High-entropy, high-polarization and wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase change as well as preparation method and application of high-entropy, high-polarization and wide-temperature stable sodium bismuth titanate-based ceramic material

Abstract

The invention discloses a high-entropy high-polarization wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase change as well as a preparation method and application thereof, the stoichiometric formula of the sodium bismuth titanate-based ceramic material is Na < 0.375 > Bi < 0.375 > Ca < 0.125 > Sr < 0.125 > Ti < 1-x > (Ga < 0.20 > Zr < 0.20 > Sn < 0.20 > Hf < 0.20 > Nb < 0.20 >) xO < 3 >, x is smaller than or equal to 0.20; the preparation method comprises the following steps: 1, weighing Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 according to a stoichiometric equation, mixing, and sequentially carrying out wet ball milling, drying and calcining to obtain a main crystal phase full ingredient; 2, sequentially carrying out wet-process ball milling, drying and sieving on the main crystal phase full ingredient to obtain a sieved material; and 3, carrying out compression molding on the sieved material to obtain a ceramic wafer, putting the ceramic wafer into a muffle furnace, heating the ceramic wafer to 1100-1200 DEG C from room temperature at a rate of 2-5 DEG C / min, carrying out heat preservation for 120-240 minutes, then cooling the ceramic wafer to 500 DEG C at a rate of 2-5 DEG C / min, and finally carrying out furnace cooling to room temperature to obtain the compact sodium bismuth titanate-based ceramic material which has obvious field-induced phase change and ultrahigh saturation polarization intensity, and has the characteristics of high specific surface area and high specific surface area in an ultra-wide temperature interval. The excellent dielectric stability is shown.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ceramic materials, and specifically relates to a high-entropy high-polarization wide-temperature-stable sodium bismuth titanate ceramic material with a field-induced phase change and a preparation method and application thereof. BACKGROUND

[0002] The large-scale construction of new energy power systems, the comprehensive electrification transformation of the automobile industry, and the rapid development of portable pulse power devices have put forward unprecedented performance requirements for dielectric energy storage materials. However, traditional ferroelectric energy storage materials are often limited by the paradox between high polarization difference and high breakdown field strength, because high polarization difference needs to be generated by high dielectric constant, and the domain wall movement of large domains will produce high hysteresis loss, at the same time, space charges are easy to accumulate at the domain wall, resulting in electric field concentration, thereby restricting the breakdown field strength; in addition, the dielectric properties of traditional ferroelectric energy storage materials usually degrade sharply in a wide temperature range, which seriously limits their practical application.

[0003] In recent years, Na 0.5 Bi 0.5 Titanate ceramic materials have good energy storage application prospects due to the high polarization strength caused by the formation of asymmetric covalent bonds by unique hybrid orbitals, and the high breakdown field strength caused by doping modification, however, under conventional methods, the improvement of the breakdown field strength is brought by reducing the polarization difference, and the dielectric stability at a wide temperature is usually significantly weakened, therefore, special strategies need to be designed to improve the dielectric and ferroelectric properties. SUMMARY

[0004] The application aims to provide a high-entropy high-polarization wide-temperature-stable sodium bismuth titanate ceramic material with a field-induced phase change and a preparation method and application thereof, which has obvious field-induced phase change and super-high saturation polarization strength, and exhibits excellent dielectric stability in a super-wide temperature range.

[0005] The application is realized by the following technical scheme:

[0006] A high-entropy high-polarization wide-temperature-stable sodium bismuth titanate ceramic material with a field-induced phase change, the stoichiometric formula of which is: Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, wherein 0 < x < 0.20.

