CN111018518A

CN111018518A - NBT-KBT-BT-based multifunctional ceramic material with compact strong fluorescence and high voltage performance and preparation method thereof

Info

Publication number: CN111018518A
Application number: CN201911304581.7A
Authority: CN
Inventors: 郭益平; 焦南
Original assignee: Maanshan Economic And Technological Development Zone Construction Investment Co ltd; Shanghai Jiaotong University
Current assignee: Maanshan Economic And Technological Development Zone Construction Investment Co ltd; Shanghai Jiaotong University
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-04-17

Abstract

The invention relates to a NBT-KBT-BT based multifunctional ceramic material with compact strong fluorescence and high voltage performance and a preparation method thereof, wherein the general formula of the material is 0.95Na_0.5Bi_{(0.5‑x/0.95)}TiO₃‑0.05K_0.5Bi_0.5TiO₃‑0.05BaTiO₃-xSm, wherein x ranges from 0 to 0.005. The method comprises the following steps: selecting and proportioning raw materials, ball-milling and presintering blanks, forming blanks and sintering under the conditions of normal pressure and high temperature. By introducing rare earth element Sm with different concentrations³⁺And the fluorescent property and the piezoelectric property of the system are adjusted. Compared with the prior art, the invention has simple process and high production efficiency, and the prepared ceramic has high piezoelectric coefficient and strong fluorescence property, and can be applied to sensors and fluorescent light-emitting devicesAnd the like.

Description

NBT-KBT-BT-based multifunctional ceramic material with compact strong fluorescence and high voltage performance and preparation method thereof

Technical Field

The invention relates to an NBT-KBT-BT based multifunctional ceramic material, in particular to compact, strong-fluorescence and high-piezoelectric-activity Sm-doped sodium bismuth titanate-potassium bismuth titanate-barium titanate³⁺A ceramic material.

Background

With the increasing demand of lead-free materials and the increasing environmental protection forms, more and more fields begin to carry out the research related to the lead-free materials. Among them, piezoelectric materials and fluorescent materials are important fields of research, and they play a crucial role in the fields of sensors and fluorescent devices. Lead-containing piezoelectric ceramics [ based on Pb (Zr, Ti) O₃]Generally has better temperature stability and higher piezoelectric coefficient, however, lead can enter the environment during use, and finally endanger human health. The lead-free functional ceramic mainly comprises (BaTiO)₃System of (K, Na) NbO₃System and (Bi, Na) TiO₃-systems etc.). In order to improve the performance of the lead-free functional ceramic, there are generally three methods, the first method is to improve the forming process, and the lead-free piezoelectric ceramic with higher piezoelectric performance can be prepared by a template texture method and a combustion sol-gel method, however, the preparation methods are complex, high in cost, low in efficiency, unstable and not beneficial to commercialization. The second method is to introduce oxygen vacancies, and oxygen vacancies and dopant ions form defect dipoles in a doping mode, so as to enhance the piezoelectric performance of the system, however, the promotion of the method is limited, and as the doping concentration is increased, too many defects can make the material easily break down when in polarization. The third mode is to enhance the piezoelectric performance of the system by regulating the phase boundary. For NBT-KBT-BT based piezoelectric ceramic system, the piezoelectric ceramic prepared by the traditional high-temperature solid-phase sintering method has the piezoelectric coefficient d₃₃Lower, typically 100-^-1. As for fluorescent ceramic materials, the current orange-red fluorescent system mainly comprises Sm³⁺：(K_0.5Na_0.5)NbO₃:Sm³⁺/Zr⁴⁺Is based on (K)_0.5Na_0.5)NbO₃(KNN) fluorescent ceramic, while the KNN-based ceramic has the problems of complex sintering process, difficult obtainment of high-density finished products and the like.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, provides a dense NBT-KBT-BT based multifunctional ceramic material with strong fluorescence and high piezoelectric property and a preparation method thereof, and is used for solving the problems of weak piezoelectric property, weak fluorescence luminous intensity and low density of the lead-free piezoelectric ceramic material in the prior art.

The purpose of the invention can be realized by the following technical scheme: the NBT-KBT-BT based multifunctional ceramic material with compact strong fluorescence and high piezoelectric performance is characterized in that the general formula of the material is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm; wherein x ranges from 0 to 0.005. Preferably, the value range of x is 0.001-0.005.

The crystal structure of the ceramic material is a perovskite structure.

