(1. 南昌航空大学 材料科学与工程学院，南昌 330063；
2. 广西大学 物理科学与工程技术学院，南宁 530004)
摘 要: 尖晶石型钴铁氧体因具有良好的电磁性质，广泛应用于电子装备、微波装备及高密度磁存储等领域。采用基于密度泛函理论(DFT)的第一性原理平面波赝势法，结合广义梯度近似(GGA+U)，系统研究不同Ni掺杂量对CoFe2O4晶体结构、电子结构和磁性能的影响。结果表明：Ni离子倾向于占据八面体位置且随着Ni掺杂量的增加，晶格常数呈递减趋势。通过电子结构分析表明，带隙随着Ni掺杂量的变化而变化，大部分都呈绝缘体，且存在强烈的3d-2p轨道杂化。磁性能依赖于Ni掺杂量，随着Ni掺杂量的增加，晶格中的原子磁矩变化不明显，但总磁矩呈线性递减趋势，这主要是因为Ni离子最外层的3d未配对电子数与Co离子最外层3d未配对电子数不同，因而对磁性能的影响较大。
关键字: 钴铁氧体；第一性原理计算；掺杂；电子结构
（1. School of Materials science and Engineering, Nanchang Hangkong University, Nanchang 330063, China;
2. School of Physical Science and Technology, Guangxi University, Nanning 530004, China）
Abstract:Spinel ferrites, such as CoFe2O4, can be applied in varied fields such as electronic equipment, microwave equipment and high density magnetic storage due to their good electromagnetic properties. The crystal structure, electronic structure and magnetic properties of Ni doped CoFe2O4 were investigated within the density functional theory in the generalized gradient approximation with Hubbard U correction (GGA+U). The results show that Ni ions tend to occupy the octahedral site and with the increase of Ni doping content, the lattice constant decreases. The electronic structure analysis shows that the band gap changes with the change of Ni doping content, and generally it is an insulator and there is a strong 3d-2p orbital hybridization. Magnetic properties depend on the Ni doping content, and with the increase of the Ni doping content, the lattice atomic magnetic moments of change is not obvious, but the total magnetic moment shows linear decreasing trend. It is mainly attributed to the different numbers of the unpaired electrons between Ni-3d orbitals and Co-3d orbitals, thus affects the magnetic properties obviously.
Key words: cobalt ferrite; first-principle calculation; dopping; electronic structure
