CN118545997B - High-dielectric-property electronic ceramic and preparation method thereof - Google Patents

Abstract

The invention relates to the field of electronic ceramic materials, in particular to high dielectric property electronic ceramic and a preparation method thereof, wherein the chemical composition of the high dielectric property electronic ceramic comprises ：Pb(Zr_xTi_1‑x)(Mg_yW_1‑y)(Sc_zTa_1‑z)O₃-αwt%Ba(Al_qSb_1‑q)O₃-βwt%Bi₄Ti₃O₁₂,x、y、z、q as atomic percent; alpha and beta respectively represent Ba (Al _qSb_1‑q)O₃ and Bi ₄Ti₃O₁₂ account for the mass percent of the whole electronic ceramic; the electronic ceramic prepared by the invention has good dielectric property and piezoelectric property.

Description

A kind of electronic ceramic with high dielectric performance and preparation method thereof

Technical Field

The invention relates to the field of electronic ceramic materials, in particular to an electronic ceramic with high dielectric properties and a preparation method thereof.

Background Art

Traditional electronic ceramic materials are limited in application due to their low dielectric constant. In recent years, as piezoelectric electroacoustic devices have developed towards miniaturization and thinning, electronic ceramic materials are required to have higher dielectric constants and lower dielectric losses.

Summary of the invention

Purpose of the invention: In view of the above technical problems, the present invention proposes an electronic ceramic with high dielectric properties and a preparation method thereof.

The technical solutions adopted are as follows:

A high dielectric performance electronic ceramic, the chemical composition of which includes:

Pb(Zr _x Ti _1-x )(Mg _y W _1-y )(Sc _z Ta _1-z )O ₃ -αwt%Ba(Al _q Sb _1-q )O ₃ -βwt%Bi ₄ Ti ₃ O ₁₂

x, y, z, q are atomic percentages;

α and β represent the mass percentage of Ba(Al _q Sb _1-q )O ₃ and Bi ₄ Ti ₃ O ₁₂ in the whole electronic ceramic, respectively;

x is 0.4-0.6, y is 0.4-0.6, z is 0.4-0.6, q is 0.4-0.6;

α is 5-10, and β is 0.1-1.

Further, x is 0.45-0.55, y is 0.45-0.55, z is 0.45-0.55, and q is 0.45-0.55.

Further, x is 0.48, y is 0.5, z is 0.5, and q is 0.5.

Furthermore, α is 6-8, and β is 0.4-0.8.

Further, α is 6.5 and β is 0.5.

The present invention also provides a method for preparing electronic ceramics with high dielectric properties:

Pb ₃ O ₄ , ZrO ₂ , TiO ₂ , MgO, WO ₃ , Sc ₂ O ₃ , Ta ₂ O ₅ , BaCO ₃ , Al ₂ O ₃ , Sb ₂ O ₃ and Bi ₄ Ti ₃ O ₁₂ are mixed, ball-milled and dried, pre-pressed into green sheets and pre-fired, the pre-fired products are crushed and ball-milled again and dried, a binder is added to the obtained powder to granulate, and the green bodies are pressed into green bodies, which are placed in a sintering furnace, first heated to 550-650°C for 1-3 hours for debinding, and then heated to 1150-1300°C for 2-4 hours for sintering.

Furthermore, the pre-firing temperature is 800-900° C., and the pre-firing time is 1-3 hours.

Furthermore, the binder is polyvinyl alcohol and/or polyvinyl butyral.

Furthermore, sintering is performed in an oxygen atmosphere.

Furthermore, the first stage heating rate is 0.5-20°C/min, and the second stage heating rate is 0.5-20°C/min.

