Piezoelectric ceramic, piezoelectric ceramic component, and piezoelectric device using such piezoelectric ceramic component

Patent metadata

Field	Value
Publication number	US-9537082-B2
Application number	US-201113876453-A
Country	US
Kind code	B2
Filing date	Dec 13, 2011
Priority date	Dec 24, 2010
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

In a piezoelectric ceramic which has an alkali-containing niobate-based perovskite structure in which constituent elements are Li, Na, K, Nb, and O, a Li 3 NbO 4 crystal phase is intentionally deposited on a piezoelectric ceramic having an alkali-containing niobate-based perovskite structure, whereby sintering becomes possible at about 1000° C. rather than at the normally required sintering temperature of 1050° C. or greater.

First claim

What is claimed is:

1. A piezoelectric ceramic having an alkali-containing niobate perovskite structure and Li, Na, K, Nb and O as constituent elements, and holding a crystal phase expressed by a composition formula Li 3 NbO 4 , wherein the piezoelectric ceramic shows peaks of Li 3 NbO 4 crystal phase in an X-ray diffraction profile and is expressed by a composition formula {Li x [Na y K 1-y ] 1-x } a NbO 3 (in the formula, 0<x≦0.20, 0≦y≦1, and 1.0≦a≦1.01) containing no Sb nor Ta.

2. A piezoelectric ceramic according to claim 1 , which contains Ag by 0.1 mol or more and 0.5 mol or less in equivalent Ag 2 O relative to 100 mol of the piezoelectric ceramic.

3. A piezoelectric ceramic component having a first electrode and a second electrode facing each other via a piezoelectric ceramic layer, wherein the piezoelectric ceramic layer is formed by a piezoelectric ceramic according to claim 1 .

4. A piezoelectric ceramic component having multiple first electrodes and multiple second electrodes alternately layered via piezoelectric ceramic layers, as well as a first terminal electrode that electrically connects to the first electrodes and a second terminal electrode that electrically connects to the second electrodes, wherein the piezoelectric ceramic layer is formed by a piezoelectric ceramic according to claim 1 .

5. A piezoelectric ceramic component having a substrate with a piezoelectric ceramic layer, as well as a first electrode and a second electrode placed on top of the piezoelectric ceramic layer in a manner facing each other, wherein the piezoelectric ceramic layer is formed by a piezoelectric ceramic according to claim 1 .

6. A piezoelectric ceramic component having multiple first electrodes and multiple second electrodes layered alternately on a substrate with piezoelectric ceramic layers, as well as a first terminal electrode that electrically connects to the first electrodes and a second terminal electrode that electrically connects to the second electrodes, wherein the piezoelectric ceramic layer is formed by a piezoelectric ceramic according to claim 1 .

7. A piezoelectric device comprising a piezoelectric ceramic component according to claim 3 .

8. A piezoelectric ceramic component having a first electrode and a second electrode facing each other via a piezoelectric ceramic layer, wherein the piezoelectric ceramic layer is formed by a piezoelectric ceramic according to claim 2 .

9. A piezoelectric ceramic component having multiple first electrodes and multiple second electrodes alternately layered via piezoelectric ceramic layers, as well as a first terminal electrode that electrically connects to the first electrodes and a second terminal electrode that electrically connects to the second electrodes, wherein the piezoelectric ceramic layer is formed by a piezoelectric ceramic according to claim 2 .

10. A piezoelectric ceramic component having a substrate with a piezoelectric ceramic layer, as well as a first electrode and a second electrode placed on top of the piezoelectric ceramic layer in a manner facing each other, wherein the piezoelectric ceramic layer is formed by a piezoelectric ceramic according to claim 2 .

11. A piezoelectric ceramic component having multiple first electrodes and multiple second electrodes layered alternately on a substrate with piezoelectric ceramic layers, as well as a first terminal electrode that electrically connects to the first electrodes and a second terminal electrode that electrically connects to the second electrodes, wherein the piezoelectric ceramic layer is formed by a piezoelectric ceramic according to claim 2 .

12. A piezoelectric device comprising a piezoelectric ceramic component according to claim 4 .

13. A piezoelectric device comprising a piezoelectric ceramic component according to claim 5 .

14. A piezoelectric device comprising a piezoelectric ceramic component according to claim 6 .

15. A piezoelectric ceramic constituted by an alkali-containing niobate perovskite structure having Li, Na, K, Nb and O as constituent elements in the absence of Pb, Sb, Ta, B, and C, wherein a crystal phase expressed by a composition formula Li 3 NbO 4 is deposited in the structure such that the piezoelectric ceramic shows peaks of Li 3 NbO 4 crystal phase in an X-ray diffraction profile and is expressed by a composition formula {Li x [Na y K 1-y ] 1-x } a NbO 3 (in the formula, 0<x≦0.20, 0≦y≦1, and 1.0≦a≦1.01).

16. A piezoelectric ceramic according to claim 15 , wherein the alkali-containing niobate perovskite structure is formed from materials having the stoichiometric ratio of Li, Na, K, and Nb, and a surplus amount of Li 2 CO 3 relative to the stoichiometric ratio.

17. A piezoelectric ceramic according to claim 16 , further contains Ag by 0.1 mol or more and 0.5 mol or less in equivalent Ag 2 O relative to 100 mol of the piezoelectric ceramic.

Assignees

• Hatano Keiichi
• Shimizu Hiroyuki
• Doshida Yutaka
• Taiyo Yuden Kk

Inventors

• Hatano Keiichi
• Shimizu Hiroyuki
• Doshida Yutaka

Classifications

• C04B2235/768

  Perovskite structure ABO3 · CPC title

• C04B2235/3255

  Niobates or tantalates, e.g. silver niobate · CPC title

• C04B2235/77

  Density · CPC title

• C04B35/495 Primary

  based on vanadium, niobium, tantalum, molybdenum or tungsten oxides or solid solutions thereof with other oxides, e.g. vanadates, niobates, tantalates, molybdates or tungstates · CPC title

• C04B2235/80

  Phases present in the sintered or melt-cast ceramic products other than the main phase · CPC title