High dielectric, low loss, temperature stability, trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material and preparation method thereof

Abstract

The present invention discloses a high dielectric, low loss, temperature stability, trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material and a preparation method thereof. The general formula of the ceramic material is (A 2 / 3 W 1 / 3 ) x Ti 1‑x O2, where A is any one of Bi, Y, and Ga, and the value of x is 0.005 to 0.04. The ceramic material of the present invention is prepared by a traditional solid phase sintering method, which has a simple preparation method, good repeatability, and high yield. By introducing the metal element A into the rutile titanium dioxide-based ceramic material 3+ and W 6+ The dielectric constant of the obtained ceramic material is as high as 18470, and the dielectric loss is as low as 0.018 (1kHz). At the same time, it has excellent temperature stability, maintained between ‑10% and 10%, which meets the parameter requirements of ceramic capacitors such as X9S and X9P, and has great application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic materials, and in particular relates to a high-dielectric-low-loss temperature-stable trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of microelectronics technology, the integration of electronic components has made the design of miniaturized modules essential. Consequently, giant dielectric materials with low dielectric loss and high temperature stability are highly anticipated in the research and application of multilayer ceramic capacitors (MLCCs). To meet the application requirements of MLCCs, the development of giant dielectric ceramics with low dielectric loss and good temperature / frequency stability has become an important research direction in the materials field.

[0003] However, traditional high dielectric materials have some defects that are difficult to overcome, such as CaCu3Ti4O 12 Although dielectric ceramics possess ultra-high dielectric constants, they suffer from high dielectric losses, typically exceeding 0.1. The high dielectric constants of PbTiO3 and BaTiO3-based ceramics are significantly temperature-dependent due to their phase transitions, resulting in poor temperature stability and potential environmental pollution, hindering their practical application in MLCC and other applications.

[0004] Because titanium dioxide based ceramics has the excellent properties such as relatively high dielectric constant, low dielectric loss, therefore caused the extensive concern of researcher.In recent years, no matter be single doping, or the research of the titanium dioxide based ceramic material of dipentavalent, tripentavalent, one hexavalent co-doping emerges in an endless stream, but most of materials can not meet the requirement of high dielectric constant, low dielectric loss simultaneously, and temperature stability is relatively low, can not meet market demand, be difficult to be widely used in the electronic devices of the high dielectric constant needed in the electronic markets such as capacitor (for example: X9P ceramic capacitor etc.), memory.Therefore, research and develop a kind of titanium dioxide based ceramic material with high dielectric constant, low dielectric loss, having high thermal stability concurrently and be the difficulty of current research. Summary of the Invention

[0005] The purpose of the present invention is to provide a trivalent ion co-doped rutile titanium dioxide-based ceramic material with high dielectric constant, low dielectric loss, high temperature stability, strong practicality and easy production, and to provide a preparation method for the ceramic material.

[0006] For the above purpose, the general formula of the trivalent ion co-doped rutile titanium dioxide-based ceramic material provided by the present invention is (A 2 / 3 W 1 / 3 ) x Ti 1-xO2, where A represents any one of Bi, Y, and Ga, and the value of x is 0.005 to 0.04.

[0007] In the above-mentioned tri-hexavalent ion co-doped rutile titanium dioxide ceramic material, preferably, A represents Bi, and the value of x is 0.01.

[0008] In the above-mentioned tri-hexavalent ion co-doped rutile titanium dioxide ceramic material, preferably, A represents Ga, and the value of x is 0.02.

[0009] In the above-mentioned tri-hexavalent ion co-doped rutile titanium dioxide ceramic material, preferably, A represents Y, and the value of x is 0.005.

[0010] The preparation method of the trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material of the present invention comprises the following steps:

[0011] Step 1: Follow (A 2 / 3 W 1 / 3 ) x Ti 1-x The stoichiometric amount of O2 is as follows: WO3, rutile TiO2 and A2O3 with a purity of more than 99.5% are weighed separately, wherein A represents any one of Bi, Y and Ga, and the mixture is thoroughly mixed and ball-milled for 16 to 24 hours, and dried at 80 to 100°C for 12 to 24 hours to obtain a raw material mixture;

[0012] Step 2: Pre-calcining the raw material mixture at 1000-1100° C. for 2-4 hours to obtain pre-calcined powder;

[0013] Step 3: After granulation, tableting and binder removal, the pre-fired powder is sintered at 1350-1450° C. for 5-15 hours in a nitrogen atmosphere and sealed conditions to obtain a trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material.

