High dielectric constant material and preparation method thereof, and capacitor

Abstract

The invention relates to the field of material preparation, and discloses a high-dielectric-constant material, a preparation method thereof and a capacitor, and the method comprises the steps: mixing and grinding a base material, tantalum pentoxide and lanthanum trioxide to obtain a powder material; wherein the base material is a dielectric material containing titanium, and the valence of titanium ions is positive 4; the powder material is sintered, so that the base material is doped with lanthanum ions and tantalum ions, and the new dielectric material is obtained. As the valence of titanium ions in the matrix material is positive tetravalent, the doped lanthanum ions are positive trivalent, and the doped tantalum ions are positive pentavalent, the valence difference exists between the lanthanum ions and the positive tetravalent titanium ions as well as between the tantalum ions and the positive tetravalent titanium ions, after the lanthanum ions and the tantalum ions are introduced, electronic defects are formed in crystal lattices, local electrons are generated, and the local electrons are generated. Local electrons cause the change of the polarity in the matrix material, so that the dielectric constant is greatly improved, and the dielectric constant of the new dielectric material is greater than 104.

Description

Technical Field

[0001] This application relates to the field of materials preparation, and in particular to a high dielectric constant material and its preparation method, and a capacitor. Background Technology

[0002] The dielectric constant is a core data point describing the polarization ability and energy storage ability of dielectric materials (insulators) in an electric field. The larger the dielectric constant, the more electrostatic energy the material can store when used as a dielectric, and the stronger its weakening effect on the electric field.

[0003] Materials with high dielectric constants are widely used in capacitors. With the development of microelectronics technology, capacitors, as a key basic component of the microelectronics industry, need to achieve higher storage density in a smaller volume. The core of their performance lies in the dielectric properties of the filling dielectric material. Therefore, the preparation of materials with high dielectric constants is crucial. Titanium dioxide (TiO2) is an important dielectric material with a high dielectric constant of around 100. However, for high-performance capacitors, the dielectric constant of titanium dioxide is still insufficient.

[0004] Therefore, how to obtain materials with higher dielectric constants should be a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a high dielectric constant material, a method for preparing the same, and a capacitor, so as to obtain a dielectric material with an even higher dielectric constant.

[0006] To solve the above-mentioned technical problems, this application provides a method for preparing a high dielectric constant material, comprising: A matrix material, tantalum pentoxide, and lanthanum trioxide are mixed and ground to obtain a powder material; wherein the matrix material is a dielectric material containing titanium, and the titanium ions have a valence of +4. The powder material is sintered to dope the matrix material with lanthanum and tantalum ions, resulting in a new dielectric material.

[0007] As an alternative, when the matrix material is titanium dioxide, the powder material is sintered to dope the matrix material with lanthanum ions and tantalum ions, including: The powder material is placed in a sintering furnace and heated from room temperature to a target temperature in an air atmosphere and held at that temperature, so that the titanium dioxide is doped with lanthanum ions and tantalum ions; wherein the target temperature ranges from 1350 degrees Celsius to 1450 degrees Celsius, and the holding time ranges from 6 hours to 10 hours.

[0008] As an alternative approach, when the matrix material is titanium dioxide, the matrix material, tantalum pentoxide, and lanthanum trioxide are mixed and ground to obtain a powder material comprising: Weigh the matrix material, tantalum pentoxide, and lanthanum trioxide according to the molar ratio of titanium ions: tantalum ions: lanthanum ions = (1-mn):m:n; wherein the sum of m and n is greater than or equal to 0.005 and less than or equal to 0.03. The weighed matrix material, tantalum pentoxide and lanthanum trioxide are placed in a ball mill jar and ball milled with deionized water as the grinding medium to obtain a slurry containing powder materials. The slurry is dried to obtain a dried slurry; The dried slurry is ground and sieved to obtain the powder material.

[0009] Alternatively, the molar ratio of the tantalum ions to the lanthanum ions may be equal.

[0010] Alternatively, the molar ratio of the tantalum ions and the lanthanum ions may not be equal.

[0011] As an alternative method, before sintering the powder material to dope the matrix material with lanthanum and tantalum ions, the process further includes: A binder is added to the powder material and mixed evenly to obtain a mixed powder material; The mixed powder material is sieved to obtain the sieved mixed material; The sieved powder material is granulated to obtain a granulated mixed material; The granulated mixture is pressed into a compact using a tablet press to obtain a block-shaped powder material; Sintering the powder material to dope the matrix material with lanthanum and tantalum ions includes: The bulk powder material is heated in an air atmosphere from room temperature to an intermediate temperature and held at that temperature to remove the binder from the bulk powder material. The bulk powder material is heated from an intermediate temperature to a target temperature and held at that temperature, so that the matrix material is doped with lanthanum ions and tantalum ions.