The ceramic material can generate fluorescence with the wavelengths of 563nm, 597nm and 645nm under the excitation light with the wavelength of 480nm and respectively corresponds to Sm³⁺Of elements⁴G_5/2->⁶H_5/2，⁴G_5/2->⁶H_7/2，⁴G_5/2->⁶H_9/2And (4) energy level transition.

The density of the ceramic material can reach 5.73g/cm³The density reached a maximum at x of 0.005, about 5.73g/cm³. The piezoelectric coefficient can reach 193pC N^-1Piezoelectric coefficient d at a polarization of 2.25kV/mm₃₃The maximum value is obtained when x is 0.003, which is about 193pC N^-1。

The preparation method of the NBT-KBT-BT based multifunctional ceramic material with the dense strong fluorescence and high voltage performance is characterized by comprising the following steps:

1) according to the formula 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm (x ═ 0-0.005) is dosed by selecting a plurality of sodium carbonate, barium carbonate, potassium carbonate, bismuth oxide, titanium dioxide and samarium oxide as raw materials;

2) adding absolute ethyl alcohol as a ball milling medium for ball milling, and drying after ball milling to obtain mixed dry powder;

3) pre-burning the mixed dry powder at 800-1000 ℃ for 2-6 hours to form powder, and adding a polyvinyl alcohol aqueous solution into the powder for granulation to obtain a blank;

4) pressing the blank into a round blank, carrying out glue discharging treatment, and then sintering to obtain a ceramic wafer;

5) the ceramic wafer was polished, plated with silver electrodes, and then polarized in silicone oil.

The mass ratio of the polyvinyl alcohol aqueous solution to the powder in the step 3) is (0.05-0.1) to 1; the concentration of the polyvinyl alcohol aqueous solution is 2 wt% -8 wt%.

Step 4), pressing the blank into a blank body with the pressure of 180-220 MPa, wherein the diameter of the round blank body is 8-15 mm; the temperature of the rubber discharge treatment is 450-550 ℃, and the rubber discharge treatment time is 3-5 hours; the sintering temperature is 1150-1200 ℃, and the sintering time is 1-3 h.

The polarization temperature in the step 5) is 20-80 ℃; the intensity of the polarized electric field is 2.25-3kV/mm, and the polarization time is 20-30 min.

The ceramic wafer is a regular cylinder, and the density can be calculated by weighing and measuring the thickness and the diameter.

The invention also discloses the application of the piezoelectric fluorescent multifunctional material in the fields of multifunctional sensors, fluorescence, luminescence and the like.

Compared with the prior art, the piezoelectric fluorescent multifunctional material has the following beneficial effects:

1. the piezoelectric fluorescent multifunctional material provided by the invention has high piezoelectric performance and piezoelectric coefficient d in the same system₃₃Can reach 193pC N^-1The method has the potential of being applied to the fields of sensors and the like.

2. The piezoelectric fluorescent multifunctional material provided by the invention has strong fluorescent effect, and can pass Sm under the excitation of 480nm excitation wavelength³⁺Ion(s)⁴G_5/2->⁶H_5/2，⁴G_5/2->⁶H_7/2，⁴G_5/2->⁶H_9/2The energy level transition of (a) emits intense orange light.

3. The functional ceramic provided by the invention has higher density and longer service life in a complex application environment.

Drawings

FIG. 1 is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃The X-ray diffraction pattern of the-xSm multifunctional ceramic material when X is respectively 0, 0.001, 0.003 and 0.005 change values.

FIG. 2 is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃The piezoelectric coefficient d of the-xSm multifunctional ceramic material is changed when x is respectively 0, 0.001, 0.003 and 0.005₃₃。

FIG. 3 is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃The photoluminescence spectrum of the-xSm multifunctional ceramic material when x is respectively 0.001, 0.003 and 0.005 change values.

FIG. 4 is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm Athens fluorescent material has a density at x of 0.00, 0.001, 0.003, 0.005, respectively.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Before the present embodiments are further described, it is to be understood that the scope of the invention is not limited to the particular embodiments described below; it is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. Test methods in which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under conditions recommended by the respective manufacturers.

When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any value therebetween can be selected unless the invention otherwise indicated. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition to the specific methods, devices, and materials used in the examples, any methods, devices, and materials similar or equivalent to those described in the examples may be used in the practice of the invention in addition to the specific methods, devices, and materials used in the examples, in keeping with the knowledge of one skilled in the art and with the description of the invention.

