CN110372377A - A kind of preparation method of huge dielectric constant dielectric substance - Google Patents

Abstract

The invention discloses a method for preparing a dielectric material with a giant dielectric constant. Firstly, Ba(Zr _0.2 Ti _0.8 )O ₃ (BZT) is synthesized according to the molar ratio of BaCO ₃ : ZrO ₂ : TiO ₂ =5:1:4, and then massaging Synthesize Bi ₂ (Zn _2/3 Nb _4/3 )O ₇ (BZN) with the ratio of Bi ₂ O ₃ , ZnO, Nb ₂ O ₅ =3:2:4, and then Ba(Zr _0.2 Ti _0.8 )O ₃ and Bi ₂ (Zn _2/3 Nb _4/3 )O ₇ molar ratio = 1:0.0001～0.0006 ingredients, after ball milling, drying, sieving, granulation, pressing into green body, green body at 1325℃～1425℃ Under sintering, a giant dielectric constant dielectric material is made. The dielectric constant of the present invention is ε _25°C ~ 20449, and the dielectric loss tanσ ~ 0.0029.

Description

A kind of preparation method of giant permittivity dielectric material

technical field

The invention belongs to a ceramic composition characterized by composition, and specifically relates to a BZT with a giant dielectric constant (the dielectric constant is greater than 10000, that is, ε>10 ⁴ , called "giant dielectric constant") and ultra-low loss. -BZN system dielectric ceramic material and preparation method thereof.

Background technique

In recent years, pulse power systems have developed rapidly and are widely used in various fields: in terms of military use, pulse power systems are electromagnetic pulse weapons (microwave high-power electromagnetic pulse weapons, particle beam weapons) and electromagnetic kinetic energy weapons (electromagnetic rail guns, aircraft carrier aircraft electromagnetic ejection) In terms of civilian use, resource exploration, particle accelerators, and extracorporeal shock waves for crushing kidney stones are also inseparable from pulse power systems.

The energy storage module of the pulse power system is supported by the pulse power capacitor, and the key to determine the energy storage characteristics of the pulse power capacitor is the dielectric material. In order to meet the energy storage requirements of the energy storage module, the dielectric material that needs to be used has a very large dielectric constant. The dielectric material with a huge dielectric constant can store more charge under the same external electric field conditions, so as to achieve The purpose of energy storage; in addition, to resist thermal shock under high power, the dielectric material also needs to meet low loss characteristics. At present, giant dielectric constant dielectric materials often have shortcomings in practical applications, and it is necessary to develop giant dielectric constant dielectric materials with better stability.

Contents of the invention

The purpose of the present invention is to provide a BZT-BZN system dielectric material with a huge dielectric constant and ultra-low loss and a preparation method thereof through formula adjustment and process optimization under normal temperature sintering conditions, which are used to meet the requirements of pulse power capacitors and other storage devices. The energy storage requirements required by the energy module.

The present invention is realized through the following technical solutions.

A preparation method of a dielectric material with a giant permittivity, the specific steps are as follows:

(1) BZT synthesis: Dosing according to the molar ratio of BaCO ₃ : ZrO ₂ : TiO ₂ =5:1:4, mixed in deionized water and ball milled for 9 hours, dried at 120°C, and passed through a 40-mesh sieve. After sieving, the powder is pre-calcined at 1100°C to synthesize Ba(Zr _0.2 Ti _0.8 )O ₃ (BZT);

(2) Synthesis of BZN: mix according to the molar ratio of Bi ₂ O ₃ , ZnO, Nb ₂ O ₅ =3:2:4, mix and ball mill in deionized water for 4 hours, dry at 120°C, and pass through a 40-mesh sieve . After sieving, the powder is pre-calcined at 750°C to synthesize Bi ₂ (Zn _2/3 Nb _4/3 )O ₇ (BZN);

(3) Mix the prepared Ba(Zr _0.2 Ti _0.8 )O ₃ , Bi ₂ (Zn _2/3 Nb _4/3 )O ₇ in a molar ratio=1:0.0001～0.0006, and mix them in deionized water for secondary ball milling For 14 hours, dry at 120°C and pass through a 40-mesh sieve;

(4) Granulation: adding 7wt% paraffin to the sieved powder in step (3) to granulate, and passing through a 80-mesh sieve;

(5) Tabletting: Press the powder sieved in step (4) into a green body.

(6) Sintering: Sinter the body pressed in step (5) in a high-temperature furnace at 1325° C. to 1425° C. to make a dielectric material with a large dielectric constant.

The heating process of the step (1) is as follows: from room temperature to 1100° C. at a rate of 5° C./min, and keeping the temperature for 4 hours.

The heating process of the step (2) is as follows: 3°C/min to 200°C, then 3.5°C/min to 750°C, and keeping the temperature for 4 hours.

The green body in the step (5) is a disc green body with a diameter of Φ10×1.0-2.0 mm.

