阅读说明：本技术 一种Na0.25K0.25Bi2.5Nb2O9陶瓷的制备方法及其产品 (Na0.25K0.25Bi2.5Nb2O9Method for preparing ceramic and product thereof ) 是由 邹振卫 于 2020-07-18 设计创作，主要内容包括：本发明公开了一种Na<Sub>0.25</Sub>K<Sub>0.25</Sub>Bi<Sub>2.5</Sub>Nb<Sub>2</Sub>O<Sub>9</Sub>陶瓷的制备方法及其产品。通过固相反应制备的Na<Sub>0.25</Sub>K<Sub>0.25</Sub>Bi<Sub>2.5-x-y-z</Sub>Ce<Sub>x</Sub>Sm<Sub>y</Sub>Ho<Sub>z</Sub>Nb<Sub>2</Sub>O<Sub>9</Sub>,其中x＝0.001～0.04,y＝0.002～～0.04,z＝0.002～～0.04。由于对Na<Sub>0.25</Sub>K<Sub>0.25</Sub>Bi<Sub>2.5</Sub>Nb<Sub>2</Sub>O<Sub>9</Sub>陶瓷掺杂能够有效提高压电性能和铁电性能,进而使其具有压电常数d<Sub>33</Sub>为34.2～38.4pC/N,2P<Sub>r</Sub>＝2.87～3.24；d<Sub>33</Sub>在400℃处理后仍能够维持在32.9～37pC/N,故其是用于光电多功能材料领域的理想材料。(The invention discloses Na 0.25 K 0.25 Bi 2.5 Nb 2 O 9 A method for preparing ceramics and a product thereof. Na produced by solid phase reaction 0.25 K 0.25 Bi 2.5‑x‑y‑z Ce x Sm y Ho z Nb 2 O 9 Wherein x is 0.001 to 0.04, y is 0.002 to 0.04, and z is 0.002 to 0.04. Due to the pair of Na 0.25 K 0.25 Bi 2.5 Nb 2 O 9 The ceramic doping can effectively improve the piezoelectric property and the ferroelectric property, thereby leading the piezoelectric ceramic to have the piezoelectric constant d 33 Is 34.2 to 38.4pC/N, 2P r ＝2.87～3.24；d 33 Can still maintain 32.9 to 37pC/N after being treated at 400 ℃, so the material is an ideal material for the field of photoelectric multifunctional materials.)

1. Na_0.25K_0.25Bi_2.5Nb₂O₉The preparation method of the ceramic is characterized by comprising the following steps: the preparation method comprises the following steps:

1) bi with the purity of more than 99.0 percent₂O₃、Nb₂O₅、Na₂CO₃、K₂CO₃、Ce₂O₃、Sm₂O₃And Ho₂O₃Respectively drying;

2) the raw material dried in the step 1) is processed according to Na_0.25K_0.25Bi_2.5-x-y-zCe_xSm_yHo_zNb₂O₉Wherein x is 0.001-0.04, y is 0.002-0.04, and z is 0.002-0.04, and then placing the mixture into a ball milling tank for ball milling, wherein the ball milling medium is absolute ethyl alcohol;

3) after the ball milling is finished, carrying out vacuum drying on the obtained mixed material, grinding the dried mixed material, and sieving the ground powder with a 200-mesh sieve;

4) calcining the sieved powder in a muffle furnace at 800-900 ℃ for 1-6 h, cooling to room temperature, adding a polyvinyl alcohol (PVA) aqueous solution with the mass fraction of 5% for granulation, preforming the granulated powder by a tablet press, pressing under 10-15 MPa to form a blank, discharging the obtained blank in the muffle furnace at 150-350 ℃ and 500-700 ℃ for 10-20 min, sintering at 950-1100 ℃ for 1-6 h, and cooling to room temperature along with the furnace to obtain the ceramic.

2. The method of claim 1, wherein: in the step 1), the drying temperature is 80-100 ℃, and the drying time is 20-30 h.

3. The method of claim 1, wherein: in the step 2), the ball milling tank is a polyethylene ball milling tank, and zirconium dioxide balls are used for ball milling.

4. The method of claim 1, wherein: in the step 2), the ball milling speed is 100-200 r/min, and the ball milling time is 20-30 h.

5. The method of claim 1, wherein: in the step 3), the vacuum drying is to remove ethanol by drying in a vacuum oven at 60-90 ℃ for 15-20 h.

6. The method of claim 1, wherein: in the step 4), the temperature rise rate of calcining at 800-900 ℃ for 1-6 h is 3-6 ℃/min; the heating rate in the glue discharging process is 2-3 ℃/min, and the heating rate of sintering for 1-6 h at 950-1100 ℃ is 6-8 ℃/min.

7. A Na produced by the production method according to any one of claims 1 to 6_0.25K_0.25Bi_2.5Nb₂O₉A ceramic.

8. A Na according to claim 7_0.25K_0.25Bi_2.5Nb₂O₉Ceramic, characterized in that: the Ce, Sm and Ho codoped Na_0.25K_0.25Bi_2.5Nb₂O₉Piezoelectric constant d of ceramic₃₃Is 34.2 to 38.4pC/N, 2P_r＝2.87～3.24；d₃₃Can still maintain 32.9-37 pC/N after being treated at 400 ℃.