[0012] As an alternative, adding a binder to the powder material and mixing it uniformly includes: Add paraffin wax to the powder material and mix thoroughly.

[0013] As an alternative method, adding paraffin wax to the powder material and mixing it evenly includes: Paraffin wax is added to the powder material and mixed evenly, wherein the weight of the paraffin wax is 6% to 8% of the weight of the powder material.

[0014] This application also provides a high dielectric constant material, which is prepared by any of the above-described methods for preparing high dielectric constant materials.

[0015] This application also provides a capacitor comprising the high dielectric constant material described above.

[0016] The method for preparing high dielectric constant materials provided in this application involves mixing and grinding a matrix material, tantalum pentoxide, and lanthanum trioxide to obtain a powder material. The powder material is then sintered to dope the matrix material with lanthanum and tantalum ions, resulting in a new dielectric material. Since the matrix material is a titanium-containing dielectric material with a +4 valence, while the doped lanthanum ions are +3 and tantalum ions are +5, there is a valence difference between the lanthanum and tantalum ions and the +4 titanium ions. When these two dopants are introduced, electronic defects are formed within the crystal lattice, generating localized electrons. These localized electrons cause a change in the polarity within the matrix material, thereby significantly increasing the dielectric constant, resulting in a dielectric constant greater than 10 for the new dielectric material. 4 .

[0017] In addition, this application also provides a high dielectric constant material and a capacitor having the above-mentioned advantages. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The process of preparing a high dielectric constant material provided in the embodiments of this application Figure 1 ; Figure 2 The process of preparing a high dielectric constant material provided in the embodiments of this application Figure 2 ; Figure 3 The process of preparing a high dielectric constant material provided in the embodiments of this application Figure 3 ; Figure 4 The process of preparing a high dielectric constant material provided in the embodiments of this application Figure 4 . Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] As described in the background section, current high dielectric constant materials cannot meet the requirements of high-performance capacitors.

[0023] In view of this, this application provides a method for preparing a high dielectric constant material, please refer to... Figure 1 The method may include: Step S101: Mix and grind the matrix material, tantalum pentoxide and lanthanum trioxide to obtain a powder material; wherein the matrix material is a dielectric material containing titanium, and the valence of titanium ions is positive tetravalent.

[0024] It should be noted that this application does not limit the type of matrix material, and users may choose their own.

[0025] For example, the matrix material can be titanium dioxide, strontium titanate (SrTiO3), or barium titanate (BaTiO3), etc.

[0026] Tantalum pentoxide (Ta2O5) is a white microcrystalline powder, in which the tantalum ion has a valence of +5.

[0027] Lanthanum trioxide (La2O3) is a compound formed by lanthanum and oxygen. It is a white powder in which the lanthanum ion has a positive oxidation state of +3.

[0028] The matrix material, tantalum pentoxide, and lanthanum trioxide can be placed in a container for grinding. This application does not limit the grinding method, as long as the matrix material, tantalum pentoxide, and lanthanum trioxide can be ground into powder.

[0029] Step S102: Sinter the powder material to dope the matrix material with lanthanum ions and tantalum ions, thereby obtaining a new dielectric material.

[0030] The sintering of the powder material in this step can be carried out in a muffle furnace. The sintering temperature depends on the specific circumstances and is not specifically limited in this application. Sintering is carried out at a high temperature. During the sintering process, lanthanum ions (La...) 3+ ) and tantalum ions (Ta 5+ When two doped ions enter the crystal lattice of the matrix material, they form electronic defects inside the lattice and generate localized electrons. These localized electrons cause a change in the polarity inside the matrix material, resulting in a significant change in the dielectric constant.

[0031] The new matrix material is a matrix material doped with lanthanum ions and tantalum ions.

[0032] The method for preparing the high dielectric constant material provided in this embodiment involves mixing and grinding a matrix material, tantalum pentoxide, and lanthanum trioxide to obtain a powder material. The powder material is then sintered to dope the matrix material with lanthanum and tantalum ions, resulting in a new dielectric material. Since the matrix material is a titanium-containing dielectric material with a +4 valence, and the doped lanthanum ions have a +3 valence and the tantalum ions have a +5 valence, there is a valence difference between the lanthanum and tantalum ions and the +4 valence titanium ions. When these two dopants are introduced, electronic defects are formed within the crystal lattice, generating localized electrons. These localized electrons cause a change in the polarity within the matrix material, thereby significantly increasing the dielectric constant, resulting in a dielectric constant greater than 10 for the new dielectric material. 4 .

