Mediating distribution of magnetic Co ions by Cr-codoping in (Co,Cr): ZnO thin films
Mediating distribution of magnetic Co ions by Cr-codoping in (Co,Cr): ZnO thin films
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DOI：
10.1063/1.3470090
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发表时间：
2010-07
影响因子：
4
通讯作者：
Wensheng Yan;Zhihu Sun;Qinghua Liu;T. Yao;Q. Jiang;F. Hu;Yuanyuan Li;Jingfu He;Yanhua Peng;Shiqiang Wei
中科院分区：
文献类型：
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作者：
Wensheng Yan;Zhihu Sun;Qinghua Liu;T. Yao;Q. Jiang;F. Hu;Yuanyuan Li;Jingfu He;Yanhua Peng;Shiqiang Wei
控制基质中磁性离子的分布对于磁性掺杂半导体的功能至关重要。在本文中，（Co，Cr）共掺杂ZnO显示了通过操纵Co离子的电荷状态来介导磁性Co离子分布的Cr共掺杂工程的可能性。Co K边的X射线吸收精细结构分析表明，在Zn_（0.92）Co_（0.08）O薄膜中形成了金属Co团簇的第二相。而Cr共掺杂抑制了Co团簇的形成，使所有掺杂的Co离子都占据了ZnO中的替位。第一性原理计算结果表明，Cr对Co分布的调节作用是由于Cr离子的取代引起的Co 3d态与Co 3d态之间的强杂化，促进了Co 3d态与Co 3d态之间的电荷转移，改变了Co离子的电荷状态，改变了Co离子之间的静电相互作用.
The control over the distribution of magnetic ions in a host is crucial for the functionality of magnetically doped semiconductors. Herein, (Co,Cr)-codoped ZnO shows a possibility of Cr-codoping engineering in mediating the distribution of magnetic Co ions via manipulating the charge state of the Co ions. The x-ray absorption fine structure analyses at Co K-edge indicate that a secondary phase of metallic Co clusters is formed in the Zn0.92Co0.08O film. However, Cr-codoping suppresses the formation of Co clusters, so that all doped Co ions occupy the substitutional sites in ZnO. The ability of Cr in mediating Co distribution, as revealed by first-principles calculations, arises from the strong hybridization between the Co 3d states and the donor band induced by substitutional Cr ions, which facilitates the charge transfer from the donor band to the Co 3d states, changes the charge state of Co ions and modifies the electrostatic interactions among Co ions.