Beneficial effects of the present invention:

The invention provides an electronic ceramic with high dielectric properties. PZT is an extremely important piezoelectric ceramic. In order to improve its piezoelectric and dielectric properties, PZT-PMW-PST is widely studied. The PZT-PMW-PST of the invention is near the quasi-morphous phase boundary (MPB). The electronic ceramic material structure is in the coexistence of the rhombic phase and the tetragonal phase, and the barrier between the rhombic phase and the tetragonal phase is reduced. The macroscopic dielectric and piezoelectric effects of the electronic ceramic are good. Ba(Al _q Sb _1-q )O ₃ is a perovskite structure and can form a good solid solution with PZT-PMW-PST. The ions Ba ²⁺ , Cu ²⁺ , and Sb ³⁺ contained in the Ba(Al q Sb 1-q )O 3 can all play a good modification role on PZT-PMW-PST, thereby improving various properties of the electronic ceramic. Bi ₄ Ti ₃ O ₁₂ as a composite oxide can reduce the sintering temperature, and produce a large amount of liquid phase during the sintering process to promote sintering densification. Sintering in an oxygen atmosphere can obtain high-performance electronic ceramics. This is mainly because sintering in an oxygen atmosphere can reduce the oxygen vacancy content in the electronic ceramics and weaken the pinning effect on the domain wall caused by space charge aggregation, so that the polarization degree of the electronic ceramics is higher under the same conditions. The electronic ceramics prepared by the present invention have good dielectric properties and piezoelectric properties. Moreover, by comparison, it can be seen that the addition of Ba(Al _0.5 Sb _0.5 )O ₃ and Bi ₄ Ti ₃ O ₁₂ and sintering in an oxygen atmosphere play a positive role in improving the dielectric properties and piezoelectric properties of electronic ceramics.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a SEM image of the electronic ceramic prepared in Example 1.

DETAILED DESCRIPTION

If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially. The techniques not mentioned in the present invention are all referenced to the prior art. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

Embodiment 1: A high dielectric performance electronic ceramic, the chemical composition of which comprises:

Pb(Zr _0.48 Ti _0.52 )(Mg _0.5 W _0.5 )(Sc _0.5 Ta _0.5 )O ₃ -6.5wt%Ba(Al _0.5 Sb _0.5 )O ₃ -0.5wt%Bi ₄ Ti ₃ O ₁₂

Preparation method of the above-mentioned high dielectric performance electronic ceramics:

Pb ₃ O ₄ , ZrO ₂ , TiO ₂ , MgO, WO ₃ , Sc ₂ O ₃ , Ta ₂ O ₅ , BaCO ₃ , Al ₂ O ₃ , Sb ₂ O ₃ and Bi ₄ Ti ₃ O ₁₂ were weighed according to their chemical compositions. , add them to the ball mill of a planetary ball mill after mixing, use anhydrous ethanol as the ball milling medium, use zirconium balls to mill for 10 hours and then dry, and then pre-press them under a pressure of 10MPa to form a green sheet, heat the green sheet to 850℃ and pre-sinter for 2h, crush the pre-sintered product and add it to the ball mill of a planetary ball mill again, use anhydrous ethanol as the ball milling medium, use zirconium balls to mill for 5h and then dry to obtain a mixed powder, dissolve the binder polyvinyl alcohol in water to obtain a polyvinyl alcohol solution with a mass concentration of 8%, mix the mixed powder with the polyvinyl alcohol solution to granulate, sieve and press them into a green body at 200MPa, place the green body in a sintering furnace under an air atmosphere, first heat to 600℃ at a speed of 1℃/min in one stage, keep warm for 2h to debind, replace the air in the sintering furnace with high-purity oxygen, and then heat to 1250℃ in two stages at a speed of 5℃/min in an oxygen atmosphere, keep warm and sinter for 3h.

