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JP-2026075798-A - Method for manufacturing piezoelectric material composition, piezoelectric element, and apparatus

JP2026075798AJP 2026075798 AJP2026075798 AJP 2026075798AJP-2026075798-A

Abstract

[Problem] To manufacture a piezoelectric material composition having a high relative density. [Solution] The present invention provides a method for producing a piezoelectric material composition, comprising: a calcination step of calcining a raw material powder containing a potassium compound, a sodium compound, and a niobium compound to obtain a calcined product; a grinding step of grinding the calcined product to obtain a sintering powder; and a final calcination step of calcining the sintering powder, wherein the final calcination step includes a first final calcination step of calcining the sintering powder at a temperature of 500°C to 650°C for 2 hours or more, and a second final calcination step of calcining the sintering powder at a temperature of 900°C to 1150°C for 2 hours or more after the first final calcination step. [Selection Diagram] Figure 2

Inventors

  • ▲イェ▼ 載憲
  • 永田 肇
  • ▲高▼木 優香
  • 南 ▲ヒュン▼ 旭

Assignees

  • エルジー ディスプレイ カンパニー リミテッド
  • 学校法人東京理科大学

Dates

Publication Date
20260511
Application Date
20241023

Claims (20)

  1. A calcination process involves calcining a raw material powder containing potassium compounds, sodium compounds, and niobium compounds to obtain a calcined product. A grinding step to crush the calcined material to obtain sintering powder, The process includes a final calcination step in which the sintering powder is calcined, A method for producing a piezoelectric material composition, characterized in that the firing process includes a first firing process in which the sintering powder is fired at a temperature of 500°C to 650°C for 2 hours or more, and a second firing process in which the sintering powder is fired at a temperature of 900°C to 1150°C for 2 hours or more, after the first firing process.
  2. The method for producing a piezoelectric material composition according to claim 1, characterized in that, in the calcination step, the raw material powder is calcined at a temperature of 150°C to 300°C for 2 hours or more.
  3. The method for producing a piezoelectric material composition according to claim 1, characterized in that, in the calcination step, the raw material powder is calcined at a temperature of 500°C to 650°C for 2 hours or more.
  4. The method for producing a piezoelectric material composition according to claim 1, characterized in that, in the calcination step, the raw material powder is calcined at a temperature of 900°C to 1150°C for 2 hours or more.
  5. The method for producing a piezoelectric material composition according to claim 1, characterized in that a metal oxide is added to the calcined material in the grinding step.
  6. The aforementioned metal oxide is copper oxide. The method for producing a piezoelectric material composition according to claim 5, characterized in that, in the second firing step, the sintering powder is fired at a temperature of 990°C to 1150°C for 2 hours or more.
  7. The aforementioned metal oxide is cobalt oxide. The method for producing a piezoelectric material composition according to claim 5, characterized in that, in the second firing step, the sintering powder is fired at a temperature of 1040°C to 1150°C for 2 hours or more.
  8. The method for producing the piezoelectric material composition according to claim 1, characterized in that the potassium compound is potassium bicarbonate.
  9. The method for producing the piezoelectric material composition according to claim 1, characterized in that the niobium compound is niobium oxide.
  10. The method for producing the piezoelectric material composition according to claim 9, characterized in that the niobium oxide is T-type niobium oxide.
  11. The method for producing a piezoelectric material composition according to claim 1, further comprising a molding step for molding the sintering powder before the main firing step.
  12. A preparation step involves adding a niobium compound to an alkaline solution containing sodium hydroxide and potassium hydroxide to prepare the raw materials. The system includes a synthesis step of obtaining a sintering powder from the raw materials by hydrothermal synthesis. The reaction temperature for the aforementioned hydrothermal synthesis is 160°C or higher. The reaction time for the aforementioned hydrothermal synthesis is 6 hours or more. The concentration of hydroxide ions in the aforementioned alkaline solution is 7 mol/L or more and 10 mol/L or less. A method for producing a piezoelectric material composition, characterized in that the alkali ratio of potassium ions to sodium ions in the aforementioned alkaline solution is 8 or more and 20 or less.
  13. The method for producing a piezoelectric material composition according to claim 12, characterized in that the reaction temperature is 300°C or lower.
  14. The method for producing a piezoelectric material composition according to claim 12, characterized in that the reaction temperature is 240°C or lower.
  15. The method for producing a piezoelectric material composition according to claim 12, characterized in that the reaction time is 24 hours or less.
  16. The method for producing the piezoelectric material composition according to claim 12, characterized in that the niobium compound is niobium oxide.
  17. The method for producing the piezoelectric material composition according to claim 16, characterized in that the niobium oxide is H-type niobium oxide.
  18. The process further comprises a sintering step for sintering the aforementioned sintering powder, The method for producing a piezoelectric material composition according to claim 12, characterized in that the sintering step includes a first sintering step of sintering the sintering powder at a temperature of 500°C to 650°C for 2 hours or more, and a second sintering step of sintering the sintering powder at a temperature of 900°C to 1150°C for 2 hours or more, after the first sintering step.
  19. A piezoelectric element characterized by comprising a piezoelectric material composition manufactured by the method for manufacturing a piezoelectric material composition described in claim 1 or claim 12.
  20. The piezoelectric element according to claim 19, The apparatus is characterized by comprising a vibrating member connected to the piezoelectric element.

