CN-122010552-A - Rod-shaped barium titanate template for textured ceramic and preparation method thereof

Abstract

The invention discloses a rod-shaped barium titanate template for textured ceramics and a preparation method thereof, belonging to the technical field of preparation of ceramics and piezoelectric materials. The method comprises the steps of dissolving an organic titanium source in an alcohol solvent to form a transparent titanium solution, slowly adding an alkaline solution into the transparent titanium solution under the condition of stirring to adjust the pH value to be alkaline to obtain an alkaline titanium solution, adding a barium source and a mineralizer into the alkaline titanium solution, adding a morphology regulator to form a uniform precursor solution, placing the precursor solution into a closed reaction kettle to carry out hydrothermal reaction at 180-220 ℃, and sequentially carrying out centrifugal separation, washing and drying on a product obtained after the hydrothermal reaction, and then calcining at 600-900 ℃ to obtain the barium titanate template crystal with a rod-shaped morphology.

Inventors

• YANG SHUAI
• FU MINGLI
• LI FEI
• XIAO YIZHOU
• YANG WEIHONG
• WANG MINGWEN
• LI CHUNCHUN
• LI JINGLEI
• ZHUO RAN
• YANG CHEN

Assignees

• 西安交通大学
• 中国南方电网有限责任公司
• 南方电网科学研究院有限责任公司

Dates

Publication Date

20260512

Application Date

20251118

Claims (10)

1. 1. The preparation method of the rod-shaped barium titanate template for the textured ceramic is characterized by comprising the following steps of: Dissolving an organic titanium source in an alcohol solvent to form a transparent titanium solution; slowly adding an alkaline solution into the transparent titanium solution under the stirring condition to adjust the pH value to 10-13, so as to obtain an alkaline titanium solution; adding a barium source and a mineralizer into the alkaline titanium solution, and adding a morphology regulator to form a uniform precursor solution; Placing the precursor solution in a closed reaction kettle, and performing hydrothermal reaction at 180-220 ℃; And (3) sequentially carrying out centrifugal separation, washing and drying on the product obtained after the hydrothermal reaction is finished, and calcining at 600-900 ℃ to obtain the barium titanate template crystal with the rod-shaped morphology.
2. 2. The method for preparing a rod-shaped barium titanate template for textured ceramics according to claim 1, wherein the organic titanium source is any one of tetrabutyl titanate, isopropanol titanate or acetylacetone titanate, and the alcohol solvent is absolute ethanol or isopropanol.
3. 3. The method for producing a rod-shaped barium titanate template for textured ceramics according to claim 1, wherein the barium source is barium nitrate, barium acetate or barium chloride.
4. 4. The method for preparing a rod-shaped barium titanate template for textured ceramics according to claim 1, wherein the molar ratio of the Ba element to the Ti element is 1:1.02-1:1.05.
5. 5. The method for preparing a rod-shaped barium titanate template for textured ceramics according to claim 1, wherein the mineralizer is sodium hydroxide or potassium hydroxide, and the concentration thereof is 0.1mol/L to 2mol/L.
6. 6. The method for producing a rod-shaped barium titanate template for textured ceramics according to claim 1, wherein a rod-shaped crystal having a length of 2 μm and a diameter of 0.25 μm is obtained at a mineralizer concentration of 0.5mol/L, and the aspect ratio is 15 when the concentration is raised to 1 mol/L.
7. 7. The method for preparing a rod-shaped barium titanate template for textured ceramics according to claim 1, wherein the morphology regulator is at least one of polyethylene glycol, polyvinylpyrrolidone, sodium citrate or sodium acetate, and the dosage is 5-20wt% of the total mass of the raw materials.
8. 8. The method for producing a rod-shaped barium titanate template for textured ceramics according to claim 1, wherein the temperature rising rate during calcination is 8 ℃ per minute to 12 ℃ per minute, and the calcination time is 3 to 5 hours.
9. 9. A rod-shaped barium titanate template for textured ceramics, characterized in that the rod-shaped barium titanate template for textured ceramics is obtained by the preparation method of the rod-shaped barium titanate template for textured ceramics according to any one of claims 1 to 8, the obtained rod-shaped barium titanate crystal is perovskite structure phase, has a crystallinity of not less than 96.5%, an aspect ratio of 5 to 20, an average length of 1 to 5 μm, a diameter of 0.1 to 0.5 μm, a dispersibility index of 0.16 to 0.21, and no visible agglomeration.
10. 10. A barium titanate bulk material, characterized in that a rod-like barium titanate template for textured ceramics according to claim 9 is used as a template.