[0014] In the above step 2, the raw material mixture is preferably heated to 1000° C. at a heating rate of 2 to 5° C. / min and pre-calcined at the constant temperature for 3 hours.

[0015] In the above step 3, the tableting is performed by using a powder tablet press at a pressure of 6 to 10 MPa for 3 to 6 minutes to form a cylindrical green body.

[0016] In the above step 3, it is preferred to first heat the temperature to 1000° C. in a nitrogen atmosphere and sealed conditions over 100 minutes, then heat the temperature to 1400° C. at a heating rate of 2-4° C. / min, and keep the temperature for 5-15 hours.

[0017] The present invention simultaneously adds trivalent elements (Bi, Y, Ga) and hexavalent element W to rutile titanium dioxide, and adopts a traditional solid phase sintering method to control the sintering temperature during sintering to obtain a titanium dioxide-based ceramic material with high dielectric constant and low dielectric loss. The basic principle of the titanium dioxide-based ceramic material to produce high dielectric constant and low dielectric loss is: when W 6+ When doped, some Ti in the material 4+ ions become Ti 3+ ions and generate free electrons, which will be suppressed when they migrate to the grain boundaries, resulting in strong interfacial polarization and thus a higher dielectric constant; A 3+ Ion doping will produce oxygen vacancies, which will prevent long-range carrier migration and thus reduce dielectric loss. Therefore, this good giant dielectric performance is attributed to the internal barrier layer capacitance (IBLC) model, that is, in the formed solid solution, the grains and grain boundaries have different conductivity mechanisms, and the presence of oxygen vacancies will make Ti 4+ Xiang Ti 3+ conversion; high conductivity is formed at the grain boundaries due to the migration of oxygen vacancies; low dielectric loss is due to the high activation energy at the grain boundaries.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The present invention introduces trivalent metal element A into titanium dioxide ceramic material 3+ and hexavalent metal element W 6+ , so that the ceramic material has low dielectric loss and high dielectric constant in reducing atmosphere, while also having high frequency stability and high thermal stability. At 1kHz, which meets the actual application conditions, (Ga 2 / 3 W 1 / 3 ) 0.02 Ti 0.98 The dielectric constant of O2 ceramic material is as high as 10139, and the dielectric loss is only 0.018, which meets the parameter requirements of X8R ceramic capacitors; (Y 2 / 3 W 1 / 3 ) 0.005 Ti 0.995 The dielectric constant of O2 ceramic material is 18470, the dielectric loss is 0.030, and it has excellent frequency and temperature stability in the temperature range of -55 to 200 ° C. The capacitance change rate is maintained between 4% and 10% at 1kHz and between -3% and 3% at 10kHz, both of which meet the application requirements of X9P (±10%) ceramic capacitors. (Bi 2 / 3 W 1 / 3 ) 0.01 Ti 0.99 The dielectric constant of O2 ceramic material is 15744 and the dielectric loss is 0.070, which meets the parameter requirements of X9R ceramic capacitors.

[0020] 2. The present invention utilizes W 6+ and A 3+ The internal barrier layer capacitance (IBLC) model is constructed to obtain excellent dielectric properties and temperature stability, namely W 6+ Doping makes Ti 4+ Become Ti 3+ The generated free electrons are suppressed from migrating to the grain boundaries, resulting in a high dielectric constant; A 3+ Oxygen vacancies created by ion doping prevent long-range carrier migration, thereby reducing dielectric loss. Furthermore, the ceramic material's preparation method is simple, reproducible, with a high yield rate, strong practicality, and ease of production, making it promising for applications in the MLCC and other electronics markets. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1 is a graph showing the relationship between the dielectric constant and dielectric loss of the ceramic materials prepared in Examples 1 to 4 and the test frequency.

[0022] Figure 2 3 is a graph showing the relationship between the capacitance change rate of the ceramic material prepared in Example 3 at different frequencies and the test temperature.

