Oxide ceramic and ceramic electronic component

Patent metadata

Field	Value
Publication number	US-2016155562-A1
Application number	US-201615017784-A
Country	US
Kind code	A1
Filing date	Feb 8, 2016
Priority date	Aug 22, 2013
Publication date	Jun 2, 2016
Grant date	—

Abstract

An oxide ceramic represented by the general formula [Sr 2−x Ba x Co 2−y (Zn u Ni 1−u ) y Fe 12−z Al z O 22 ]. In the formula, 0.7≦x≦1.3 and 0.8≦z≦1.2. y is 0≦y≦0.8 when 0.5≦u≦1.0 and is 0≦y≦1.6 when 0≦u≦0.5. y is preferably 0.4 or less. Further, a variable inductor as a ceramic electronic component has a component base body formed from the oxide ceramic.

First claim

1 . An oxide ceramic comprising:
a ferrite compound containing at least Sr, Ba, Co, and Fe, wherein the Ba is contained in a form of substitution for some of the Sr, and x is 0.7 to 1.3 when a content of the Ba is expressed as x/2 in molar ratio with respect to a total of the Ba and the Sr, at least either one element M of Zn and Ni is contained in a form of substitution for some of the Co, and when a content of the element M is expressed as y/2 in molar ratio with respect to a total of the element M and the Co,
y is 0.8 or less when the element M is the Zn and when the element M is combined so that a content of the Zn is equal to or more than a content of the Ni in molar ratio, or
y is 1.6 or less when the element M is the Ni and when the element M is combined so that the content of the Zn is less than the content of the Ni in molar ratio, and
Al is contained in a form of substitution for some of the Fe, and z is 0.8 to 1.2 when a content of the Al is expressed as z/12 in molar ratio with respect to a total of the Al and the Fe.

2 . The oxide ceramic according to claim 1 , wherein the oxide ceramic has a hexagonal Y-type crystal structure.

3 . The oxide ceramic according to claim 1 , wherein the ferrite compound is represented by a general formula [Sr 2−x Ba x Co 2−y (Zn u Ni 1−u ) y Fe 12−z Al z O 22 ], where 0≦y≦0.8 and 0.5≦u≦1.0.

4 . The oxide ceramic according to claim 1 , wherein the ferrite compound is represented by a general formula [Sr 2−x Ba x Co 2−y (Zn u Ni 1−u ) y Fe 12−z Al z O 22 ], where 0≦y≦1.6 and 0≦u<0.5.

5 . The oxide ceramic according to claim 2 , wherein the y is 0.4 or less.

6 . The oxide ceramic according to claim 3 , wherein the y is 0.4 or less.

7 . The oxide ceramic according to claim 4 , wherein the y is 0.4 or less.

8 . The oxide ceramic according to claim 5 , wherein the oxide ceramic was heat treated in an air atmosphere.

9 . The oxide ceramic according to claim 6 , wherein the oxide ceramic was heat treated in an air atmosphere.

10 . The oxide ceramic according to claim 7 , wherein the oxide ceramic was heat treated in an air atmosphere.

11 . The oxide ceramic according to claim 1 , wherein the oxide ceramic has a maximum value electromagnetic coupling coefficient in a substantial zero field magnetic field.

12 . The oxide ceramic according to claim 1 , wherein the oxide ceramic is structured such that a polarity of electric polarization is reversed when a polarity of a magnetic field is reversed.

13 . A ceramic electronic component comprising:
a component base body and an external electrode on a surface of the component base body, wherein the component base body is formed from the oxide ceramic according to claim 1 .

14 . The ceramic electronic component according to claim 13 , further comprising a coil disposed around the component base body, wherein the coil has an inductance that depends on a magnetic permeability of the component base body.

15 . The ceramic electronic component according to claim 14 , further comprising an internal electrode embedded in the component base body.

16 . The ceramic electronic component according to claim 13 , further comprising an internal electrode embedded in the component base body.

17 . The ceramic electronic component according to claim 13 , wherein the ferrite compound is represented by a general formula [Sr 2−x Ba x Co 2−y (Zn u Ni 1−u ) y Fe 12−z Al z O 22 ], where 0≦y≦0.8 and 0.5≦u≦1.0.

18 . The ceramic electronic component according to claim 13 , wherein the ferrite compound is represented by a general formula [Sr 2−x Ba x Co 2−y (Zn u Ni 1−u ) y Fe 12−z Al z O 22 ], where 0≦y≦1.6 and 0≦u<0.5.

19 . The ceramic electronic component according to claim 17 , wherein the y is 0.4 or less.

20 . The ceramic electronic component according to claim 18 , wherein the y is 0.4 or less.

Assignees

• Murata Manufacturing Co

Inventors

• Hirose Sakyo
• Kimura Tsuyoshi

Classifications

• C04B2235/3213

  Strontium oxides or oxide-forming salts thereof · CPC title

• C04B2235/3215

  Barium oxides or oxide-forming salts thereof · CPC title

• C04B2235/3279

  Nickel oxides, nickalates, or oxide-forming salts thereof · CPC title

• C04B35/2666

  Other ferrites containing nickel, copper or cobalt · CPC title

• C04B2235/3272

  Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite · CPC title