Description

Rod-shaped barium titanate template for textured ceramic and preparation method thereof Technical Field The invention belongs to the technical field of preparation of energy ceramics and piezoelectric materials, and particularly relates to a rod-shaped barium titanate template for textured ceramics and a preparation method thereof. Background Barium Titanate (BTO) is one of the earliest ferroelectric materials discovered, having excellent dielectric, ferroelectric and piezoelectric properties, and is widely used in multilayer ceramic capacitors, piezoelectric transducers and energy harvesting devices. In order to further improve the comprehensive performance of the material, the concept of 'textured ceramic (textured ceramics)' has appeared in recent years, namely, by introducing oriented template crystals, the crystal grains in the polycrystalline ceramic are induced to be arranged in a preferential orientation along a specific crystal direction, so that the feasibility of the ceramic process is maintained and the performance close to single crystals is obtained. Conventional templates are mostly plate-shaped template seed crystals, such as plate-shaped BTO, bi 4Ti3O12 or SrTiO 3 single crystal plates. Such templates tend to induce grain growth along the <001> or <111> plane orientation in the planar direction. However, the sheet-shaped template has the obvious defects of strong orientation limitation, low template transfer efficiency, easiness in warping or breaking of the template sheet in the sintering process, low effectiveness in orientation transfer, poor process adaptability, large size and thin thickness of the sheet-shaped template, uneven dispersion in die pressing and casting molding and difficulty in maintaining uniform distribution, and the sheet-shaped crystals are easy to stack randomly or overlap in the molding and sintering processes to cause insufficient texture orientation. In contrast, rod template seed crystals exhibit significant advantages in terms of morphology, orientation control, and texture transfer: (1) The rod-shaped crystal is of a one-dimensional growth structure, directional accumulation and grain boundary pairing are easy to realize along the direction of the c axis, and the rod-shaped crystal is naturally oriented along the direction of the long axis of the crystal in the sintering process, so that a three-dimensional texture structure is formed; (2) The contact point diffusion driving is more sufficient, when the particles are contacted, the rod-shaped template has larger end surface curvature and low contact energy, so that the migration potential barrier of the grain boundary can be effectively reduced, and the preferential crystal growth is promoted; (3) The shape stability is higher, the thickness of the rod-shaped crystal is more uniform than that of the flaky crystal, the mechanical strength is high, the rod-shaped crystal is not easy to break or warp, and the shape is kept complete in sintering with a Wen Zhi structure. In the prior art, the patent with the publication number CN113912106A discloses a preparation method of tetragonal phase nano barium titanate, which is characterized in that a titanium source, a barium source, a mineralizer and water are mixed and subjected to hydrothermal reaction to obtain a precursor, the obtained precursor is calcined to obtain tetragonal phase nano barium titanate, the tetragonal phase nano barium titanate is prepared by a hydrothermal method and a solid phase method in two steps, firstly, the nano barium titanate is prepared by the hydrothermal method, then the solid phase calcination is carried out, the crystallinity of the nano barium titanate is improved, and the hydroxyl defect generated in the hydrothermal preparation process is eliminated. Therefore, the preparation method of the rod-shaped barium titanate template seed crystal with controllable morphology, high purity and strong orientation capability is developed, and the important direction of the texture ceramic performance can be effectively improved. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a rod-shaped barium titanate template for textured ceramics and a preparation method thereof, and the preparation method is simple in process and high in controllability. In order to achieve the above object, in a first aspect, the present invention provides a method for preparing a rod-shaped barium titanate template for textured ceramics, comprising the steps of: Dissolving an organic titanium source in an alcohol solvent to form a transparent titanium solution; slowly adding an alkaline solution into the transparent titanium solution under the stirring condition to adjust the pH value to 10-13, so as to obtain an alkaline titanium solution; adding a barium source and a mineralizer into the alkaline titanium solution, and adding a morphology regulator to form a uniform precursor solution; Placing the precursor solution in