[0023] Figure 3 3 is a graph showing the relationship between the dielectric constant and dielectric loss of the ceramic materials prepared in Examples 5 and 6 and the test frequency.

[0024] Figure 4 3 is a graph showing the relationship between the capacitance change rate of the ceramic material prepared in Example 5 at different frequencies and the test temperature.

[0025] Figure 5 3 is a graph showing the relationship between the dielectric constant and dielectric loss of the ceramic materials prepared in Examples 7 to 10 and the test frequency.

[0026] Figure 6 3 is a graph showing the relationship between the capacitance change rate of the ceramic material prepared in Example 9 at different frequencies and the test temperature. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and examples, but the protection scope of the present invention is not limited to these examples.

[0028] Example 1

[0029] 1. According to (Bi 2 / 3 W 1 / 3 ) 0.005 Ti 0.995The stoichiometric amount of O2 was as follows: 0.1916 g of Bi2O3 (purity 99.99%), 0.0955 g of WO3 (purity 99.80%), and 19.7128 g of rutile TiO2 (purity 99.5%) were weighed respectively, and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as ball milling media. The total mass ratio of anhydrous ethanol to raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours, and the zirconium balls were separated. The ball milled raw materials were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture.

[0030] 2. Place the raw material mixture in an alumina crucible, cover it, heat it to 1000°C at a heating rate of 3°C / min, keep it at that temperature for 3 hours, cool it naturally to room temperature, remove it from the furnace, and grind it in a mortar for 5 minutes to obtain pre-fired powder.

[0031] 3. Grind the calcined powder in a mortar for 30 minutes, then add a 5% polyvinyl alcohol aqueous solution to it, the amount of polyvinyl alcohol aqueous solution added is 50% of the mass of the calcined powder, granulate, pass through a 120-mesh sieve, and make spherical powder particles. Place the spherical powder particles in a stainless steel mold with a diameter of 11.5 mm, and use a powder tablet press to press it at a pressure of 6 MPa for 3 minutes to form a cylindrical blank with a thickness of 1.5 mm; spread a layer of calcined powder on a zirconia plate, and place the cylindrical blank on an oxygen plate. A layer of pre-sintered powder was placed on the zirconium oxide plate, and then the blank was placed in an alumina porcelain boat. The temperature was first raised to 500 ° C in a muffle furnace for 380 minutes, kept warm for 2 hours, and naturally cooled to room temperature with the furnace. Then, the temperature was first raised to 1000 ° C in a tube furnace under nitrogen atmosphere and closed conditions for 100 minutes, and then raised to 1400 ° C at a heating rate of 2 ° C / min, kept warm for 10 hours, and naturally cooled to room temperature with the furnace to obtain BiW co-doped rutile titanium dioxide ceramic material (Bi 2 / 3 W 1 / 3 ) 0.005 Ti 0.995 O2.

[0032] Example 2

[0033] In step 1 of this embodiment, according to (Bi 2 / 3 W 1 / 3 ) 0.0075 Ti 0.9925The stoichiometric amount of O2 was 0.2861 g of Bi2O3 (purity 99.99%), 0.1426 g of WO3 (purity 99.80%), and 19.5713 g of rutile TiO2 (purity 99.5%). The raw materials were weighed and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The total mass ratio of anhydrous ethanol to the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours. The zirconium balls were separated. The raw materials after ball milling were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. The other steps were the same as in Example 1 to obtain BiW co-doped rutile titanium dioxide ceramic material (Bi 2 / 3 W 1 / 3 ) 0.0075 Ti 0.9925 O2.

[0034] Example 3

[0035] In step 1 of this embodiment, according to (Bi 2 / 3 W 1 / 3 ) 0.01 Ti 0.99 The stoichiometric amount of O2 was 0.3797 g of Bi2O3 (purity 99.99%), 0.1893 g of WO3 (purity 99.80%), and 19.4311 g of rutile TiO2 (purity 99.5%). The raw materials were weighed and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The total mass ratio of anhydrous ethanol to the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours. The zirconium balls were separated. The raw materials after ball milling were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. The other steps were the same as in Example 1 to obtain BiW co-doped rutile titanium dioxide ceramic material (Bi 2 / 3 W 1 / 3 ) 0.01 Ti 0.99 O2.