Embodiment 2: A high dielectric performance electronic ceramic, the chemical composition of which comprises:

Pb(Zr _0.48 Ti _0.52 )(Mg _0.5 W _0.5 )(Sc _0.5 Ta _0.5 )O ₃ -6.5wt%Ba(Al _0.5 Sb _0.5 )O ₃ -0.5wt%Bi ₄ Ti ₃ O ₁₂

Preparation method of the above-mentioned high dielectric performance electronic ceramics:

Pb ₃ O ₄ , ZrO ₂ , TiO ₂ , MgO, WO ₃ , Sc ₂ O ₃ , Ta ₂ O ₅ , BaCO ₃ , Al ₂ O ₃ , Sb ₂ O ₃ and Bi ₄ Ti ₃ O ₁₂ were weighed according to their chemical compositions. , add the mixed materials into the ball mill of a planetary ball mill, use anhydrous ethanol as the ball milling medium, use zirconium balls to mill for 10 hours and then dry, and then pre-press them into green sheets under a pressure of 10 MPa, heat the green sheets to 900°C and pre-sinter for 3 hours, crush the pre-sintered products and add them into the ball mill of a planetary ball mill again, use anhydrous ethanol as the ball milling medium, use zirconium balls to mill for 5 hours and then dry to obtain a mixed powder, dissolve the binder polyvinyl alcohol in water to obtain a polyvinyl alcohol solution with a mass concentration of 8%, mix the mixed powder with the polyvinyl alcohol solution to granulate, sieve and press them into a green body under 200 MPa, place the green body in a sintering furnace under an air atmosphere, first heat to 650°C at a rate of 5°C/min in one stage to remove binder for 2 hours, replace the air in the sintering furnace with high-purity oxygen, and then heat to 1300°C in an oxygen atmosphere at a rate of 10°C/min in two stages to sinter for 2 hours.

Embodiment 3: A high dielectric performance electronic ceramic, the chemical composition of which comprises:

Pb(Zr _0.48 Ti _0.52 )(Mg _0.5 W _0.5 )(Sc _0.5 Ta _0.5 )O ₃ -6.5wt%Ba(Al _0.5 Sb _0.5 )O ₃ -0.5wt%Bi ₄ Ti ₃ O ₁₂

Preparation method of the above-mentioned high dielectric performance electronic ceramics:

Pb ₃ O ₄ , ZrO ₂ , TiO ₂ , MgO, WO ₃ , Sc ₂ O ₃ , Ta ₂ O ₅ , BaCO ₃ , Al ₂ O ₃ , Sb ₂ O ₃ and Bi ₄ Ti ₃ O ₁₂ were weighed according to their chemical compositions. , add them to the ball mill of a planetary ball mill after mixing, use anhydrous ethanol as the ball milling medium, use zirconium balls to mill for 10 hours and then dry, and then pre-press them under a pressure of 10 MPa to form a green sheet, heat the green sheet to 800℃ and pre-sinter for 1 hour, crush the pre-sintered product and add it to the ball mill of a planetary ball mill again, use anhydrous ethanol as the ball milling medium, use zirconium balls to mill for 5 hours and then dry to obtain a mixed powder, dissolve the binder polyvinyl alcohol in water to obtain a polyvinyl alcohol solution with a mass concentration of 8%, mix the mixed powder with the polyvinyl alcohol solution to granulate, sieve and press them into a green body at 200 MPa, place the green body in a sintering furnace under an air atmosphere, first heat to 550℃ at a speed of 0.5℃/min in one stage to remove binder for 3 hours, replace the air in the sintering furnace with high-purity oxygen, and then heat to 1150℃ in two stages at a speed of 0.5℃/min in an oxygen atmosphere and sinter for 2 hours.

Comparative Example 1:

The method is basically the same as Example 1, except that Ba(Al _0.5 Sb _0.5 )O ₃ is not added.

Comparative Example 2:

The process is basically the same as Example 1, except that Bi ₄ Ti ₃ O ₁₂ is not added.

Comparative Example 3:

The method is basically the same as Example 1, except that the air in the sintering furnace is not replaced by high-purity oxygen, and the sintering is continued in an air atmosphere.