[0033] Please refer to Figure 2 When the matrix material is titanium dioxide, based on the above embodiments, in one embodiment of this application, the method for preparing the high dielectric constant material may include: Step S201: Mix and grind titanium dioxide, tantalum pentoxide and lanthanum trioxide to obtain powder material.

[0034] Step S202: Place the powder material in a sintering furnace, heat it from room temperature to the target temperature in an air atmosphere and hold it at that temperature, so that the titanium dioxide is doped with lanthanum ions and tantalum ions; wherein the target temperature ranges from 1350 degrees Celsius to 1450 degrees Celsius, and the holding time ranges from 6 hours to 10 hours.

[0035] If the target temperature is less than 1350 degrees Celsius, the reaction between lanthanum and tantalum ions and titanium dioxide will be insufficient, and the lanthanum and tantalum ions will not be able to form good electronic defects inside the crystal lattice, thus affecting the dielectric constant of the new dielectric material; if the target temperature is greater than 1450 degrees Celsius, impurity phases will be generated, affecting the performance.

[0036] It should be noted that this application does not specify a target temperature; it depends on the specific circumstances.

[0037] For example, the target temperature could be 1350 degrees Celsius, or 1400 degrees Celsius, or 1450 degrees Celsius, etc.

[0038] If the heat preservation time is less than 6 hours, the reaction between lanthanum and tantalum ions and titanium dioxide will be insufficient, and lanthanum and tantalum ions will not be able to form good electronic defects inside the crystal lattice, thus affecting the dielectric constant of the new dielectric material; if the heat preservation time is greater than 10 hours, it will waste energy and cause unnecessary losses.

[0039] It should be noted that this application does not specify a particular time for heat preservation; it depends on the specific circumstances.

[0040] For example, the heat preservation time can be 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours, etc.

[0041] It should also be noted that this application does not limit the heating rate to the target temperature, which depends on the specific sintering furnace. However, it is important to avoid heating too quickly, as this can lead to an increase in impurities within the new dielectric material, affecting its performance.

[0042] Please refer to Figure 3 When the matrix material is titanium dioxide, based on any of the above embodiments, in one embodiment of this application, the method for preparing the high dielectric constant material may include: Step S301: Weigh the matrix material, tantalum pentoxide and lanthanum trioxide respectively according to the molar ratio of titanium ions: tantalum ions: lanthanum ions = (1-mn):m:n, where the sum of m and n is greater than or equal to 0.005 and less than or equal to 0.03.

[0043] In this embodiment, the sum of m and n is set to be greater than or equal to 0.005 and less than or equal to 0.03 because: when the sum of m and n is less than 0.005, the increase in dielectric constant of the new dielectric material formed after doping is not significant; when the sum of m and n is greater than 0.03, the dielectric loss of the new dielectric material formed after doping increases. Therefore, in this embodiment, the sum of m and n is set to be greater than or equal to 0.005 and less than or equal to 0.03.

[0044] It should be noted that this application does not limit the molar ratio of tantalum ions to lanthanum ions; the specific ratio can be set by the applicant.

[0045] Step S302: Place the weighed matrix material, tantalum pentoxide and lanthanum trioxide into a ball mill jar and ball mill them with deionized water as the grinding medium to obtain a slurry containing powder materials.

[0046] In this embodiment, a planetary ball mill can be used for ball milling. The planetary ball mill has the characteristics of high rotation speed, fine grinding and high efficiency when ball milling.

[0047] When using a planetary ball mill for ball milling, zirconium balls can be used. Zirconium balls have a high density, resulting in higher grinding efficiency. They can grind powder materials into finer particles and cause minimal contamination, thus achieving high purity of the powder materials.

[0048] In this embodiment, the purpose of adding deionized water to the ball mill jar is twofold: First, deionized water has the function of cooling and preventing overheating, because ball milling generates a large amount of heat. Water has a high heat capacity and absorbs heat quickly, which can prevent problems such as overheating, phase change, oxidation, and sticking of powder materials. Second, deionized water has the function of lubrication and buffering, making it easier for powder materials to be ground and dispersed. Furthermore, after ball milling, the discharge is smoother and easier to clean the ball mill jar.

[0049] The weight ratio of ionized water, zirconium spheres, and powder material can be 2:1:1. Of course, the weight ratio of ionized water, zirconium spheres, and powder material can also be adjusted according to the actual situation.

[0050] It should be noted that this application does not specify a particular time for ball milling the powder material, but rather determines the required fineness of the powder material. For example, the ball milling time can be 6 hours, 8 hours, or 12 hours, etc.

[0051] After grinding is complete, the small balls used in the ball mill are sieved out to obtain a slurry containing powder materials.

[0052] Step S303: Dry the slurry to obtain the dried slurry.

[0053] Because deionized water is added during ball milling, the slurry containing powder materials needs to be dried to remove moisture.

