Low temperature sintered composite microwave medium ceramic in series of lithium, niobium and titanium, and prepartion method

A microwave dielectric ceramic and low-temperature sintering technology, applied in ceramics, inorganic insulators, etc., can solve the problems of high sintering temperature, low temperature of materials and excellent microwave dielectric properties, and lower sintering temperature. Microwave dielectric properties, good reproducibility

Inactive Publication Date: 2007-02-21
SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The purpose of the present invention is to start from enriching the development of new low-temperature sintered microwave dielectric materials and overcoming the problems of high sintering temperature, low temperature material and excellent microwave dielectric properties existing in the existing microwave dielectric material technology. 2 O-Nb 2 o 5 -TiO 2 In the system, by designing a suitable raw material ratio, another new type of LNT composite microwave dielectric ceramic material with low inherent sintering temperature and excellent microwave dielectric properties is provided, and by doping a small amount of low melting point oxide B 2 o 3 or V 2 o 5 , successfully reduced its sintering temperature to around 900 °C while maintaining excellent microwave dielectric properties

Method used

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  • Low temperature sintered composite microwave medium ceramic in series of lithium, niobium and titanium, and prepartion method
  • Low temperature sintered composite microwave medium ceramic in series of lithium, niobium and titanium, and prepartion method
  • Low temperature sintered composite microwave medium ceramic in series of lithium, niobium and titanium, and prepartion method

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Embodiment 1

[0027] Each raw material ratio (mol ratio) of the present embodiment is: Li 2 CO 3 : Nb 2 o 5 :TiO 2 =5:1.15:4.27. Analytical pure Li 2 CO 3 , Nb 2 o 5 and TiO 2 Weigh according to the above ratio, add deionized water according to the weight ratio of mixture and deionized water is 1:1.8, wet ball mill for 24~36h, dry at 100~150℃, put it into a high alumina crucible, Pre-fire at 700℃~1000℃ for 5h~8h to synthesize the main crystal phase. After pre-burning and synthesis, the powder is crushed again, and alcohol is directly added for wet ball milling for 24h-36h, then the material is discharged and dried, granulated with 4%-8% PVA, and pressed into small discs under a pressure of 100-200MPa. Debinding at 600-700°C, placing undoped ceramic samples in an alumina crucible for sintering at 1000-1200°C for 1-3 hours, and cooling naturally to obtain the material of the present invention. The ceramic samples are tested after being smoothed on both sides by sandpaper, and their...

Embodiment 2

[0031] Each raw material ratio (mol ratio) of the present embodiment is: Li 2 CO 3 : Nb 2 o 5 :TiO 2 =5:1.05:4.85. Analytical pure Li 2 CO 3 , Nb 2 o 5 and TiO 2 Weighing was carried out according to the above-mentioned proportion, and the preparation process described in Example 1 was used to prepare the materials with the above composition. The ceramic samples were polished on both sides by sandpaper and then tested. Through the test of the microwave performance, the microwave dielectric properties of the composite ceramic material at different sintering temperatures are shown in Table 2, and the phase composition of the ceramic sheet sintered at 1100 ° C was identified by X-Ray ( figure 1 (b) shows the X-Ray diffraction pattern of the Example 2 sample at 1100 ° C sintered ceramics), XRD results show that the ceramics are made of Li 2 TiO 3 ss and M-phase two-phase composition, the volume fraction ratio of these two phases is about 0.91.

[0032] Sinteri...

Embodiment 3

[0035] Each raw material ratio (mol ratio) of the present embodiment is: Li 2 CO 3 : Nb 2 o 5 :TiO 2 =5:1:5. Analytical pure Li 2 CO 3 , Nb 2 o 5 and TiO 2 Weighing was carried out according to the above-mentioned proportion, and the preparation process described in Example 1 was used to prepare the materials with the above composition. The ceramic samples were polished on both sides by sandpaper and then tested. Through the test of the microwave performance, the microwave dielectric properties of the composite ceramic material at different sintering temperatures are shown in Table 3, and the phase composition of the ceramic sheet sintered at 1120 ° C was identified by X-Ray ( figure 1 (c) shows the X-Ray diffraction pattern of the sample of Example 3 at 1120 ° C sintered ceramics), XRD results show that the ceramic Li 2 TiO 3 ss and M-phase two-phase composition, the volume fraction ratio of the two phases is about 5.3. The microstructure photo of the sintered mate...

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Abstract

This invention relates to a method for preparing low-temperature-sintered lithium-niobium-titanate composite microwave dielectric ceramic, which is composed of Li2TiO3 solid solution and M-phase solid solution. The composite microwave dielectric ceramic is prepared from Li2CO3, Nb2O5 and TiO2 at a mol ratio of 5: x: y (x is in 1-2 and y in 4-6), and B2O3 or V2O5 0-5 wt. % by conventional solid-phase reaction. The composite microwave dielectric ceramic has a low sintering temperature (about 1100 deg.C), good dielectric property with a dielectric constant of 34-50, a high Q*f value (Q is quality factor), and a low resonance frequency temperature coefficient, and can be used in sheet dielectric resonator, filter, antenna, balun, etc. when added with a small quantity of low-melting-point oxide, the composite microwave dielectric ceramic has a lower sintering temperature of about 900 deg.C, while its good microwave dielectric property can be maintained.

Description

technical field [0001] The invention relates to a low-temperature sintered lithium-niobium-titanium composite microwave dielectric ceramic and a preparation method thereof, belonging to the field of microwave dielectric ceramics. Background technique [0002] Microwave dielectric ceramics are new functional electronic ceramics developed rapidly in recent decades. They have the characteristics of low loss, small frequency temperature coefficient, and high dielectric constant. They can be used to manufacture dielectric resonators, filters, microwave dielectric antennas, etc., and are widely used in It is a new type of material with great application value and development potential in many fields such as mobile communication, satellite TV broadcast communication, and radar. [0003] In recent years, with the development of modern mobile communication equipment towards miniaturization, integration, high reliability, low cost, chip type, and environmental protection, in order to ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/465C04B35/622H01B3/12
Inventor 李蔚曾群施剑林郭景坤
Owner SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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