Co掺杂闪锌矿ZnO的磁性和光学性质

Magnetic and Optical Properties of Co-doped Zinc Blende ZnO

采用自旋极化密度泛函理论方法对Co掺杂闪锌矿Zn O的能带结构、态密度、磁学和光学属性进行了研究。计算结果显示:Co掺杂闪锌矿Zn O的基态是反铁磁态,具有金属性特征;而铁磁态具有半金属性特征。铁磁耦合在费米能级附近出现了明显的自旋劈裂现象,表现出明显的不对称性和强烈的Co 3d和O 2p杂化效应。磁矩主要来源于Co 3d轨道电子以及部分近邻耦合的O 2p轨道电子,大小与Co原子的掺杂位置有关。光学性质计算结果显示,Co掺杂闪锌矿Zn O在可见光范围内都有较强的光吸收能力,吸收峰在高能区发生了红移现象。理论计算结果表明,Co掺杂闪锌矿Zn O或许是一种优异的磁光材料。

The band structure,density of state,magnetic and optical properties of Co doped zinc blende Zn O were systematically studied by using the first-principles based on the spin polarized density functional theory. The calculated results show that the ground state of Co doped zinc blende Zn O is antiferromagnetic and shows metal characteristics,while the ferromagnetic state shows the half-metallic characteristics. For the ferromagnetic coupling state,strong spin-orbit coupling appears near the Fermi level and shows no obvious asymmetry for up and down spins,which indicates a significant hybrid effects from Co 3d and O 2p states. The magnetic moments are mainly contributed by unpaired electrons in Co 3d and neighbor O 2p orbital and are correlated to the doped site of Co atoms.In addition,the calculated results of optical properties show that Co doped zinc blende Zn O has a strong absorptive capacity at the visible light,and the absorption peaks have red shift in the high energy region. The theoretical calculated results demonstrate that Co-doped zinc blende Zn O may become excellent magneto-optic materials.