[0054] This application does not limit the drying temperature of the slurry containing powder materials; it can be set by the user. For example, the slurry containing powder materials can be dried at a temperature of 200 degrees Celsius to quickly remove moisture from the slurry.

[0055] Step S304: Grind and dry the slurry and sieve it to obtain powder material.

[0056] After the slurry containing powder materials is dried, the powder materials may clump together. Therefore, the dried slurry needs to be ground again and sieved to obtain uniform powder materials.

[0057] It should be noted that the mesh size of the sieve used in this step is not limited in this embodiment, and depends on the specific circumstances. For example, after the dried slurry is ground again, a 40-mesh sieve is used for sieving.

[0058] Step S305: Place the powder material in a sintering furnace, heat it from room temperature to the target temperature in an air atmosphere and hold it at that temperature, so that the titanium dioxide is doped with lanthanum ions and tantalum ions; wherein the target temperature ranges from 1350 degrees Celsius to 1450 degrees Celsius, and the holding time ranges from 6 hours to 10 hours.

[0059] It should be noted that step S305 in this embodiment can refer to step S202 in the above embodiment, and will not be described in detail here.

[0060] When the matrix material is titanium dioxide, based on any of the above embodiments, in one embodiment of this application, the method for preparing the high dielectric constant material may include: Step S401: Weigh the matrix material, tantalum pentoxide, and lanthanum trioxide according to the molar ratio of titanium ions: tantalum ions: lanthanum ions = (1-mn):m:n, where the sum of m and n is greater than or equal to 0.005 and less than or equal to 0.03, and the molar ratio of tantalum ions and lanthanum ions is equal.

[0061] In this embodiment, the molar ratio of tantalum ions and lanthanum ions is equal, that is, m and n are equal. Since the molar ratio of tantalum ions and lanthanum ions is equal, it is convenient to calculate the molar amount of titanium ions.

[0062] Step S402: Place the weighed matrix material, tantalum pentoxide and lanthanum trioxide into a ball mill jar and ball mill them with deionized water as the grinding medium to obtain a slurry containing powder materials.

[0063] Step S403: Dry the slurry to obtain the dried slurry.

[0064] Step S404: Grind and dry the slurry and sieve it to obtain powder material.

[0065] Step S405: Place the powder material in a sintering furnace, heat it from room temperature to the target temperature in an air atmosphere and hold it at that temperature, so that the titanium dioxide is doped with lanthanum ions and tantalum ions; wherein the target temperature ranges from 1350 degrees Celsius to 1450 degrees Celsius, and the holding time ranges from 6 hours to 10 hours.

[0066] It should be noted that steps S402 to S405 in this embodiment can refer to steps S302 to S305 in the above embodiment, and will not be described in detail here.

[0067] When the matrix material is titanium dioxide, based on any of the above embodiments, in one embodiment of this application, the method for preparing the high dielectric constant material may include: Step S501: Weigh the matrix material, tantalum pentoxide, and lanthanum trioxide according to the molar ratio of titanium ions: tantalum ions: lanthanum ions = (1-mn):m:n, where the sum of m and n is greater than or equal to 0.005 and less than or equal to 0.03, and the molar ratio of tantalum ions and lanthanum ions is not equal.

[0068] In this embodiment, the molar ratio of tantalum ions and lanthanum ions is not equal, that is, m and n are not equal. Because the molar ratio of tantalum ions and lanthanum ions is not equal, the setting of the molar amounts of tantalum ions and lanthanum ions is more flexible.

[0069] Step S502: Place the weighed matrix material, tantalum pentoxide and lanthanum trioxide into a ball mill jar and ball mill them with deionized water as the grinding medium to obtain a slurry containing powder materials.

[0070] Step S503: Dry the slurry to obtain the dried slurry.

[0071] Step S504: Grind and dry the slurry and sieve it to obtain powder material.

[0072] Step S505: Place the powder material in a sintering furnace, heat it from room temperature to the target temperature in an air atmosphere and hold it at that temperature, so that the titanium dioxide is doped with lanthanum ions and tantalum ions; wherein the target temperature ranges from 1350 degrees Celsius to 1450 degrees Celsius, and the holding time ranges from 6 hours to 10 hours.

[0073] It should be noted that steps S502 to S505 in this embodiment can refer to steps S302 to S305 in the above embodiment, and will not be described in detail here.

[0074] Based on any of the above embodiments, in one embodiment of this application, the method for preparing a high dielectric constant material may include: Step S601: Mix and grind the matrix material, tantalum pentoxide and lanthanum trioxide to obtain a powder material; wherein the matrix material is a dielectric material containing titanium, and the valence of titanium ions is positive tetravalent.

