# US 8,770,723 B2 · Piezoelectric element, liquid ejecting head, and liquid ejecting apparatus

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- Number: US 8,770,723 B2
- Document ID: US8770723B2
- Status: Granted
- Kind: B2
- Application number: 13/295,326
- Filed: 2011-11-14
- Published: 2012-05-17
- Granted: 2014-07-08
- Earliest claimed: 2010-11-16
- Assignees: Seiko Epson Corporation
- Applicants: Tomohiro Sakai; Koichi Morozumi; Tsutomu Asakawa
- Inventors: Tomohiro Sakai; Koichi Morozumi; Tsutomu Asakawa
- Web page: https://patentgrep.com/patent/US8770723B2

## CPC

- H10N 30/708: {Intermediate layers, e.g. barrier, adhesion or growth control buffer layers}
- B41J 2/055: Devices for absorbing or preventing back-pressure
- B41J 2/14233: {of film type, deformed by bending and disposed on a diaphragm}
- B41J 2/161: {of film type, deformed by bending and disposed on a diaphragm}
- B41J 2/1628: {dry etching}
- B41J 2/1629: {wet etching}
- B41J 2/1634: {laser machining}
- B41J 2/1642: {thin film formation by CVD [chemical vapor deposition]}
- B41J 2/1645: {thin film formation by spincoating}
- B41J 2/1646: {thin film formation by sputtering}
- H10N 30/078: by sol-gel deposition
- H10N 30/8561: {Bismuth-based oxides}
- B41J 2002/14241: {having a cover around the piezoelectric thin film element}
- B41J 2002/14258: {Multi layer thin film type piezoelectric element}
- B41J 2002/14419: {Manifold}
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A piezoelectric element comprises a electrode and a piezoelectric layer made of a complex oxide having a perovskite structure containing at least bismuth, barium, iron, and titanium. A layered compound containing iron, barium, titanium and oxygen is formed between the piezoelectric layer and the electrode.

## Claims

### Claim 1

A piezoelectric element comprising:
a first electrode;
a second electrode; and
a layered compound; and
a piezoelectric layer made of a complex oxide having a perovskite structure containing at least bismuth, barium, iron, and titanium;
wherein the layered compound contains iron, barium, titanium and oxygen and is formed between the piezoelectric layer and the first electrode and
wherein the piezoelectric layer is formed between the layered compound and the second electrode, and
wherein the layered compound is preferentially oriented along the (001) plane.

### Claim 2 (depends on 1)

The piezoelectric element according to claim 1, wherein the layered compound is formed in an island shape.

### Claim 3 (depends on 1)

The piezoelectric element according to claim 1, wherein the layered compound further contains manganese.

### Claim 4 (depends on 1)

A liquid ejecting head comprising the piezoelectric element as set forth in claim 1.

### Claim 5 (depends on 4)

A liquid ejecting apparatus comprising the liquid ejecting head as set forth in claim 4.

### Claim 6 (depends on 1)

A method for forming the piezoelectric element of claim 1, comprising firing the piezoelectric element at a firing temperature greater than 650° C.

### Claim 7

A method for forming a piezoelectric element, the method comprising:
forming a first electrode;
forming a layered compound on the first electrode, the layered compound containing iron, barium, titanium and oxygen;
forming a piezoelectric layer on the layered compound, wherein the piezoelectric layer is made of a complex oxide having a perovskite structure containing at least bismuth, barium, iron, and titanium;
forming a second electrode on the piezoelectric layer; and
firing at a temperature greater than 650° C.

### Claim 8 (depends on 7)

The method of claim 7, further comprising forming the layered compound in an island shape, wherein at least some of the piezoelectric layer contacts the first electrode.