复杂化学键理论与晶格振动光谱学协同解析CaMgSi2O6基陶瓷的微波介电响应

低介电常数的CaMgSi2O6基陶瓷在微波毫米波通信系统中有广泛的应用前景，其晶体结构演变对本征微波介电性能影响机理仍不够清晰。本项目借鉴透明陶瓷的制备方法，通过冷等静压成型、真空烧结和氧气氛退火等关键工艺步骤，制备高致密度且氧空位缺陷少的CaMgSi2O6基陶瓷，有效降低非本征因素对微波介电性能的影响；采取复杂化学键理论计算晶体结构中不同化学键特性，建立化学键特性与微波介电性能之间的关联，并结合拉曼、远红外光谱测试确定晶格振动对介电常数及介质损耗的贡献，从化学键和晶格振动层面解析CaMgSi2O6基的本征微波介电响应，获得通过晶体结构调控优化其微波介电性能的方法。相关研究结果将丰富微波电介质理论。

CaMgSi2O6-based ceramics with low dielectric constant have a wide range of application prospects in microwave and millimeter wave communication systems. However, the mechanism of crystal structure evolution on microwave dielectric properties is not clear enough yet. In this project, we can obtain CaMgSi2O6-based ceramics with high density and few oxygen vacancies defects which effectively eliminate the influence of non-intrinsic factors on microwave dielectric properties, using the preparation method of laser transparent ceramics, through the key process steps such as cold isostatic pressing, vacuum sintering and oxygen atmosphere annealing. Besides, the complex chemical bond theory is used to calculate chemical bond characteristics in crystal structure and establish the relationship between chemical bond characteristics and microwave dielectric properties. The contribution of lattice vibration to dielectric constant and dielectric loss is determined by Raman and far-infrared spectra. Then, the intrinsic microwave dielectric response of CaMgSi2O6-based ceramics can be analyzed by chemical bonds and lattice vibration. On this basis, the method of optimizing the microwave dielectric properties by crystal structure control will be obtained.The results will enrich the theory of microwave dielectric.