KDP晶体用高活性介孔氧化铈非刚性复合磨料的研究

氧化铈磨料是化学机械抛光法超精密加工KDP晶体的关键影响因素，纯氧化铈抛光KDP晶体易引起表面、亚表面损伤。本项目针对KDP抛光用氧化铈复合磨料的非刚性、稳定性及高活性所涉及的关键问题开展研究。采用第一性原理计算获得分布均匀且承受一定机械强度的共格外延聚合物/氧化铈核壳界面。计算掺杂元素在壳层生长过程中吸附、迁移情况，阐明不同掺杂状态下氧化铈晶面与氧空位增强壳层表面活性的作用机制。采用分子动力学模拟表面活性剂吸附、缔合和脱附，研究放射状有序介孔氧化铈壳层形成机理。基于理论分析结果，实验制备相应结构复合磨料，研究核壳结构、介孔壳层形貌、掺杂模式与磨料抛光效果的关系，以揭示氧化铈复合磨料高质高效抛光所遵循的规律。预期成果可为KDP晶体抛光用高活性介孔氧化铈非刚性复合磨料的研究与制备提供理论支持。

The CeO2 abrasive is the key factor affecting the ultra-precision processing of KDP crystal by chemical mechanical polishing. Polishing KDP crystal with pure cerium oxide easily cause surface and subsurface damage. In this project, the key issues related to the non-rigidity, stability and high activity of CeO2 composite abrasive for KDP polishing are studied. The first-principles calculation is used to obtain the core-shell interface of coherent epitaxy polymer/ceria with uniform distribution and certain mechanical strength. The adsorption and migration of doped elements during shell growth are calculated, and the mechanism of the enhancement of shell surface activity by CeO2 crystal surface and oxygen vacancy under different doping conditions is clarified. Molecular dynamics is used to simulate the adsorption, association and desorption of surfactants, and the formation mechanism of radially ordered mesoporous CeO2 shell is studied. Based on the theoretical analysis results, the composite abrasives with corresponding structures are prepared by experiments. The relationship between core-shell structure, mesoporous shell morphology, doping mode and abrasive polishing effect is studied to reveal the rules followed by high-quality and high-efficiency polishing of CeO2 composite abrasives. The expected results can provide theoretical support for the research and preparation of non-rigid CeO2 composite abrasives with high activity and mesoporous for KDP crystal polishing.