[0075] It should be noted that step S601 in this embodiment can refer to step S101 in the above embodiment, and will not be described in detail here.

[0076] Step S602: Add a binder to the powder material and mix evenly to obtain a mixed powder material.

[0077] The function of a binder is to bind powder materials together and improve their adhesion. After the binder is added to the powder material, it needs to be thoroughly mixed to ensure uniformity.

[0078] It should be noted that this application does not limit the type of binder and can be selected at will, as long as it has a binding effect and can be removed from the blocky powder material by heating.

[0079] Step S603: Sieve the mixed powder material to obtain the sieved mixed material.

[0080] It should be noted that in this embodiment, the mesh size of the sieve used when sieving the mixed powder is not limited, and it depends on the specific situation.

[0081] For example, the mixed powder is sieved using an 80-mesh sieve. The larger mesh size of the sieve used in this step indicates that the particle size of the mixed material is relatively fine after sieving, which facilitates better formation of blocky powder material during subsequent compaction.

[0082] Step S604: Granulate the sieved powder material to obtain the granulated mixed material.

[0083] Granulation involves turning finely sieved powder into small granules, which has the following advantages: First, it improves the flowability of the sieved powder material, making it easier to load and uniformly during compaction; second, it increases the compaction density, making the blocky powder material more compact and stronger; third, it prevents stratification, segregation, and porosity, thus improving the quality stability of new dielectric materials.

[0084] Step S605: Use a tablet press to compress the granulated mixed material into a compact to obtain a block powder material.

[0085] A certain mass of granulated mixed material can be weighed, and then the granulated mixed material can be transferred into a pressing mold and pressed into block powder material under certain pressure conditions.

[0086] It should be noted that the shape of the blocky powder material is not limited in this application and depends on the specific circumstances. For example, the shape of the blocky powder material can be a cylinder, cuboid, or cube, etc.

[0087] It should also be noted that the size of the blocky powder material is not limited in this application, but depends on the specific circumstances.

[0088] For example, 0.5 g of the granulated mixed material can be weighed and then transferred into a compact mold and pressed into a block powder material under a pressure of 2 MPa. The block powder material is cylindrical with a diameter of 10 mm and a thickness of 2 mm.

[0089] Step S606: In an air atmosphere, the bulk powder material is heated from room temperature to an intermediate temperature and held at that temperature to remove the binder from the bulk powder material.

[0090] The intermediate temperature is lower than the target temperature. The temperature is then raised to the intermediate temperature and held for a certain period to remove the binder from the bulk powder material. It should be noted that the intermediate temperature is not necessarily the midpoint between room temperature and the target temperature, but can be any temperature between them.

[0091] It should be noted that this application does not limit the magnitude of the intermediate temperature; it depends on the material of the adhesive.

[0092] It should also be noted that this application does not limit the holding time when the temperature is raised to the intermediate temperature; it depends on the specific circumstances.

[0093] Step S607: Continue heating the bulk powder material from the intermediate temperature to the target temperature and hold it at that temperature, so that the matrix material is doped with lanthanum ions and tantalum ions to obtain a new dielectric material.

[0094] It should be noted that step S607 in this embodiment can refer to step S102 in the above embodiment, and will not be described in detail here.

[0095] In this embodiment, by adding a binder to the powder material and mixing it evenly, and then sieving, granulating, and pressing the mixed powder material, a new block-shaped dielectric material can be obtained, which can meet the shape requirements of dielectric materials in different application scenarios. It also facilitates the measurement of the dielectric constant of the new dielectric material.

[0096] Please refer to Figure 4 Based on any of the above embodiments, in one embodiment of this application, the method for preparing a high dielectric constant material may include: Step S701: Mix and grind the matrix material, tantalum pentoxide and lanthanum trioxide to obtain a powder material; wherein the matrix material is a dielectric material containing titanium, and the valence of titanium ions is positive tetravalent.

[0097] It should be noted that step S701 in this embodiment can refer to step S601 in the above embodiment, and will not be described in detail here.

[0098] Step S702: Add paraffin wax to the powder material and mix evenly to obtain a mixed powder material.

[0099] In this embodiment, paraffin wax is used as a binder to bond the powder material and improve the adhesion between powder particles.

[0100] The reason for using paraffin wax as a binder in this embodiment is that paraffin wax is relatively easy to remove from the block powder material, reducing the binder residue in the block powder material; paraffin wax has a certain lubricating effect, which makes it easier for the block powder material to be demolded from the mold after pressing; paraffin wax can generate a small non-uniform microstructure inside the structure, enhance the internal polarization intensity, and improve the dielectric constant.

[0101] Step S703: Sieve the mixed powder material to obtain the sieved mixed material.

[0102] Step S704: Granulate the sieved powder material to obtain the granulated mixed material.