[0007] A preparation method of a high-entropy, high-polarization, wide-temperature-stable sodium bismuth titanate-based ceramic material with field-induced phase transition, comprising the following steps:

[0008] Step 1: According to the chemical formula Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, 0 < x ≤ 0.20, weigh Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 and mix them to obtain a mixed material. After wet ball milling the mixed material, dry it, and then calcine it at 815 - 875 °C for 2 - 5 h to obtain a full ingredient of the main crystal phase;

[0009] Step 2: After successively performing wet ball milling, drying and sieving on the full ingredient of the main crystal phase, obtain a sieved material;

[0010] Step 3: Press the sieved material into a shape to obtain a ceramic wafer. Put the ceramic wafer into a muffle furnace, heat it from room temperature to 1100 - 1200 °C at a rate of 2 - 5 °C / min, hold it for 120 - 240 min, then cool it to 500 °C at a rate of 2 - 5 °C / min, and finally cool it to room temperature with the furnace to obtain a dense sodium bismuth titanate-based ceramic material.

[0011] Further, the wet ball milling in Step 1 is to put the mixed material, zirconia balls and liquid into a planetary ball mill according to a mass ratio of 1:(3 - 6):1, and ball mill at a rotation speed of 300 - 500 r / min for 8 - 24 h, where: the zirconia balls are composed of small, medium and large particle size zirconia balls mixed according to a mass ratio of 1:(3 - 6):1; the liquid is deionized water or absolute ethanol.

[0012] Further, the wet ball milling in Step 2 is to put the full ingredient of the main crystal phase, zirconia balls and liquid into a planetary ball mill according to a mass ratio of 1:(3 - 6):1, and ball mill at a rotation speed of 300 - 500 r / min for 12 - 24 h, where: the zirconia balls are composed of small, medium and large particle size zirconia balls mixed according to a mass ratio of 1:(3 - 5):1; the liquid is deionized water or absolute ethanol.

[0013] Further, the drying in Step 1 and Step 2 is carried out at 80 - 100 °C for 8 - 24 h.

[0014] Further, the sieving in Step 2 is through a sieve mesh of 120 - 300 meshes.

[0015] Furthermore, the pressing process in step 3 is as follows: first, pressurize at a rate of 20-40 MPa / min, then hold at 180-300 MPa for 3-5 minutes, and finally depressurize at a rate of 20-40 MPa / min.

[0016] Application of a high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase transition in high-power pulse systems.

[0017] The present invention has the following beneficial technical effects:

[0018] This invention utilizes high-entropy ions (Ga) with large band gaps exhibiting significant radius and valence state differences. 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) 4+ Introduced into 0.75Na 0.5 Bi 0.5 TiO3-0.25Ca 0.125 Sr 0.125 In TiO3, increasing configurational entropy disrupts the long-range ferroelectric order, suppresses interfacial polarization, and enhances polarization saturation delay and breakdown field strength. Simultaneously, the reduction in the proportion of temperature-sensitive octahedrons in TiO6 and the generation of local pinning effects significantly improve temperature stability. In other words, by leveraging the large ionic radius difference and electronegativity difference to induce a field-induced phase transition, combined with high-entropy engineering, the breakdown field strength is increased to achieve full polarization, resulting in the formation of TiO3 with Na... 0.5 Bi 0.5 TiO3-based high-entropy ceramic material at the B-site Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.2 Zr 0.2 Sn 0.2 Hf 0.2 Nb 0.20 ) x TiO3 exhibits excellent dielectric stability over an ultra-wide temperature range. In the ultra-wide temperature range of 59 to 478℃, the TCC fluctuation range is ±5%, demonstrating good dielectric stability. In an even wider temperature range of -46 to 600℃, the TCC fluctuation range is ±15%, also exhibiting excellent dielectric stability. This solves the technical problems of existing energy storage ceramic dielectric materials being difficult to fully polarize and having poor temperature stability.

[0019] This invention not only features a simple and environmentally friendly preparation process suitable for industrial production, but also produces sodium bismuth titanate-based ceramic materials that exhibit field-induced phase transitions, high entropy, high polarization, and wide-temperature dielectric stability. These materials are suitable for high-power pulse systems operating in harsh temperature environments and have significant industrial application value. Attached Figure Description

[0020] Figure 1 This is a SEM image of the microstructure of the high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase transition prepared in Example 2 of the present invention.

[0021] Figure 2 The dielectric stability spectra of the high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic materials with field-induced phase transition prepared in Comparative Example 1 and Examples 1 to 4 of this invention are shown.

