CN117645475A - CaTiO (CaTiO) 3 -LaAlO 3 Basic microwave dielectric ceramic and preparation method thereof - Google Patents
CaTiO (CaTiO) 3 -LaAlO 3 Basic microwave dielectric ceramic and preparation method thereof Download PDFInfo
- Publication number
- CN117645475A CN117645475A CN202311682252.2A CN202311682252A CN117645475A CN 117645475 A CN117645475 A CN 117645475A CN 202311682252 A CN202311682252 A CN 202311682252A CN 117645475 A CN117645475 A CN 117645475A
- Authority
- CN
- China
- Prior art keywords
- ceramic
- catio
- laalo
- ceramic powder
- sintering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000919 ceramic Substances 0.000 title claims abstract description 368
- 238000002360 preparation method Methods 0.000 title claims description 43
- 239000000843 powder Substances 0.000 claims abstract description 172
- 239000013078 crystal Substances 0.000 claims abstract description 70
- 229910017682 MgTi Inorganic materials 0.000 claims abstract description 24
- 238000000498 ball milling Methods 0.000 claims description 67
- 238000001035 drying Methods 0.000 claims description 41
- 239000000463 material Substances 0.000 claims description 26
- 238000002156 mixing Methods 0.000 claims description 25
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 23
- 238000010438 heat treatment Methods 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 20
- 238000001354 calcination Methods 0.000 claims description 19
- 239000002994 raw material Substances 0.000 claims description 18
- 238000005245 sintering Methods 0.000 claims description 17
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 12
- 229910021193 La 2 O 3 Inorganic materials 0.000 claims description 12
- 238000003837 high-temperature calcination Methods 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000000853 adhesive Substances 0.000 claims description 6
- 230000001070 adhesive effect Effects 0.000 claims description 6
- 238000005303 weighing Methods 0.000 claims description 6
- 238000003825 pressing Methods 0.000 claims description 4
- 239000003054 catalyst Substances 0.000 claims description 3
- 238000000748 compression moulding Methods 0.000 claims description 3
- 229920001495 poly(sodium acrylate) polymer Polymers 0.000 claims description 3
- NNMHYFLPFNGQFZ-UHFFFAOYSA-M sodium polyacrylate Chemical compound [Na+].[O-]C(=O)C=C NNMHYFLPFNGQFZ-UHFFFAOYSA-M 0.000 claims description 3
- 229910052573 porcelain Inorganic materials 0.000 claims description 2
- 238000005469 granulation Methods 0.000 claims 1
- 230000003179 granulation Effects 0.000 claims 1
- 238000004891 communication Methods 0.000 abstract description 4
- 239000012071 phase Substances 0.000 description 46
- 239000008367 deionised water Substances 0.000 description 15
- 229910021641 deionized water Inorganic materials 0.000 description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 230000000052 comparative effect Effects 0.000 description 7
- 238000000227 grinding Methods 0.000 description 7
- 239000004677 Nylon Substances 0.000 description 5
- 239000004372 Polyvinyl alcohol Substances 0.000 description 5
- 238000000280 densification Methods 0.000 description 5
- 229920001778 nylon Polymers 0.000 description 5
- 229920002451 polyvinyl alcohol Polymers 0.000 description 5
- 238000001878 scanning electron micrograph Methods 0.000 description 5
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 238000009826 distribution Methods 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000003989 dielectric material Substances 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 238000007704 wet chemistry method Methods 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 1
- 229910008572 Li2O—B2O3-SiO2 Inorganic materials 0.000 description 1
- 229910008585 Li2O—B2O3—SiO2 Inorganic materials 0.000 description 1
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 239000011363 dried mixture Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Inorganic Insulating Materials (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
The invention provides a CaTiO 3 ‑LaAlO 3 The microwave dielectric ceramic comprises one or a combination of main crystal ceramic, doped phase or sintering-assisting ceramic powder; the main crystal ceramic is (1-x) CaTiO 3 ‑xLaAlO 3 X is more than or equal to 0.30 and less than or equal to 0.35; the doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 One or more of the ceramic powders. CaTiO in the invention 3 ‑LaAlO 3 The base microwave dielectric ceramic can be sintered at 1280-1400 ℃, has good compactness, excellent dielectric property, dielectric constant of 40-48, Q-xf value of 20000-38000 GHz, resonant frequency temperature coefficient of-10 ppm/DEGC,the microwave device has practical application value in the communication field.
Description
Technical Field
The invention belongs to the field of electronic ceramics and manufacturing thereof, in particular to a CaTiO 3 -LaAlO 3 A microwave dielectric ceramic and a preparation method thereof.
Background
Wireless communication in the 80 s of the 20 th centuryThe device gradually enters the commercial market and rapidly occupies the market. Particularly, in recent years, mobile communication technology is vigorously developed, microwave devices are developed towards miniaturization and integration, and more microwave dielectric materials are deeply researched and applied and popularized. The perovskite type microwave dielectric ceramic has the advantages of high quality factor, adjustable dielectric constant and temperature coefficient and the like, and has high application value. CaTiO 3 As a representative of the simple perovskite structure, has a high dielectric constant (. Epsilon.) r =170), but its resonant frequency temperature coefficient is large (τ f = +850ppm/°c), it is difficult to satisfy the conditions of commercial microwave ceramic materials. CaTiO 3 Crystal and LaAlO 3 The crystal has a similar ideal perovskite structure, moon et Al, "Singtering behavior and microwave dielectric properties of (Ca, la) (Ti, al) O 3 The term "ceramics" herein demonstrates that when 0.4 < x < 0.6, (1-x) CaTiO 3 -xLaAlO 3 Form a solid solution with a pseudo-cubic symmetrical structure, thus CaTiO 3 -LaAlO 3 The solid solution ceramic is expected to be a microwave dielectric material with excellent performance.
