计算物理 ›› 2014, Vol. 31 ›› Issue (3): 372-378.

• 研究论文 • 上一篇    

Co掺杂(ZnO)12团簇的结构和磁性质

谢建明, 陈红霞   

  1. 盐城师范学院物理科学与电子技术学院, 江苏 盐城 224002
  • 收稿日期:2013-06-25 修回日期:2013-09-23 出版日期:2014-05-25 发布日期:2014-05-25
  • 作者简介:谢建明,男,实验师,主要从事稀磁半导体材料的研究,E-mail:dtxiejianming@sina.com
  • 基金资助:
    国家自然科学基金(11247235);江苏省高校自然科学基金(11KJB140013);青蓝工程(QLP)资助项目

Structure and Magnetic Properties of Co-doped (ZnO)12 Clusters

XIE Jianming, CHEN Hongxia   

  1. Department of Physics, Yancheng Teachers University, Yancheng 224002, China
  • Received:2013-06-25 Revised:2013-09-23 Online:2014-05-25 Published:2014-05-25

摘要: 采用第一性原理密度泛函理论系统地研究Co原子单掺杂和双掺杂(ZnO)12团簇的结构和磁性质.考虑三种掺杂方式:替代掺杂,外掺杂和内掺杂.首先比较各种掺杂团簇的稳定性.结果表明,不管是单掺杂还是双掺杂,外掺杂团簇都是最稳定结构.在结构优化的基础上,对掺杂的(ZnO)12团簇进行磁性计算.发现团簇磁矩主要来自Co-3d态的贡献,4s和4p态也贡献了一小部分磁矩.由于轨道杂化,相邻的Zn和O原子也产生少量自旋.Co原子之间的磁性耦合由直接的Co-Co反铁磁耦合和Co和O原子之间通过p-d杂化产生的铁磁耦合这两种相互作用的竞争决定.研究发现外双掺杂团簇存在铁磁耦合,在纳米量子器件有潜在的应用价值.

关键词: 稀磁半导体, 团簇, 密度泛函理论

Abstract: Structure and magnetic properties of (ZnO)12 clusters doped with one (monodoped) and two (bidoped) Co atoms are studied with first-principles method. Substitutional, exohedral, and endohedral doping are considered. Exohedral isomers are found the most favorable in both monodoped and bidoped clusters. Magnetic coupling between Co atoms is short-range. Magnetic coupling between Co atoms at the nearest neighbor is mainly governed by competition between direct Co-Co antiferromagnetic interaction and ferromagnetic interaction between two Co atoms via O atom due to strong p-d hybridization. We demonstrate that exohedral bidoped cluster favors ferromagnetic state, which has potential applications in nanoscale quantum devices.

Key words: diluted magnetic semiconductor, clusters, density functional theory

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