The green body in the step (6) is heated from room temperature to 550° C. for 3.5 hours after debinding, and then heated to 1325° C. to 1425° C. at 5° C./min, and kept for 4 hours.

The sintering temperature of the step (6) is 1350°C.

The beneficial effects of the present invention are as follows:

1. The raw material is doped with Zr ²⁺ larger than the radius of Ti ⁴⁺ to effectively increase the lattice constant, strengthen the polarizability, and increase the dielectric constant;

2. Use Zn ²⁺ and Nb ⁵⁺ co-doping to further increase the dielectric constant and reduce the dielectric loss;

3. The BZT-BZN system dielectric material disclosed in the present invention has excellent dielectric properties. By adjusting the sintering temperature and formula ratio, the material properties can reach the dielectric constant ε _25°C ~ 20449, and the dielectric loss tanσ ~ 0.0029.

Detailed ways

The present invention will be described in further detail below in conjunction with specific examples, and the present invention is not limited to the following examples.

Example 1

First, use an electronic balance to weigh BaCO ₃ : ZrO ₂ : TiO ₂ in a molar ratio of 5:1:4 for batching, and deionized water: zirconium ball: powder = 2:1:1 is mixed with deionized water, and after mixing Ball milled for 9 hours, dried and passed through a 40-mesh sieve, and pre-calcined at 1100°C to synthesize Ba(Zr _0.2 Ti _0.8 )O ₃ (BZT).

Secondly, weigh Bi ₂ O ₃ , ZnO, Nb ₂ O ₅ with an electronic balance in a molar ratio of 3:2:4 for batching, with deionized water: zirconium ball: powder = 2:1:1 mixed with deionized water, Ball mill for 4 hours after mixing, pass through a 40-mesh sieve after drying, and pre-calcine at 750°C to synthesize Bi ₂ (Zn _2/3 Nb _4/3 )O ₇ (BZN).

Mix the two synthesized powders in a molar ratio of 1:0.0002, mix them with deionized water: zirconium balls: powder = 2:1:1, mix them with ball mill for 14 hours, and pass through a 40-mesh sieve after drying , plus 7% paraffin by mass percentage, passing through an 80-mesh sieve for granulation.

The granulated powder is pressed at 3MPa to form a green disc of Ф10×1.1mm. After 3.5 hours in the air, the temperature is raised to 550°C for debinding, and then the temperature is raised to 1350°C at 5°C/min, and the temperature is kept for 4 hours. Dielectric constant, low loss dielectric material.

The upper and lower surfaces of the obtained product were evenly coated with silver paste, and the electrode was prepared by firing at 840°C, and the sample to be tested was prepared to test the dielectric properties and TC characteristics.

The dielectric constant of the prepared sample reaches 20449, and the dielectric loss is 0.0029.

Example 2

First, use an electronic balance to weigh BaCO ₃ : ZrO ₂ : TiO ₂ in a molar ratio of 5:1:4 for batching, and deionized water: zirconium ball: powder = 2:1:1 is mixed with deionized water, and after mixing Ball milled for 9 hours, dried and passed through a 40-mesh sieve, and pre-calcined at 1100°C to synthesize Ba(Zr _0.2 Ti _0.8 )O ₃ (BZT).

Secondly, weigh Bi ₂ O ₃ , ZnO, Nb ₂ O ₅ with an electronic balance in a molar ratio of 3:2:4 for batching, with deionized water: zirconium ball: powder = 2:1:1 mixed with deionized water, Ball mill for 4 hours after mixing, pass through a 40-mesh sieve after drying, and pre-calcine at 750°C to synthesize Bi ₂ (Zn _2/3 Nb _4/3 )O ₇ (BZN).

Mix the two synthesized powders in a molar ratio of 1:0.0002, mix them with deionized water: zirconium balls: powder = 2:1:1, mix them with ball mill for 14 hours, and pass through a 40-mesh sieve after drying , plus 7% paraffin by mass percentage, passing through an 80-mesh sieve for granulation.

The granulated powder is pressed at 3MPa to form a green disc of Ф10×1.1mm. After 3.5 hours in the air, the temperature is raised to 550°C for debinding, and then the temperature is raised to 1400°C at 5°C/min, and the temperature is kept for 4 hours. Dielectric constant, low loss dielectric material.

The upper and lower surfaces of the obtained product were evenly coated with silver paste, and the electrode was prepared by firing at 840°C, and the sample to be tested was prepared to test the dielectric properties and TC characteristics.

The dielectric constant of the prepared sample reaches 15616, and the dielectric loss is 0.0045.

Example 3

First, use an electronic balance to weigh BaCO ₃ : ZrO ₂ : TiO ₂ in a molar ratio of 5:1:4 for batching, and deionized water: zirconium ball: powder = 2:1:1 is mixed with deionized water, and after mixing Ball milled for 9 hours, dried and passed through a 40-mesh sieve, and pre-calcined at 1100°C to synthesize Ba(Zr _0.2 Ti _0.8 )O ₃ (BZT).