ATiO 3 -LnAlO 3 (A=Sr, ca, ln=Nd, la) has the advantages of low dielectric loss, adjustable dielectric constant, near zero resonant frequency temperature coefficient and the like, is a representative material in medium dielectric constant, and is widely applied to microwave devices such as dielectric antennas, dielectric filters, phase shifters and the like. The materials are firstly proposed by the soviet expert in the last 60 th century, and the preparation process and the electrical properties are reported, but no attention is paid at that time. In recent years, the multifunctionality of microwave dielectric ceramics is increasingly emphasized, and the materials are returned to the field of hot spot scientific research. More and more scholars have studied CaTiO 3 -LaAlO 3 The relationship between the chemical composition, crystal structure and microwave dielectric properties of the base dielectric ceramic, but CaTiO 3 -LaAlO 3 Ceramic sintering temperatures are typically above 1500 ℃, which is also an important factor limiting the application of such materials.
Although scholars have proposed the use of wet chemistry to prepare ultrafine powders to reduce CaTiO 3 -LaAlO 3 Sintering temperature of ceramic, but wet chemical process costHigh stability and low mass production. Synthesis of CaTiO in solid phase 3 -LaAlO 3 In the case of ceramics, li is introduced 2 O-B 2 O 3 -SiO 2 、0.76Bi 2 O 3 -0.24NiO、Li 2 O-B 2 O 3 -SiO 2 +CeO 2 And sintering auxiliary agents, effectively reduce CaTiO 3 -LaAlO 3 Sintering temperature of ceramic, but CaTiO prepared by solid phase reaction sintering 3 -LaAlO 3 The defects of air holes and the like easily appear in the ceramic, and the practical application of the material is limited.
Accordingly, there is a need to provide an improved solution to the above-mentioned deficiencies of the prior art.
Disclosure of Invention
In view of the above-described drawbacks of the prior art, an object of the present invention is to provide a CaTiO 3 -LaAlO 3 Base microwave dielectric ceramic and preparation method thereof for solving CaTiO in the prior art 3 -LaAlO 3 The sintering temperature of the ceramic is high, air holes appear in the ceramic, the stability is poor, and the ceramic is unfavorable for mass production.
To achieve the above and other related objects, the present invention provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic and one or a combination of doped phase or sintering-assisting ceramic powder;
the main crystal ceramic is (1-x) CaTiO 3 -xLaAlO 3 X is more than or equal to 0.30 and less than or equal to 0.35; the doping phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 Mixing of one or more of the ceramic powders.
Preferably, the mass ratio of the doped phase to the main crystal ceramic is 0-2 wt%, and the sintering-assisting ceramic powder and the CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 0-4wt%, and the addition amount of the sintering-assisting ceramic powder is not 0.
Preferably, the CaTiO 3 -LaAlO 3 Firing of microwave dielectric ceramicsJunction temperature is 1280-1400 ℃, dielectric constant is 40-48, Q-xf value is 20000-38000 GHz, and resonant frequency temperature coefficient is-10 ppm/°c.
The invention also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic comprises the following steps:
s1, weighing CaCO (CaCO) which is raw material powder of main crystal ceramic 3 、TiO 2 、La 2 O 3 、Al 2 O 3 Adding the mixture into a ball milling tank, and then adding CeO 2 Performing ball milling and mixing for the first time, and drying to obtain a mixed main material;
s2, calcining the mixed main material at high temperature, then putting the calcined main material into a ball milling tank again for secondary ball milling, and drying to obtain (1-x) CaTiO 3 -xLaAlO 3 -CeO 2 Ceramic pre-synthesized powder;
s3, the (1-x) CaTiO 3 -xLaAlO 3 -CeO 2 Placing the ceramic pre-synthesized powder and the sintering-assisting ceramic powder into a ball milling tank for ball milling and mixing, then drying, granulating, pressing and forming, and then calcining at high temperature in air atmosphere to obtain CaTiO 3 -LaAlO 3 And (3) a microwave-based dielectric ceramic.
Preferably, in step S3, the sintering-aid ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 At least one of the ceramic powders.
Preferably, the addition amount of the firing-aid ceramic powder in step S3 is the obtained CaTiO 3 -LaAlO 3 And the addition amount of the sintering-assisting ceramic powder is not 0, wherein the weight of the sintering-assisting ceramic powder is 0-4% of the total weight of the microwave dielectric ceramic.
Preferably, the Li 2 ZnTi 3 O 8 The preparation method of the ceramic powder comprises the following steps: li is weighed according to the mol ratio of 1:1:3 2 CO 3 、ZnO、TiO 2 Ball milling, mixing, drying, calcining at 850-950 ℃ for 4-6 h, ball milling and drying to obtain Li 2 ZnTi 3 O 8 Ceramic powder.
Preferably, the method comprises the steps of,the Li is 2 MgTi 3 O 8 The preparation method of the ceramic powder comprises the following steps: li is weighed according to the mol ratio of 1:1:3 2 CO 3 、MgO、TiO 2 Ball milling, mixing, drying, calcining at 850-950 ℃ for 4-6 h, ball milling and drying to obtain Li 2 MgTi 3 O 8 Ceramic powder.
Preferably, the BaZn 2 Ti 4 O 11 The preparation method of the ceramic powder comprises the following steps: baCO is weighed according to the mol ratio of 1:2:4 3 、ZnO、TiO 2 Ball milling, mixing, drying, calcining at 900-1000 ℃ for 4-6 h, ball milling and drying to obtain BaZn 2 Ti 4 O 11 Ceramic powder.
Preferably, in step S1, the raw material powder CaCO 3 、TiO 2 、La 2 O 3 、Al 2 O 3 According to the main crystal ceramic (1-x) CaTiO 3 -xLaAlO 3 Wherein x is more than or equal to 0.30 and less than or equal to 0.35; the CeO 2 The addition amount of the catalyst is 0-2 wt% of the total mass of the main crystal ceramic.
