Electromagnetic effect material and ceramic electronic component

Patent metadata

Field	Value
Publication number	US-9950958-B2
Application number	US-201514851752-A
Country	US
Kind code	B2
Filing date	Sep 11, 2015
Priority date	Mar 14, 2013
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A magnetoelectric effect material includes as a primary component, a polycrystalline oxide ceramic containing at least Sr, Co, and Fe. In the polycrystalline oxide ceramic, the crystal c-axis is oriented in a predetermined direction, and the degree of orientation of the c-axis is 0.2 or more by a Lotgering method. A component substrate is formed of this magnetoelectric effect material.

First claim

The invention claimed is:

1. A ferromagnetic dielectric material in which electric polarization is induced by application of a magnetic field and in which magnetization is controlled by application of an electric field, the ferromagnetic dielectric material comprising as a primary component, a polycrystalline oxide ceramic containing at least Sr, Co, and Fe,
wherein in the polycrystalline oxide ceramic, a crystal c-axis is oriented and electrically polarized perpendicular to the crystal c-axis orientation,
wherein a degree of orientation of the c-axis is 0.2 or more by a Lotgering method, and
wherein the polycrystalline oxide ceramic is (Sr 1-α Ba α ) 3 (Co 1-β X β ) 2 Fe 24 O 41+δ ,
where X represents at least one element selected from Ni, Zn, Mn, Mg, and Cu,
0≤α≤0.4,

0≤β≤0.3, and

−1≤δ≤1.

2. The ferromagnetic dielectric material according to claim 1 , wherein the degree of orientation of the c-axis is 0.6 or more by the Lotgering method.

3. The ferromagnetic dielectric material according to claim 1 , wherein the crystal particles of the oxide ceramic have an anisotropic shape.

4. The ferromagnetic dielectric material according to claim 3 , wherein the crystal particles have a ratio of particle lengths in longitudinal directions to particle lengths in lateral directions of 2 or more, and the longitudinal directions are crystallographically aligned in one direction.

5. The ferromagnetic dielectric material according to claim 4 , wherein the ratio is 5 or more.

6. The ferromagnetic dielectric material according to claim 5 , wherein the ratio is 10 or more.

7. The ferromagnetic dielectric material according to claim 1 , wherein a polarity of the magnetization is changed in accordance with a polarity of the applied electric field, and when the electric field is changed from an application state to a non-application state, the polarity of the magnetization that is changed is retained.

8. The ferromagnetic dielectric material according to claim 7 , wherein an intensity of the magnetization is controllable in accordance with an intensity of the applied electric field.

9. The ferromagnetic dielectric material according to claim 1 , wherein an intensity of the magnetization is controllable in accordance with an intensity of the applied electric field.

10. The ferromagnetic dielectric material according to claim 7 , wherein when the electric field is changed from an application state to a non-application state, the polarity of the magnetization that is changed is retained.

11. The ferromagnetic dielectric material according to claim 1 , wherein the ferromagnetic dielectric material is used in an allowable temperature range of an electronic device.

12. The ferromagnetic dielectric material according to claim 11 , wherein the allowable temperature range is 300K±50K.

13. A ceramic electronic component comprising:
a component substrate; and
an external electrode on a surface of the component substrate,
wherein the component substrate is formed of the ferromagnetic dielectric material according to claim 1 .

14. The ceramic electronic component according to claim 13 , wherein the ceramic electronic component is one of a variable inductor, a nonvolatile memory, a voltage sensor, a magnetic sensor, and a magnetic switch.

Assignees

• Murata Manufacturing Co

Inventors

• Kimura Tsuyoshi
• Okumura Koji
• Yamaguchi Yasuhiro
• HARUKI Kohei

Classifications

• C04B2235/3215

  Barium oxides or oxide-forming salts thereof · CPC title

• H01F1/0317

  Manganites · CPC title

• C04B2235/3274

  Ferrites · CPC title

• H01L43/08

  Electricity · mapped topic

• C04B35/6262

  of calcined, sintered clinker or ceramics · CPC title