Surface State Induced Ferromagnetism in Co- and Mn-Doped ZnO Surfaces
Surface State Induced Ferromagnetism in Co- and Mn-Doped ZnO Surfaces
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钴和锰掺杂 ZnO 表面的表面态诱导铁磁性
DOI：
10.1021/jp110220g
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发表时间：
2011-02
影响因子：
3.7
通讯作者：
Liu, Enzuo
中科院分区：
文献类型：
--
作者：
Du, Xiwen;Zhao, Naiqin;Shi, Chunsheng;Li, Jiajun;Liu, Enzuo
利用第一性原理总能量计算方法研究了ZnO（0001）表面磁性原子间的磁耦合。结果表明，在ZnO（0001）表面，Co和Mn的取代态倾向于占据最外层的阳离子层。与体相ZnO中Co和Mn原子间的磁性行为不同，在O端ZnO（0001）中，由于表面态的存在，磁性原子间呈现铁磁耦合。电子态密度分析表明，n型和p型掺杂分别增强了O端ZnO（0001）中Co和Mn原子间的铁磁耦合，这与实验结果一致。我们的研究结果补充了对ZnO基稀磁半导体铁磁性起源的理解。
We studied the magnetic coupling between magnetic atoms at the O-terminated ZnO(0001) surface using first-principles total energy calculations. It was found that the substitutional Co and Mn in the O-terminated ZnO(0001) surface tend to occupy the outermost cation layer. Different from the magnetic behaviors between substitutional Co and Mn atoms in bulk ZnO, at O-terminated ZnO(0001), due to the presence of surface states, the magnetic atoms display ferromagnetic coupling. On the basis of the analysis of electron density of states, n- and p-type doping could enhance the ferromagnetic coupling between Co and Mn atoms at O-terminated ZnO(0001), respectively, in good agreement with previous experimental observations. Our results complement the understanding of the origin of ferromagnetism in ZnO-based diluted magnetic semiconductors.