Preferably, the high-temperature calcination temperature in the step S2 is 1100-1250 ℃, and the high-temperature calcination time is 4-6 h.
Preferably, an adhesive is added before the granulating in the step S3, and the adhesive is one of PVA, PVB or sodium polyacrylate.
Preferably, the pressure of the compression molding is 6-7 Mpa.
Preferably, the step of high temperature calcination comprises: firstly, heating from room temperature to 550-650 ℃ at a heating rate of 2 ℃/min, and preserving heat for 2h; then heating to 1280-1400 ℃ at a heating rate of 5 ℃/min, and preserving heat for 4h.
As described above, the CaTiO of the present invention 3 -LaAlO 3 The base microwave dielectric ceramic and the preparation method thereof have the following beneficial effects:
the invention is prepared by preparing (1-x) CaTiO into main crystal ceramic 3 -xLaAlO 3 CeO is introduced into 2 Effectively improve Ti 4+ Is easily reduced to Ti during sintering 3+ The problem of oxygen vacancy generation is favorable for improving the ceramicDensification of the porcelain; due to the sintering-assisting ceramic powder Li 2 ZnTi 3 O 8 、Li 2 MgTi 3 O 8 Or BaZn 2 Ti 4 O 11 The ceramic powder has low melting point and can promote CaTiO 3 -LaAlO 3 Sintering of ceramics, additionally, li 2 ZnTi 3 O 8 、Li 2 MgTi 3 O 8 Or BaZn 2 Ti 4 O 11 The ceramic powder and the main crystal ceramic generate a small amount of Al-rich second phase, thereby reducing CaTiO 3 -LaAlO 3 The distribution range of ceramic grains further improves the densification degree of the ceramic, thereby increasing the CaTiO 3 -LaAlO 3 Dielectric constant of the ceramic; meanwhile, the raw materials of the sintering-assisting ceramic are all common oxides, the raw materials are cheap and easy to obtain, no pollution is caused, and the preparation method is simple.
CaTiO in the invention 3 -LaAlO 3 The base microwave dielectric ceramic can be sintered at 1280-1400 ℃, has good compactness, excellent dielectric property, dielectric constant of 40-48, Q-xf value of 20000-38000 GHz, resonant frequency temperature coefficient of-10 ppm/DEGC, and has practical application value in the field of communication.
Drawings
FIG. 1 shows the CaTiO prepared in example 6 of the present invention 3 -LaAlO 3 SEM image of the surface of the microwave-based dielectric ceramic.
FIG. 2 shows the CaTiO prepared in example 6 of the present invention 3 -LaAlO 3 SEM pictures of the cross-section of the microwave-based dielectric ceramic.
FIG. 3 shows the CaTiO prepared in example 7 of the present invention 3 -LaAlO 3 SEM image of the surface of the microwave-based dielectric ceramic.
FIG. 4 shows the CaTiO prepared in example 7 of the present invention 3 -LaAlO 3 SEM pictures of the cross-section of the microwave-based dielectric ceramic.
FIG. 5 shows a CaTiO prepared for comparative example in the practice of the invention 3 -LaAlO 3 SEM image of the surface of the microwave-based dielectric ceramic.
FIG. 6 shows the preparation of a comparative example in the practice of the inventionCaTiO of (C) 3 -LaAlO 3 SEM pictures of the cross-section of the microwave-based dielectric ceramic.
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.
The invention provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic and one or a combination of doped phase or sintering-assisting ceramic; the main crystal ceramic is (1-x) CaTiO 3 -xLaAlO 3 X is more than or equal to 0.30 and less than or equal to 0.35, and the doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 Mixing of one or more of the ceramic powders.
Specifically, x may include values in any of the ranges of 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, etc.
As an example, the mass ratio of the doped phase to the main crystal ceramic is 0-2 wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 0-4wt%, and the addition amount of the sintering-assisting ceramic powder is not 0.
Specifically, the mass ratio of the doped phase to the main crystal ceramic can comprise any range of values such as 0, 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, and the like, and the firing assisting ceramic powder and the CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic may include values in any range of 0, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, etc.; however, the addition amount of the firing assisting ceramic is not 0.
CeO 2 Effectively improve Ti 4+ Is easily reduced to Ti during sintering 3+ But generates oxygen vacancy, and introduces sintering-aid ceramic Li 2 ZnTi 3 O 8 、Li 2 MgTi 3 O 8 、BaZn 2 Ti 4 O 11 Forming composite ceramic, effectively improving CaTiO 3 -LaAlO 3 Grain uniformity of the base microwave dielectric ceramic is improved, and CaTiO is improved 3 -LaAlO 3 The comprehensive dielectric property of the microwave dielectric ceramic.
As an example, caTiO 3 -LaAlO 3 The sintering temperature of the base microwave dielectric ceramic is 1280-1400 ℃, the dielectric constant is 40-48, the Q-xf value is 20000-38000 GHz, and the temperature coefficient of resonance frequency is-10 ppm/°c.
The invention also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic comprises the following steps:
s1, weighing CaCO (CaCO) which is raw material powder of main crystal ceramic 3 、TiO 2 、La 2 O 3 、Al 2 O 3 Adding the mixture into a ball milling tank, and then adding CeO 2 Performing ball milling and mixing for the first time, and drying to obtain a mixed main material;
s2, calcining the mixed main material at high temperature, then putting the calcined main material into a ball milling tank again for secondary ball milling, and drying to obtain (1-x) CaTiO 3 -xLaAlO 3 -CeO 2 Ceramic pre-synthesized powder;
s3, preparing (1-x) CaTiO 3 -xLaAlO 3 -CeO 2 Placing the ceramic pre-synthesized powder and the sintering-assisting ceramic powder into a ball milling tank for ball milling and mixing, adding an adhesive into the dried mixture, granulating, performing compression molding, and calcining at high temperature in an air atmosphere to obtain CaTiO 3 -LaAlO 3 And (3) a microwave-based dielectric ceramic.