[0036] Example 4

[0037] In step 1 of this embodiment, according to (Bi 2 / 3 W 1 / 3 ) 0.0125 Ti 0.9875The stoichiometric amount of O2 was 0.4724 g of Bi2O3 (purity 99.99%), 0.2355 g of WO3 (purity 99.80%), and 19.1545 g of rutile TiO2 (purity 99.5%). The raw materials were weighed and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The total mass ratio of anhydrous ethanol to the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours. The zirconium balls were separated. The raw materials after ball milling were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. The other steps were the same as in Example 1 to obtain BiW co-doped rutile titanium dioxide ceramic material (Bi 2 / 3 W 1 / 3 ) 0.0125 Ti 0.9875 O2.

[0038] Example 5

[0039] In step 1 of this embodiment, according to (Y 2 / 3 W 1 / 3 ) 0.005 Ti 0.995 The stoichiometric amount of O2 was 0.0933 g of Y2O3 (purity 99.99%), 0.0960 g of WO3 (purity 99.80%), and 19.8107 g of rutile TiO2 (purity 99.5%). The raw materials were weighed and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The total mass ratio of anhydrous ethanol to the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours. The zirconium balls were separated. The raw materials after ball milling were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. The other steps were the same as in Example 1 to obtain a YW co-doped rutile titanium dioxide ceramic material (Y 2 / 3 W 1 / 3 ) 0.005 Ti 0.995 O2.

[0040] Example 6

[0041] In step 1 of this embodiment, according to (Y 2 / 3 W 1 / 3 ) 0.01 Ti 0.99The stoichiometric amount of O2 was 0.1858 g of Y2O3 (purity 99.99%), 0.1911 g of WO3 (99.80%), and 19.6230 g of rutile TiO2 (purity 99.5%). The raw materials were weighed and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The total mass ratio of anhydrous ethanol to the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours. The zirconium balls were separated. The raw materials after ball milling were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. The other steps were the same as in Example 1 to obtain a YW co-doped rutile titanium dioxide ceramic material (Y 2 / 3W 1 / 3 ) 0.01 Ti 0.99 O2.

[0042] Example 7

[0043] In step 1 of this embodiment, according to (Ga 2 / 3 W 1 / 3 ) 0.005 Ti 0.995 The raw materials Ga2O3 (purity 99.99%), WO3 (purity 99.80%), and rutile TiO2 (purity 99.5%) were weighed and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as the grinding medium. The ratio of anhydrous ethanol to the total mass of the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours. The zirconium balls were separated. The ball milled raw materials were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. In step 3 of the present embodiment, the temperature was first increased to 1000°C in a tube furnace under nitrogen atmosphere and airtight conditions in 100 minutes, then increased to 1450°C at a heating rate of 2°C / minute, kept warm for 5 hours, and naturally cooled to room temperature with the furnace. The other steps are the same as those in Example 1 to obtain GaW co-doped rutile titanium dioxide ceramic material (Ga 2 / 3 W 1 / 3 ) 0.005 Ti 0.995 O2.

[0044] Example 8

[0045] In step 1 of this embodiment, according to (Ga 2 / 3 W 1 / 3 ) 0.01 Ti 0.99The stoichiometric amount of O2 was respectively weighed as follows: 0.1541 g of Ga2O3 (purity 99.99%), 0.1909 g of WO3 (purity 99.80%), and 19.6550 g of rutile TiO2 (purity 99.5%), and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as ball milling media. The total mass ratio of anhydrous ethanol to the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours, the zirconium balls were separated, and the ball milled raw materials were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. The other steps were the same as in Example 1 to obtain GaW co-doped rutile titanium dioxide-based ceramic material (Ga 2 / 3 W 1 / 3 ) 0.01 Ti 0.99 O2.

