Piezoelectric device with piezoelectric ceramic layer constituted by alkali-containing niobate type perovskite composition

Patent metadata

Field	Value
Publication number	US-9755137-B2
Application number	US-201615178424-A
Country	US
Kind code	B2
Filing date	Jun 9, 2016
Priority date	Dec 20, 2011
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A piezoelectric device has a piezoelectric ceramic layer obtained by sintering a piezoelectric ceramic composition that contains an alkali-containing niobate type perovskite composition which is represented by (Li l Na m K 1-l-m ) n (Nb 1-o Ta o )O 3 (wherein 0.04≦l≦0.1, 0≦m≦1, 0.95≦n≦1.05, 0≦o≦1) and Ag component, as well as a conductor layer sandwiching the piezoelectric ceramic layer. The piezoelectric ceramic layer has Ag segregated in voids present in a sintered compact of the perovskite composition in terms of oxides relative to the perovskite composition.

First claim

What is claimed is:

1. A piezoelectric device having a piezoelectric ceramic layer obtained by sintering a piezoelectric ceramic composition that contains a perovskite composition and Ag component, as well as a conductor layer sandwiching the piezoelectric ceramic layer, wherein the piezoelectric ceramic layer has Ag segregated in voids present in a sintered compact of the perovskite composition, wherein the perovskite composition is an alkali-containing niobate type perovskite composition expressed by Formula (2) below, and the piezoelectric ceramic layer has a Si and K-containing crystalline or non-crystalline substance present at grain boundaries or grain boundary triple points of crystal grains constituted by a sintered compact of the perovskite composition:
(Li l Na m K 1-l-m ) n (Nb 1-o Ta o )O 3   (2)

wherein l, m, n, and o meet the respective requirements below:
0.04<l≦0.1
0≦m≦1
0.95≦n≦1.05
0≦o≦1.

2. A piezoelectric device according to claim 1 , wherein a grain size of the Ag segregated in the voids present in the sintered compact of the perovskite composition is 0.1 to 3 μm in d80 diameter which is the 80th percentile diameter of the Ag grains.

3. A piezoelectric ceramic composition according to claim 1 , wherein a maximum grain size of the Ag component is 3 μm or less.

4. A piezoelectric device according to claim 1 , wherein the conductor layer is formed by Ag, Pd, Pt, Ni, Cu, or any alloy containing at least one of the foregoing.

5. A piezoelectric device according to claim 2 , wherein the conductor layer is formed by Ag, Pd, Pt, Ni, Cu, or any alloy containing at least one of the foregoing.

6. A piezoelectric device according to claim 3 , wherein the conductor layer is formed by Ag, Pd, Pt, Ni, Cu, or any alloy containing at least one of the foregoing.

Assignees

• Taiyo Yuden Kk

Inventors

• Ikemi Shinichiro
• Doshida Yutaka

Classifications

• C04B35/62685

  characterised by the order of addition of constituents or additives · CPC title

• C04B35/50

  based on rare-earth compounds {(non-oxide rare earth compounds C04B35/5156)} · CPC title

• C04B2235/768

  Perovskite structure ABO3 · CPC title

• C04B2235/3227

  Lanthanum oxide or oxide-forming salts thereof · CPC title

• C04B35/499

  containing also titanates · CPC title