Specifically, during the first ball milling, zirconia grinding balls and deionized water are added into a ball milling tank, the mass ratio of the mixed main material to the grinding balls to the deionized water in the step S1 is 1:2:1, the first ball milling time is 2-4 hours, the drying temperature is 80 ℃, and the drying time is 6-10 hours; the second ball milling time in the step S2 is 3-5 h, the ball milling medium is deionized water, and the drying condition is the same as that in the step S1; the ball milling medium in the step S3 is deionized water, and the drying condition is that the ball milling medium is dried for 6-10 hours at 80 ℃.
In addition, the press molding in step S3 is preferably cylindrical, and in a specific embodiment is a cylinder of 15mm diameter and 6mm height.
As an example, the firing-aid ceramic powder in step S3 is Li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 At least one of the ceramic powders.
Specifically, li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 The ceramic powder has low melting point and can promote CaTiO 3 -LaAlO 3 Sintering of ceramics, additionally Li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 The ceramic powder and the main crystal ceramic generate a small amount of Al-rich second phase, thereby reducing CaTiO 3 -LaAlO 3 The distribution range of ceramic grains is increased, and the densification degree of the ceramic is improved, so that the CaTiO is increased 3 -LaAlO 3 Dielectric constant of the microwave-based dielectric ceramic.
As an example, the firing-aid ceramic powder in step S3 is added in an amount of CaTiO 3 -LaAlO 3 The weight of the basic microwave dielectric ceramic is 0-4wt%, and the addition amount of the sintering-assisting ceramic powder is not 0.
Specifically, the addition amount of the sintering-assisting ceramic powder is the CaTiO 3 -LaAlO 3 The values in any range of 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt% and the like of the total mass of the microwave dielectric ceramic can be specifically adjusted according to the actual situation.
As an example, li 2 ZnTi 3 O 8 The preparation method of the ceramic powder comprises the following steps: li is weighed according to the mol ratio of 1:1:3 2 CO 3 、ZnO、TiO 2 After ball milling, mixing and drying, the mixture is calcined at 850-950 ℃ (such as 850 ℃, 870 ℃, 890 ℃, 900 ℃, 920 ℃, 940 ℃, 950 ℃ and other values in any range) for 4-6 hours (such as 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours and other values in any range), thenThen ball milling and drying are carried out to obtain Li 2 ZnTi 3 O 8 Ceramic powder;
Li 2 MgTi 3 O 8 the preparation method of the ceramic powder comprises the following steps: li is weighed according to the mol ratio of 1:1:3 2 CO 3 、MgO、TiO 2 Ball milling, mixing, drying, calcining at 850-950 deg.C (850 deg.C, 870 deg.C, 890 deg.C, 900 deg.C, 920 deg.C, 940 deg.C, 950 deg.C, etc.) for 4-6 hr (4 hr, 4.5 hr, 5 hr, 5.5 hr, 6 hr, etc.), ball milling and drying to obtain Li 2 MgTi 3 O 8 Ceramic powder;
BaZn 2 Ti 4 O 11 the preparation method of the ceramic powder comprises the following steps: baCO is weighed according to the mol ratio of 1:2:4 3 、ZnO、TiO 2 Ball milling, mixing, drying, calcining at 900-1000 deg.c (900 deg.c, 920 deg.c, 940 deg.c, 960 deg.c, 980 deg.c, 1000 deg.c, etc.) for 4-6 hr (4 hr, 4.5 hr, 5 hr, 5.5 hr, 6 hr, etc.), ball milling and drying to obtain BaZn 2 Ti 4 O 11 Ceramic powder.
Specifically, in the preparation method of the three ceramic powders, zirconia grinding balls and deionized water are added into a ball milling tank in the ball milling mixing process, and the materials are as follows: ball: deionized water=1:2:1, ball milling and mixing for 2-4 h, and drying at 80 ℃ for 6-10 h; ball milling and crushing for 3-5 h again after calcination, and drying for 6-10 h at 80 ℃.
As an example, raw material powder CaCO in step S1 3 、TiO 2 、La 2 O 3 、Al 2 O 3 According to the main crystal ceramic (1-x) CaTiO 3 -xLaAlO 3 Wherein x is more than or equal to 0.30 and less than or equal to 0.35; ceO (CeO) 2 The addition amount of the catalyst is 0-2 wt% of the total mass of the main crystal ceramic.
Specifically, the raw material powder CaCO 3 、TiO 2 、La 2 O 3 、Al 2 O 3 According to the main crystal ceramic (1-x) CaTiO 3 -xLaAlO 3 Is prepared by weighing the molar ratio of CaCO which is actually raw material powder 3 、TiO 2 、La 2 O 3 、Al 2 O 3 According to (1-x): (1-x): 0.5x: a molar ratio of 0.5x, x may include values in any range of 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, etc.; ceO (CeO) 2 The mass ratio of the addition amount of (c) to the total mass of the main crystal ceramic may include values in any of 0, 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, etc.; small amount of Ce 4+ Is introduced to suppress Ti 4+ The price change occurs, the generation of oxygen vacancies is reduced, and the ceramic densification is improved.
As an example, the high temperature calcination temperature in step S2 is 1100 to 1250 ℃ and the high temperature calcination time is 4 to 6 hours.
Specifically, the high temperature calcination temperature in step S2 may include values in any range of 1100 ℃, 1150 ℃, 1200 ℃, 1250 ℃, etc., and may be specifically adjusted according to the actual situation; the time of high temperature calcination may include values in any range of 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, etc., and may be specifically adjusted according to the actual practice.
