论文总字数：22478字

摘 要

随着高频通信产业的迅速发展，人们相继在微波介质陶瓷领域探索其在介质天线、微波集成电路、滤波器、谐振器等器件中的应用，相关研究也越来越多^[1-5]。本论文介绍的超低温共烧（ULTCC）技术被认为是一种很有前途的制备方法^[6-8]。

本论文主要介绍了微波介质陶瓷的研究历史、分类、性能指标、运用、制备合成方法、发展现状以及掺杂改性研究。本论文的研究对象为Li₂Mg₂Mo₃O₁₂-TiO₂复相陶瓷，其烧结温度较低，可实现超低温烧结，且具有优异的微波介电性能。本论文选择分析纯的Li₂CO₃，MgO、MoO₃和TiO₂粉末作为原始粉料，采用传统固相反应法制得样品，采用X射线衍射、SEM、网络分析仪等手段表征不同TiO₂含量在不同的烧结温度时样品的介电性能。当TiO₂含量为0.4，Ts=750℃时，得到的Li₂Mg₂Mo₃O₁₂-TiO₂复相陶瓷的微波介电性能最佳，具体数值为：ε_r= 11.28，Q×f = 54804 GHz，τ_f= -3 ppm/℃。

关键词：微波介质陶瓷超低温共烧TiO₂复相陶瓷

Preparation and properties of Li₂Mg₂Mo₃O₁₂-TiO₂ composite ceramics

Abstract

With the rapid development of high-frequency communication industry, people have successively explored its application in dielectric antennas, microwave integrated circuits, filters, resonators, oscillators and other devices in the field of microwave dielectric ceramics, and more and more related researches have been conducted.^[1-5]ULTCC technology introduced in this paper is considered as a promising preparation method.^[6-8].

This paper mainly introduces the research history, classification, performance index, application, preparation and synthesis methods, development status and doping modification of microwave dielectric ceramics.The research object of this thesis is Li₂Mg₂Mo₃O₁₂-TiO₂multiphase ceramics, which has low sintering temperature, can realize ultra-low temperature sintering and has excellent microwave dielectric properties.In this paper, analytically pure Li₂CO₃, MgO, MoO₃ and TiO₂ powders are selected as raw powders, and samples are prepared by traditional solid-phase reaction method.X-ray diffraction, SEM and network analyzer were used to characterize the dielectric properties of samples with different TiO2 contents at different sintering temperatures.When TiO₂ content is 0.4 and Ts=750℃, the microwave dielectric properties of Li₂Mg₂Mo₃O₁₂-TiO₂ multiphase ceramics are the best, the specific values areε_r= 11.28, Q×f= 54804 GHz, τ_f= -3 ppm/℃.

Key words: Microwave dielectric ceramics; Ultra-low temperature co-firing; TiO₂; Multiphase ceramics

目录

摘要……...………………………………………………………………………………………………………………………………………………………,,.I

Abstract…………………………………………………………………………………………………………………………............................II

目录…………………………………………………………………………………………………………………………….………………………...…..,..III

第一章绪论 1

1.1引言 1

1.2研究历史 1

1.3微波介质陶瓷材料分类 2

1.3.1低介电常数类 2

1.3.2中介电常数类 2

1.3.3高介电常数类 2

1.4微波介质陶瓷的性能 2

1.4.1相对介电常数 3

1.4.2品质因数 3

1.4.3谐振频率温度系数 3

1.4.4多相陶瓷参数的确定 4

1.5微波陶瓷的运用 4

1.6微波介质陶瓷的制备 4

1.6.1固相反应法 4

1.6.2溶胶-凝胶法 5

1.6.3水热法 5

1.6.4沉淀法 5

1.7课题的提出 5

1.7.1超低温微波介质陶瓷的研究 5

1.7.2Li₂Mg₂Mo₃O₁₂微波介质陶瓷简介 6

1.7.3课题研究内容 7

第二章实验方案 8

2.1实验方法 8

2.1.1实验原料 8

2.1.2实验设备 8

2.1.3实验流程 8

2.2测试与表征 10

2.2.1 X射线物相分析 10

2.2.2 SEM显微分析 10

2.2.3微波介电性能测试 10

2.2.4烧结性能测试 11

第三章 Li₂Mg₂Mo₃O₁₂-TiO₂复相微波介质陶瓷的结构与性能分析 12

3.1试验方法 12

3.1.1试样制备 12

3.1.2测试与分析 12

3.2物相分析 12

3.3烧结特性分析 13

3.4扫描电镜图像分析 14

3.5性能分析 15

3.5.1介电常数 15

3.5.3谐振频率温度系数 17

第四章结论与展望 18

4.1结论 18

4.2展望 18

参考文献 19

致谢…………………………………………………………………………………………………..24

第一章绪论

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