9. A Na according to claim 7 or 8_0.25K_0.25Bi_2.5Nb₂O₉Use of a ceramic, characterized in that the ceramic is used in a piezoelectric material.

10. The application of the piezoelectric material as claimed in claim 9, wherein the piezoelectric material is obtained by firing a silver electrode after polishing a ceramic sample with 500-600 mesh sand paper, polarizing in silicone oil at 170-200 ℃ for 40-50 min under an electric field of 10-12 kV/mm, and standing for 20-30 h.

Technical Field

The invention belongs to bismuth layer-shaped ceramics, and particularly relates to Na_0.25K_0.25Bi_2.5Nb₂O₉A method for preparing ceramics and a product thereof.

Background

The bismuth layered structure ferroelectric material has higher Curie temperature and good anti-fatigue property, and has higher application prospect in the fields of ferroelectric random access memories, high-temperature piezoelectric devices and the like. However, since Bi ions volatilize at high temperature to generate oxygen vacancies, which deteriorate the electrical properties of the bismuth layer structured ceramic and further limit the high temperature application field of the bismuth layer structured ceramic, how to make it have good ferroelectric piezoelectric properties under high temperature and high frequency environment is still an important issue at present.

At present, the electrical properties of piezoelectric and ferroelectric materials are improved by doping rare earth ions in bismuth layer-structured ferroelectric materials, Zhang and the like research Sm³⁺Doping (K)_0.5Na_0.5)NbO₃Piezoelectric ceramics, a multifunctional material having orange light emission properties and piezoelectric properties was found. Er passing through the Luo-rain culvert³⁺Doping with Na_0.25K_0.25Bi_2.5Nb₂O₉The piezoelectric ceramic is used for improving the electrical and photoelectric properties thereof, and a proper amount of Er³⁺The doping can improve the piezoelectric performance of the ceramic, and when x is 0.02, the electrical performance is best: piezoelectric constant d₃₃22pC/N, dielectric loss tan 0.38%, quality factor Qm 2324, and the samples all have good fluorescence properties, which indicates that the component ceramic can be used as an opto-electronic multifunctional material for high temperature application. Yao et al by Ce³⁺Doping preparation of NKBN-xCe³⁺Ceramic, piezoelectric constant d₃₃The temperature is increased from 19pC/N with x being 0 to 28pC/N with x being 0.2. Although the electrical properties of the ferroelectric and piezoelectric materials of the NKBN ceramic are improved by ion doping in the prior art, the effect is not ideal, so that how to improve the piezoelectric and ferroelectric properties and the stability at high temperature of the NKBN ceramic is still a problem which needs to be solved urgently at present.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide Na to overcome the above disadvantages in the prior art_0.25K_0.25Bi_2.5Nb₂O₉A method for preparing ceramics and a product thereof. The chemical composition of the material is Na_0.25K_0.25Bi_{2.5-x-y- z}Ce_xSm_yHo_zNb₂O₉Wherein x is 0.001 to 0.04,y is 0.002 to 0.04, and z is 0.002 to 0.04. By the reaction of Na_0.25K_0.25Bi_2.5Nb₂O₉The ceramic doping can effectively improve the piezoelectric property and the ferroelectric property, and is an ideal material for the field of photoelectric multifunctional materials.

The invention adopts the following technical scheme:

na_0.25K_0.25Bi_2.5Nb₂O₉A method for preparing a ceramic, the method comprising the steps of:

1) bi with the purity of more than 99.0 percent₂O₃、Nb₂O₅、Na₂CO₃、K₂CO₃、Ce₂O₃、Sm₂O₃And Ho₂O₃Respectively drying;

2) the raw material dried in the step 1) is processed according to Na_0.25K_0.25Bi_2.5-x-y-zCe_xSm_yHo_zNb₂O₉Wherein x is 0.001-0.04, y is 0.002-0.04, and z is 0.002-0.04, and then placing the mixture into a ball milling tank for ball milling, wherein the ball milling medium is absolute ethyl alcohol;

3) after the ball milling is finished, carrying out vacuum drying on the obtained mixed material, grinding the dried mixed material, and sieving the ground powder with a 200-mesh sieve;

4) calcining the sieved powder in a muffle furnace at 800-900 ℃ for 1-6 h, cooling to room temperature, adding a polyvinyl alcohol (PVA) aqueous solution with the mass fraction of 5% for granulation, preforming the granulated powder by a tablet press, pressing under 10-15 MPa to form a blank, discharging the obtained blank in the muffle furnace at 150-350 ℃ and 500-700 ℃ for 10-20 min, sintering at 950-1100 ℃ for 1-6 h, and cooling to room temperature along with the furnace to obtain the ceramic.

Preferably, in the step 1), the drying temperature is 80-100 ℃, and the drying time is 20-30 h.