As an example, the adhesive in step S3 is one of PVA (polyvinyl alcohol), PVB (polyvinyl butyral) or sodium polyacrylate.
As an example, the pressure of the press forming in step S3 is 6 to 7Mpa.
Specifically, the pressure of the press molding may include values in any range of 6Mpa, 6.2Mpa, 6.4Mpa, 6.6Mpa, 6.8Mpa, 7Mpa, etc., and may be specifically adjusted according to the actual situation.
As an example, the step of high temperature calcination in step S3 includes: firstly, heating from room temperature to 550-650 ℃ at a heating rate of 2 ℃/min (such as 550 ℃, 580 ℃, 600 ℃, 620 ℃, 650 ℃ and other values in any range), and preserving heat for 2h; then heating to 1280-1400 deg.C (such as 1280, 1300, 1350, 1400, etc. values) at a heating rate of 5 deg.C/min, and maintaining for 4h.
For a better understanding of CaTiO in the present invention 3 -LaAlO 3 The CaTiO in the invention is prepared by the following specific examples 3 -LaAlO 3 The microwave dielectric ceramic and the preparation method thereof are described, and it should be noted that these examples are onlyThe invention is described without limiting it in any way.
The preparation method of the firing-aid ceramic powders used in the following examples 1 to 12 is as follows:
Li 2 ZnTi 3 O 8 ceramic powder or Li 2 MgTi 3 O 8 The preparation method of the ceramic powder specifically comprises the following steps: li is weighed according to the mol ratio of 1:1:3 2 CO 3 、ZnO(MgO)、TiO 2 Ball milling, mixing, drying, calcining at 850 ℃ for 4 hours, ball milling for 5 hours, drying at 80 ℃ for 8 hours to obtain Li 2 ZnTi 3 O 8 Ceramic powder.
BaZn 2 Ti 4 O 11 The preparation method of the ceramic powder specifically comprises the following steps: baCO is weighed according to the mol ratio of 1:2:4 3 、ZnO、TiO 2 Ball milling, mixing, drying, calcining at 900 ℃ for 4 hours, ball milling for 5 hours, drying at 80 ℃ for 8 hours to obtain BaZn 2 Ti 4 O 11 Ceramic powder
Example 1
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic and sintering-assisting ceramic powder; the main crystal ceramic is 0.7CaTiO 3 -0.3LaAlO 3 The sintering-assisting ceramic powder is Li 2 MgTi 3 O 8 Ceramic powder, firing-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 1wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the base microwave dielectric ceramic comprises the following steps:
s1, weighing CaCO (CaCO) serving as raw material powder of the main crystal ceramic according to the molar ratio of 0.7:0.7:0.15:0.15 3 、TiO 2 、La 2 O 3 、Al 2 O 3 Adding the mixture into a nylon ball milling tank, performing ball milling and mixing for 2 hours for the first time (the mixed ball milling medium is deionized water, and the mass ratio of the mixed main material to the grinding balls to the deionized water is 1:2:1), and then drying at 80 ℃ for 8 hours to obtain the mixed main material;
s2, calcining the mixed main material in a muffle furnace at 1100 ℃ for 4 hours, then putting the calcined main material in a nylon ball milling tank again for secondary ball milling for 5 hours (the mixed ball milling medium is deionized water, the mass ratio of the mixed main material to the grinding balls to the deionized water is 1:2:1), and drying the mixture at 80 ℃ for 8 hours to obtain ceramic pre-synthesized powder;
s3, pre-synthesizing ceramic powder and sintering-assisting ceramic powder (Li 2 MgTi 3 O 8 Ceramic powder) (firing-aid ceramic powder and CaTiO 3 -LaAlO 3 Placing the base microwave medium ceramic with the mass ratio of 1wt% into a ball milling tank for ball milling mixing (the ball milling medium is deionized water), then drying at 80 ℃ for 8 hours, adding PVA into the dried powder for granulating, pressing into a cylinder with the diameter of 15mm and the height of 6mm under 6Mpa, then placing the pressed cylinder into a muffle furnace, heating up to 550 ℃ from room temperature at a heating rate of 2 DEG/min in air atmosphere, preserving heat for 2 hours to remove organic matters in a sample, heating up to 1400 ℃ at a heating rate of 5 DEG/min, and preserving heat for 4 hours to obtain CaTiO 3 -LaAlO 3 And (3) a microwave-based dielectric ceramic.
Example 2
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic and sintering-assisting ceramic powder; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder; sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 1wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in the embodiment 1 in that: in the step S1, the raw material powder CaCO of the main crystal ceramic is weighed according to the mol ratio of 0.65:0.65:0.175:0.175 3 、TiO 2 、La 2 O 3 、Al 2 O 3 The method comprises the steps of carrying out a first treatment on the surface of the The sintering-assisting ceramic powder in the step S3 is Li 2 ZnTi 3 O 8 The ceramic powder, other methods and steps are the same as in example 1, and will not be described here.
Example 3
The present embodiment provides a CaTiO 3 -LaAlO 3 Microwave dielectric ceramic, packageComprises main crystal ceramic, doped phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 1wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in the embodiment 2 in that: in the step S1, the raw material powder CaCO of the main crystal ceramic is weighed according to the mol ratio of 0.65:0.65:0.175:0.175 3 、TiO 2 、La 2 O 3 、Al 2 O 3 Adding the mixture into a nylon ball milling tank, and then adding CeO 2 (CeO 2 The addition amount of the (B) is 1 weight percent of the total mass of the main crystal ceramic; other steps and methods are the same as those in embodiment 2, and will not be described here.