Example 1

According to the formula 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃Sm doped with-xSm³⁺The sodium bismuth titanate-potassium bismuth titanate-barium titanate material is a high-voltage electricity and strong fluorescence multifunctional material for blending.

When x is 0.001,

the formula is 0.95Na_0.5Bi_0.4989TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-0.001Sm。

The first step is as follows: using multiple analytically pure sodium carbonate, barium carbonate, potassium titanate, bismuth oxide, titanium dioxide and samarium oxide as raw materials, calculating the mass of each required raw material component according to the stoichiometric ratio, and weighing to obtain a mixture;

the second step is that: the ingredients are ball-milled for 48 hours by a roller by using absolute ethyl alcohol as a ball-milling medium, and then dried to obtain mixed dry powder;

the third step: preserving the heat of the mixed dry powder obtained in the second step at 850 ℃ for 4 hours for presintering, adding a polyvinyl alcohol aqueous solution with the concentration of 5 wt% into the presintered powder for granulation, wherein the mass ratio of the polyvinyl alcohol aqueous solution to the powder is 0.088: 1;

the fourth step: pressing the powder granulated in the third step into a wafer-shaped blank under 200MPa by using a cylindrical die, discharging glue at 500 ℃ for 4 hours, and then preserving heat at 1170 ℃ for 2 hours and sintering to obtain a ceramic wafer;

the fifth step: polishing the ceramic wafer sintered in the fourth step, and then coating a silver electrode on the ceramic wafer; the ceramic sheet coated with silver electrode is at 25 deg.CIn the silicone oil, the electric field intensity is 2.25kV mm^-1Polarization for 20min at voltage of (3);

and after the polarization is finished, taking the ceramic wafer out of the silicone oil to obtain the NBT-KBT-BT based multifunctional ceramic material, standing the ceramic wafer in the air for 24 hours, and measuring the piezoelectric property of the system by adopting the IEEE standard.

The sample is placed in a fluorescence tester to test the photoluminescence spectrum, and during the test, a 550nm filter is placed, and the excitation wavelength is 480 nm.

The fluorescence wavelengths generated by the energy level transition are respectively: 563nm, 597nm, 645 nm. Respectively correspond to Sm³⁺Of elements⁴G_5/2->⁶H_5/2，⁴G_5/2->⁶H_7/2，⁴G_5/2->⁶H_9/2And (4) energy level transition.

The electrical properties of the material are as follows: d₃₃＝183pC N^-1Density: 5.46g/cm³。

Example 2

When x is equal to 0.00,

the formula is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm(x＝0.00)

The preparation method in this example is the same as that in example 1, except that Sm is incorporated during the preparation³⁺In different amounts, the amount of the incorporated substance of the present example is 0% of Sm in a percentage by weight₂O₃。

The electrical properties of the material are as follows: d₃₃＝133pC N^-1Density: 5.64g/cm³。

Example 3

When x is 0.003,

the formula is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm(x＝0.003)

The preparation method in this example is the same as that in example 1, except that Sm is incorporated during the preparation³⁺In different amounts, thisExample amounts of incorporated materials are 0.3% Sm₂O₃。

The electrical properties of the material are as follows: d₃₃＝193pC N^-1Density: 5.58g/cm³。

Example 4

When x is equal to 0.005,

the formula is 0.95Na_0.5Bi_0.4947TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm(x＝0.005)

The preparation method in this example is the same as that in example 1, except that Sm is incorporated during the preparation³⁺In an amount different from that of Sm, the amount of the incorporated material of the present example was 0.5% in terms of a fraction of Sm₂O₃。

The electrical properties of the material are as follows: d₃₃＝183pC N^-1Density: 5.73g/cm³。

FIG. 1 shows that 0.95Na is added when x is changed to 0.00, 0.001, 0.003 and 0.005 respectively_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-X-ray diffraction pattern of xSm piezoelectric fluorescent material. The atlas shows that all ceramic plates prepared by the technical scheme of the invention have perovskite structures at room temperature. With Sm³⁺The amount of incorporation was increased, and the diffraction peaks (100), (111), (200) and (2)11) From a distinct peak morphology, it gradually becomes less distinct. This is because of Sm³⁺The system gradually deflects to a tetragonal phase from a morphotropic phase boundary, and other properties such as piezoelectric property can reach the optimum of the system by adjusting the proportion of the tetragonal phase of the system.