Secondly, weigh Bi ₂ O ₃ , ZnO, Nb ₂ O ₅ with an electronic balance in a molar ratio of 3:2:4 for batching, with deionized water: zirconium ball: powder = 2:1:1 mixed with deionized water, Ball mill for 4 hours after mixing, pass through a 40-mesh sieve after drying, and pre-calcine at 750°C to synthesize Bi ₂ (Zn _2/3 Nb _4/3 )O ₇ (BZN).

Mix the two synthesized powders in a molar ratio of 1:0.0006, mix them with deionized water: zirconium balls: powder = 2:1:1, mix them with ball mill for 14 hours, and pass through a 40-mesh sieve after drying , plus 7% paraffin by mass percentage, passing through an 80-mesh sub-sieve for granulation.

The granulated powder is pressed at 3MPa to form a green disc of Ф10×1.1mm. After 3.5 hours in the air, the temperature is raised to 550°C for debinding, and then the temperature is raised to 1350°C at 5°C/min, and the temperature is kept for 4 hours. Dielectric constant, low loss dielectric material.

The upper and lower surfaces of the obtained product were evenly coated with silver paste, and the electrode was prepared by firing at 840°C, and the sample to be tested was prepared to test the dielectric properties and TC characteristics.

The dielectric constant of the prepared sample reaches 20853, and the dielectric loss is 0.1049.

Test method and detection equipment of the present invention are as follows:

(1) Dielectric performance test (AC test signal: frequency is 20Hz ~ 1MHz, voltage is 1V)

Use TH2828S 1MHz Tonghui Precision LCR digital bridge to test the capacitance C and loss tanδ of the sample, and calculate the dielectric constant of the sample. The calculation formula is:

(2) TC characteristic test

Use GZ-ESPEC MPC-710P high and low temperature cycle thermostat, HM27002 special tester for capacitor C-T/V characteristics and HEWLETT PACKARD 4278A for testing. Measure the capacitance of the sample in the temperature range of -55°C to 150°C, and use the following formula to calculate the capacitance change rate:

The present invention is not limited to the above-described embodiments, and changes in many details are possible without departing from the scope and spirit of the present invention.

Claims (6)

1. a kind of preparation method of huge dielectric constant dielectric substance, the specific steps are as follows:

(1) BZT is synthesized: BaCO in molar ratio₃: ZrO₂: TiO₂=5:1:4 carries out ingredient, and mixing and ball milling 9 is small in deionized water When, it is dried in 120 DEG C, crosses 40 mesh sub-sieves.Powder carries out pre-burning at 1100 DEG C after sieving, synthesizes Ba (Zr_0.2Ti_0.8)O₃ (BZT)；

(2) BZN is synthesized: Bi in molar ratio₂O₃、ZnO、Nb₂O₅=3:2:4 carries out ingredient, and mixing and ball milling 4 is small in deionized water When, it is dried in 120 DEG C, crosses 40 mesh sub-sieves.Powder carries out pre-burning at 750 DEG C after sieving, synthesizes Bi₂(Zn_2/3Nb_4/3)O₇ (BZN)；

(3) Ba (Zr that will be prepared_0.2Ti_0.8)O₃、Bi₂(Zn_2/3Nb_4/3)O₇In molar ratio=the ingredient of 1:0.0001~0.0006, It mixes secondary ball milling 14 hours, is dried in 120 DEG C in deionized water, cross 40 mesh sub-sieves；

(4) it is granulated: the paraffin that 7wt% is added in the powder after step (3) sieving being granulated, 80 mesh sub-sieves are crossed；

(5) tabletting: by the powder pressing after step (4) sieving at green body.

(6) it is sintered: the green body that step (5) presses being sintered at 1325 DEG C~1425 DEG C in high temperature furnace, huge Jie is made K dielectric materials.

2. a kind of preparation method of huge dielectric constant dielectric substance according to claim 1, which is characterized in that the step Suddenly the heating process of (1) are as follows: be warming up to 1100 DEG C by room temperature with 5 DEG C/min, and keep the temperature 4 hours.

3. a kind of preparation method of huge dielectric constant dielectric substance according to claim 1, which is characterized in that the step Suddenly the heating process of (2) are as follows: 3 DEG C/min is warming up to 200, and rear 3.5 DEG C/min is warming up to 750 degrees Celsius, and keeps the temperature 4 hours.

4. a kind of preparation method of huge dielectric constant dielectric substance according to claim 1, which is characterized in that the step Suddenly the green body of (5) is the disk green body of 10 × 1.0~2.0mm of Ф.

5. a kind of preparation method of huge dielectric constant dielectric substance according to claim 1, which is characterized in that the step Suddenly the green body of (6) is warming up to 1325 DEG C~1425 DEG C after 3.5h is warming up to 550 DEG C of dumpings, then with 5 DEG C/min by room temperature, and protects Temperature 4 hours.

6. a kind of preparation method of huge dielectric constant dielectric substance according to claim 1, which is characterized in that the step Suddenly the sintering temperature of (6) is 1350 DEG C.