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采用自旋极化密度泛函理论系统研究了Cr掺杂ZnO纳米线的电学、磁学以及光学属性.计算结果显示,Cr原子沿[0001]方向替代ZnO纳米线中的Zn原子时体系一般呈现铁磁耦合,沿[10-10]和[01-10]方向替代Zn原子时体系呈现反铁磁耦合,且磁性耦合状态在费米能级附近出现了明显的自旋劈裂现象,发生了强烈的Cr3d和O2p杂化效应.自旋态密度计算结果显示,磁矩主要来源于Cr原子未成对3d态电子的贡献,磁矩的大小与Cr原子的电子排布有关.光学性质计算结果显示,Cr掺杂ZnO纳米线在远紫外和近紫外都具有明显的吸收峰,吸收峰发生了明显的红移.这些结果都表明Cr掺杂ZnO纳米线也许是一种很有前途的稀磁半导体材料.
The electrical, magnetic and optical properties of Cr-doped ZnO nanowires were investigated by using spin-polarized density functional theory. The calculated results show that the substitution of Cr atoms along the [0001] direction for Zn atoms in ZnO nanowires generally appears Ferromagnetic coupling, the system exhibits anti-ferromagnetic coupling when the Zn atoms are replaced by [10-10] and [01-10] directions, and a significant spin splitting occurs near the Fermi level in the magnetic coupling state. Strong Cr3d and O2p hybridization results show that the magnetic moment mainly comes from the contribution of unpaired 3d state electrons of Cr atoms and the magnetic moment is related to the electronic arrangement of Cr atoms.The calculation of optical properties shows that , Cr-doped ZnO nanowires have obvious absorption peaks in far ultraviolet and near ultraviolet, and obvious red shift of absorption peak.These results indicate that Cr-doped ZnO nanowires may be a promising dilute magnetic semiconductor material.