Example 4
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 2wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 1wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in the embodiment 3 in that: ceO is added in step S1 2 The addition amount of the powder is 2wt% of the total mass of the raw material powder; other steps and methods are the same as those in embodiment 3, and will not be described here.
Example 5
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 1.5wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in the embodiment 3 in that: step S3, sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 1.5wt%; other steps and methods are the same as those in embodiment 3, and will not be described here.
Example 6
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder or Li 2 MgTi 3 O 8 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 2wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in example 5 in that: step S3, sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 2wt%; other steps and methods are the same as those in embodiment 5, and will not be described here.
Referring to FIGS. 1 and 2, the CaTiO prepared in this example is shown 3 -LaAlO 3 SEM images of the surface and the section of the microwave-based dielectric ceramic show that the grains on the surface of the ceramic are closely arranged, the surface is compact and has no obvious air holes, the second phase rich in aluminum is obvious, the second phase can be observed on the section of the ceramic, and the second phase can be caused by the introduction of sintering aid ceramic powder; compared with the comparative example, the CaTiO prepared in this example 3 -LaAlO 3 The grain size of the microwave dielectric ceramic is reduced, the pore volume of the ceramic section is obviously reduced, and the ceramic density is obviously improved.
Example 7
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 2.5 weight percent.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in example 5 in that: step S3, sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 2.5wt%; other steps and methods are the same as those in embodiment 5, and will not be described here.
Referring to FIGS. 3 and 4, the CaTiO prepared in this example is shown 3 -LaAlO 3 SEM (scanning electron microscope) images of the surface and the section of the microwave-based dielectric ceramic, and FIG. 3 shows that the ceramic surface is compact and no obvious air holes exist; the grain size in this example tended to increase and the Al-rich second phase increased as compared to fig. 1; FIG. 4 shows that the ceramic prepared by this embodiment is also relatively dense and does not exhibit larger pores, which also indicates that the CaTiO can be enhanced by the incorporation of appropriate amounts of dopants and sintering aids 3 -LaAlO 3 And (3) the density of the microwave dielectric ceramic.
Example 8
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1.5wt%, and the sintering-assisting ceramic powderWith CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 3wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in the embodiment 3 in that: ceO in step S1 2 The addition amount of the powder is 1.5 weight percent of the total mass of the raw material powder; step S3, sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 3wt%; other steps and methods are the same as those in embodiment 3, and will not be described here.
Example 9
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1.5wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 3.5wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in example 8 in that: step S3, sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 3.5wt%; other steps and methods are the same as those in embodiment 8, and will not be described here.
Example 10
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1.5wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 4wt%.
The embodiment also provides a method for manufacturing the optical fiberCaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in example 8 in that: step S3, sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 4wt%; other steps and methods are the same as those in embodiment 8, and will not be described here.
Example 11
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is BaZn 2 Ti 4 O 11 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1.5wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 2wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 The preparation method of the microwave-based dielectric ceramic is different from that in example 8 in that: the sintering-assisting ceramic powder added in the step S3 is BaZn 2 Ti 4 O 11 Ceramic powder and BaZn 2 Ti 4 O 11 Ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 2wt%; other steps and methods are the same as those in embodiment 8, and will not be described here.
Example 12
The present embodiment provides a CaTiO 3 -LaAlO 3 The microwave dielectric ceramic comprises main crystal ceramic, doping phase and sintering-assisting ceramic; the main crystal ceramic is 0.65CaTiO 3 -0.35LaAlO 3 The doped phase is CeO 2 The sintering-assisting ceramic powder is BaZn 2 Ti 4 O 11 Ceramic powder; the mass ratio of the doped phase to the main crystal ceramic is 1.5wt%, and the sintering-assisting ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 3wt%.
The embodiment also provides a CaTiO 3 -LaAlO 3 Preparation method of the microwave-based dielectric ceramic is the same as that in example 8Is different in that: the sintering-assisting ceramic powder added in the step S3 is BaZn 2 Ti 4 O 11 Ceramic powder and BaZn 2 Ti 4 O 11 Ceramic powder and CaTiO 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 3wt%; other steps and methods are the same as those in embodiment 8, and will not be described here.
Comparative example 1
The present comparative example provides a CaTiO 3 -LaAlO 3 The preparation method of the ceramic comprises the following steps:
s1, weighing CaCO (CaCO) serving as raw material powder of the main crystal ceramic according to the molar ratio of 0.65:0.65:0.175:0.175 3 、TiO 2 、La 2 O 3 、Al 2 O 3 Adding the mixture into a nylon ball milling tank, performing ball milling and mixing for 2 hours for the first time (the mixed ball milling medium is deionized water, and the mass ratio of the mixed main material to the grinding balls to the deionized water is 1:2:1), and then drying at 80 ℃ for 8 hours to obtain the mixed main material;
s2, calcining the mixed main material in a muffle furnace at 1100 ℃ for 4 hours, then putting the calcined main material in a nylon ball milling tank again for secondary ball milling for 5 hours (the mixed ball milling medium is deionized water, the mass ratio of the mixed main material to the grinding balls to the deionized water is 1:2:1), and drying the mixture at 80 ℃ for 8 hours to obtain ceramic pre-synthesized powder;
s3, adding PVA into the ceramic pre-synthesized powder for granulating, pressing the powder into a cylinder with the diameter of 15mm and the height of 6mm under 6Mpa, then placing the pressed cylinder into a muffle furnace, heating the cylinder to 550 ℃ from room temperature at a heating rate of 2 DEG/min in air atmosphere, preserving heat for 2 hours to remove organic matters in a sample, heating to 1500 ℃ at a heating rate of 5 DEG/min, and preserving heat for 4 hours to obtain CaTiO 3 -LaAlO 3 And (3) ceramics.