Performance Test:

The high dielectric performance electronic ceramics prepared in Examples 1-3 of the present invention and Comparative Examples 1-3 were polished and coated with silver paste on the upper and lower surfaces, cured at 600° C. for 30 min, immersed in silicone oil at 70° C. and polarized with a DC electric field of 3 kv/mm for 30 min as samples for performance testing;

The piezoelectric constant of the sample was measured by using a ZJ-3A quasi-static d ₃₃ tester, and the relative dielectric constant ε _r (room temperature 100kHz), dielectric loss tanδ (room temperature 100kHz), resonant frequency, anti-resonant frequency and corresponding impedance of the sample were measured by using an Agilent HP4192 precision impedance analyzer, and the electromechanical coupling coefficient k _p of the sample was calculated based on this.

The test results are shown in Table 1 below:

Table 1:

;

It can be seen from Table 1 above that the electronic ceramics prepared in the present invention have good dielectric properties and piezoelectric properties. Moreover, by comparison, it can be seen that the addition of Ba(Al _0.5 Sb _0.5 )O ₃ and Bi ₄ Ti ₃ O ₁₂ and sintering in an oxygen atmosphere play a positive role in improving the dielectric properties and piezoelectric properties of the electronic ceramics.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. An electronic ceramic with high dielectric properties, characterized in that its chemical composition includes: Pb(Zr _x Ti _1-x )(Mg _y W _1-y )(Sc _z Ta _1-z )O ₃ -αwt%Ba(Al _q Sb _1-q )O ₃ -βwt%Bi ₄ Ti ₃ O ₁₂ x, y, z, q are atomic percentages; α and β represent the mass percentage of Ba(Al _q Sb _1-q )O ₃ and Bi ₄ Ti ₃ O ₁₂ in the whole electronic ceramic, respectively; x is 0.4-0.6, y is 0.4-0.6, z is 0.4-0.6, q is 0.4-0.6; α is 5-10, and β is 0.1-1. 2. The electronic ceramic with high dielectric properties as claimed in claim 1, characterized in that x is 0.45-0.55, y is 0.45-0.55, z is 0.45-0.55, and q is 0.45-0.55. 3. The electronic ceramic with high dielectric properties as claimed in claim 1, characterized in that x is 0.48, y is 0.5, z is 0.5, and q is 0.5. 4. The electronic ceramic with high dielectric properties as claimed in claim 1, characterized in that α is 6-8 and β is 0.4-0.8. 5. The electronic ceramic with high dielectric properties as claimed in claim 1, characterized in that α is 6.5 and β is 0.5. 6. A method for preparing an electronic ceramic with high dielectric properties as claimed in any one of claims 1 to ₅ , characterized in that _Pb3O4 , ZrO2, _TiO2 , _MgO , _{WO3 , Sc2O3} , _Ta2O5 , _BaCO3 , _Al2O3 , _Sb2O3 and _Bi4Ti3O12 are mixed _, ball-milled and dried, pre _- pressed into green sheets and pre-fired, the pre-fired products _are crushed and _ball -milled again and dried, a binder is added to the obtained powder _to granulate, the powder is pressed into a green body, the green body is placed in a sintering furnace, the temperature is first raised to 550-650℃ for insulation and debinding for 1-3h, and then the temperature is raised to 1150-1300℃ for insulation and sintering for 2-4h. 7. The method for preparing electronic ceramics with high dielectric properties as claimed in claim 6, characterized in that the pre-firing temperature is 800-900°C and the pre-firing time is 1-3h. 8 . The method for preparing electronic ceramics with high dielectric properties according to claim 6 , wherein the binder is polyvinyl alcohol and/or polyvinyl butyral. 9. The method for preparing electronic ceramics with high dielectric properties as claimed in claim 6, characterized in that sintering is carried out in an oxygen atmosphere. 10. The method for preparing electronic ceramics with high dielectric properties as claimed in claim 6, characterized in that the rate of the first stage heating is 0.5-20°C/min, and the rate of the second stage heating is 0.5-20°C/min.