FIG. 2 shows that the concentration of Na is 0.95_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃The piezoelectric coefficient d of the-xSm piezoelectric fluorescent material when x is respectively changed and taken as 0.00, 0.001, 0.003 and 0.005₃₃The test of (1). When x is 0.003, piezoelectric coefficient d₃₃The maximum value, 193pC N, was obtained^-1. At the same time, when only 0.1% of Sm is introduced, the piezoelectric coefficient d₃₃From 133pC N^-1Up to 183pC N^-1. This is because Sm is incorporated³⁺The phase boundary of the system is moved, and the phase proportion and the composition of the system are adjusted, so that the piezoelectric performance of the system is improved.

FIG. 3 is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃Photoluminescence spectra of the-xSm piezoelectric fluorescent material at x of 0.00, 0.001, 0.003 and 0.005 respectively, and the excitation wavelength is not 480 nm. From the photoluminescence spectrum, it can be seen that Sm is associated with Sm³⁺The fluorescence performance of the system is improved by increasing the introduction amount of the ions, and the optimal fluorescence performance is obtained when x is 0.003.

FIG. 4 is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm Athens fluorescent material has a density at x of 0.00, 0.001, 0.003, 0.005, respectively. As can be seen from the figure, by incorporating Sm³⁺The density of the sample decreased first and then gradually increased, and the maximum density was 5.73g/cm when x was 0.005³。

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. The NBT-KBT-BT based multifunctional ceramic material with compact strong fluorescence and high piezoelectric performance is characterized in that the general formula of the material is 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm; wherein x ranges from 0 to 0.005.

2. The NBT-KBT-BT based multifunctional ceramic material with dense strong fluorescence and high piezoelectric properties according to claim 1, wherein the crystal structure of the ceramic material is perovskite structure.

3. The NBT-KBT-BT based multifunctional ceramic material with dense strong fluorescence and high voltage performance as claimed in claim 1, wherein the ceramic material generates fluorescence with wavelengths of 563nm, 597nm and 645nm under excitation light with a wavelength of 480nm, respectively, and corresponds to Sm respectively³⁺Of elements⁴G_5/2->⁶H_5/2，⁴G_5/2->⁶H_7/2，⁴G_5/2->⁶H_9/2And (4) energy level transition.

4. The NBT-KBT-BT based multifunctional ceramic material with dense strong fluorescence and high voltage performance of claim 1, wherein the density of the ceramic material is up to 5.73g/cm³Piezoelectric coefficient up to 193pC N^-1。

5. The preparation method of the NBT-KBT-BT based multifunctional ceramic material with dense strong fluorescence and high voltage performance according to claim 1, which comprises the following steps:

2) according to the formula 0.95Na_0.5Bi_(0.5-x/0.95)TiO₃-0.05K_0.5Bi_0.5TiO₃-0.05BaTiO₃-xSm (x ═ 0-0.005) is dosed by selecting a plurality of sodium carbonate, barium carbonate, potassium carbonate, bismuth oxide, titanium dioxide and samarium oxide as raw materials;

6. The preparation method of the NBT-KBT-BT based multifunctional ceramic material with the dense strong fluorescence and high voltage performance according to claim 5, wherein the mass ratio of the polyvinyl alcohol aqueous solution to the powder in the step 3) is (0.05-0.1) to 1; the concentration of the polyvinyl alcohol aqueous solution is 2 wt% -8 wt%.

7. The preparation method of the NBT-KBT-BT based multifunctional ceramic material with the dense strong fluorescence and high piezoelectric property according to claim 5, wherein the pressure of pressing the blank in the step 4) is 180-220 MPa, and the diameter of the round blank is 8-15 mm; the temperature of the rubber discharge treatment is 450-550 ℃, and the rubber discharge treatment time is 3-5 hours; the sintering temperature is 1150-1200 ℃, and the sintering time is 1-3 h.

8. The preparation method of the NBT-KBT-BT based multifunctional ceramic material with dense strong fluorescence and high voltage performance according to claim 5, wherein the temperature of polarization in step 5) is 20-80 ℃; the intensity of the polarized electric field is 2.25-3kV/mm, and the polarization time is 20-30 min.

9. Use of the NBT-KBT-BT-based multifunctional ceramic material with dense strong fluorescence high voltage performance according to claim 1 as multifunctional sensor material or fluorescent luminescent material.