[0103] Step S705: Use a tablet press to compress the granulated mixed material into a compact to obtain a block powder material.

[0104] Step S706: In an air atmosphere, the block powder material is heated from room temperature to an intermediate temperature and held at that temperature to remove paraffin from the block powder material.

[0105] In this embodiment, paraffin wax is used as the adhesive, and the intermediate temperature range can be 500 degrees Celsius to 600 degrees Celsius.

[0106] For example, the intermediate temperature can be 500 degrees Celsius, or 530 degrees Celsius, or 550 degrees Celsius, or 5080 degrees Celsius, or 600 degrees Celsius, etc.

[0107] Step S707: Continue heating the bulk powder material, raising it from the intermediate temperature to the target temperature and holding it at that temperature, so that the matrix material is doped with lanthanum ions and tantalum ions, thus obtaining a new dielectric material.

[0108] It should be noted that steps S702 to S707 in this embodiment can refer to steps S602 to S607 in the above embodiment, and will not be described in detail here.

[0109] Based on any of the above embodiments, in one embodiment of this application, the method for preparing a high dielectric constant material may include: Step S801: Mix and grind the matrix material, tantalum pentoxide and lanthanum trioxide to obtain a powder material; wherein the matrix material is a dielectric material containing titanium, and the valence of titanium ions is +4.

[0110] It should be noted that step S801 in this embodiment can refer to step S601 in the above embodiment, and will not be described in detail here.

[0111] Step S802: Add paraffin wax to the powder material and mix evenly to obtain a mixed powder material, wherein the weight of paraffin wax is 6% to 8% of the weight of the powder material.

[0112] It should be noted that this application does not specify the amount of paraffin wax added when adding it to powder materials. For example, the finer the particle size of the powder material, the more paraffin wax needs to be added.

[0113] For example, when adding paraffin to a powder material, the weight of the paraffin can be 6%, 6.5%, 7%, 7.5%, or 8% of the weight of the powder material, etc.

[0114] When adding paraffin wax to powder materials, if the weight of paraffin wax is less than 6% of the weight of the powder material, i.e., the added weight of paraffin wax is relatively small, the following problems are likely to occur: First, the paraffin wax film on the surface of the powder particles is incomplete, and the powder particles are in direct contact. During compaction, the relative movement between the powder particles destroys the surface film, and the powder particles generate severe friction with the mold wall, resulting in a significant increase in extrusion pressure during pressing. Second, the huge additional internal stress generated by pressing cannot be effectively released, resulting in transverse cracks inside the block powder material obtained by pressing. The binder film is discontinuous, and the block powder material obtained by pressing is prone to local "dry powder" with no strength. The green block powder material obtained by pressing is brittle, prone to slag shedding and edge damage, resulting in poor strength of the block powder material obtained by pressing. Third, during sintering, local stress concentration may lead to uneven deformation of the new dielectric material after sintering.

[0115] If the weight of paraffin wax exceeds 8% of the weight of the powder material, meaning the added weight of paraffin wax is excessive, the following problems may occur: First, excessive paraffin wax forms a thick insulating layer between the powder particles. Although this can reduce the extrusion pressure during compaction, it severely weakens the direct bonding force between the powder particles, resulting in a lack of rigid skeleton in the compact and making the resulting blocky powder material too soft. Second, the higher the amount of paraffin wax added, the lower the resistance to damage (tensile strength, flexural strength) of the resulting blocky powder material, making it prone to deformation when handled. Third, during sintering, a large amount of paraffin wax liquefies per unit time, and the excess paraffin wax melts and flows away, carrying away the surface powder particles of the blocky powder material, forming pores or flow marks. In the early stages of sintering, the softened paraffin wax causes the compact to lose support and is prone to collapse under gravity. The volatilization of a large amount of paraffin wax requires a slower heating curve, leading to a longer sintering time; otherwise, bubbling is likely to occur.

[0116] Step S803: Sieve the mixed powder material to obtain the sieved mixed material.

[0117] Step S804: Granulate the sieved powder material to obtain the granulated mixed material.

[0118] Step S805: Use a tablet press to compress the granulated mixed material into a compact to obtain a block powder material.

[0119] Step S806: In an air atmosphere, the block powder material is heated from room temperature to an intermediate temperature and held at that temperature to remove paraffin from the block powder material.

[0120] Step S807: Continue heating the bulk powder material from the intermediate temperature to the target temperature and hold it at that temperature, so that the matrix material is doped with lanthanum ions and tantalum ions to obtain a new dielectric material.

[0121] It should be noted that steps S802 to S807 in this embodiment can refer to steps S602 to S607 in the above embodiment, and will not be described in detail here.

