Co掺杂ZnSe团簇稳定性和磁性质

Stability and magnetic properties of Co-doped ZnSe clusters

采用密度泛函理论研究了Co原子单掺杂和双掺杂(ZnSe)12团簇的结构、电子性质和磁性质.考虑了三种掺杂方式:替代掺杂、外掺杂和内掺杂.首先比较了各种掺杂团簇的稳定性.单掺杂时,外掺杂团簇是最稳定结构,双掺杂时,内掺杂团簇是最稳定结构.在结构优化的基础上,对掺杂团簇又进行了磁性计算.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Se原子上也产生少量自旋.最重要的是,我们指出内双掺杂团簇是铁磁耦合,在纳米量子器件领域有潜在的应用价值.

The structures, electronic and magnetic properties of （ZnSe） 12 clusters doped with one and two Co atoms have been studied in term of a first-principles method. Substitutional, exohedral, and endohedral dopings are considered. The exohedral isomer is found to be most favorable in energy for monodoped clusters, while the endohedral isomer is found to be most favorable for bidoped clusters. The magnetic moments are contributed mainly by the 3d component of Co atom, while the 4s and 4p orbitals also have certain contributions. Due to the hybridization interaction, a small magnetic moment is induced in the nearest neighboring Se and Zn atoms. Most importantly, we demonstrate that the endohedral bidoped （ZnSe） 12 clusters favor the ferromagnetic state, which has potential applications in nanoscale quantum devices.