MZrTa2O8陶瓷烧结机制与微波介电响应研究

Microwave dielectric ceramic is the key material for the development of communication technology. MZrTa2O8 (M=Mg、Zn、Co、Ni) ceramics with ultra-low dielectric loss will be prepared by the solid state method. This project explores the formation mechanism and determines the sintering kinetics of MZrTa2O8 ceramics using MO、ZrO2、Ta2O5 as raw materials. A theory basis for the low-temperature sintering of ceramics will be demonstrated. With the help of vibrational spectrums, we will evaluate and predict the intrinsic dielectric properties. Based on the complex chemical bond theory, the present project aims to discuss the dielectric loss mechanism, clarify the causes and dominant factors for τf changes, and then realize excellent microwave dielectric properties. More importantly, this project will provide theoretical and practical foundation for the modification of current materials and development of new varieties. At last, a series of novel temperature stable low-firing dielectric ceramics with low-loss will be manufactured by adjusting the content of intermediate phase during MZrTa2O8 synthesis.

微波介质陶瓷是促进通讯技术迅猛发展的关键基础材料。本项目拟采用固相法合成超低损耗MZrTa2O8(M=Mg、Zn、Co、Ni)陶瓷材料。探索MO-ZrO2-Ta2O5体系固相反应机理以及烧结动力学行为，为陶瓷低温烧结提供理论依据。解析MZrTa2O8陶瓷振动光谱，分析和预测本征介电性能。采用复杂晶体化学键的介电理论，探讨化学键参量与介电损耗的内在联系，揭示谐振频率温度系数的变化原因，建立微波介电性能响应与调控机制。本项目的实施有望为现有微波材料的改性和新材料体系的开发奠定理论和实践基础。最终，定量调控MZrTa2O8合成过程中间相的含量，一步获得兼顾低烧、低损耗、温度稳定的微波介质陶瓷材料。

微波通讯技术的迅猛发展离不开高品质电子陶瓷材料的有力支撑。本项目围绕低损耗钨锰铁矿MZrTa2O8(M=Mg、Zn、Co、Ni)微波介质陶瓷展开。通过热力学分析，明确固相反应机理。研究晶粒生长行为，建立动力学方程。基于离子取代，分别在M位引入Li+、(LiV1/5)2+、Ni2+、Ga3+以及Zr位引入Sm3+、La3+，有效改善其微波介电性能。借助XRD精修、拉曼、透射电镜、XPS等技术，研究了氧空位缺陷、原子堆积密度、化学键性质（键的离子性、键能、晶格能）、氧八面体畸变等因素对介电性能的影响规律，建立了微观结构参数与微波介电性能的关联机制，揭示陶瓷改性及介电损耗机理。设计MO-ZrO2-Ta2O5固相反应定向进行，定量调控MZrTa2O8合成过程中间相MTa2O6的含量，成功实现谐振频率温度系数精准调零与烧结温度协同优化。引入助烧剂V2O5和BaCu(B2O5)，分析了0.25MgZrTa2O8-0.75MgTa2O6复合陶瓷烧结过程，明确活化烧结的有效途径。本项目获得了一系列性能优异的微波介质陶瓷材料，比如Mg0.95Li0.05ZrTa2O7.975 (εr=12.0, Q×f=72,782 GHz, τf=3.29 ppm/°C)、Zn0.99Ga0.01ZrTa2O7.995 (εr=22.5, Q×f=103,236 GHz, τf=-17.65 ppm/°C)、CoO-ZrO2-Ta2O5 (εr=28.2, Q×f=70,562 GHz, τf=-2.67 ppm/°C)。本项目还拓展了研究内容，开发了MnZrTa2O8、CoSnNb2O8中介微波介质陶瓷材料。