[0046] Example 9

[0047] In step 1 of this embodiment, according to (Ga 2 / 3 W 1 / 3 ) 0.02 Ti 0.98 The stoichiometric amount of O2 was respectively weighed as follows: 0.3037 g of Ga2O3 (purity 99.99%), 0.3764 g of WO3 (purity 99.80%), and 19.3199 g of rutile TiO2 (purity 99.5%), and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The total mass ratio of anhydrous ethanol to the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours, the zirconium balls were separated, and the ball milled raw materials were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. The other steps were the same as in Example 1 to obtain GaW co-doped rutile titanium dioxide ceramic material (Ga 2 / 3 W 1 / 3 ) 0.02 Ti 0.98 O2.

[0048] Example 10

[0049] In step 1 of this embodiment, according to (Ga 2 / 3 W 1 / 3 ) 0.4 Ti 0.96The stoichiometric amount of O2 was respectively weighed as follows: 0.5888 g of Ga2O3 (purity 99.99%), 0.7297 g of WO3 (purity 99.80%), and 18.6814 g of rutile TiO2 (purity 99.5%), and placed in a nylon jar. Zirconium balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The total mass ratio of anhydrous ethanol to the raw materials was 1:1.2. The raw materials were ball milled at 401 rpm for 24 hours, the zirconium balls were separated, and the ball milled raw materials were dried at 80°C for 24 hours and ground in a mortar for 30 minutes to obtain a raw material mixture. The other steps were the same as in Example 1 to obtain GaW co-doped rutile titanium dioxide ceramic material (Ga 2 / 3 W 1 / 3 ) 0.4 Ti 0.96 O2.

[0050] The ceramic material prepared in the above example was polished to a thickness of 0.7-0.8 mm using 1000-, 1500-, and 2000-grit sandpaper, respectively. Silver paste was then applied to the upper and lower surfaces of the ceramic to a thickness of 0.01-0.03 mm. The ceramic was then placed in a resistance furnace at 840°C for 30 minutes. The dielectric properties of the ceramic were tested using a Cuilient 4294A precision impedance analyzer and an E4980A LCR meter.

[0051] The ceramic materials prepared in Examples 1 to 4 (Bi 2 / 3 W 1 / 3 ) x Ti 1-x The electrical properties of O2 (x = 0.005, 0.0075, 0.01, 0.0125) are shown in Table 1. The curves of dielectric constant and dielectric loss changing with test frequency are shown in Table 1. Figure 1 The relationship between the capacitance change rate of the ceramic material prepared in Example 3 at different frequencies and the test temperature is shown in FIG. Figure 2 shown.

[0052] Table 1 Electrical properties of ceramic materials of Examples 1 to 4 at room temperature

[0053]

[0054] The ceramic materials (Y 2 / 3 W 1 / 3 ) x Ti 1-x The electrical properties of O2 (x = 0.005, 0.01) are shown in Table 2. The curves of dielectric constant and dielectric loss changing with test frequency are shown in Table 2. Figure 3 The relationship between the capacitance change rate of the ceramic material prepared in Example 5 at different frequencies and the test temperature is shown in FIG. Figure 4 shown.

[0055] Table 2 Electrical properties of ceramic materials of Examples 5 to 6 at room temperature

[0056]

[0057] The ceramic materials prepared in Examples 7 to 10 (Ga 2 / 3 W 1 / 3 ) x Ti 1-x The electrical properties of O2 (x = 0.005, 0.01, 0.02, 0.04) are shown in Table 3. The curves of dielectric constant and dielectric loss changing with test frequency are shown in Table 3. Figure 5 The relationship between the capacitance change rate of the ceramic material prepared in Example 9 at different frequencies and the test temperature is shown in FIG. Figure 6 shown.

[0058] Table 3 Electrical properties of ceramic materials of Examples 7 to 10 at room temperature

[0059]