[0022] Figure 3 The PE hysteresis loop of the high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase transition prepared in Example 2 of this invention;

[0023] Figure 4 JE polarization current-electric field curves of the high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase transition prepared in Example 2 of this invention;

[0024] Figure 5 The following is a bar chart showing the polarization difference of sodium bismuth titanate-based ceramic materials prepared in Example 2 and Comparative Example 1 of this invention.

[0025] Figure 6 The breakdown field strength histograms of the sodium bismuth titanate-based ceramic materials prepared in Example 2 and Comparative Example 1 of this invention are shown below.

[0026] Figure 7 The bar chart shows the energy storage density of sodium bismuth titanate-based ceramic materials prepared in Example 2 and Comparative Example 1 of this invention. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0028] Comparative Example 1

[0029] Step 1: First, according to the chemical formula Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) xO3, x=0, weigh Na2CO3, Bi2O3, CaCO3, SrCO3 and TiO2 and mix them to obtain a mixture. Then, mix small, medium and large-sized zirconium balls in a mass ratio of 1:6:1. Next, put the mixture, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:3:1 and ball mill at 390 r / min for 11 h. Dry at 80℃ for 20 h and then calcine at 865℃ for 4 h to obtain the complete formula of the main crystalline phase.

[0030] Step 2: First, mix small, medium and large zirconium balls in a mass ratio of 1:3.5:1. Then, put the main crystalline phase feedstock, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:6:1. Mill at 390 r / min for 13 h, dry at 80 ℃ for 10 h, and then pass through a 250 mesh sieve to obtain the sieved material.

[0031] Step 3: Press the sieved material into shape. The specific process is as follows: first, press at a rate of 25 MPa / min, then hold at 250 MPa for 3 minutes, and finally release the pressure at a rate of 25 MPa / min to obtain ceramic discs.

[0032] Step 4: Place the ceramic disc into an alumina crucible with zirconium oxide as a backing plate, then place it in a muffle furnace, heat it from room temperature to 1160℃ at a rate of 2℃ / min, hold it at that temperature for 150min, then cool it down to 500℃ at a rate of 2℃ / min, and finally cool it to room temperature with the furnace to obtain sodium bismuth titanate-based ceramic material.

[0033] Example 1

[0034] Step 1: First, according to the chemical formula Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, x=0.05, weigh Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 and mix them to obtain a mixture. Then, mix small, medium and large-sized zirconium balls in a mass ratio of 1:3:1. Next, put the mixture, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:5:1 and ball mill for 11 hours at 390 r / min. Dry at 80℃ for 8 hours and then calcine at 835℃ for 3 hours to obtain the complete formula of the main crystalline phase.

[0035] Step 2: First, mix small, medium and large zirconium balls in a mass ratio of 1:4:1. Then, put the main crystalline phase feedstock, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:5:1. Mill at 390 r / min for 16 h, dry at 80℃ for 15 h, and then pass through a 200 mesh sieve to obtain the sieved material.

[0036] Step 3: Press the sieved material into shape. The specific process is as follows: first, press at a rate of 20 MPa / min, then hold at 180 MPa for 5 minutes, and finally release the pressure at a rate of 30 MPa / min to obtain ceramic discs.

[0037] Step 4: Place the ceramic disc into an alumina crucible with zirconium oxide as a backing plate, then place it in a muffle furnace, heat it from room temperature to 1170℃ at a rate of 5℃ / min, hold it at that temperature for 120min, then cool it down to 500℃ at a rate of 3℃ / min, and finally cool it down to room temperature with the furnace to obtain a dense sodium bismuth titanate-based ceramic material.

[0038] Example 2

[0039] Step 1: First, according to the chemical formula Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, x=0.1, weigh Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 and mix them to obtain a mixture. Then, mix small, medium and large-sized zirconium balls in a mass ratio of 1:6:1. Next, put the mixture, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:3:1 and ball mill at 390 r / min for 11 h. Dry at 80℃ for 20 h and then calcine at 865℃ for 4 h to obtain the complete formula of the main crystalline phase.