[0122] The following section uses titanium dioxide as the matrix material as an example to introduce the preparation method of the high dielectric constant material in this application under different conditions.

[0123] Example 1

[0124] Step 1: Select an electronic balance as the weighing tool, and accurately weigh the titanium dioxide, tantalum pentoxide and lanthanum trioxide according to the molar ratio of titanium dioxide: tantalum pentoxide: lanthanum trioxide = 0.995: 0.00125: 0.00125 to obtain the mixed powder material.

[0125] Step 2: Place the weighed titanium dioxide, tantalum pentoxide and lanthanum trioxide into a ball mill jar. Weigh the deionized water, zirconium balls and mixed powder materials in a weight ratio of 2:1:1. Then place the deionized water and zirconium balls into the ball mill jar.

[0126] Step 3: Use a planetary ball mill to ball mill the powder material for 6 hours to obtain a slurry containing the powder material.

[0127] Step 4: Dry the slurry and pass it through a 40-mesh sieve to obtain the dried powder material.

[0128] Step 5: Add 8% by weight of paraffin to the dried powder material, mix well and stir-fry to obtain a mixed powder material.

[0129] Step 6: Pass the mixed powder material through an 80-mesh sieve to obtain the sieved mixed material, and granulate the sieved mixed material to obtain the granulated mixed material.

[0130] Step 7: Accurately weigh 0.5g of the granulated mixture and press it into a Ф10mm×2mm round blank using a tablet press under a pressure of 2MPa.

[0131] Step 8: Place the circular green blank in a high-temperature muffle furnace and heat it from room temperature to 550 degrees Celsius in an air atmosphere for 210 minutes to remove the paraffin from the circular green blank; then continue to heat it to 1400 degrees Celsius and hold it for 10 hours. After sufficient sintering, a new dielectric constant material in the shape of a circular blank is obtained.

[0132] Example 2

[0133] Step 1: Select an electronic balance as the weighing tool, and accurately weigh the titanium dioxide, tantalum pentoxide and lanthanum trioxide according to the molar ratio of titanium dioxide: tantalum pentoxide: lanthanum trioxide = 0.97: 0.0075: 0.0075 to obtain the mixed powder material.

[0134] Step 2: Place the weighed titanium dioxide, tantalum pentoxide and lanthanum trioxide into a ball mill jar. Weigh the deionized water, zirconium balls and mixed powder materials in a weight ratio of 2:1:1. Then place the deionized water and zirconium balls into the ball mill jar.

[0135] Step 3: Use a planetary ball mill to ball mill the powder material for 12 hours to obtain a slurry containing the powder material.

[0136] Step 4: Dry the slurry and pass it through a 40-mesh sieve to obtain the dried powder material.

[0137] Step 5: Add 8% by weight of paraffin to the dried powder material, mix well and stir-fry to obtain a mixed powder material.

[0138] Step 6: Pass the mixed powder material through an 80-mesh sieve to obtain the sieved mixed material, and granulate the sieved mixed material to obtain the granulated mixed material.

[0139] Step 7: Accurately weigh 0.5g of the granulated mixture and press it into a Ф10mm×2mm round blank using a tablet press under a pressure of 2MPa.

[0140] Step 8: Place the circular green blank in a high-temperature muffle furnace and heat it from room temperature to 550 degrees Celsius in an air atmosphere for 210 minutes to remove the paraffin from the circular green blank; then continue to heat it to 1400 degrees Celsius and hold it for 10 hours. After sufficient sintering, a new dielectric constant material in the shape of a circular blank is obtained.

[0141] The dielectric constants of the new dielectric materials in Examples 1 and 2 are tested below.

[0142] Silver paste was uniformly coated on the upper and lower surfaces of the new dielectric constant materials in Examples 1 and 2. The new dielectric constant material in Example 1 was prepared by calcination at 700°C to form an electrode, and the new dielectric constant material in Example 2 was prepared by calcination at 840°C to form an electrode, and the sample to be tested was obtained. The capacitance of the two samples was measured using an Agilent 4990 precision impedance analyzer, and the dielectric constant of the sample was calculated using formula (1).

[0143] (1)

[0144] In the formula, Let C represent the dielectric constant of the sample, C represent the capacitance of the sample, d represent the thickness of the sample, and D represent the diameter of the sample.

[0145] The dielectric constants of the new dielectric materials in Examples 1 and 2 at room temperature are shown in Table 1.

[0146] Table 1

[0147] As shown in Table 1, the new dielectric constant materials prepared in Examples 1 and 2 are all greater than 10. 4 .

[0148] This application also provides a high dielectric constant material, which is prepared by the preparation method of the high dielectric constant material in any of the above embodiments.

