采用高丰度稀土Ce替代Pr、Nd制备Nd-Ce-Fe-B磁体已成为当前研究热点，近来有结果表明Ce添加量20wt.%附近磁体矫顽力异常提升，其数值优于未添加Ce的Nd-Fe-B磁体。经前期研究发现，Ce添加量20wt.%时磁体RE2Fe14B主相晶胞参数c呈离散变化，并凭借晶胞错配等缺陷形成磁畴钉扎中心，使矫顽力提升，但对主相晶胞参数c离散形成机制尚缺乏有效解析。因此，本项目采用同步辐射X射线吸收精细结构测定Ce在晶胞中价态、混合比率及择优代位情况，结合第一性原理计算获取不同类型Ce在各晶位固溶取代结合能及晶胞参数相关信息，从实验测定与理论计算两方面，系统研究Ce取代时价态演化规律及固溶取代热力学过程，构建Ce添加量、价态混合比率、择优代位与晶胞参数的映射规律，揭示Ce添加量20wt.%时主相晶胞参数c离散机制，为调控制备高性能Nd-Ce-Fe-B稀土永磁材料提供理论与实验新思路。

It has become a popular topic to prepare Nd-Ce-Fe-B magnets with high abundance rare earth Ce instead of Pr and Nd. In recent years, some studies have found that the magnetic coercivity abnormal improvement in specific Ce content (20 wt.%), and its value is better than Nd-Fe-B magnet without Ce addition. Through the preliminary research, it was found that the cell parameter c of the RE2Fe14B main phase in the magnet is discrete when the amount of Ce is 20 wt.%, and the magnetic domain pinning center is formed by the defects such as cell mismatch, so that the coercivity is promoted. However, the cell parameter c discrete mechanism of the main phase is still lack of effective analysis. Therefore, this project uses synchrotron radiation X - ray absorption fine structure to determine the valence state, mixing ratio and site preference of Ce in the cell. Combined with the results of the first-principles calculations, the binding energy of solid solution substitution and the cell parameters of Ce with different types at various crystal sites are to be obtained. It is systematically to investigate the evolution of the valence state and the thermodynamic process of solid solution substitution via experimental measurements and theoretical modeling. The relationship between Ce content, valence mixing ratio, sites preference and cell parameters is to be analysed in order to find the cell parameter c discrete mechanism of main phase when the Ce was added 20 wt.%, which is provide theoretical and experimental guidance for preparation of high performance Nd-Ce-Fe-B rare earth permanent magnets.