Search

CN-122029622-A - Magnetic body, actuator, and sensor

CN122029622ACN 122029622 ACN122029622 ACN 122029622ACN-122029622-A

Abstract

A magnetic material comprising, in order, a base material, a magnetic film comprising a hard magnetic material containing a rare earth R and a transition metal T, wherein the rare earth R comprises Sm, nd or Pr, and the transition metal T comprises Co or Fe, and a soft magnetic film comprising a soft magnetic material containing the rare earth R and the transition metal T.

Inventors

  • Fujiwara Ryoshimoto
  • FUJIKAWA YOSHINORI
  • Futian future

Assignees

  • TDK株式会社

Dates

Publication Date
20260512
Application Date
20241011
Priority Date
20231013

Claims (8)

  1. 1. A magnetic body, wherein, The magnetic body sequentially includes: A substrate; a magnet film comprising a hard magnetic material containing a rare earth R comprising Sm, nd or Pr and a transition metal T comprising Co or Fe, and A soft magnetic film comprising a soft magnetic material containing the rare earth element R and the transition metal T.
  2. 2. The magnetic body according to claim 1, wherein, The soft magnetic body comprises R 2 T 7 、RT 3 or RT 2 .
  3. 3. The magnetic body according to claim 1 or 2, wherein, The hard magnetic body includes RT 5 、R 2 T 17 or RT 12 .
  4. 4. The magnetic body according to claim 1 or 2, wherein, The hard magnetic material contains SmCo 5 、Sm 2 Co 17 、SmFe 12 or NdFe 12 .
  5. 5. The magnetic body according to claim 1 or 2, wherein, The thickness of the soft magnetic film is 1-50 μm.
  6. 6. The magnetic body according to claim 1 or 2, wherein, The thickness of the magnet film is 10-300 μm.
  7. 7. An actuator, wherein, The actuator includes the magnetic body according to claim 1.
  8. 8. A sensor, wherein, The sensor includes the magnetic body according to claim 1.

Description

Magnetic body, actuator, and sensor Technical Field The invention relates to a magnetic body, an actuator and a sensor. Background In recent years, various devices using a magnetic material such as an actuator and a sensor are required to be miniaturized or thinned. For this reason, the magnetic material used in the device is also required to be miniaturized or thinned. A thin magnetic body may be magnetized in the thickness direction because other element members are arranged in the vertical direction. For example, patent document 1 discloses a magnet including a yoke portion made of a soft magnetic material and a magnet portion made of a hard magnetic material formed on a main surface of the yoke portion, wherein an interface between the yoke portion and the magnet portion has a concave-convex shape. Prior art literature Patent literature Patent document 1 International publication No. 2022/045260 Disclosure of Invention Technical problem to be solved by the invention However, it is known to form a magnetic field in the opposite direction to the magnetization, called a demagnetizing field, inside the magnet. The smaller the thickness of the magnet in the magnetization direction, the larger the demagnetizing field, and the smaller the permeability coefficient. Thus, the operating point is moved to the low magnetic flux density side, and is easily demagnetized by, for example, a high temperature environment, application of a demagnetizing field, or the like. From the viewpoint of suppressing the demagnetization, a magnetic body having a large magnetic permeability coefficient is demanded while achieving a reduction in thickness. The present invention has been made to solve the above-described problems, and an object thereof is to provide a magnetic substance having a large magnetic permeability, an actuator and a sensor including the magnetic substance. Means for solving the technical problems The present invention includes the following means. <1> A magnetic material comprising, in order, a base material, a magnetic film comprising a hard magnetic material comprising a rare earth R comprising Sm, nd or Pr and a transition metal T comprising Co or Fe, and a soft magnetic film comprising a soft magnetic material comprising the rare earth R and the transition metal T. <2> The magnetic body according to <1>, wherein the soft magnetic body comprises R 2T7、RT3 or RT 2. <3> The magnetic body according to <1> or <2>, wherein the hard magnetic body comprises RT 5、R2T17 or RT 12. The magnetic material according to any one of <1> to <3>, wherein the hard magnetic material contains SmCo 5、Sm2Co17、SmFe12 or NdFe 12. The magnetic material according to any one of <1> to <4>, wherein the soft magnetic film has a thickness of 1 μm to 50 μm. The magnetic material according to any one of <1> to <5>, wherein the thickness of the magnetic film is 10 μm to 200 μm. <7> An actuator comprising the magnetic material according to any one of <1> to <6 >. <8> A sensor comprising the magnetic material according to any one of <1> to <6 >. ADVANTAGEOUS EFFECTS OF INVENTION According to the present invention, a magnetic substance having a large permeability coefficient, and an actuator and a sensor including the magnetic substance can be provided. Drawings Fig. 1 is a schematic cross-sectional view of a SmCo-based magnetic material as an example of the magnetic material of the present embodiment. Fig. 2 is a schematic cross-sectional view of a magnetic body in the method for manufacturing a columnar magnetic body according to the present embodiment. In fig. 3, (a) is an axial cross-sectional view of the motor 100x, and (b) is a cross-sectional view perpendicular to the axial direction of (a). Fig. 4 is an exploded perspective view showing a voice coil actuator as an example of the present embodiment. Fig. 5 is a cross-sectional view of the voice coil actuator 100y along the central axis AX of the coil portion 30 y. Fig. 6 is a cross section of the first magnetic body 10y and the second magnetic body 20y perpendicular to the central axis AX. Fig. 7 is a schematic diagram of a two-dimensional model. FIG. 8 is an image obtained by observing the magnetic material of example 6-1 with a scanning electron microscope. Fig. 9 is an image obtained by observing the magnetic material of comparative example 1-1 with a scanning electron microscope. Symbol description 14 X..the cylindrical magnetic body, 20 x..the stator, 22 x..the yoke, the magnetic core, the 23 x..the teeth, 24 x..the coil, 30 x..the container; 14 x..once again, a cylindrical magnetic body, 20 x..once again, a stator, 22 x..once again, a yoke, 23 x..once again, teeth, 24 x..once again, a coil, 30 x..once again, a container, a magnetic body, a magnetic yoke, a magnetic body, a magnetic tooth, a magnetic body, a magnetic coil, a magnetic body, a magnetic container, a magnetic body, a magnetic container, a magnetic body, a 40 x..the bearing, 100 x..the motor, 100y, 101 y..the voice coil