[0149] In this embodiment, the high dielectric constant material is doped with lanthanum and tantalum ions. The matrix material of the high dielectric constant material is a titanium-containing dielectric material, and the titanium ion has a valence of +4. The doped lanthanum ions have a valence of +3, and the tantalum ions have a valence of +5. Therefore, there is a valence difference between the lanthanum and tantalum ions and the +4 titanium ions. When the two dopants, lanthanum and tantalum ions, are introduced, electronic defects are formed inside the crystal lattice, generating localized electrons. These localized electrons cause a change in the polarity inside the matrix material, thereby greatly increasing the dielectric constant, making the dielectric constant of the new dielectric material greater than 10. 4 .

[0150] This application also provides a capacitor comprising the high dielectric constant material of the above embodiments.

[0151] It should be noted that the structure of the capacitor is not described in detail in this application; however, relevant technologies can be consulted.

[0152] The dielectric material in the capacitor of this application is a high dielectric constant material (dielectric constant greater than 10). 4 This can improve the performance of capacitors, enabling them to have higher storage density.

[0153] The capacitors described in this application can be used in dynamic random access memory, filtering, coupling, and decoupling circuits in wearable devices, mobile communications, artificial intelligence, and cloud computing.

[0154] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0155] The high dielectric constant material, its preparation method, and the capacitor provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A method for preparing a high dielectric constant material, characterized in that, include: A matrix material, tantalum pentoxide, and lanthanum trioxide are mixed and ground to obtain a powder material; wherein the matrix material is a dielectric material containing titanium, and the titanium ions have a valence of +4. The powder material is sintered to dope the matrix material with lanthanum and tantalum ions, resulting in a new dielectric material.

2. The method for preparing the high dielectric constant material as described in claim 1, characterized in that, When the matrix material is titanium dioxide, the powder material is sintered to dope the matrix material with lanthanum ions and tantalum ions, including: The powder material is placed in a sintering furnace and heated from room temperature to a target temperature in an air atmosphere and held at that temperature, so that the titanium dioxide is doped with lanthanum ions and tantalum ions; wherein the target temperature ranges from 1350 degrees Celsius to 1450 degrees Celsius, and the holding time ranges from 6 hours to 10 hours.

3. The method for preparing the high dielectric constant material as described in claim 1, characterized in that, When the matrix material is titanium dioxide, the matrix material, tantalum pentoxide, and lanthanum trioxide are mixed and ground to obtain a powder material comprising: Weigh the matrix material, tantalum pentoxide, and lanthanum trioxide according to the molar ratio of titanium ions: tantalum ions: lanthanum ions = (1-mn):m:n; wherein the sum of m and n is greater than or equal to 0.005 and less than or equal to 0.

03. The weighed matrix material, tantalum pentoxide and lanthanum trioxide are placed in a ball mill jar and ball milled with deionized water as the grinding medium to obtain a slurry containing powder materials. The slurry is dried to obtain a dried slurry; The dried slurry is ground and sieved to obtain the powder material.

4. The method for preparing the high dielectric constant material as described in claim 3, characterized in that, The molar ratio of the tantalum ions and the lanthanum ions is equal.

5. The method for preparing the high dielectric constant material as described in claim 3, characterized in that, The molar ratio of the tantalum ions and the lanthanum ions is not equal.

6. The method for preparing the high dielectric constant material as described in claim 1, characterized in that, Before sintering the powder material to dope the matrix material with lanthanum and tantalum ions, the process further includes: A binder is added to the powder material and mixed evenly to obtain a mixed powder material; The mixed powder material is sieved to obtain the sieved mixed material; The sieved powder material is granulated to obtain a granulated mixed material; The granulated mixture is pressed into a compact using a tablet press to obtain a block-shaped powder material; Sintering the powder material to dope the matrix material with lanthanum and tantalum ions includes: The bulk powder material is heated in an air atmosphere from room temperature to an intermediate temperature and held at that temperature to remove the binder from the bulk powder material. The bulk powder material is heated from an intermediate temperature to a target temperature and held at that temperature, so that the matrix material is doped with lanthanum ions and tantalum ions.

7. The method for preparing the high dielectric constant material as described in claim 6, characterized in that, Adding a binder to the powder material and mixing it evenly includes: Add paraffin wax to the powder material and mix thoroughly.

8. The method for preparing the high dielectric constant material as described in claim 7, characterized in that, Adding paraffin wax to the powder material and mixing it evenly includes: Paraffin wax is added to the powder material and mixed evenly, wherein the weight of the paraffin wax is 6% to 8% of the weight of the powder material.

9. A high dielectric constant material, characterized in that, The high dielectric constant material is prepared by the preparation method of the high dielectric constant material as described in any one of claims 1 to 8.

10. A capacitor, characterized in that, Including the high dielectric constant material as described in claim 9.

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