[0040] Step 2: First, mix small, medium and large zirconium balls in a mass ratio of 1:3.5:1. Then, put the main crystalline phase feedstock, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:6:1. Mill at 390 r / min for 13 h, dry at 80 ℃ for 10 h, and then pass through a 250 mesh sieve to obtain the sieved material.

[0041] Step 3: Press the sieved material into shape. The specific process is as follows: first, press at a rate of 25 MPa / min, then hold at 250 MPa for 3 minutes, and finally release the pressure at a rate of 25 MPa / min to obtain ceramic discs.

[0042] Step 4: Place the ceramic disc into an alumina crucible with zirconium oxide as a backing plate, then place it in a muffle furnace, heat it from room temperature to 1160℃ at a rate of 2℃ / min, hold it at that temperature for 150min, then cool it down to 500℃ at a rate of 2℃ / min, and finally cool it down to room temperature with the furnace to obtain a dense sodium bismuth titanate-based ceramic material.

[0043] Example 3

[0044] Step 1: First, according to the chemical formula Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, x=0.15, weigh Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 and mix them to obtain a mixture. Then, mix small, medium and large-sized zirconium balls in a mass ratio of 1:6:1. Next, put the mixture, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:4:1 and ball mill at 450 r / min for 15 h. Dry at 80℃ for 12 h and then calcine at 845℃ for 2 h to obtain the complete formula of the main crystalline phase.

[0045] Step 2: First, mix small, medium and large zirconium balls in a mass ratio of 1:5:1. Then, put the main crystalline phase, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:4.5:1. Mill at 450 r / min for 12 h, dry at 80℃ for 11 h, and then pass through a 120 mesh sieve to obtain the sieved material.

[0046] Step 3: Press the sieved material into shape. The specific process is as follows: first, press at a rate of 20 MPa / min, then hold at 200 MPa for 4 minutes, and finally release the pressure at a rate of 20 MPa / min to obtain ceramic discs.

[0047] Step 4: Place the ceramic disc into an alumina crucible with zirconium oxide as a backing plate, then place it in a muffle furnace, heat it from room temperature to 1200℃ at a rate of 5℃ / min, hold it at that temperature for 120min, then cool it down to 500℃ at a rate of 5℃ / min, and finally cool it down to room temperature with the furnace to obtain a dense sodium bismuth titanate-based ceramic material.

[0048] Example 4

[0049] Step 1: First, according to the chemical formula Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, x=0.2, weigh Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 and mix them to obtain a mixture. Then, mix small, medium and large-sized zirconium balls in a mass ratio of 1:4:1. Next, put the mixture, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:4:1 and ball mill for 13 hours at 400 r / min. Dry at 80℃ for 24 hours and then calcine at 855℃ for 5 hours to obtain the complete formula of the main crystalline phase.

[0050] Step 2: First, mix small, medium and large zirconium balls in a mass ratio of 1:5:1. Then, put the main crystalline phase feedstock, zirconium balls and anhydrous ethanol into a planetary ball mill in a mass ratio of 1:3:1. Mill at 400 r / min for 13 h, dry at 90℃ for 20 h, and then pass through a 200 mesh sieve to obtain the sieved material.

[0051] Step 3: Press the sieved material into shape. The specific process is as follows: first, press at a rate of 40 MPa / min, then hold at 280 MPa for 5 minutes, and finally release the pressure at a rate of 40 MPa / min to obtain ceramic discs.

[0052] Step 4: Place the ceramic disc into an alumina crucible with zirconium oxide as a backing plate, then place it in a muffle furnace, heat it from room temperature to 1100℃ at a rate of 2℃ / min, hold it at that temperature for 240min, then cool it down to 500℃ at a rate of 2℃ / min, and finally cool it down to room temperature with the furnace to obtain a dense sodium bismuth titanate-based ceramic material.