[0060] Combined with the results listed in Tables 1 to 3 and Figures 1 to 6 It can be seen that the three hexavalent ion co-doped rutile titanium dioxide ceramic materials prepared in the above examples have obvious advantages in dielectric constant, dielectric loss and temperature stability among similar high dielectric constant dielectric materials. When the test frequency is 1kHz, the dielectric constants of the ceramic materials prepared in Examples 1 to 4 are 15212, 18245, 15744, and 14935, respectively, and the dielectric loss is 0.073, 0.094, 0.070, and 0.075, respectively, while the frequency is 10 2 ~10 4 The dielectric loss in the Hz range is always kept below 0.1, meeting the low loss requirement of ceramic materials. In order to further prove the thermal stability of the prepared ceramic materials, the capacitance change rate of the ceramic materials was calculated. The dielectric constant of the ceramic materials prepared in Example 3 at different frequencies in the range of -55 to 150 ° C is mainly concentrated between 13000 and 16000, and its temperature change rate is -15% to 15%, meeting the application requirements of X9R ceramic capacitors; the dielectric constants of the ceramic materials prepared in Examples 5 and 6 are 18470 and 14890 respectively, and the dielectric loss is 0.03 and 0.05 respectively, while the frequency is 10 2 ~10 5The dielectric loss in the Hz range is always maintained below 0.07, meeting the low loss requirements of ceramic materials. The dielectric constant of the ceramic material prepared in Example 5 is mainly concentrated between 14000 and 16000 in the range of -55 to 150 ° C at different frequencies, and the capacitance change rate is maintained between 4% and 10% at 1kHz and between -3% and 3% at 10kHz, which all meet the application requirements of X9P (±10%) ceramic capacitors. The dielectric constants of the ceramic materials prepared in Examples 8 to 10 are 9853, 10139, and 10871, respectively, and the dielectric loss is 0.031, 0.018, and 0.024, respectively, and the frequency is 10 2 ~10 5 The dielectric loss within the Hz range is consistently maintained below 0.035, meeting the low-loss requirements for ceramic materials. Furthermore, the dielectric constant of the ceramic material prepared in Example 9 is primarily concentrated between 11,000 and 16,000 at different frequencies within the range of -55°C to 150°C, with a temperature variation rate of -15% to 15%, meeting the application requirements for X8R ceramic capacitors.

Claims

1. A high dielectric, low loss, temperature-stable trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material, characterized by: The general formula of the ceramic material is (A 2 / 3 W 1 / 3 ) x Ti 1-x O2, where A represents any one of Bi, Y, and Ga, and the value of x is 0.005 to 0.04; The preparation method of the ceramic material comprises the following steps: Step 1: Follow (A 2 / 3 W 1 / 3 ) x Ti 1-x For the stoichiometric measurement of O2, raw materials WO3, rutile TiO2, and A2O3 with a purity of more than 99.5% are weighed separately for mixing, wherein A represents any one of Bi, Y, and Ga, and the mixture is thoroughly mixed and ball-milled for 16 to 24 hours, and dried at 80 to 100°C for 12 to 24 hours to obtain a raw material mixture; Step 2: Pre-calcining the raw material mixture at 1000-1100° C. for 2-4 hours to obtain pre-calcined powder; Step 3: After granulation, tableting and binder removal, the pre-fired powder is sintered at 1350-1450° C. for 5-15 hours in a nitrogen atmosphere and sealed conditions to obtain a trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material.

2. The high dielectric, low loss, temperature stable trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material according to claim 1, characterized in that: Where A represents Bi and the value of x is 0.

01.

3. The high dielectric, low loss, temperature stable trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material according to claim 1, characterized in that: Where A represents Ga and the value of x is 0.

02.

4. The high dielectric, low loss, temperature stable trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material according to claim 1, characterized in that: Where A represents Y and the value of x is 0.

005.

5. The high dielectric, low loss, temperature stable trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material according to claim 1, characterized in that: In step 2, the raw material mixture is heated to 1000° C. at a heating rate of 2 to 5° C. / min and pre-calcined at the constant temperature for 3 hours.

6. The high dielectric, low loss, temperature stable trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material according to claim 1, characterized in that: In step 3, the tableting is performed by using a powder tablet press at a pressure of 6 to 10 MPa for 3 to 6 minutes to form a cylindrical green body.

7. The high dielectric, low loss, temperature stable trivalent and hexavalent ion co-doped rutile titanium dioxide ceramic material according to claim 1, characterized in that: In step 3, under nitrogen atmosphere and sealed conditions, the temperature is first raised to 1000° C. in 100 minutes, then raised to 1400° C. at a heating rate of 2 to 4° C. / min, and kept at this temperature for 5 to 15 hours.

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