetic flux. On the other hand, the magnetic flux also depends on the magnetization of the magnet. In order to increase the magnetic flux while achieving miniaturization, a magnet having a high magnetization is desired. Prior art literature Patent literature Patent document 1 International publication No. 2022/045260 Disclosure of Invention Problems 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 having high magnetization among magnetic films having a thickness of several tens to several hundreds micrometers, a member with the magnetic film having the magnetic film, an actuator, and a sensor. Technical scheme for solving problems In order to achieve the above object, an aspect of the present disclosure provides a magnetic film comprising: 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 at least one or more crystal particles, Along the thickness direction of the main magnetic layer, the concentration (T/(R+T)) of the transition metal element (T) in the at least one or more crystal grains relative to the total (R+T) of the rare earth element (R) and the transition metal element (T) varies, The first concentration of the transition metal element near the surface-side end of the at least one or more crystalline particles on the surface of the magnetic film differs by a predetermined ratio or more from the second concentration of the transition metal element near the back-side end of the at least one or more crystalline particles on the back surface of the magnetic film on the opposite side of the surface. In the magnetic film according to the aspect of the present disclosure, for example, by providing a gradient in the concentration of a transition metal element such as Co along the film thickness direction, a magnetic body containing more transition metal element than the stoichiometric composition can be formed while maintaining the crystal structure. Therefore, magnetization can be improved. In addition, a high coercive force can be maintained. The first concentration may be lower than the second concentration by a predetermined ratio or more. In this case, the concentration of the transition metal element on the surface side of the magnetic film becomes low, and the concentration of the rare earth element becomes relatively high, so that magnetization reversal from the surface side of the magnetic film is liable to be suppressed, and therefore, the coercive force tends to be further improved. The first concentration may be higher than the second concentration by a predetermined ratio or more. In this case, the concentration of the transition metal element on the surface side of the magnetic film becomes high, magnetization is further improved, and corrosion resistance tends to be improved. Preferably, the predetermined ratio is 0.1% or more. For example, by produci