METHOD FOR MANUFACTURING RECTANGULAR PARALLELEPIPED-SHAPED SINGLE CRYSTAL, RECTANGULAR PARALLELEPIPED-SHAPED SINGLE CRYSTAL, METHOD FOR MANUFACTURING CERAMICS, CERAMICS, PIEZOELECTRIC ELEMENT, PIEZOELECTRIC DEVICE, AND ELECTRONIC DEVICE

• US 20160273125A1
• Filed: 03/15/2016
• Published: 09/22/2016
• Est. Priority Date: 03/17/2015
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Murakami, Shunsuke, Watanabe, Takayuki, Kubota, Makoto
• Granted Patent: US 10,461,241 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C30B 29/30 Niobates; Vanadates; Tantalates
• CPC Class Codes: C30B 7/08 by cooling of the solution
• CPC Class Codes: H10N 30/097 by sintering
• CPC Class Codes: H10N 30/8542 Alkali metal based oxides, e.g. lithium, sodium or potassium niobates

Abstract

This invention is a method for manufacturing a rectangular parallelepiped-shaped single crystal containing sodium niobate of a perovskite structure as the main component, and the method includes a process of heating a mixture 1 of bismuth sodium niobate which is formed from particles containing a plurality of crystals represented by General Formula (1): Bi_2.5Na_m−1.5NbmO_3m+3 (m is an integer of 2 or more) and in which an average value m_a of the m values is larger than 6 and sodium containing alkali metal halide at 1200° C. or more and 1250° C. or less to obtain a rectangular parallelepiped-shaped single crystal containing sodium niobate as the main component.

Claims

1. A method for manufacturing a rectangular parallelepiped-shaped single crystal containing sodium niobate of a perovskite structure as a main component,

the method comprising:

heating a mixture 1 of bismuth sodium niobate which is formed from particles containing a plurality of crystals of a composition represented by General Formula (1);

Bi_2.5Na<sub>m−

1.5</sub>NbmO_3m+3 (m is an integer of 2 or more) and in which an average value m_a of the m values in the particles is larger than 6 and sodium containing alkali metal halide at 1200°

C. or more and 1250°

C. or less to obtain a mixture 2 containing sodium niobate of a perovskite structure; and

removing a water soluble component from the mixture 2.

2. The method for manufacturing a rectangular parallelepiped-shaped single crystal containing sodium niobate as a main component according to claim 1, wherein a weight of the sodium containing alkali metal halide is 1.0 times or more and 10 times or less a weight of the bismuth sodium niobate in the mixture 1.

3. The method for manufacturing a rectangular parallelepiped-shaped single crystal containing sodium niobate as a main component according to claim 1, wherein the m value represents a number of layers of oxygen octahedrons in a c-axis direction in the bismuth sodium niobate with a bismuth layer structure.

4. The method for manufacturing a rectangular parallelepiped-shaped single crystal containing sodium niobate as a main component according to claim 1, wherein the average value m_a is 6.4 or more and 8.0 or less.

5. The method for manufacturing a rectangular parallelepiped-shaped single crystal containing sodium niobate as a main component according to claim 1, wherein the sodium containing alkali metal halide is sodium chloride.

6. A method for manufacturing ceramics, comprising:

obtaining a rectangular parallelepiped-shaped single crystal by the method for manufacturing a rectangular parallelepiped-shaped single crystal according to claim 1;

obtaining a green body using the rectangular parallelepiped-shaped single crystal; and

sintering the green body to obtain ceramics.

7. A rectangular parallelepiped-shaped single crystal containing sodium niobate of a perovskite structure as a main component, wherein

the rectangular parallelepiped-shaped single crystal contains bismuth in an amount of 0.05 mol or more and 0.15 mol or less per mole of the sodium niobate,

a Na/Nb ratio of the rectangular parallelepiped-shaped single crystal is 0.82 or more and 1.00 or less, and

a ratio of a longest side length (L_max) to a shortest side length (L_min) of the rectangular parallelepiped is in a range of L_max/L_min of 4.0≦

L_max/L_min≦

8.5.

8. The rectangular parallelepiped-shaped single crystal containing sodium niobate as a main component according to claim 7, wherein the L_max is 9.4 μ

m or more and 20 μ

m or less.

9. Ceramics, which is obtained by sintering a green body containing the rectangular parallelepiped-shaped single crystal containing sodium niobate as a main component according to claim 7.

10. The ceramics according to claim 9, wherein the ceramics is oriented in a (110) plane or a (001) plane.

11. A piezoelectric element, comprising:

a first electrode;

a piezoelectric material portion; and

a second electrode, wherein a piezoelectric material configuring the piezoelectric material portion is the ceramics according to claim 10.

12. A piezoelectric device, comprising:

the piezoelectric element according to claim 11; and

at least one of a voltage application unit to the piezoelectric element and a power extracting unit from the piezoelectric element.

13. An electronic device;

comprising the piezoelectric element according to claim 11.