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CN-122010557-A - SrTiO for electric field assisted sintering3Basic giant dielectric ceramic material and preparation method thereof

CN122010557ACN 122010557 ACN122010557 ACN 122010557ACN-122010557-A

Abstract

An electric field assisted sintered SrTiO 3 (ST) base giant dielectric ceramic material and a preparation method thereof are provided, rare earth element Y is doped into ST ceramic, and a Sr 1‑1.5x Y x TiO 3 ceramic sample is obtained through primary ball milling, drying, briquetting, presintering, crushing, secondary ball milling, sieving, cold isostatic pressing and electric field assisted sintering. The Sr 1‑ 1.5x Y x TiO 3 ceramic provided by the invention has the performances of giant dielectric constant and low dielectric loss under the condition that the sintering time and the sintering temperature are far lower than those of the traditional solid phase method, so that the energy consumption for producing the giant dielectric ceramic is greatly reduced, and a reference method is provided for the industrial production of the giant dielectric ceramic.

Inventors

  • ZHAO XINXIN
  • WANG BO
  • XU CONGZHE
  • WANG HAOKUN
  • ZHANG YIRUI
  • YAO JINGYI
  • ZHANG JIE

Assignees

  • 陕西科技大学

Dates

Publication Date
20260512
Application Date
20260206

Claims (9)

  1. 1. An electric field assisted sintered SrTiO 3 -based giant dielectric ceramic material is characterized in that the stoichiometric formula is Sr 1- 1.5x Y x TiO 3 , and x=0-0.018.
  2. 2. The preparation method of the SrTiO 3 giant dielectric ceramic by electric field assisted sintering is characterized by comprising the following steps: (1) Weighing SrCO 3 , tiO 2 powder and rare earth oxide Y 2 O 3 powder according to a stoichiometric formula Sr 1-1.5x Y x TiO 3 , and uniformly mixing to form a mixed ingredient; (2) Performing primary ball milling, drying, briquetting and presintering on the mixed ingredients to obtain powder of a main crystalline phase; (3) And (2) presintering, crushing the powder, performing secondary ball milling, sieving, pressing into a green body, and performing electric field assisted sintering on the prepared green body to obtain the ST-based giant dielectric ceramic.
  3. 3. The method for preparing the SrTiO 3 -based giant dielectric ceramic material by electric field assisted sintering according to claim 2 is characterized in that in the step (1), sr 1-1.5x Y x TiO 3 and x=0-0.018 powder are prepared according to the following steps, synthesized SrCO 3 ,TiO 2 and Y 2 O 3 powder are weighed and mixed according to a molar ratio of 1:1:0-0.018, mixed powder, zirconia ball stone and deionized water are ball-milled according to a mass ratio of 1:1.5-5:1-1.5, the ball-milling rotating speed is 300-500 rpm, the time is 8-12 h, the ball-milled slurry is dried and pressed into blocks, the blocks are presintered for 2-4 h at 1100-1200 ℃ in air and nitrogen, and the main crystal phase powder is obtained by grinding.
  4. 4. The method for preparing the SrTiO 3 -based giant dielectric ceramic material by electric field assisted sintering according to claim 2, wherein the main crystal phase powder synthesized in the step (2) is subjected to secondary ball milling with zirconia ball stone and deionized water according to the mass ratio of 1:1.5-5:1-1.5, and the ball milling rotating speed is 300-500 rpm, and the time is 8-24 h.
  5. 5. The method for preparing the electric field assisted sintered SrTiO 3 -based giant dielectric ceramic material according to claim 2, wherein the dog-bone-shaped sample is pressed in the third step, and a compact blank is pressed by cold isostatic pressing under the pressure of 200-250 MPa.
  6. 6. The method for preparing the ST-based giant dielectric ceramic material by electric field assisted sintering according to claim 2, wherein the specific electric field assisted sintering step in the step (3) is that two ends of an isostatic pressing compact dog-bone sample are punched, two sections of platinum wires penetrate through holes to be suspended in a tube furnace, and the two sections of platinum wires are connected to the positive and negative stages of a high-voltage direct current power supply. The tube furnace was heated to 400 ℃. Then, under the action of an electric field of 75-200V/cm, continuously increasing the furnace temperature, maintaining the initial temperature within a range of 850-1000 ℃, continuously maintaining the current density of a passing sample at 20-80 mA/mm 2 after the flash firing occurs, cutting off the power supply of a direct current power supply, cooling to 500 ℃ for 80-100 min, and finally cooling to room temperature along with the furnace, wherein the electric field assisted sintering process is performed in air.
  7. 7. A preparation method of an electric field assisted sintered SrTiO 3 -based giant dielectric ceramic material is characterized by taking a sintered dog-bone sample, cutting the sample into small blocks, polishing and cleaning the small blocks, coating silver paste on the surface of the cut sample, and performing heat treatment on the ceramic material coated with a silver electrode to obtain the Sr 1-1.5x Y x TiO 3 , wherein x=0-0.018 giant dielectric ceramic material.
  8. 8. The method for preparing a giant dielectric ceramic material of Sr 1-1.5x Y x TiO 3 , x=0 to 0.018 according to claim 8, wherein the heat treatment condition of the ceramic material coated with silver electrode is heat treatment at 650 to 750 ℃ for 10 to 20min.
  9. 9. The method for preparing an electric field assisted sintered SrTiO 3 -based giant dielectric ceramic material according to claim 7 or 8, wherein the prepared Sr 1-1.5x Y x TiO 3 , x=0 to 0.018 giant dielectric ceramic material.

