# US 8,783,838 B2 · Liquid ejecting head, liquid ejecting apparatus, and piezoelectric element

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- Number: US 8,783,838 B2
- Document ID: US8783838B2
- Status: Granted
- Kind: B2
- Application number: 13/744,709
- Filed: 2013-01-18
- Published: 2013-07-25
- Granted: 2014-07-22
- Earliest claimed: 2012-01-19
- Assignees: Seiko Epson Corporation
- Applicants: Seiko Epson Corporation
- Inventors: Tomohiro Sakai; Tsutomu Asakawa
- Web page: https://patentgrep.com/patent/US8783838B2

## CPC

- B41J 2/14201: {Structure of print heads with piezoelectric elements}
- 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 2/1629: {wet etching}
- B41J 2/1632: {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 30/708: {Intermediate layers, e.g. barrier, adhesion or growth control buffer layers}
- H10N 30/8561: {Bismuth-based oxides}
- B41J 2002/14241: {having a cover around the piezoelectric thin film element}
- B41J 2002/14419: {Manifold}
- B41J 2202/03: Specific materials used
- H10N 30/078: by sol-gel deposition
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR

## Abstract

A piezoelectric layer includes a buffer layer containing an oxide containing Bi and Co and disposed on an electrode, and a layer disposed on the buffer layer and containing a perovskite oxide containing Bi, Ba, Fe and Ti. A piezoelectric element includes the piezoelectric layer and the electrode. A liquid ejecting head includes a pressure generating chamber communicating with a nozzle aperture, and the piezoelectric element. A liquid ejecting apparatus includes the liquid ejecting head.

## Claims

### Claim 1

A liquid ejecting head comprising:
a pressure generating chamber communicating with a nozzle aperture; and
a piezoelectric element including a piezoelectric layer and an electrode, the piezoelectric layer including a buffer layer containing an oxide containing Bi and Co and disposed on the electrode, and a layer disposed on the buffer layer and containing a perovskite oxide containing Bi, Ba, Fe and Ti,
wherein the buffer layer includes at least one composition expressed by the following general formulas:
BiCoO3 (1);
(Bi,MA)CoO3 (2);
Bi(Co,MB)O3 (3);
(Bi,MA)(Co,MB)O3 (4); and
MA in formulas (2) and (4) represents at least one metal element other than Bi, and MB in formulas (3) and (4) represents at least one metal element other than Co.

### Claim 2 (depends on 1)

The liquid ejecting head according to claim 1, wherein the oxide of the buffer layer further contains Fe.

### Claim 3 (depends on 1)

The liquid ejecting head according to claim 1, wherein the oxide of the buffer layer further contains Ti.

### Claim 4 (depends on 1)

The liquid ejecting head according to claim 1, wherein the perovskite oxide further contains Mn.

### Claim 5 (depends on 1)

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

### Claim 6 (depends on 2)

A liquid ejecting apparatus comprising the liquid ejecting head as set forth in claim 2.

### Claim 7 (depends on 3)

A liquid ejecting apparatus comprising the liquid ejecting head as set forth in claim 3.

### Claim 8 (depends on 4)

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

### Claim 9

A piezoelectric element comprising:
an electrode; and
a piezoelectric layer disposed on the electrode, the piezoelectric layer including a buffer layer containing an oxide containing Bi and Co, and a layer disposed on the buffer layer and containing a perovskite oxide containing Bi, Ba, Fe and Ti,
wherein the buffer layer includes at least one composition expressed by the following general formulas:
BiCoO3 (1);
(Bi,MA)CoO3 (2);
Bi(Co,MB)O3 (3);
(Bi,MA)(Co,MB)O3 (4); and
MA in formulas (2) and (4) represents at least one metal element other than Bi, and MB in formulas (3) and (4) represents at least one metal element other than Co.