Referring to FIGS. 5 and 6, the CaTiO prepared in comparative example 1 is shown 3 -LaAlO 3 SEM image of the surface and section of the microwave medium ceramic, no obvious air holes are formed on the surface of the ceramic, no second phase exists, the grains are relatively coarse, but more air holes exist in the interior of the ceramic, and the compactness is poor.
Performance testing
CaTiO in the above examples 1 to 12 was treated by a cylindrical dielectric resonator method 3 -LaAlO 3 Base microwave dielectric ceramic, and CaTiO in comparative example 1 3 -LaAlO 3 The ceramic was subjected to microwave dielectric property evaluation, and the detection method was a GB/T7265.2-1987 cavity opening method, and sintering temperature, dielectric constant, Q.times.f. value and resonant frequency temperature coefficient of each ceramic were obtained respectively, as shown in Table 1.
Table 1, caTiO in examples 1-12 3 -LaAlO 3 Microwave dielectric property evaluation result of base microwave dielectric ceramic
As described above, the present invention is achieved by forming (1-x) CaTiO into a host crystal ceramic 3 -xLaAlO 3 CeO is introduced into 2 Effectively improve Ti 4+ Is easily reduced to Ti during sintering 3+ The problem of oxygen vacancy is generated, which is beneficial to improving ceramic densification; due to the sintering-assisting ceramic powder Li 2 ZnTi 3 O 8 、Li 2 MgTi 3 O 8 Or BaZn 2 Ti 4 O 11 The ceramic powder has low melting point and can promote CaTiO 3 -LaAlO 3 Sintering of ceramics, additionally, li 2 ZnTi 3 O 8 、Li 2 MgTi 3 O 8 Or BaZn 2 Ti 4 O 11 The ceramic powder and the main crystal ceramic generate a small amount of Al-rich second phase, thereby reducing CaTiO 3 -LaAlO 3 The distribution range of ceramic grains further improves the densification degree of the ceramic, thereby increasing the CaTiO 3 -LaAlO 3 Dielectric constant of the ceramic; meanwhile, the raw materials of the sintering-assisting ceramic are all common oxides, the raw materials are cheap and easy to obtain, no pollution is caused, and the preparation method is simple; caTiO in the invention 3 -LaAlO 3 The base microwave dielectric ceramic can be sintered at 1280-1400 ℃ and has compactnessThe microwave device has good dielectric property, dielectric constant of 40-48, Q-xf value of 20000-38000 GHz, resonant frequency temperature coefficient of-10 ppm/DEG C, and practical application value in the communication field. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (10)
1. CaTiO (CaTiO) 3 -LaAlO 3 The microwave dielectric ceramic is characterized by comprising main crystal ceramic and one or a combination of doping phase or sintering-assisting ceramic powder;
the main crystal ceramic is (1-x) CaTiO 3 -xLaAlO 3 X is more than or equal to 0.30 and less than or equal to 0.35; the doping phase is CeO 2 The sintering-assisting ceramic powder is Li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 Mixing of one or more of the ceramic powders.
2. The CaTiO of claim 1 3 -LaAlO 3 The microwave-based dielectric ceramic is characterized in that the mass ratio of the doped phase to the main crystal ceramic is 0-2wt%, and the sintering-assisting ceramic powder and the CaTiO are mixed together 3 -LaAlO 3 The mass ratio of the total mass of the base microwave dielectric ceramic is 0-4wt%, and the addition amount of the sintering-assisting ceramic powder is not 0.
3. CaTiO according to claim 1 or 2 3 -LaAlO 3 A microwave-based dielectric ceramic, characterized in that the CaTiO 3 -LaAlO 3 Basic microwave dielectric ceramicThe sintering temperature of the porcelain is 1280-1400 ℃, the dielectric constant is 40-48, the Q f value is 20000-38000 GHz, and the temperature coefficient of resonance frequency is-10 ppm/°c.
4. CaTiO (CaTiO) 3 -LaAlO 3 The preparation method of the base microwave dielectric ceramic is characterized by comprising the following steps of: the preparation method comprises the following steps:
s1, weighing CaCO (CaCO) which is raw material powder of main crystal ceramic 3 、TiO 2 、La 2 O 3 、Al 2 O 3 Adding the mixture into a ball milling tank, and then adding CeO 2 Performing ball milling and mixing for the first time, and drying to obtain a mixed main material;
s2, calcining the mixed main material at high temperature, then putting the calcined main material into a ball milling tank again for secondary ball milling, and drying to obtain (1-x) CaTiO 3 -xLaAlO 3 -CeO 2 Ceramic pre-synthesized powder;
s3, the (1-x) CaTiO 3 -xLaAlO 3 -CeO 2 Placing the ceramic pre-synthesized powder and the sintering-assisting ceramic powder into a ball milling tank for ball milling and mixing, then drying, granulating, pressing and forming, and then calcining at high temperature in air atmosphere to obtain CaTiO 3 -LaAlO 3 And (3) a microwave-based dielectric ceramic.
5. The method of manufacturing according to claim 4, wherein: the sintering-assisting ceramic powder in the step S3 is Li 2 ZnTi 3 O 8 Ceramic powder, li 2 MgTi 3 O 8 Ceramic powder and BaZn 2 Ti 4 O 11 At least one of the ceramic powders.
6. The method of manufacturing according to claim 5, wherein: the addition amount of the sintering-assisting ceramic powder in the step S3 is the CaTiO 3 -LaAlO 3 And the addition amount of the sintering-assisting ceramic powder is not 0, wherein the weight of the sintering-assisting ceramic powder is 0-4% of the total weight of the microwave dielectric ceramic.