Preferably, in the step 2), the ball milling tank is a polyethylene ball milling tank, and zirconium dioxide balls are used for ball milling.

Preferably, in the step 2), the ball milling rotation speed is 100-200 r/min, and the ball milling time is 20-30 h.

Preferably, in the step 3), the vacuum drying is drying for 15-20 hours at 60-90 ℃ in a vacuum oven to remove ethanol.

Preferably, in the step 4), the temperature rise rate of calcining at 800-900 ℃ for 1-6 h is 3-6 ℃/min; the heating rate in the glue discharging process is 2-3 ℃/min, and the heating rate of sintering for 1-6 h at 950-1100 ℃ is 6-8 ℃/min.

According to another technical scheme, the Ce, Sm and Ho co-doped Na prepared based on the preparation method_0.25K_0.25Bi_2.5Nb₂O₉A ceramic.

Preferably, said one Na_0.25K_0.25Bi_2.5Nb₂O₉Piezoelectric constant d of ceramic₃₃Is 34.2 to 38.4pC/N, 2P_r＝2.87～3.24；d₃₃Can still maintain 32.9-37 pC/N after being treated at 400 ℃.

The other technical scheme of the invention is based on the Ce, Sm and Ho co-doped Na_0.25K_0.25Bi_2.5Nb₂O₉The use of a ceramic, the use of said ceramic in a piezoelectric material.

Preferably, the ceramic sample is polished by 500-600-mesh sand paper and then fired into a silver electrode, polarized in silicone oil at 170-200 ℃ for 40-50 min under an electric field of 10-12 kV/mm, and placed for 20-30 h to obtain the piezoelectric material.

Compared with the prior art, the invention has at least the following beneficial effects:

1) the invention provides Na_0.25K_0.25Bi_2.5Nb₂O₉The preparation method is simple, and the product is obtained by weighing raw materials according to the stoichiometric ratio, ball milling, pre-calcining, secondary ball milling, compression molding, binder removal and sintering_0.25K_0.25Bi_2.5Nb₂O₉The ceramic doping can effectively improve the piezoelectric property and the ferroelectric property and is used for photoelectricityIdeal materials in the field of multifunctional materials.

2) Due to the synergistic effect among Ce, Sm and Ho, Ce passes through³⁺、Sm³⁺And Ho³⁺By replacing Bi³⁺Site-synthesized Na_0.25K_0.25Bi_2.5-x-y-zCe_xSm_yHo_zNb₂O₉Wherein x is 0.001 to 0.04, y is 0.002 to 0.04, and z is 0.002 to 0.04, so that Na is_0.25K_0.25Bi_2.5Nb₂O₉The compactness of the base ceramic is improved, and the piezoelectric property, the ferroelectric property and the high-temperature stability are effectively improved.

3) Na is made by controlling the heating rate and the binder removal temperature_0.25K_0.25Bi_2.5Nb₂O₉The compactness of the base ceramic is obviously improved, and the improvement of the piezoelectric property and the ferroelectric property is promoted.

In conclusion, the Na prepared by the invention_0.25K_0.25Bi_2.5Nb₂O₉The ceramic is an ideal material in the field of photoelectric multifunctional materials.

The technical solution of the present invention is further described in detail by the following examples.

Detailed Description

One kind of Na of the invention_0.25K_0.25Bi_2.5Nb₂O₉A method for preparing a ceramic, the method comprising the steps of:

1) bi with the purity of more than 99.0 percent₂O₃、Nb₂O₅、Na₂CO₃、K₂CO₃、Ce₂O₃、Sm₂O₃And Ho₂O₃Drying at 80-100 ℃ for 20-30 h respectively;

2) the raw material dried in the step 1) is processed according to Na_0.25K_0.25Bi_2.5-x-y-zCe_xSm_yHo_zNb₂O₉Wherein x is 0.001-0.04, y is 0.002-0.04, and z is 0.002-0.04, then weighing them according to the stoichiometric ratioPutting the mixture into a polyethylene ball-milling tank, and ball-milling the mixture by using zirconium dioxide and zirconium balls, wherein the ball-milling rotating speed is 100-200 r/min, and the ball-milling time is 20-30 h, and the ball-milling medium is absolute ethyl alcohol;

3) after the ball milling is finished, drying the obtained mixed material in a vacuum oven at 60-90 ℃ for 15-20 h to remove ethanol, grinding after drying, and sieving the ground powder with a 200-mesh sieve;

4) calcining the sieved powder in a muffle furnace at 800-900 ℃ for 1-6 h, cooling to room temperature at the heating rate of 3-6 ℃, adding a polyvinyl alcohol (PVA) aqueous solution with the mass fraction of 5% for granulation, preforming the granulated powder through a tablet press, pressing under 10-15 MPa to prepare a blank, discharging the obtained blank in the muffle furnace at 150-350 ℃ and 500-700 ℃ for 10-20 min respectively at the heating rate of 2-3 ℃, sintering at 950-1100 ℃ for 1-6 h at the heating rate of 6-8 ℃, and cooling to room temperature along with the furnace to obtain the ceramic.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the present invention generally shown may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.