Abstract Electronic structures and magnetic properties for (Cr, X) (X = Ga, In) co-doped 4H silicon carbide (SiC) are studied by first-principles calculations. Our results show that all configuration of (Cr, X) (X = Ga, In) co-doped 4H–SiC are favor ferromagnetic state. The (Cr, Ga4) and (Cr, In4) configurations are the most stable one with ΔEFM of −224.9 meV and −269.6 meV, respectively. Based on the mean-field approximation, the ferromagnetic Curie temperatures (TC) are estimated to be 579 K and 695 K, respectively. The ferromagnetism can be attributed to strong p-d hybridization interaction between Cr atoms and their nearest neighbor C atoms. Due to the interaction between the holes introduced by Ga atoms and their surrounding C atoms, doping with Ga and In atoms could decrease the total magnetic moments and increase the ferromagnetic stability. Additionally, we find that the magnetic moments induced by Cr atoms strongly depend on Ga (In) atom's location. The element doping of homologous group is an effective method to precisely regulate the electronic properties. Our results indicate that (Cr, X) (X = Ga, In) co-doped 4H–SiC system may be the promising ferromagnetic materials for spin injection applications. And our work of homologous elements doping can also guide the experiment to a certain extent.

中文翻译：

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(Cr, X) (X= Ga, In)共掺杂4H-SiC电子结构和铁磁性的第一性原理研究

摘要 通过第一性原理计算研究了 (Cr, X) (X = Ga, In) 共掺杂 4H 碳化硅 (SiC) 的电子结构和磁性能。我们的结果表明 (Cr, X) (X = Ga, In) 共掺杂 4H-SiC 的所有构型都有利于铁磁态。(Cr, Ga4) 和 (Cr, In4) 配置是最稳定的一种，其 ΔEFM 分别为 -224.9 meV 和 -269.6 meV。基于平均场近似，铁磁居里温度 (TC) 估计分别为 579 K 和 695 K。铁磁性可归因于 Cr 原子与其最近邻 C 原子之间的强 pd 杂化相互作用。由于Ga原子引入的空穴与其周围的C原子之间的相互作用，掺杂Ga和In原子可以降低总磁矩并增加铁磁稳定性。此外，我们发现由 Cr 原子引起的磁矩强烈依赖于 Ga (In) 原子的位置。同族元素掺杂是精确调控电子特性的有效方法。我们的结果表明，(Cr, X) (X = Ga, In) 共掺杂 4H-SiC 系统可能是用于自旋注入应用的有前途的铁磁材料。而我们的同源元素掺杂工作也可以在一定程度上指导实验。