Method for preparing high dielectric constant barium titanate ceramic

A high dielectric constant, barium titanate technology, applied in the field of electronic ceramic materials, can solve the problems of difficult to meet electronic components, low product activity, large powder particle size, etc., and achieve high reliability, easy chemical reaction, powder The effect of small particle size

Inactive Publication Date: 2011-03-16
TIANJIN NORMAL UNIVERSITY
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Generally speaking, the methods for preparing barium titanate powder include solid-phase reaction method and liquid-phase synthesis method, wherein liquid-phase reaction includes chemical precipitation method, sol-gel method, hydrothermal synthesis method, microemulsion method, and solid-phase reaction Generally, a higher sintering temperature is required. It is a

Method used

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  • Method for preparing high dielectric constant barium titanate ceramic
  • Method for preparing high dielectric constant barium titanate ceramic
  • Method for preparing high dielectric constant barium titanate ceramic

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] 1. Weigh 0.1mol (25.542g) of barium acetate and dissolve it in 90ml of acetic acid solution with a mass fraction of 36% (32.4ml for acetic acid, 57.6ml for water) and mix well as solution A;

[0032]2. Measure 0.1mol (35ml) butyl titanate, 0.6mol (35ml) ethanol, 0.3mol (17.16ml) acetic acid and mix them uniformly as B solution;

[0033] 3. Mix A and B solutions in a water bath at 60°C for 20 minutes, and they are in a sol state.

[0034] 4. Then sink in the air for four hours, and bake at 120°C for 12 hours to obtain a dry gel.

[0035] 5. The first sintering in the muffle furnace, the sintering curve is as follows figure 2 The sintering curve of barium titanate powder sintering temperature changes with time,

[0036] 6. Take out the powder and grind it in the air for 1 hour under the condition of ethanol as the solvent, put the obtained powder into the muffle furnace for secondary sintering, the sintering curve is as follows figure 2 The sintering curve of barium ...

Embodiment 2

[0040] 1. Weigh 0.1mol (25.542g) of barium acetate and dissolve it in 33.4ml of acetic acid solution with a mass fraction of 36% (12ml of acetic acid and 21.4ml of water) and mix well as solution A;

[0041] 2. Measure 0.1mol (35ml) butyl titanate, 0.2mol (11.67ml) ethanol, 0.1mol (5.72ml) acetic acid and mix well as B solution;

[0042] 3. Mix the A and B solutions in a water bath at 40°C for 40 minutes to be in a sol state;

[0043] 4. Then sink in the air for four hours, and bake at 100°C for 20 hours to obtain a dry gel;

[0044] 5. The first sintering in the muffle furnace, the sintering curve is as follows figure 2 The sintering curve of barium titanate powder sintering temperature changes with time (the sintering rate is constant, the sintering temperature is 800°C, and the holding time is constant);

[0045] 6. Take out the powder and grind it in the air for 1 hour under the condition of ethanol as the solvent, and put the obtained powder into the muffle furnace for...

Embodiment 3

[0049] 1. Weigh 0.1mol (25.542g) of barium acetate and dissolve it in 166.8ml of acetic acid solution with a mass fraction of 36% (60ml of acetic acid and 106.8ml of water) and mix well as solution A;

[0050] 2. Measure 0.1mol (35ml) butyl titanate, 0.6mol (35ml) ethanol, 0.2mol (11.5ml) acetic acid and mix them uniformly as B solution;

[0051] 3. Mix the A and B solutions in a water bath at 80°C for 10 minutes to be in a sol state;

[0052] 4. Then sink in the air for six hours, and bake at 100°C for 20 hours to obtain a dry gel;

[0053] 5. The first sintering in the muffle furnace, the sintering curve is as follows figure 2 The sintering curve of barium titanate powder sintering temperature changes with time (the sintering rate is constant, the sintering temperature is 1000°C, and the holding time is constant);

[0054] 6. Take out the powder and grind it in the air for 1 hour under the condition of ethanol as the solvent, put the obtained powder into the muffle furnac...

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Abstract

The invention relates to a method for preparing high-dielectric constant barium titanate ceramic. The preparation method comprises the following steps of: mixing solution A and solution B; reacting to obtain a sol state substance at the temperature of between 40 and 80 DEG C; precipitating the sol state substance for 4 to 6 hours in the air; drying the sol state substance in an oven at the temperature of between 100 and 160 DEG C for 10 to 24 hours to obtain xerogel; sintering the xerogel twice in a muffle furnace at the temperature of between 700 and 1,100 DEG C, and grinding the xerogel for 1 to 3 hours during the sintering; taking powder out, grinding the powder in the air for 0.5 to 1 hour; compressing the powder into wafers with the diameter of between 10 and 20mm under the pressure of 1GPA with a powder compressing machine; and sintering the wafers in the muffle furnace at the temperature of between 1,250 and 1,340 DEG C to obtain secondary-sintered barium titanate ceramic. The maximum dielectric constant of the barium titanate ceramic prepared by the preparation method can reach 24,173 when the frequency at room temperature is 100Hz. Compared with the conventional method for preparing barium titanate, a sol-gel method can reduce the temperature, and a secondary sintering method can greatly improve the dielectric constant of the barium titanate.

Description

Technical field: [0001] The invention belongs to the technical field of electronic ceramic materials, and relates to a preparation method of high dielectric constant barium titanate ceramics. More specifically, it is a method of preparing high dielectric constant barium titanate powder by using sol-gel, and then preparing barium titanate ceramics through two sinterings. Background technique: [0002] Barium titanate is a ferroelectric material and one of the most widely used materials in electronic ceramics, known as "the pillar of the electronic ceramics industry". Barium titanate is a mixed oxide of barium and titanium with the molecular formula BaTiO 3 . Barium titanate is a ferroelectric ceramic material with light refraction effect and piezoelectric properties. It can have five crystal structures in solid state, and the order of temperature from high to low is: hexagonal, equiaxed, tetragonal, orthorhombic and trigonal. Except equiaxed, the rest of the structures ex...

Claims

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Application Information

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IPC IPC(8): C04B35/468C04B35/624
Inventor 邓湘云张艳杰杨仁波韩立仁谭忠文陆程关晓芬
Owner TIANJIN NORMAL UNIVERSITY
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