利用第一性原理研究Ni掺杂ZnO铁磁性起源

采用基于密度泛函理论和局域密度近似的第一性原理分析了Ni掺杂ZnO磁性质.文中计算了8个不同几何结构的铁磁(FM)和反铁磁耦合能量,结果表明FM耦合更稳定.态密度结果显示Ni 3d 与O 2p发生杂化,导致费米能级附近电子态自旋极化.文中也分析了O空位对Ni掺杂ZnO铁磁性质的影响,O空位通过诱导电子调节FM耦合,从而稳定Ni掺杂ZnO铁磁性质,其强度足以引发室温铁磁性.通过Ni 3d能级耦合具体分析了Ni 掺杂ZnO铁磁性起源.另外,也分析了晶格应变对Ni掺杂ZnO FM耦合的影响.关键词：第一性原理半导体铁磁性缺陷

Origin of ferromagnetic properties in Ni doped ZnO by the first principles study

Theoretical calculation based on density functional theory (DFT) and local density approximation (LDA) has been carried out to study the magnetic properties of Ni doped ZnO. The results show that ferromagnetism (FM) coupling between Ni atoms is more stable for 8 geometrically distinct configurations. The results from density of states show that O 2p hybridizes with Ni 3d, which results in electronic states spin polarization at the Fermi energy. Moreover, the effect of oxygen vacancy on FM properties of Ni doped ZnO has also been investigated. It was found that FM coupling is enhanced in the presence of oxygen vacancy, which is strong enough to lead to electron-mediated ferromagnetism at room temperature. In addition, the origin of the FM state in Ni doped ZnO has also been discussed by analyzing the coupling of Ni 3d levels. We also analyzed the strain effect on FM properties of Ni doped ZnO.