Description

SrTiO 3 -based giant dielectric ceramic material sintered with assistance of electric field and preparation method thereof Technical Field The invention relates to the field of high energy storage dielectric ceramic capacitors, in particular to a preparation method of an ST-based giant dielectric ceramic material for electric field assisted sintering. Background The giant dielectric constant ceramic (Ɛ r＞104) has wide application in the emerging industrial fields of automatic driving, immersive virtual reality, future factories, intelligent medical treatment and the like in the 6G era, and has important significance for conforming to the development trend of high frequency, high voltage and miniaturization of electronic equipment. However, the preparation of ST-based ceramics by conventional sintering methods can obtain giant dielectric properties only by long-term high-temperature treatment in a reducing atmosphere, which not only consumes huge amounts of energy, but also brings challenges to industrial production. The electric field assisted sintering technology, commonly called "flash sintering", has been widely focused on since the first report on the advantages of low sintering temperature, short heat preservation time and high densification rate, and is a green and environment-friendly industrial production technology with great potential. ST has a high dielectric constant (Ɛ r apprxeq 300) and a band gap of 3.2eV at room temperature, and simultaneously exhibits excellent intrinsic characteristics such as high breakdown field strength (> 200 kV/cm), excellent insulation resistance and low dielectric loss (tan delta < 0.01), is a matrix material very suitable for preparing giant dielectric ceramics, is sensitive to an applied electric field reaction, and is a material suitable for performing a flash firing process. The invention prepares a giant dielectric ceramic by doping rare earth oxide Y 2O3 into ST and adopting an electric field assisted sintering technology. Disclosure of Invention The invention aims to provide a preparation method of an electric field assisted sintered ST-based giant dielectric ceramic material, which aims to overcome the technical defects of high energy consumption, reduction atmosphere treatment and the like in the preparation of ST-based giant dielectric ceramic by adopting a traditional solid phase method. The ceramic obtained by the method has the characteristics of giant dielectric constant, low dielectric loss and environment-friendly process. In order to achieve the above purpose, the invention adopts the following technical scheme: The electric field assisted sintered ST-base giant dielectric ceramic material has the chemical formula of Sr 1-1.5xYxTiO3 and x=0-0.018. And, the preparation method of the ST-based giant dielectric ceramic material comprises the following steps: (1) Weighing SrCO 3, tiO 2 powder and rare earth oxide Y 2O3 powder according to a stoichiometric formula Sr 1-1.5xYxTiO3, and uniformly mixing to form a mixed ingredient; (2) Performing primary ball milling, drying, briquetting and presintering on the mixed ingredients to obtain powder of a main crystalline phase; (3) And (2) presintering, crushing the powder, performing secondary ball milling, sieving, pressing into a green body, and performing electric field assisted sintering on the prepared green body to obtain the ST-based giant dielectric ceramic. In the step (1), sr 1-1.5xYxTiO3 and x=0-0.018 powder is prepared by weighing and mixing the synthesized SrCO 3,TiO2 and Y 2O3 powder according to a molar ratio of 1:1:0-0.018, ball milling the mixed powder, zirconia ball stone and deionized water according to a mass ratio of 1:1.5-5:1-1.5, wherein the ball milling speed is 300-500 rpm, the time is 8-12 h, drying and briquetting the ball milled slurry, presintering the ball milled slurry in air and nitrogen at 1100-1200 ℃ for 2-4 h, and crushing the ball milled slurry to obtain main crystal phase powder. And (2) performing secondary ball milling on the synthesized main crystal phase powder in the step (2), zirconia ball stone and deionized water according to a mass ratio of 1:1.5-5:1-1.5, wherein the ball milling rotating speed is 300-500 rpm. And the ball milling time in the second step is 8-24 hours. Further, the number of the screen meshes at the time of screening in the second step was 120 mesh. And further, in the third step, the pressure is maintained for 4 minutes under 200MPa, then the pressure is maintained for 4 minutes under 190MPa, and finally the pressure is released under 40 MPa/min. And (3) electric field assisted sintering, namely punching two ends of the isostatic pressing compact dog bone-shaped sample, hanging the sample in a tubular furnace through two sections of platinum wires passing through the holes, and connecting the two sections of platinum wires to the positive and negative stages of a high-voltage direct current power supply. The tube furnace was heated to 400 ℃. Then,