Description

This invention relates to a method for producing a piezoelectric material composition, a piezoelectric element, and an apparatus. Lead zirconate titanate (PZT) is widely known as a piezoelectric material composition for piezoelectric elements. Lead zirconate titanate has the advantages of good piezoelectric properties and high stability. However, because lead zirconate titanate contains lead, it has the technical challenge of having a high environmental impact. Potassium sodium niobate (KNN) is known as a piezoelectric material composition that can replace lead zirconate titanate. Potassium sodium niobate is lead-free and possesses piezoelectric properties equivalent to those of lead zirconate titanate. This is a cross-sectional view of the piezoelectric element of the present invention.This is a schematic diagram of a sintering apparatus used in a method for manufacturing a piezoelectric material composition according to the first embodiment.This is a flowchart of the method for manufacturing the piezoelectric material composition according to the first embodiment.This diagram illustrates the hygroscopic properties of potassium compounds.This diagram shows an example of heating conditions for calcination.This is an example of the results of thermogravimetric and differential thermal analysis of potassium bicarbonate.This is an example of the results of X-ray diffraction measurements of potassium bicarbonate.This diagram shows the reaction that occurs when potassium bicarbonate is heated.This is an example of XRD measurement results for calcined material.These are SEM images of calcined materials and piezoelectric material compositions.This diagram shows an example of heating conditions for the final firing process.This is a SEM image of a calcined material.This is a schematic diagram illustrating the formation of potassium sodium niobate during the calcination of T-type niobium oxide.This is a schematic diagram illustrating the formation of potassium sodium niobate during the calcination of H-type niobium oxide.This graph shows the relative density of piezoelectric material compositions.This graph shows the relative density of piezoelectric material compositions.This graph shows the relative density of piezoelectric material compositions.This graph shows the relative density of piezoelectric material compositions.This graph shows the relative density of piezoelectric material compositions.This graph shows the measurement results of the small-amplitude piezoelectric properties of piezoelectric material compositions.This graph shows the measurement results of the small-amplitude piezoelectric properties of piezoelectric material compositions.This graph shows the measurement results of the small-amplitude piezoelectric properties of piezoelectric material compositions.This graph shows the measurement results of the small-amplitude piezoelectric properties of piezoelectric material compositions.This is a schematic diagram of a reaction apparatus used in a method for manufacturing a piezoelectric material composition according to the second embodiment.This is a flowchart of the method for manufacturing the piezoelectric material composition according to the second embodiment.This diagram shows an example of heating conditions for sintering.This diagram illustrates another example of heating conditions for sintering.This is the XRD measurement result of the sintering powder.This diagram shows the particle size of the sintering powder.This is the XRD measurement result of the sintering powder.This is the XRD measurement result of the sintering powder.This diagram shows the particle size of the sintering powder.This is the XRD measurement result of the sintering powder.This diagram shows the particle size of the sintering powder.This is a schematic diagram showing a part of the crystal structure of niobium oxide.This is the XRD measurement result of the sintering powder.This is a schematic diagram illustrating the dissolution of T-type niobium oxide.This is a schematic diagram illustrating the dissolution of H-type niobium oxide.These are SEM images of sintering powder and piezoelectric material compositions.This diagram shows the particle size of the sintering powder.This is a block diagram showing the schematic configuration of the apparatus according to the third embodiment.This is a plan view showing the arrangement of piezoelectric elements according to the third embodiment.This is a cross-sectional view showing the arrangement of piezoelectric elements according to the third embodiment.This is a cross-sectional view showing the structure of the piezoelectric element according to the third embodiment in more detail.This is a schematic diagram showing the deformation of the piezoelectric element according to the third embodiment when a voltage is applied to it.This is a schematic diagram showing the deformation of the piezoelectric element according to the third embodiment when a voltage is applied to it.This