Co掺杂(ZnO)_(12)团簇的结构和磁性质  

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

作　　者：谢建明[1] 陈红霞[1] 

机构地区：[1]盐城师范学院物理科学与电子技术学院,江苏盐城224002

出　　处：《计算物理》2014年第3期372-378,共7页Chinese Journal of Computational Physics

基　　金：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

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.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.

关 键 词：稀磁半导体 团簇 密度泛函理论 

分 类 号：O469[理学—凝聚态物理]