[0053] Example 5

[0054] Step 1: First, according to the chemical formula Na 0.375 Bi0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, x=0.1, weigh Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 and mix them to obtain a mixture. Then, mix small, medium and large-sized zirconium balls in a mass ratio of 1:5:1. Next, put the mixture, zirconium balls and deionized water into a planetary ball mill in a mass ratio of 1:5:1 and ball mill at 300 r / min for 24 h. Dry at 100℃ for 15 h and then calcine at 815℃ for 4 h to obtain the complete formula of the main crystalline phase.

[0055] Step 2: First, mix small, medium and large zirconium balls in a mass ratio of 1:5:1. Then, put the main crystalline phase, zirconium balls and deionized water into a planetary ball mill in a mass ratio of 1:5:1. Mill at 300 r / min for 20 h, dry at 90℃ for 24 h, and then pass through a 300 mesh sieve to obtain the sieved material.

[0056] Step 3: Press the sieved material into shape. The specific process is as follows: first, press at a rate of 25 MPa / min, then hold at 250 MPa for 5 minutes, and finally release the pressure at a rate of 25 MPa / min to obtain ceramic discs.

[0057] Step 4: Place the ceramic disc into an alumina crucible with zirconium oxide as a backing plate, then place it in a muffle furnace, heat it from room temperature to 1150℃ at a rate of 3℃ / min, hold it at that temperature for 210min, then cool it down to 500℃ at a rate of 3℃ / min, and finally cool it down to room temperature with the furnace to obtain a dense sodium bismuth titanate-based ceramic material.

[0058] Example 6

[0059] Step 1: First, according to the chemical formula Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) xO3, x=0.15, weigh Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 and mix them to obtain a mixture. Then, mix small, medium and large-sized zirconium balls at a mass ratio of 1:5:1. Next, put the mixture, zirconium balls and deionized water into a planetary ball mill at a mass ratio of 1:6:1 and ball mill at 500 r / min for 8 h. Dry at 90℃ for 18 h and then calcine at 875℃ for 3 h to obtain the complete formula of the main crystalline phase.

[0060] Step 2: First, mix small, medium and large zirconium balls in a mass ratio of 1:3:1. Then, put the main crystalline phase, zirconium balls and deionized water into a planetary ball mill in a mass ratio of 1:5:1. Mill at 500 r / min for 24 h, dry at 100℃ for 8 h, and then pass through a 300 mesh sieve to obtain the sieved material.

[0061] Step 3: Press the sieved material into shape. The specific process is as follows: first, press at a rate of 30 MPa / min, then hold at 300 MPa for 4 minutes, and finally release the pressure at a rate of 30 MPa / min to obtain ceramic discs.

[0062] Step 4: Place the ceramic disc into an alumina crucible with zirconium oxide as a backing plate, then place it in a muffle furnace, heat it from room temperature to 1180℃ at a rate of 4℃ / min, hold it at that temperature for 180min, then cool it down to 500℃ at a rate of 4℃ / min, and finally cool it down to room temperature with the furnace to obtain a dense sodium bismuth titanate-based ceramic material.

[0063] from Figure 1 It can be seen that the sodium bismuth titanate-based ceramic material prepared in real-time Example 2 has a single perovskite structure, indicating that the elements are mixed uniformly and no chemical segregation occurs. This is beneficial to reducing grain boundary defects, preventing electric field concentration, and thus significantly optimizing dielectric properties.

[0064] Comparative Example 1 and Examples 1-4 prepared sodium bismuth titanate-based ceramic materials were respectively polished and cleaned, then coated with Ag electrodes on both sides, and calcined with silver at 700°C for 20 min for dielectric property testing. The results are as follows. Figures 2 to 4 As shown:

[0065] from Figure 2 It can be seen that the sodium bismuth titanate-based ceramic materials prepared in Examples 1 to 4 have excellent dielectric stability over an ultra-wide temperature range. Specifically, the TCC fluctuation range is ±5% in the ultra-wide temperature range of 59 to 478°C. In contrast, the sodium bismuth titanate-based ceramic material prepared in Comparative Example 1 has a TCC fluctuation range of ±15% in the ultra-wide temperature range of 59 to 478°C.

