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Method for preparing high-performance barium strontium titanate pyroelectric ceramics by post-annealing process

A technology of pyroelectric ceramics and barium strontium titanate, which is applied to thermoelectric devices with thermal changes in dielectric constant, etc., can solve the problem of difficulty in preparing high-performance BST pyroelectric ceramics, and achieves low cost, high sample purity, and high thermal stability. The effect of high discharge coefficient

Active Publication Date: 2016-01-06
SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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Problems solved by technology

[0007] In order to solve the problem that it is difficult to prepare high-performance BST pyroelectric ceramics in the prior art, the present invention provides a method for preparing high-performance BST pyroelectric ceramics using a post-annealing process, so as to meet the requirements of current uncooled infrared focal plane devices for BST materials. Require

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  • Method for preparing high-performance barium strontium titanate pyroelectric ceramics by post-annealing process
  • Method for preparing high-performance barium strontium titanate pyroelectric ceramics by post-annealing process
  • Method for preparing high-performance barium strontium titanate pyroelectric ceramics by post-annealing process

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preparation example Construction

[0038] The preparation method of the sintered barium strontium titanate ceramics is not limited, for example, the following method can be used:

[0039] a) first according to the general formula Ba x Sr 1-x TiO 3 Weigh out the stoichiometric BaCO 3 , SrCO 3 and TiO 2 Powder, use wet ball milling process to mix all powders evenly, doping elements can be added in the general formula, such as Ca, Y, Mn, Sm, Fe, etc., doping elements can be oxides and / or carbonates, for example form to join;

[0040] b) drying and briquetting, and synthesizing in air at a synthesis temperature of 1000-1200°C and a holding time of 1-3 hours to obtain BST blocks;

[0041] c) pulverizing and sieving the BST block obtained in step b), and refining the powder with a wet ball milling process;

[0042]d) drying after discharge, adding a certain amount of binder, pre-pressing after granulation, aging, sieving, isostatic pressing, and plastic discharge to obtain the BST embryo body;

[0043] e) Sin...

Embodiment 1

[0056] First weigh BaCO 3 , SrCO 3 and TiO 2 powder, and add a small amount of CaCO 3 , Y 2 o 3 , MnCO 3 For powder, use wet ball milling process to mix all the powders evenly; the mass ratio of material, ball milling medium and deionized water is 1:1.5:1.2, the ball milling time is 24 hours, and the ball milling medium is agate balls.

[0057] Dry the abrasive, add deionized water with 4% of the total powder mass, briquette, and synthesize in the air at a synthesis temperature of 1150°C and a holding time of 2 hours to obtain BST blocks; pulverize, pass through a 40-mesh sieve, and then add For 2.7wt% ZnO powder, mix the powder evenly by wet ball milling process; the mass ratio of material, ball milling medium and deionized water is 1:2.0:0.8, the ball milling time is 48 hours, and the ball milling medium is agate balls.

[0058] Drying, adding PVA solution as a binder, granulating, aging for 24 hours, sieving, pre-pressing and isostatic pressing, the blank is discharge...

Embodiment 2

[0062] The annealing temperature of the BST ceramics is 1250° C., and the annealing time is 2 hours, and the remaining contents are the same as those described in Example 1.

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Abstract

The invention relate to a method for preparing high-performance BST (barium strontium titanate) pyroelectric ceramics by adopting a post-annealing process. According to the method, BST ceramics obtained through sintering is subjected to annealing at the oxygen atmosphere, the annealing temperature ranges from 800 DEG C to 1,250 DEG C, the annealing time ranges from 2 hours to 5 hours, and then the high-performance BST pyroelectric ceramics can be prepared. According to the method for preparing the high-performance BST pyroelectric ceramics by adopting the post-annealing process, the annealing treatment is performed after the BST pyroelectric ceramics is obtained through sintering, and the high-performance BST pyroelectric ceramics can be prepared; the dielectric constant is high and can be higher than 9,500; the pyroelectric coefficient is high and can be higher than 18*10<-8>C / cm<2>K; and further, a sample is high in purity and performance and good in uniformity, manufacturing requirements of an uncooled infrared focal plane device can be met, and the problem that the BST ceramics cannot be sintered to high density is effectively solved.

Description

technical field [0001] The invention relates to a method for preparing high-performance BST pyroelectric ceramics by adopting a post-annealing process, and belongs to the technical field of pyroelectric ceramic materials. Background technique [0002] Barium strontium titanate (Ba x Sr 1-x TiO 3 (0<x<1), BST) ceramic materials have become important candidates for pyroelectric uncooled infrared focal planes due to their adjustable Curie temperature, low dielectric loss, and easy processing. [0003] When BST pyroelectric ceramics are made into uncooled infrared focal plane devices, they adopt a new dielectric working mode, that is, they work near the Curie temperature (the Curie temperature is at room temperature), and apply a certain DC bias electric field. In this way, its intrinsic pyroelectric effect and field-induced pyroelectric effect (the rate of change of dielectric constant with temperature) can be used at the same time. Equation (1) shows its pyroelectric ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L37/02C04B35/468C04B35/47C04B35/622
Inventor 毛朝梁姚春华曹菲陈建和王根水董显林
Owner SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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