7. The method of manufacturing according to claim 5, wherein: including one or a combination of the following conditions:
the Li is 2 ZnTi 3 O 8 The preparation method of the ceramic powder comprises the following steps: li is weighed according to the mol ratio of 1:1:3 2 CO 3 、ZnO、TiO 2 Ball milling, mixing, drying, calcining at 850-950 ℃ for 4-6 h, ball milling and drying to obtain Li 2 ZnTi 3 O 8 Ceramic powder;
the Li is 2 MgTi 3 O 8 The preparation method of the ceramic powder comprises the following steps: li is weighed according to the mol ratio of 1:1:3 2 CO 3 、MgO、TiO 2 Ball milling, mixing, drying, calcining at 850-950 ℃ for 4-6 h, ball milling and drying to obtain Li 2 MgTi 3 O 8 Ceramic powder;
the BaZn 2 Ti 4 O 11 The preparation method of the ceramic powder comprises the following steps: baCO is weighed according to the mol ratio of 1:2:4 3 、ZnO、TiO 2 Ball milling, mixing, drying, calcining at 900-1000 ℃ for 4-6 h, ball milling and drying to obtain BaZn 2 Ti 4 O 11 Ceramic powder.
8. The method of preparation according to claim 4, 5 or 6, characterized in that: step S1, raw material powder CaCO 3 、TiO 2 、La 2 O 3 、Al 2 O 3 According to the main crystal ceramic (1-x) CaTiO 3 -xLaAlO 3 Wherein x is more than or equal to 0.30 and less than or equal to 0.35;
the CeO 2 The addition amount of the catalyst is 0-2 wt% of the total mass of the main crystal ceramic.
9. The method of preparation according to claim 4, 5 or 6, characterized in that: the high-temperature calcination temperature in the step S2 is 1100-1250 ℃, and the high-temperature calcination time is 4-6 h.
10. The method of preparation according to claim 4, 5 or 6, characterized in that: step S3 includes one or a combination of the following conditions:
an adhesive is added before granulation, wherein the adhesive is one of PVA, PVB or sodium polyacrylate;
the pressure of the compression molding is 6-7 Mpa;
the high-temperature calcination step comprises the following steps: firstly, heating from room temperature to 550-650 ℃ at a heating rate of 2 ℃/min, and preserving heat for 2h; then heating to 1280-1400 ℃ at a heating rate of 5 ℃/min, and preserving heat for 4h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311682252.2A CN117645475A (en) | 2023-12-08 | 2023-12-08 | CaTiO (CaTiO) 3 -LaAlO 3 Basic microwave dielectric ceramic and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311682252.2A CN117645475A (en) | 2023-12-08 | 2023-12-08 | CaTiO (CaTiO) 3 -LaAlO 3 Basic microwave dielectric ceramic and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117645475A true CN117645475A (en) | 2024-03-05 |
Family
ID=90044882
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311682252.2A Pending CN117645475A (en) | 2023-12-08 | 2023-12-08 | CaTiO (CaTiO) 3 -LaAlO 3 Basic microwave dielectric ceramic and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117645475A (en) |
-
2023
- 2023-12-08 CN CN202311682252.2A patent/CN117645475A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109180178A (en) | A kind of barium-strontium titanate-based unleaded relaxation ferroelectric ceramic of high energy storage density and preparation method thereof | |
| CN101774803B (en) | A (Ba, sr) TiO3-based ceramic medium and its prepn | |
| CN111004030B (en) | MgTiO (magnesium-titanium-oxide) powder3Microwave-based dielectric ceramic and preparation method thereof | |
| Jiayu et al. | Effects of rare earth oxides on dielectric properties of Y2Ti2O7 series ceramics | |
| Gu et al. | Low temperature sintering and microwave dielectric properties of 0.2 Ca0. 8Sr0. 2TiO3–0.8 Li0. 5Sm0. 5TiO3 ceramics with BaCu (B2O5) additive and TiO2 dopant | |
| CN108530056B (en) | Giant dielectric low-loss barium strontium titanate ceramic and preparation method thereof | |
| CN111410526A (en) | Perovskite-doped barium stannate material and preparation method and application thereof | |
| CN114436643A (en) | Giant dielectric constant and low dielectric loss ceramic and preparation method thereof | |
| JP3559434B2 (en) | Method for producing dielectric porcelain composition | |
| JP5142700B2 (en) | Dielectric ceramic composition and dielectric resonator | |
| CN108484160A (en) | Nine barium phthalate base microwave dielectric ceramic materials of one kind and preparation method | |
| CN109456058B (en) | Barium zirconate titanate and barium niobate zincate composite capacitor ceramic material and preparation method thereof | |
| JP2000007429A (en) | Dielectric material and its production | |
| CN115368132B (en) | Barium titanate-based ceramic material and preparation method thereof | |
| JP3793485B2 (en) | Microwave dielectric porcelain composition and method for producing the porcelain | |
| CN117645475A (en) | CaTiO (CaTiO) 3 -LaAlO 3 Basic microwave dielectric ceramic and preparation method thereof | |
| CN103172365B (en) | Preparation method of microwave dielectric ceramic material | |
| JP7238127B2 (en) | Doped perovskite-type barium stannate material, production method thereof, and use thereof | |
| CN112898022A (en) | Ultralow temperature sintered microwave dielectric material Ca2V2O7-H3BO3And method for preparing the same | |
| JP2004256360A (en) | Microwave dielectric porcelain composition and its manufacturing method | |
| JP2004091266A (en) | Gallium-added dielectric porcelain composition, dielectric resonator, and microwave communication apparatus | |
| CN111825445A (en) | High-dielectric-constant microwave dielectric ceramic material, preparation and application thereof | |
| CN108794004B (en) | Lanthanum-neodymium doped nickelate ceramic and preparation method and application thereof | |
| CN111960817A (en) | Ceramic dielectric material for high-dielectric low-loss high-voltage-resistant capacitor and preparation method thereof | |
| CN110862256A (en) | Preparation method of microwave dielectric sintered powder material, microwave dielectric ceramic and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |