论文总字数：21341字

摘 要

本文综述了微波介质陶瓷的基本性能和发展，MgAl₂O₄-(Ca_0.8Sr_0.2)TiO_3，(MACST)体系陶瓷具有介电常数低，及近零的谐振频率温度系数，但是其品质因数仍然需继续提高，Q·f≈50563GHz。在陶瓷材料制备过程中常采用离子半径相近的Ni² 与Zn² 分别取代Mg² 来提高品质因数。因此，本课题研究的目的是通过离子掺杂对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO₃(MACST)微波介质陶瓷进行改性，确定最佳配方及烧成温度，制备出致密高性能的MgAl₂O₄-(Ca_0.8Sr_0.2)TiO₃微波介质陶瓷。

本论文以0.92MgAl₂O₄-0.08(Ca_0.8Sr_0.2)TiO₃基体材料，选用Ni² 和Zn² 作为掺杂离子，通过X射线衍射(XRD)，扫描电镜(SEM)，网络分析仪等分析方法，研究了单独添加Ni² 和Zn² 对MACST陶瓷烧结性能、相组成、显微结构以及介电性能。实验结果显示，0.2mol% Ni² 取代，在1440℃时介电性能达到最佳，此时ε_r ≈10.73，Q·f ≈47106GHz。Zn² 掺入量为0.3mol%，在1440℃时介电性能达到最佳，此时ε_r ≈10.94，Q·f ≈ 57232GHz。

关键词：微波介质陶瓷 MgAl₂O₄-(Ca_0.8Sr_0.2)TiO₃体系 微波介电性能 取代

Abstract

The basic performance and the recent research progress of microwave dielectric ceramics were introduced in this paper. MgAl₂O₄-(Ca_0.8Sr_0.2)TiO₃ system has a low dielectric constant (ԑ_r), and near-zero temperature coefficient of resonant frequency (τ_f). But its quality factor (Q·f) is low, Q·f≈50563GHz. In this paper, the Ni² and Zn² of the similar ionic radius were used to replace Mg² to improve the quality factor. Therefore, the purpose of this research is to modify the MgAl₂O₄ based microwave dielectric ceramics by ion doping to prepare the dense and high performance MgAl₂O₄ based microwave dielectric ceramics and determine the optimum formulation and sintering temperature.

0.92MgAl₂O₄-0.08(Ca_0.8Sr_0.2)TiO₃ was selected as the research objects, then used X-ray diffraction (XRD), Scanning electron microscope (SEM) and Network analyzer to analysis the effects of Ni² and Zn² on sintering behavior, phase compositions, microstructures and dielectric properties of MACST ceramics were studied systematically.The results showed that when the Ni² addition amount was 0.2 mol%, MACST samples sintered at 1440℃ got the best dielectric properties：ε_r≈10.73，Q·f≈ 47106GHz。When the Zn² addition amount was 0.3mol%, MACST samples sintered at 1440℃ got the best dielectric properties：ε_r≈10.94，Q·f≈57232GHz。

Key words: Microwave dielectric ceramic; (Ca_0.8Sr_0.2)TiO₃-MgAl₂O₄ system; Microwave properties; Replace

目录

摘要 Ⅰ

Abstract Ⅱ

第一章 绪论 1

1.1引言 1

1.2微波介质陶瓷概述 1

1.2.1微波介质陶瓷的分类 1

1.2.2微波介质陶瓷的应用 2

1.2.3微波介质陶瓷的研究现状 2

1.3理论基础 2

1.4 (Mg,Zn,Ni)Al₂O₄系微波介质陶瓷 3

1.4.1 MgAl₂O₄尖晶石的结构 3

1.4.2 (Mg,Zn,Ni)Al₂O₄基微波介质陶瓷的概况 4

1.4.3 (Ca_0.8Sr_0.2)TiO₃ 陶瓷 5

1.5课题的提出和研究内容 5

1.5.1 研究目标 5

1.5.2课题的提出 5

1.5.3 研究思路 5

1.5.4 研究内容 6

第二章 实验部分 7

2.1引言 7

2.2 样品制备 7

2.2.1 实验原料： 7

2.2.2 实验设备： 7

2.2.3 实验流程 8

2.3 材料性能测试及表征 9

2.3.1 陶瓷样品烧结性能测试 9

2.3.2 陶瓷介电性能测试 9

2.4 相组成与微观结构分析 12

2.4.1 XRD分析 12

2.4.2 SEM分析 12

第三章 离子改性对0.08MgAl₂O₄-0.92(Ca_0.8Sr_0.2)TiO₃陶瓷性能的影响 12

3.1 引言 13

3.2 Ni² 取代对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO₃微波介质陶瓷性能的影响 13

3.2.1 Ni² 取代对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO₃陶瓷烧结性能的影响 13

3.2.2 Ni² 取代对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO ₃陶瓷介电性能的影响 15

3.2.3 Ni² 取代对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO ₃微波介质陶瓷相组成及微观形貌的影响 16

3.3 Zn² 取代对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO₃微波介质陶瓷性能的影响 188

3.3.1 Zn² 取代对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO₃陶瓷烧结性能的影响 188

3.3.2 Zn² 取代对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO ₃陶瓷介电性能的影响 19

3.3.3 Zn² 取代对MgAl₂O₄-(Ca_0.8Sr_0.2)TiO ₃微波介质陶瓷相组成的影响 21

第四章 结论与展望 22

4.1 结论 22

4.2 展望 22

参考文献 23

致谢…………………………………………………………………………………26

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