钴铝共掺3C-SiC电子结构和磁性的第一性原理计算
First-principles Calculation of Electronic Structures and Magnetic Properties of Co, Al doped 3C-SiC

采用基于密度泛函理论的第一性原理计算方法，分别计算了不同Co原子比例单掺杂、Al原子单掺杂和Co-Al共掺杂3C-SiC的电子结构和磁性参数。结果表明：随着掺杂Co原子比例的增大，单个Co原子对体系总磁矩贡献的平均值反而减小。由电子态密度分析掺杂3C-SiC体系中的磁性来源，主要是由Co-3d以及Co原子附近的C-2p电子轨道的自旋极化产生的。Al单掺3C-SiC时体系中每个原子的平均磁矩和体系总磁矩均为0，即Al单掺杂体系不具有磁性。而Co-Al共掺杂得到的体系总磁矩比单掺等量Co时要大约0.09μB，即Co-3d与Al-3p电子轨道发生轨道杂化，使得Co-Al共掺杂可以增大Co原子对体系总磁矩的贡献。
By using first-principle calculation method based on density functional theory, the electronic structures and magnetic properties of 3C-SiC doped with Co at different concentrations, doped with Al and co-doped with Co and Al are studied. The results show that the average contribution of single Co atom to the total magnetic moment is reduced with the increasing Co doping concentration. By analyzing the spin state density of electron in 3C-SiC, the magnetic moment is primarily contributed by Co-3d electrons and C-2p electrons near the Co atoms. Both the average magnetic moment per atom and the total magnetic moment are zero in Al-doped 3C-SiC. In other words, the single Al-dopant is nonmagnetic. And the total magnetic moment of Co-Al co-doped 3C-SiC is more than 0.09μB to the 3C-SiC doped with a comparable amount of Co. The reason is that Co atoms located in Co-Al co-doped 3C-SiC show more average contribution to magnetic moment due to the orbital hybridization between Co-3d and Al-3p electrons.