Method of producing piezoelectric device using Be, Fe and Co under excess oxygen atmosphere

Patent metadata

Field	Value
Publication number	US-9362482-B2
Application number	US-201213707897-A
Country	US
Kind code	B2
Filing date	Dec 7, 2012
Priority date	Mar 12, 2009
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

Provided are a bismuth-based piezoelectric material whose insulation property is improved while its performance as a piezoelectric body is not impaired and a piezoelectric device using the piezoelectric material. The piezoelectric material includes a perovskite-type metal oxide represented by the following general formula (1):

Bi x (Fe 1-y Co y )O 3   (1)

where 0.95≦x≦1.25 and 0≦y≦0.30, and a root mean square roughness Rq (nm) of a surface of the piezoelectric material satisfies a relationship of 0<Rq≦25y+2 (0≦y≦0.30).

First claim

What is claimed is:

1. A method of producing a piezoelectric device comprising a substrate bearing a piezoelectric material and a pair of electrodes provided to contact the piezoelectric material, the method comprising:
subjecting a raw material comprising Bi, Fe and Co to a heat treatment at 430° C. or lower under an atmosphere comprising at least 25 vol % oxygen to obtain a piezoelectric material formed of a perovskite-type metal oxide represented by formula (1):
Bi x (Fe 1-y Co y )O 3   (1)

where 0.95≦x≦1.25 and 0.10≦y≦0.30.

2. The method of producing a piezoelectric device according to claim 1 , wherein the piezoelectric material is formed by a chemical solution deposition method.

3. The method of producing a piezoelectric device according to claim 1 , wherein the atmosphere comprises ozone.

4. The method of producing a piezoelectric device according to claim 2 , wherein the chemical solution deposition method is performed by multi-layer coating at a coating thickness per layer of from 8 nm to 30 nm.

5. The method of producing a piezoelectric device according to claim 1 , wherein the substrate comprises a single crystal substrate oriented toward one of a (100) plane and a (111) plane.

6. The method of producing a piezoelectric device according to claim 2 , wherein a precursor solution used in the chemical solution deposition method comprises bismuth 2-ethylhexanoate, tris(acetylacetonato)iron, and tris(acetylacetonato)cobalt.

7. The method of producing a piezoelectric device according to claim 6 , wherein a difference between a total content of Fe and Co in the precursor solution and a content of Bi in the solution is 1 mol % or less.

8. The method of producing a piezoelectric device according to claim 1 , wherein the electrodes each comprise either (i) M1RuO 3 where M1 represents at least one member selected from the group consisting of Sr, Ba, and Ca or (ii) Sr (1-z) M2 z CoO 3 where M2 represents at least one member selected from the group consisting of La, Pr, Sm, and Nd, and z satisfies a relationship of 0≦z<1.

Assignees

• Canon Kk
• Univ Kyoto
• Nat Inst Of Advanced Ind Scien
• Nat Inst Of Advanced Ind Scien

Inventors

• Kubota Makoto
• Takashima Kenji
• Azuma Masaki
• Nakamura Yoshitaka
• Shimakawa Yuichi
• Iijima Takashi
• Lee Bong-Yeon

Classifications

• C04B2235/768

  Perovskite structure ABO3 · CPC title

• C04B2235/3298

  Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate · CPC title

• C04B2235/3275

  Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite · CPC title

• C04B35/01 Primary

  based on oxide ceramics · CPC title

• C04B2235/658

  Atmosphere during thermal treatment · CPC title