[0066] from Figure 3 and Figure 4 It can be seen that the sodium bismuth titanate-based ceramic material prepared in Example 2 underwent significant antiferroelectric transitions as the electric field increased, indicating that a field-induced phase transition process exists and exhibiting ultra-high saturation polarization intensity.

[0067] from Figures 5 to 7 It can be seen that the polarization difference, breakdown field strength, and storage density of the sodium bismuth titanate-based ceramic material prepared in Example 2 are significantly higher than those of the sodium bismuth titanate-based ceramic material prepared in Comparative Example 1, proving that Na... 0.5 Bi 0.5 TiO3-based high-entropy ceramic material at the B-site Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.2 Zr 0.2 Sn 0.2 Hf 0.2 Nb 0.20 ) x TiO3 exhibits excellent dielectric and ferroelectric properties.

Claims

1. A high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase transition, characterized in that, The stoichiometric formula is: Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, where 0 <x≤0.20。 2. A method for preparing a high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase transition as described in claim 1, characterized in that, Includes the following steps: Step 1. According to the chemical formula Na 0.375 Bi 0.375 Ca 0.125 Sr 0.125 Ti 1-x (Ga 0.20 Zr 0.20 Sn 0.20 Hf 0.20 Nb 0.20 ) x O3, where 0 < x ≤ 0.

20. Weigh Na2CO3, Bi2O3, CaCO3, SrCO3, TiO2, Ga2O3, ZrO2, SnO2, HfO2 and Nb2O5 and mix them to obtain a mixed material. After wet ball milling the mixed material, dry it, and then calcine it at 815 - 875 °C for 2 - 5 h to obtain the full main crystal phase ingredients; Step 2: After the main crystalline phase is fully prepared, it is successively subjected to wet ball milling, drying and sieving to obtain sieved material; Step 3: Press the sieved material into a ceramic disc. Place the ceramic disc into a muffle furnace and heat it from room temperature to 1100-1200℃ at a rate of 2-5℃ / min. Hold the temperature for 120-240min. Then, cool it down to 500℃ at a rate of 2-5℃ / min. Finally, cool it down to room temperature with the furnace to obtain a dense sodium bismuth titanate-based ceramic material.

3. The method for preparing high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic materials with field-induced phase transition according to claim 2, characterized in that, The wet ball milling in step 1 involves placing the mixture, zirconium balls, and liquid into a planetary ball mill at a mass ratio of 1:(3-6):1 and milling for 8-24 hours at a speed of 300-500 r / min. The zirconium balls are composed of small, medium, and large-sized zirconium balls mixed at a mass ratio of 1:(3-6):

1. The liquid is deionized water or anhydrous ethanol.

4. The method for preparing high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic materials with field-induced phase transition according to claim 2, characterized in that, The wet ball milling in step 2 is carried out by placing the main crystalline phase, zirconium balls, and liquid into a planetary ball mill at a mass ratio of 1:(3-6):1 and milling for 12-24 hours at a speed of 300-500 r / min. The zirconium balls are composed of small, medium, and large-sized zirconium balls mixed at a mass ratio of 1:(3-5):

1. The liquid is deionized water or anhydrous ethanol.

5. The method for preparing high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic materials with field-induced phase transition according to claim 2, characterized in that, The drying in steps 1 and 2 is carried out at 80-100°C for 8-24 hours.

6. The method for preparing high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic materials with field-induced phase transition according to claim 2, characterized in that, The sieving in step 2 involves passing the material through a 120-300 mesh sieve.

7. The method for preparing high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic materials with field-induced phase transition according to claim 2, characterized in that, The pressing process in step 3 is as follows: first, pressurize at a rate of 20-40 MPa / min, then hold at 180-300 MPa for 3-5 minutes, and finally depressurize at a rate of 20-40 MPa / min.

8. The application of the high-entropy, high-polarization, wide-temperature stable sodium bismuth titanate-based ceramic material with field-induced phase transition as described in claim 1 in high-power pulse systems.

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